The area under the curve (AUC) values were utilized to evaluate the accuracy of m5CPS in predicting the survival of IPF patients. The Kaplan-Meier curves and Cox regression analyses were used to assess the prognostic effect of m5CPS. The AUC was utilized to evaluate the reliability of m5CPS in distinguishing IPF patients from healthy individuals. In terms of the results, m5CPS could predict the one-, three-, and five-year survival rates of IPF patients with high accuracy (AUC = .803–.973). In fact, m5CPS is not only an independent indicator of the poor prognosis of IPF patients  but can also distinguish IPF patients from healthy individuals (AUC = .862). Also, m5CPS may affect the immune response and inflammatory response, and it was positively associated with the infiltration levels of active mast cells (p < .05). In sum, the current study establishes a novel m5CPS for IPF and reveals the role of m5CPS as a reliable marker for predicting the prognosis and disease status of IPF patients.Idiopathic pulmonary fibrosis (IPF) is the most common and highly lethal pulmonary interstitial lung disease. The current study is aimed at investigating reliable markers suitable for the treatment and identification of IPF. This study constructed the first 5-methylcytosine- (m5C-) and immune-related prognostic signature (m5CPS) based on coexpressed genes of m5C regulatory genes and immune-related genes. The m5CPS was established using the training cohort ( Idiopathic pulmonary fibrosis (IPF) ranks first in incidence in terms of interstitial lung diseases, given the fact that there are 5–20 persons per 100,000 suffering from this disease in the United States and Europe annually . Thus, tRibonucleic acid (RNA) methylations are a series of modifications constantly occurring in the epigenetics of eukaryotes, affecting essential genes in the progression of multiple diseases. Based on analyzing the RNA methylation-related regulatory genes, a series of prognostic signatures were constructed and considered reliable markers for a variety of diseases in previous studies. For instance, a signature developed based on N6-methyladenosine regulatory genes was identified as a prognostic risk marker for head and neck squamous cell carcinoma, and the signature may be related to the level of immune infiltration . AnotherIn this study, for the first time, a reliable prognostic signature that can be used to predict and identify IPF patients was constructed based on m5C's regulatory-related genes (m5CRGs) and immune-related genes (IRGs). The m5C- and immune-related prognostic signature (m5CPS) was established using a training cohort and validated using another two cohorts. Moreover, corresponding analyses were also performed to promote the understanding of m5C in IPF, including prospective information about the clinical application potential, underlying molecular functions and signaling pathways, and underlying drugs regarding m5CPS in IPF.2 (x + 1) algorithm was applied to normalize the gene expression profile of both the GPL14550 and GPL17077 cohorts.Cell samples from the bronchoalveolar lavage (BAL) of 176 IPF patients and 20 healthy control persons used in this study were collected from the Gene Expression Omnibus database with series number GSE70866, which contained two cohorts—GPL14550 and GPL17077. At the same time, the clinical parameters (including GAP (gender-age-physiologic) scores, age, and gender) of the patients in the two cohorts were also obtained. A logDNMT3A , DNMT3B (DNA methyltransferase 3 beta), NOP2 (NOP2 nucleolar protein), NSUN (NOP2/Sun RNA methyltransferase) 2–7, and TET2 (tet methylcytosine dioxygenase 2)—that were obtained from the previous literature [ρ > .5 (p < .05). The univariate Cox regression analysis was utilized to identify prognosis-related genes (PRGs) of IPF. IRGs  were obtained from the ImmPort Portal on March 7, 2022. Candidate genes for the development of m5CPS were selected in the intersection of m5C-CEGs, PRGs, and IRGs.Ten m5CRGs—terature  and incln of IPF = 68), and the remainder of IPF individuals were set as the test cohort (n of IPF = 44). GPL17077 was considered an independent validation cohort (n of samples = 64).The “sample” algorithm can be used to divide a cohort into several cohorts randomly, based on which some IPF patients from the GPL14550 dataset were identified as the training cohort (The least absolute shrinkage and selection operator (LASSO) Cox regression was applied to develop m5CPS for the training cohort (including 68 IPF patients). The area under the curve (AUC) values of time-dependent receiver operating characteristic curves  were utiThe Kaplan-Meier curves and Cox regression analyses were used to assess the prognostic effect of m5CRGs and m5CPS. A nomogram was established to determine whether m5CPS had potential in clinical application for IPF patients, which was verified by calibration curves. Decision curve analysis (DCA)  curves w2(fold change) > 1 and false discovery rate < .05. These DEGs were utilized to investigate the underlying molecular functions of the gene ontology and signaling pathways of KEGG (Kyoto Encyclopedia of Genes and Genomes) [The “limma” package  was usedGenomes) , which wGenomes) , 15.The infiltration levels of 22 immune cells for each IPF patient in the training, test, and validation cohorts were calculated using the CIBERSORT algorithm . The difGiven that limited healthy samples were included in the current study, more samples  were produced based on the GPL14550 cohort using the SMOTE (synthetic minority oversampling technique) algorithm of the “DMwR” package. The extensive samples were used to validate the different expression levels of m5CRGs between the IPF group and healthy group, the distinct expression levels of constitutive genes of m5CPS between the IPF group and healthy group, and the ability of m5CPS to distinguish IPF patients from healthy individuals.A Wilcoxon rank-sum test was applied in comparing certain risk scores between distinct groups . A Spearman coefficient was utilized for the correlation analysis. All the analyses were performed in R (v4.1.0). A flow chart for this study can be referenced in TET2 expression was detected in IPF rather than healthy BAL cells  and 3,995 IPF-PRGs (p < .05) were selected via the correlation analysis and univariate Cox regression analysis, respectively  and test cohort , while patients from the GPL17077 cohort were identified as the validation set for verifying the m5CPS (n = 64). The characteristics of the training, test, and validation cohorts can be viewed in According to the GPL14550 datasets, 8,157 m5C-CEGs (ectively . Sixty-tectively . Those IAKT3 (AKT serine/threonine kinase 3), CMTM8 (CKLF like MARVEL transmembrane domain containing 8), IRF9 (interferon regulatory factor 9), RORA (RAR related orphan receptor A), TNFRSF12A (TNF receptor superfamily member 12A), and VAV3 (vav guanine nucleotide exchange factor 3), the coefficients of which are shown in AKT3, IRF9, RORA, and TNFRSF12A were observed between the healthy group and the IPF group  and long-term (three-year and five-year) survival of patients from the training cohort (AUC = .803–.973), and such a phenomenon was also observed in the test and validation cohorts (AUC = .642–.829) . MoreoveCMTM8 and TNFRSF12A expression levels between the high-risk score group and the low-risk score group was detected  of his survival for less than one, three, and five years were 0.0896, 0.434, and 0.665, respectively , which wAKT3, RORA, TNFRSF12A, and the m5CPS risk score made it feasible to screen IPF patients via detecting BAL cell samples (AUC ≥ .797), and among these factors, the m5CPS risk score showed the optimal effect in terms of screening for IPF patients  of specific molecules  and thereby affects a series of biological functions, such as RNA stabilization and translation –21. AlsoConsidering the potentially important role of m5CRGs and IRGs in IPF and the lack of key substances in clinical treatment of IPF, this study constructed the first m5CPS based on m5C-CEGs and IRGs and revealed the clinical value of m5CPS. In fact, m5CPS could predict the short-term and long-term survival rates of IPF patients with high accuracy. It is not only an indicator of poor prognoses for IPF patients but can also distinguish between IPF patients and healthy individuals. These potential clinical values on the part of m5CPS were identified in the training set and verified in the test and validation cohorts. Our study also revealed the potential molecular functions and signaling pathways for m5CPS regarding IPF, which may increase the understanding of the mechanism of m5C and IRGs in IPF to some extent. Finally, this study also investigated novel drugs that may apply to patients with high m5CPS scores, providing clues for drug-related research.Previous studies have suggested the feasibility of the application of a prognostic signature in patients with IPF. For example, Li et al.  construcα expression represented prognostic risk signaling for IPF. However, confirming the efficacy of using a single molecule as a marker may require multiqueue verification. For instance, TNFRSF12A was determined to be an independent risk marker for the prognosis of IPF individuals in the training cohort; nevertheless, neither the test cohort nor the validation cohort supported this finding. Instead, the m5CPS consisting of six genes was shown to be a reliable biomarker in all three cohorts. Moreover, a biomarker consisting of several molecules may have advantages in some respects. For instance, m5CPS was more excellent than any single constitutive gene of m5CPS in terms of predicting the one-year survival of IPF individuals in our study. Moreover, the nomogram consisting of GAP score and m5CPS risk score can be applied directly to effectively predict the short-time survival probabilities of IPF patients. In addition to the prognostic effect, m5CPS made it feasible to screen IPF persons from the healthy by using BAL cells with high accuracy. However, more efforts should be made to verify the screening effect of m5CPS for IPF via more convenient detection methods. For example, Aoshima et al. [In cases of IPF, m5CPS demonstrated conspicuous clinical value. Crucially, IPF is the pulmonary interstitial disease with the worst prognosis, so it is necessary to explore effective indicators that can be directly used to predict the prognoses of IPF patients. The m5CPS constructed in our study may be such a biomarker because it has represented high accuracy in predicting one-, three-, and five-year survival in IPF patients, and the results of the training, test, and validation cohorts supported such a finding. Indeed, previous reports have revealed several prognostic markers for IPF. For example, Nakanishi et al.  identifia et al.  focused AKT3 [CMTM8 [IRF9 [RORA [TNFRSF12A [VAV3 [Although m5CRGs and IRGs are relevant to fibrosis , 23, 30,AKT3 , CMTM8 [3 [CMTM8 , IRF9 [3M8 [IRF9 , RORA [3F9 [RORA , TNFRSF1NFRSF12A , and VAV2A [VAV3 —of m5CPS2A [VAV3  identifi2A [VAV3  also revSeveral limitations of this study must be emphasized. Above all, we failed to collect more samples from the multicenter to verify the clinical value of m5CPS. Due to the lack of clinical parameters  for IPF patients, the application of m5CPS in IPF patients is relatively limited. It is also necessary to explore and verify the potential molecular mechanism of m5CPS in vitro and in vivo in the future.This study develops a novel m5CPS for IPF. The m5CPS may serve as a prediction and prognosis marker for IPF patients. This research also investigates the underlying mechanisms of IPF from the perspective of m5CRGs and IRGs, which may contribute to the understanding of IPF.


These hybrid materials were prepared via a facile physical solution mixing self-assembly reaction with rGO and PcCo solutions. The obtained PcCo/rGO hybrid sensors exhibit excellent sensing performance; especially the ABOPcCo/rGO sensor, whose response is about 23.3% (50 ppm), with a limit of detection as low as 78 ppb, and response and recovery times about as fast as 225 s and 250 s. The performance of the PcCo/rGO hybrid sensors can be optimized by adjusting the concentrations of the PcCo/rGO aqueous dispersions. More importantly, the NH3-sensing performance of the PcCo/rGO sensors was tuned by adjusting the substituent structure of PcCo. The enhanced NH3-sensing performance may be attributed to synergistic effects between PcCo and rGO, e.g., stronger adsorption interactions between PcCo with an aminophenoxy substituent and NH3, the high electrical conductivity of rGO, and fast charge transfer between PcCo and rGO. These are further confirmed via first-principle density functional theory (DFT) calculations and electrochemical impedance spectra (EIS) measurements.Three reversible ammonia (NH Three new room temperature reversible ammonia gas sensors were fabricated using PcCo/rGO hybrids with cost-efficient, highly sensitive and stable sensing performance. Nanocomposite materials have recently attracted extensive interest for gas sensing applications due to synergetic and complementary effects.5–8 Among them, graphene and its nanocomposites, with two-dimensional sp2-hybridized carbon atoms, are currently, without any doubt, the most attractive gas sensing materials due to their large specific surface areas and electron transport through them being highly sensitive to the absorption of gas molecules.9–15During the last few decades, gas sensors have boosted advances in agriculture, the food industry, industrial chemicals, and environmental and security areas.16 They showed that conductance changes in graphene are dependent on the nature of the gas molecules, which indicates that charge transfer between the gas molecules and graphene is responsible for the conductivity changes. This study has opened the door for a new type of gas sensor based on 2D graphene. While there are a few drawbacks relating to the limits of sensitivity and lack of selectivity with respect to graphene based sensors, defective and functionalized graphene may result in gas sensors with improved and efficient gas sensing performance, such as increased sensitivity, selectivity, response and recovery, through promoting charge transfer between graphene and the gas molecules.17–21 Owing to there being certain amounts of oxygen groups in reduced graphene oxide (rGO) that provide reactive sites for gas adsorption and further functionalization, rGO based gas sensors show improved sensing characteristics. Moreover, the conductance of such sensors can be restored through a chemical reduction process.10,22,23 The functionalization of rGO with functional materials  has also been reported to improve its sensing efficiency.24–30In 2007, Novoselov's group reported the first graphene sensor for detecting gases.31–34 However, the low conductivities of MPc based gas sensors have limited their practical applications.35 Importantly, MPcs are an ideal candidate for the functionalization of rGO, considering their possible further modification.36–39 The use of nanocomposites of MPcs and rGO may result in gas sensors with improved and efficient gas sensing characteristics, which may help to solve particular shortcomings through synergetic and complementary effects. Our group has reported gas sensors based on carbon nanotube (CNT)/MPc, graphene oxide (GO)/MPc and rGO/MPc hybrids.40–42 These sensors showed higher sensitivity toward NH3 than their carbon material counterparts. It was observed that the presence of functional MPcs played an important role in the sensing process. Nowadays there have been many studies reporting the effects of substituents on pristine MPcs for gas sensing,43,44 but few systematic studies to date have reported the effects of substituent groups on the NH3 sensing characteristics of rGO/MPc hybrids.45Metal phthalocyanines (MPcs) show improved sensing characteristics due to their 18π-conjugated skeletons, fine-tuned structures and high solubilities in solvents.p-aminobenzyloxy)phthalocyanine cobalt (ABOPcCo) and tetra-α-aminophthalocyanine cobalt, (APcCo) containing different amino substituents, and substituent-free phthalocyanine cobalt (FPcCo), and combine them with rGO functionalization to develop new high performance chemiresisitor-type NH3 sensors based on the ABOPcCo/rGO, APcCo/rGO and PcCo/rGO hybrids . Graphite was purchased from Nanjing XFNANO Materials Tech Co., Ltd. 3-Nitrophthalonitrile (99% purity) and DBU (98% purity) were purchased from Sigma-Aldrich Co. LLC. All other reagents in this work were of analytical grade and used without further purification.PcCo compounds were synthesized using 1,8-diazabicycloundec-7-ene (DBU) as a catalytic agent  in DMF under ultrasonic waves for 2 h. Then, 10 μl of PcCo/rGO suspension was dropped onto the IDE gaps using a microsyringe. Sensor films were deposited after the solution was evaporated and dried in a vacuum oven for 2 h at 80 °C. The sensor resistance was adjusted by varying the concentration of the PcCo/rGO hybrid in the DMF solution. For comparison, purified rGO and PcCo sensors were also obtained via the above methods.The gold interdigitated electrodes (IDEs) and gas sensor testing device used were as shown in our previous studies.via changing the mixing ratio of fully humid air and dry air, and the humidity level was checked using a humidity sensor. In this experiment, we used a high purity concentration of NH3 gas (99.99%) mixed with air as a carrier, using the static volumetric method to obtain a low concentration. The response is defined by the relative resistance change, as follows:Ra and Rg are the sensor resistance values under the initial air flow, which was used as background, and under the target gas. The response and recovery times are defined as the times needed for 90% total resistance change upon exposure to the target gas and air, respectively. High purity NH3 gas was used as the NH3 source .The gas sensing performances of the sensors were measured with a CUST G2 gas sensing test system . All measurements were performed at 28 °C ± 1 °C with a relative humidity of 50% ± 2%. First, an air flow was introduced into the sensing test chamber to record a baseline. Then, target gases at certified concentrations were injected to register sensor signals. Finally, the sensor was recovered under an air flow. The humidity in the test chamber was controlled 2.4UV-vis absorption spectra were recorded with a UV-2700 spectrometer . Raman spectra, acquired using Raman spectroscopy, were obtained with a Jobin Yvon HR800 Raman spectrometer, using a 458 nm laser source. Scanning electron microscopy (SEM) images were recorded with a Hitachi S-4800 field emission scanning electron microscope operating at 15 kV. Samples were drop-deposited onto the interdigitated electrodes and examined directly. Transmission electron microscopy was performed with a JEM 2100 instrument at 200 kV, utilizing a JEOL FasTEM system. Samples were dropped onto Cu grids with lacey carbon film and allowed to dry thoroughly before imaging. FT-IR spectra were recorded using a Spectrum Two spectrometer . Electrochemical impedance spectra (EIS) were measured using a CHI600E electrochemical work station at room temperature .2.53 on PcCo compounds using the long-range corrected functional of CAM-B3LYP with a set of hybrid basis sets  for H, C, and N).46 Charge analyses were performed using the NBO  method.47 The Gaussian 09 quantum chemical package was employed for all calculations in the present work.48DFT calculations were performed for the adsorption of NH3.3.1via TEM and SEM. The TEM images exhibit stacked few layered flakes with amorphous coatings , 1634 cm−1 (νC–OH) and 1080 cm−1 (νC–O–C).21 The stretching vibration peaks at about 3300 cm−1, 2930 cm−1 and 1000–1650 cm−1 belong to the characteristic fingerprint absorption peaks of N–H, C–H and the Pc ring of ABOPcCo in the ABOPcCo/rGO hybrid. Moreover, the APcCo/rGO hybrid shows a similar phenomenon in 52 These peaks are broadened and shifted to higher wavenumbers (by about 27 nm and 19 nm) in the APcCo/rGO and ABOPcCo/rGO hybrids. These results not only indicate that PcCo has been successfully loaded on rGO, but they also indicate that π–π stacking between PcCo and rGO exists in the hybrids.52,53 The Raman spectrum is used as a finger-print for rGO.17 As shown in −1 are the characteristic D and G bands of rGO, respectively. The D band is related to structural defects caused by oxidation or the attachment of functional groups. The G band is related to first-order scattering of E2g symmetry.21 Compared with rGO, the Raman spectra of the ABOPcCo/rGO and APcCo/rGO hybrids are centered at 1360 and 1576 cm−1, and 1363 and 1575 cm−1, respectively, and are shifted to lower wavenumbers. Meanwhile, the ID/IG values of the APcCo/rGO and ABOPcCo/rGO hybrids are 0.96 and 0.90, which are smaller than that of rGO (0.98). This indicates that the functionalization of APcCo and ABOPcCo results in less defective sites.17 These results confirm that APcCo and ABOPcCo are functionalized onto the rGO surface successfully via a noncovalent approach.APcCo and ABOPcCo can be spontaneously loaded onto the surface of rGO 3.2via the concentrations of ABOPcCo/rGO and APcCo/rGO aqueous dispersions. Table S1−1, respectively  was 0.979. The limit of detection (LOD) was estimated to be 78 ppb at 28 °C (S/N = 3), according to noise is the standard deviation of the noise, which is calculated to be equal to 0.01 based on 11 data points from the baseline of the response curve.54 Similarly, the LOD of APcCo/rGO was estimated to be 1.3 ppm at 28 °C. In order to certify the effects of substituents on gas sensing properties, the gas sensing properties of PcNi/rGO were also studied. Fig. S73. Similar to PcCo/rGO, the ABOPcNi/rGO sensor also shows a better response than the APcNi/rGO sensor.As a control, the sensing responses of rGO and PcCo molecules towards NHs Fig. S4. The rGO NH3 gas , which iC Fig. S5. AdditioC Fig. S5. For exar Fig. S6. For ABO3 and NOx: 50 ppm; other gases: 3200 ppm) and volatile organic compounds (VOCs: 3200 ppm) at different humidity levels at 28 °C. The responses of the rGO sensor to NH3, NOx, EtOH, MeOH, PA and 90% RH, other gases and VOCs are 3.2%, 2%, 1.5%, 1%, 1% and lower than 1%, respectively. Surprisingly, the responses of the ABOPcCo/rGO and APcCo/rGO sensors to NH3 increase to 23.3% and 6.4%, but the responses to other gases and different relative humidity levels are still less than 2%. It should be pointed out that the PcCo/rGO sensors exhibit high responses to NH3 and low responses to NOx at the same concentration (50 ppm), which is usually not easily achieved. The results demonstrate that the functionalization of APcCo and ABOPcCo on rGO offers a very effective way to tune and boost the gas sensing performance, such as producing improved responses and selectivities.3 over 30 days at 28 °C. The responses of the ABOPcCo/rGO and APcCo/rGO sensors up to 30 days reduced by less than 5%, indicating that the PcCo/rGO sensors display excellent long-term stability. Meanwhile, the ABOPcCo/rGO sensor also displays 3.6 and 2.4 times higher responses to 50 ppm and 200 ppm NH3, respectively, than the APcCo/rGO sensor. Moreover, the effects of humidity on the NH3-sensing properties of the PcCo/rGO sensors were also studied. 3 at different relative humidity levels at 28 °C. As can be seen, the responses of the PcCo/rGO sensors did not change obviously below 60% RH. However, the response decreases under a high RH of 80%, which might be ascribed to competitive adsorption between NH3 and H2O molecules.55,563 concentrations, from 3200 ppm to 750 ppb, and in 200 ppm NH3 gas over ten continuous cycles at 28 °C. The resistance goes through a rapid increase followed by a slow increase in NH3 gas. Then, the resistance sharply decreases when the sensors are exposed to air again  hybrid was synthesized 3.33 sensing mechanism of the PcCo/rGO hybrids is based on the resistance changes of the PcCo/rGO sensors upon exposure to NH3, which are attributed to charge transfer between PcCo/rGO and adsorbed gas molecules. A reducing gas (NH3) donates electrons to PcCo/rGO, which could lead to a decrease in charge carriers (holes) and an increase in the electrical resistance of the hybrid (2. An oxidizing gas (NO2) withdraws electrons from PcCo/rGO, which could lead to a contrary change in the electrical resistance of a hybrid  data of PcCo and PcCo/rGO hybrids were studied , exhibit better responses. These performances are mainly ascribed to: (a) the aminophenoxy groups reducing the electron donation power of the amino groups and increasing the charge transfer between PcCo/rGO and NH3; (b) rGO providing high conductivity and continuous pathways for charge transportation; and (c) PcCo/rGO hybrids showing excellent electron transportation abilities. EIS and DFT calculations confirm that the aminophenoxy groups of PcCo play a critical role in the NH3 sensing performance. This systematic study provides a valid way to improve the performances of rGO based NH3 sensors.Three NHThere are no conflicts to declare.RA-008-C8RA07509C-s001


N-methyl-2-pyrrolidinone suspensions exhibited strong polarization-dependent characteristics. In paper, a reverse saturated absorption (RSA) dip surrounded the lens focus when the horizontal polarized beam was focused in the suspension, and two saturated absorption (SA) peaks appeared adjacent to the dip. However, for the vertical polarized beam, only one RSA dip surrounded the lens focus, and the threshold was higher than the SA for a horizontally polarized beam. The transmission of RSA for the GO suspension was evidently lower than that of the graphene suspension. The polarization-dependent characteristic can be ascribed to the laser-induced alignment in case the suspension is moved in or out of the beam focal point. Furthermore, the polarization-dependent 2D carbon nanomaterial suspension can be applied in several practical purposes such as 2D material-based optical and opto-fludic devices.The Z-scan technique uses a single beam that can be used for observing the nonlinear or optical limiting properties of materials. For the first time, the Z-scan properties dependent on the polarization of 2D carbon nanomaterial suspension were experimentally investigated using optical Z-scan technology. The Z-scan curves of graphene and graphene oxide (GO) in  Carbon nanomaterials have garnered considerable interest owing to their unique properties and fascinating structure for utilizing the nonlinear properties of carbonaceous matter at the nanoscale, using an open-aperture7 or closed-aperture Z-scan technique9, especially graphene and its derivatives12. Optical limiting is an important property of materials and can be typically obtained using the open-aperture Z-scan technique, which can control the light intensity in a predetermined and predictable manner in addition to prevent laser damage. Several researchers have studied the optical limiting phenomenon16. Recently, the Z-scan properties of nanomaterial suspensions have attracted scholarly interest22. In particular, a liquid environment can provide nanostructures with more degrees of freedom in both rotational and translational motions as well as enable us to study the collective properties of macroscopically ordered assembly of nanomaterials—a condition that remains unrealized in their solid state24. Moreover, 1D or 2D nanomaterials are intrinsically anisotropic in shape, electronic, and optical properties. Therefore, their liquid suspensions can exhibit isotropic or anisotropic properties macroscopically depending on the microscopic alignment of suspended nanostructures27. An important consequence of this dynamic alignment involves the modulation of the incident laser: the aligned nanostructures will increase or decrease the optical transmission depending on the laser polarization. However, the dependence of the Z-scan properties depend on polarization is still unclarified through research, because it should not matter for either saturated absorption (SA) or reverse saturated absorption (RSA), especially for graphene and graphene oxide (GO) suspensions. Graphene has been reported to exhibit polarization-dependent optical absorption in the visible spectral range29, ultrafast carrier dynamics30, and double-resonant Raman33. Furthermore, black phosphorus exhibits anomalous polarization dependence of Raman scattering and crystallographic orientation34.The Z-scan technique is used to measure optical nonlinearities of materials, including nonlinear absorption and refraction propertiesWith pioneering novelty, this study reports the influence of polarization on the Z-scan properties of a 2D carbon nanomaterial suspension under Z-scan technology. In particular, the graphene and GO in the N-methyl-2-pyrrolidinone (NMP) and deionized (DI) water suspensions displayed polarization dependence, and the Z-scan results slightly varied for the graphene and GO suspensions.35. As-obtained graphene and graphene flakes are dispersed in DI water or N-methyl-2-pyrrolidone (NMP) by sonication and form stable suspensions with a concentration of 0.005–0.01% in weight percentage (wt%), corresponds to 0.002–0.004% in volume fraction (vol%).Few-layer graphene flakes with a lateral dimension of a few micrometers are synthesized via intercalation and exfoliation of natural graphite. Single-layer graphene oxide (GO) flakes with sizes in the range of 2 ~ 10 μm are prepared by a modified Hummers’ methodThe Z-scan properties of the carbon nanostructure suspension were measured using a traditional open-aperture Z-scan system, wherein the scan laser beam  was a polarized beam focused with a lens of 10 cm focal length. The Z-scan results of graphene in the NMP suspension under horizontally and vertically polarized beams are illustrated in Fig. As depicted in Fig. 37; the results are displayed in Fig. The influence of the solvent on the polarized Z-scan properties of the graphene suspension was investigated by using DI water as the solvent to obtain a graphene–DI water suspension, whose viscosity coefficient varied from that of the NMPThe Z-scan results of GO in the NMP and DI water suspensions are illustrated in Figs. 38, there is barely any flow when intensity laser irradiate 0.4 s, but increases considerably at 4 s. In general, a flake will experience imbalanced shear forces on its head and tail ends, which produces a net torque causing rotation of the flake39. In addition, laser-induced dynamic alignment and optical anisotropy of nanomaterials further result in polarization-dependent modulation of laser transmission38. However, the degree of laser-induced alignment varied in case the suspension was moved in or out of the focal point of the beam, and it was related to the laser intensity. Moreover, low laser intensity was observed with weak laser-induced temperature gradient and subsequent fluidic flows in case the suspension was out of focus. In comparison, a much stronger flow and subsequent alignment could be observed if the focused beam was in the vicinity of the suspension, and the flakes were vertically aligned, as depicted in Fig. 24, and two SA-like peaks appeared under horizontally polarized cases, as depicted in Figs. (3) is the laser pulse width, and only sub-picosecond or short than sub-picosecond with high peak intensity can meet the timescale of electronic transitions42. But for most nanosecond laser pulses, they are too low to induce a significant nonlinear optical effect despite the observation of obvious nonlinear-like Z-scan transmission. In Fig. In case a high-intensity laser was incident on the suspension, the suspended nanostructures absorbed the incident laser energy and converted it into heat. Subsequently, the heat was transferred to the surrounding liquid, creating a local temperature gradient and natural convection. As the simulation results of flow velocity distribution by computational fluid dynamics (CFD) in our paper43, the carbon nanomaterials absorbed the energy of the incident laser and transferred to surrounding liquid, the Raman experiment result showed that the temperature rise is only 180 °C, which is just slightly higher than the boiling temperature of water, resulting in vapor and microbuubles generation. At the same time, the CCD and ultrasound results further verified the existence of photothermal bubbles near the focus. Moreover, the photothermal microbubble strongly scattered the incident laser, which induced a normalized transmission turn-down after exhibiting the SA-like peak. The focused beam exhibited a small beam radius with an increasing number of photothermal microbubbles in the vicinity of the focus, and the scatter intensified when the focused laser passed through the suspension. Therefore, the scattering induced by the photothermal microbubbles were independent of the polarization, and both the horizontally and vertically polarized cases displayed an RSA-like dip, as depicted in Figs. However, when the focused beam was transmitted through the suspension, the highest laser intensity, highest laser-induced temperature gradient, and fastest fluidic flow caused by convection were observed at this spot. Thus, the alignment was strongly disturbed and misaligned, as depicted in Fig. To further verify the polarization-dependent transmission induced by the laser-induced alignment of nanomaterials in suspension, the carbon particle suspension was selected to derive various results. Consequently, the isotropic particles and Z-scan properties of the carbon particles suspended in DI water are represented in Fig. In summary, open-aperture Z-scan results revealed that graphene and GO flakes exhibited SA- and RSA-like curves under horizontally polarized beams, whereas only the RSA-like curves were observed for vertical polarization under the same conditions. Moreover, the RSA-like dip of the GO suspension was narrower than that of the graphene suspension. In particular, the RSA thresholds of the graphene and GO suspensions were lower for the horizontal beam than those for the vertical beam. These results signified that the Z-scan characteristics of graphene and GO suspensions depend on the polarization of the incident laser, and the suspension particles were anisotropic, which could be ascribed to the laser-induced dynamic alignment of graphene or GO flakes. However, the Z-scan properties of the isotropic materials such as carbon particles are independent of the polarization of the incident laser. Simultaneously, the solvent of the graphene suspension and concentration of the GO suspension influenced the SA-like peaks under polarized laser. Furthermore, the SA-like peaks disappeared in both the graphene–DI water suspension and the high-concentration GO suspension, and only the RSA-like dip remained. Thus, the anisotropic optical responses of the liquid suspensions provided innovative routes for studying the fundamental light–matter interaction and the Z-scan curve principle, which is essential for novel 2D material-based optical and optofluidic devices.


Raman measurements complemented by in-depth statistical analysis and density functional theory calculations enable us to comprehend the lithiation effect on the properties of bilayer-patched epitaxial graphene and ascribe the lithium intercalation-induced Raman G peak splitting to the disparity between graphene layers. The current results are helpful for further advancement of the design of graphene-based electrodes with targeted performance.Novel two-dimensional materials (2DMs) with balanced electrical conductivity and lithium (Li) storage capacity are desirable for next-generation rechargeable batteries as they may serve as high-performance anodes, improving output battery characteristics. Gaining an advanced understanding of the electrochemical behavior of lithium at the electrode surface and the changes in interior structure of 2DM-based electrodes caused by lithiation is a key component in the long-term process of the implementation of new electrodes into to a realistic device. Here, we showcase the advantages of bilayer-patched epitaxial graphene on 4H-SiC (0001) as a possible anode material in lithium-ion batteries. The presence of bilayer graphene patches is beneficial for the overall lithiation process because it results in enhanced quantum capacitance of the electrode and provides extra intercalation paths. By performing cyclic voltammetry and chronoamperometry measurements, we shed light on the redox behavior of lithium at the bilayer-patched epitaxial graphene electrode and find that the early-stage growth of lithium is governed by the instantaneous nucleation mechanism. The results also demonstrate the fast lithium-ion transport (~4.7–5.6 × 10 Rechargeable and portable lithium-ion batteries (LIBs) are currently at the forefront of device research due to their significant potential as a high-performance power source in sustainable electronics ,2,3,4,5 −1, which is much higher than the graphite capacity limit [−1 at 100 mAg−1) by using a graphene/SiC composite as an anode has been recently demonstrated by Xinli et al. [−1 [The integration of silicon and carbon technologies can enhance the lithium storage performance ,30,31,32ty limit . Furtherty limit . A signii et al. . Another al. [−1 . All theA much better storage capacity of graphenized SiC compared to graphite cannot originate entirely from the graphene presence, hinting at a significant role of the Si surface in lithium binding. Considering the technological controllability of the graphenization of SiC, there is plenty of room for improvement of the capacity through smart design of the anode material toward the most favorable structural and electrochemical properties. This indicates that two-dimensional carbons supported on SiC, represented by epitaxial graphene, have a significant potential as novel anode materials in LIBs. In this context, a clear understanding of the room-temperature lithiation of epigraphene on SiC is central to realizing future LIBs.+ ions of energy 5 eV by using a low-energy alkali metal ion gun followed by heating [Much effort has been devoted to performing lithium intercalation into epitaxial graphene ,53,54,55 heating . It was Inspired by a recent work on the electrochemical intercalation of graphene/h-BN van der Waals heterostructures , in the −1. Optical reflectance mapping was performed using the same micro-Raman setup [Q [Bilayer-patched epitaxial graphene was prepared through high-temperature thermal decomposition of the Si-face 4H-SiC substrate (which was cut out from the semi-insulating on-axis 4H-SiC wafer) in a vertical radiofrequency-heated furnace under patent-protected growth conditions . The quaan setup . To discsetup [Q .4 (lithium perchlorate) electrolyte in a glove box. To explore lithium kinetics at bilayer-patched epitaxial graphene, we then conducted chronoamperometry measurements and recorded the current–time transients during the early stages of lithium electrodeposition on the BLPMLG/SiC electrode. Finally, lithium electroplating was performed at two different potentials: −4 V and −5 V. The corresponding lithiated BLPMLG/SiC electrodes were further subjected to detailed Raman study to investigate the lithium-induced effects at the graphene–SiC interface, including possible intercalation phenomena and defects generation in graphene. X-ray photoemission electron microscopy (XPEEM) and selected-area XPS (micro-XPS) were performed at the synchrotron radiation facility at MAX IV  using the MAXPEEM beamline housing an ACLEEM microscope (Elmitec GmbH). Photoelectron spectromicroscopy was employed to ensure the presence of a Li0 and Li-containing SEI at the graphene electrode surface.Electrochemical measurements were undertaken with an O-ring-type three-electrode electrochemical cell ,71 compo−5, while the force tolerance in coordinate optimization was set to be 0.02 eV/Å. The Brillouin zone was sampled using a 9 × 9 × 1 Monkhorst–Pack k point grid. Norm-conserving Troullier–Martins pseudopotentials for C, Si, H, and lithium were generated by using ATOM code [All density functional theory (DFT) calculations were executed with Siesta-4.1-b4 code  using thTOM code . A BLPMLTOM code ,79,80. TFurther, we study the process of lithium intercalation into the electrode interface using the climbing image nudged-elastic band (CI-NEB) method. CI-NEB calculation was performed using SIESTA-LUA along with a flos library . The imaOptical reflectance mapping  showed tQ) values of monolayer and bilayer graphene at the same tip/sample bias. As the quantum capacitance is directly linked to the electronic density of states, it tends to increase with the increase in graphene thickness [To strengthen the evidence on the presence of bilayer graphene patches, we then performed AFM measurements . From thhickness . These rhickness , the prehickness .G and 2D bands, as well as weak spectral features related to the buffer layer, inter-valley scattering (G*) band, and 2D’ peak. No D peak is seen in both spectra, pointing out the high structural quality of the graphene and small defect density. This enables us to exclude the defects as possible adsorption sites and intercalation paths during the lithiation process. Usually, the analysis of the interrelationships between characteristic peaks’ parameters provides valuable information on the number of graphene layers. For the exfoliated graphene, the 2D/G peak intensity ratio is an important descriptor of the graphene thickness. However, this is not always helpful in the case of epitaxial graphene on SiC. A more reliable way to distinguish bilayer from monolayer epitaxial graphene is to compare FWHM values of the 2D peak [D peak with FWHM values ranging from 30 cm−1 to 40 cm−1 can be attributed to monolayer epitaxial graphene on SiC, while bilayer graphene typically demonstrates broader 2D peaks with FWHM ~45 cm−1 to 65 cm−1 [D in the case of bilayer graphene is 45 cm−1, we also estimated the percentage of Raman spectra with 2D peaks having FWHM values higher than 45 cm−1. It is found to be 35.5%  [The lithium plating/stripping behavior on epitaxial graphene was then scrutinized by performing cyclic voltammetry measurements. It was found that metallic lithium deposition (cathodic process) on the electrode occurs at a potential of around −3.4 V, while the reverse reaction (anodic process) is observed at −3.0 V a. The pe3, etc.) .maxt is the time at which the current , and −7 cm2∙s−1 , but at the same time, they are much higher than the sluggish lithium-ion diffusivity perpendicular to the basal plane of graphene (~10−11 cm2∙s−1) [−7 cm2∙s−1), indicating an efficient Li ion transport through the SEI [To elucidate the kinetics of lithium, we performed chronoamperometry measurements and recorded the current–time transients during the electrodeposition of lithium on bilayer-patched epitaxial graphene on 4H-SiC. When the electrode is stepped from an initial potential to larger potentials, the current density significantly increases a, which echanism b,c. It s follows :(2)D=jmaalso see , which acm2∙s−1) . It is i the SEI .n is the number of electrons involved and Vm is the molar volume. From N0 demonstrates a generally increasing trend, reaching a value of ~3.0 × 106 cm−2 at −3.3 V. This is because the nucleation rate is directly proportional to the potential applied.Finally, the saturation nucleation density on the bilayer-patched epitaxial graphene electrode was determined by using the following equation:4 system completely covers the electrode surface, facilitating lithium-ion diffusion. It should be mentioned that in the case of partial coverage of the electrode surface with an SEI, one would expect lower values of the nuclei number density due to deposition directly on the SiC surface. DFT calculations allowed us to obtain atomistic insights into lithium electrodeposition at the initial stages. Particularly, we found that the hollow site is the energetically most favorable site for lithium adsorption on MLG/SiC, AA-BLG/SiC, and AB-BLG/SiC electrodes , thereby providing additional evidence of SEI formation. Raman studies brought up another argument in favor of our assumption on SEI growth. Particularly, we attributed the wide phonon band at ~2800 to 3000 cm


Unveiling how genetic variations lead to phenotypic variations is one of the key questions in evolutionary biology, genetics, and biomedical research. Deep mutational scanning (DMS) technology has allowed the mapping of tens of thousands of genetic variations to phenotypic variations efficiently and economically. Since its first systematic introduction about a decade ago, we have witnessed the use of deep mutational scanning in many research areas leading to scientific breakthroughs. Also, the methods in each step of deep mutational scanning have become much more versatile thanks to the oligo-synthesizing technology, high-throughput phenotyping methods and deep sequencing technology. However, each specific possible step of deep mutational scanning has its pros and cons, and some limitations still await further technological development. Here, we discuss recent scientific accomplishments achieved through the deep mutational scanning and describe widely used methods in each step of deep mutational scanning. We also compare these different methods and analyze their advantages and disadvantages, providing insight into how to design a deep mutational scanning study that best suits the aims of the readers’ projects. Since Mendel’s experiments with peas  laid theDMS has been widely used in many biological systems, allowing breakthroughs in biological and biomedical research since its first introduction . For exaA typical DMS experiment involves three steps: 1) generating a genetic mutant library; 2) performing a high-throughput phenotyping assay; 3) and deep sequencing and data analysis. Several good reviews on designing DMS experiments were published  in the eIn this review, we give an up-to-date overview of the DMS experiment  with a svia transformation) for the next step—high throughput phenotyping assay. While most of the steps mentioned above follow regular molecular cloning procedures, mutagenesis in the very first step is not trivial and requires careful design. In this section, we will discuss the most widely used methods in designing and creating mutant libraries so that the readers can determine the optimal method to suit their research needs.A genetic mutant library is often first synthesized as a pool of oligos and amplified as a library of linear gene blocks. Then the amplified dsDNA is ligated to the expression vector backbones to substitute the wild-type region of the gene to be mutated. The ligation mix is introduced to the cloning cell lines to be amplified and extracted as a plasmid mutant library, which will be introduced to the destination cells  to the cell types of interest for high-throughput quantification of the phenotypes coupled by the deep sequencing. These phenotyping assays are usually designed to enrich functional genetic variants while depleting the detrimental variants in a bulk experiment (via reporter-based cell sorting (After obtaining the mutant plasmid library or gene blocks periment  or via r sorting .via the fitness-based assay.Measured phenotypes can be divided into two main categories: 1) Fitness based on the reproduction rate of cells  or 2) meFitness competition is the most straightforward and economical approach for a high-throughput functional selection. Its logic is that if the gene product is required for cell survival or reproduction, cells carrying functional genetic variants will enrich. In contrast, detrimental variants will deplete over time in a culture medium. As a result, frequency changes of genetic variants can be calculated as fitness scores . This stTherefore, it is essential to select an optimal condition that either reflects the physiological situation best  to unveiUsing the protein stability or binding affinity as a phenotype  is anothStability assays often involve tagging the target protein to a reporter, like the green fluorescent protein (GFP) as an indicator of the protein stability . Cells cIn vitro display methods, such as phage display   is basedBindingPCA uses the traditional PCA method in which two interacting partners are each tagged with interacting partners are each tagged with DHFR and DHFR[3] fragments . MutatioBesides the methods mentioned above, enzyme kinetics can be measured in a dynamic system using microfluidics technology. For instance, the High-Throughput Microfluidic Enzyme Kinetics (HT-MEK) in a DMS experiment allows the systematic investigation of enzymes in an automatically valved microfluidics expression system .Deep-sequencing of the genetic variants for both the input (before phenotyping) and the output (after phenotyping) follows the high-throughput phenotyping. Samples from a DMS experiment are special in that there are up to tens of thousands of genetic variants. Yet, they are with a low frequency of mutations at each position (sometimes as low as 0.1%) in an overall very homogenous sequence. Considering that genotype-phenotype mapping depends on frequencies of each genetic variant that are often only one or two hamming distances away from each other, choosing a high-throughput sequencing platform with high accuracy is especially important for a DMS study.The most widely used platform in DMS studies has been the Illumina HiSeq platforms for their relatively lower error rates compared to the third-generation sequencing platforms (PacBio or Nanopore sequencing) and the higher cost-effectiveness (cost/base pair) compared to Illumina MiSeq . HoweverRecently, UMI-based Nanopore sequencing  and new Experiment design and library preparation for sequencing are utterly important to obtain high-quality data, regardless of the sequencing platforms used. One should always 1) start with a sufficient number of molecules per variant in each mutant library; 2) have multiple independent biological replicates; and 3) avoid experimental bottlenecks, over-sequencing or under-sequencing. Especially, it is essential not to over-sequence as that would impactfully hinder accurate prediction of the variant frequencies . Read-deversus before selection) compared to that of the wild type, as shown in Eq. The phenotype of each genetic variant is often quantified as the normalized relative enrichment scores from the aggregated count data  and before selection (input) respectively, and Ev is the normalized enrichment score of the variant to the wild type. When the phenotype is based on the reporter fluorescence intensity and cell sorting  is also formed to maximise collaboration, benefits, and the influence of mutational scanning.A high-quality DMS dataset not only provides important information on genotype-phenotype mapping for biomedical research, but also guides other research fields including structural biology, biophysics, and protein engineering. For instance, the very comprehensive single and double-mutant GB1 DMS dataset  enabled Still, there are limitations in DMS technology. Firstly, each DMS experiment could handle up to tens of thousands of mutations but not more. One of the limiting factors in scaling mutation libraries is transformation (transfection or transduction) efficiencies, as one does not want to generate a bottleneck by randomly sampling genetic variants that go into the destination cells. The number of successfully transformed (transfected or transduced) cells should be sufficiently higher than the library sizes to minimize the loss of some genetic variants during the transformation step. Secondly, performing DMS at the endogenous genomic loci of cells is still a big challenge. Nevertheless, endogenous DMS will become available soon with improved precision in genome editing technologies and transformation/transfection efficiencies. While DMS has been applied to various organisms, including humans, viruses, bacteria and yeast, interestingly, there is no DMS research on plant genes, even though mapping genotypes to phenotypes on the plant is both important and challenging . The reaTo sum up, our ability to interpret genotypes is still lacking due to the complication of the genotype-phenotype maps . While s


Voc) as high as 1.16 V at 90 K. The high efficiency is a result of carrier multiplication (CM) effect of graphene in the graphene/GaAs heterostructure. Especially, the external quantum efficiency (EQE) in the ultraviolet wavelength can be improved up to 72.2% based on the heterostructure constructed by graphene/In0.15Ga0.85As/GaAs0.75P0.25 quantum wells/GaAs. The EQE increases as the light wavelength decreases, which indicates more carriers can be effectively excited by the higher energy photons through CM effect. Owing to these physical characters, the graphene/GaAs heterostructure solar cell will provide a possible way to exceed Shockley–Queisser (S–Q) limit.Despite the fascinating optoelectronic properties of graphene, the power conversion efficiency (PCE) of graphene based solar cells remains to be lifted up. Herein, it is experimentally shown that the graphene/quantum wells/GaAs heterostructure solar cell can reach a PCE of 20.2% and an open‐circuit voltage ( Graphene/QWs/GaAs heterostructure solar cell shows a higher EQE of 72.2% in the ultraviolet wavelength than that in the whole visible light range, as an experimental evidence of effective use of the carrier multiplication effect of graphene. This work has transferred the signal that graphene/semiconductor heterostructure‐based solar cell can be very competitive for overcoming the S–Q limit. As a member of a large family of two‐dimensional (2D) layered materials, graphene has many outstanding electrical, optical and mechanical properties, and widely applied in transistors, optoelectronic and wearable electronic devices. Also, numerous efforts have been devoted to realize graphene based high efficiency solar cells, applied in graphene electrodes, graphene electron transport layers, graphene/semiconductor heterostructure, and so on. The power conversion efficiency (PCE) of 18.5% has been realized with a designed graphene–dielectric–graphene gating structure and highly tunable Fermi level of graphene in our previous work. But, in order to overcome Shockley–Queisser (S–Q) limit, inhibiting the intrinsic thermalization energy loss channel is critical for improving the PCE of solar cell. In this context, how to make efficient use of hot carriers (HCs) and decrease the main energy losses become a particularly critical problem. Despite the existence of generating more carriers through interband carrier–carrier scattering in the conventional bulk materials, HCs can hardly be extracted because of the rapid relaxation by carrier–phonon scattering before arriving to the band edges. However, in graphene, owing to an atomic thin crystal with electrons described by Dirac equations, which points to its linear band gap structure near the Dirac point, and are predicted to illustrate highly efficient carrier multiplication (CM) effect to utilize HCs more efficient. Furthermore, graphene has been theoretically predicted and experimentally observed that HCs can be exploited to realize a significant CM through the Auger process, as a feasible path to decrease the thermal energy loss. In addition, in spite of the presence of directly competing process of Auger recombination and phonon‐induced recombination, impact ionization is efficient enough to realize a prominent CM in graphene.Graphene is composed of sptructure.1 As a The externally injected photogenerated carriers from graphene can effectively enhance the hot‐phonon bottleneck effect of GaAs, which will lead to a prolonged HCs cooling process and be beneficial to improve the PCE of solar cell.Due to the weak light‐absorbing ability of graphene, the selection of related semiconductor materials to combine with it is also particularly important. Conventional bulk materials, such as GaAs, which has a suitable bandgap of 1.42 eV to harvest the maximum possible solar spectrum, sufficiently high carrier mobility and distinctive phononic bandgap, formatting a hot‐phonon bottleneck to limit the excess energy redistribution into the lattice, which can be a suitable HCs absorber.13 The0.75P0.25 and In0.15Ga0.85As multi quantum wells (QWs), we have demonstrated the graphene/QWs/GaAs heterostructure solar cell with the Voc and PCE of 1.16 V and 20.2% at the temperature of 90 K, respectively. Notably, at 300 K, the EQE of graphene/QWs/GaAs heterostructure has reached 72.2% at ultraviolet wavelength. The higher EQE indicates that HCs in graphene can be exploited to realize a more significant CM through the integration of QWs. This research not only points out that graphene/GaAs heterostructure solar cell could provide the feasibility of harvesting HCs effectively to restrict thermalization loss channels, and further to overcome the S–Q limit, but also demonstrates its potential applications as energy source in extremely low temperature environments.In this work, we reveal an efficient CM effect of graphene, and have demonstrated graphene/GaAs heterostructure solar cell with an external quantum efficiency (EQE) of 67.8% in ultraviolet wavelength, which is higher than that in the whole visible wavelength. Especially at low temperature, graphene/GaAs heterostructure solar cell can excite and utilize HCs more effectively. Furthermore, through integration of GaAs2Figure which is conducive to the formation of ultra‐shallow heterojunction on the material surface. Simultaneously, the formation of the ultra‐high built‐in electric field between the interfaces is also beneficial to lead a faster carriers separation process. In Figure −1, corresponding to G and 2D peaks, individually. Around the D peak (about 1350 cm−1), the intensity is pretty weak, which indicates few defects in graphene. Compared with 1580 cm−1 of pure graphene, as‐grown graphene is p‐type doped after the wet transferring process. The intensity of 2D peak is higher than G peak and the shape is single peak, which reflect that as‐grown graphene is a monolayer.λ is the wavelength of absorbed light, h is Planck's constant, c is the speed of light, Eg is the band gap of semiconductor material. According to Equation . When the sunlight irradiates on the surface of active area of graphene/GaAs solar cell, the GaAs substrate absorb the photon energy and generates electron–hole pairs. Subsequently, as shown in Figure The mechanism of graphene/GaAs heterostructure has been shown in As mentioned above, the graphene/GaAs heterostructure solar cell shows obvious absorption characteristics in ultraviolet wavelengths. In Figure  Further to explore the feasible strategy to utilize HCs intuitively and sufficiently, the variable temperature experiments with certain gradients have been designed. The dark J–V curves with different temperature of graphene/GaAs heterostructure solar cell have been measured in Figure Voc synchronously.Also, there are many fundamental theoretical calculations to discuss limit factors of CM in graphene, such as applied magnetic field, pump fluence, ambient temperature, and so on.16 FurVoc of graphene/GaAs heterostructure solar cell varied with different temperature have been measured in the low temperature optical measurement system. As the temperature gradually decreasing, the Voc has increased to 0.92 V at the 90 K. Contrasted with the Voc at the 300 K, the Voc has been increased 43.8% at the 90 K. In graphene, due to the gradual decrease of ambient temperature to improve carrier mobility, speed up the cooling of the internal phonon transmission channel, and lead to the lower electron–photon coupling, which will delay cooling process of HCs. Simultaneously, a lower temperature will result in a high‐efficient impact excitation to decrease an initial occupation and promote the CM effect. Eventually, the decreased temperature would lead to a performance enhancement of the graphene/GaAs heterostructure solar cell. Also, the enhanced PCE of solar cell , have been studied in multi‐junction solar cells, as an effective structure to optimize the absorption of solar spectra and reduce the thermalization losses of solar cells, which ultimately lead to increase the number of photogenerated carriers to improve the performance of solar cells.18 Add0.75P0.25 and In0.15Ga0.85As are 1.63 and 1.21 eV, individually. Due to the difference of bandgap between GaAs and QWs materials, the absorption spectrum can be expanded effectively, where the QWs epitaxially grown on GaAs are undoped. So, the light at the edge of the spectrum can be utilized by the QWs as the intrinsic region, which also absorb the energy of photon and generate extra electron–hole pairs. Simultaneously, thin enough depletion layer  have been measured in Figure The photogenerated carriers transport process has been shown in Figure er . Owing to the multi QWs structure, the extra absorbed photons to generate photogenerated carriers, which contribute to the increased photocurrent. Hence, the PCE of solar cell based on the graphene/QWs/GaAs structure has been greatly increased to 11.5%. In the same way, the variable temperature experiments have been also measured. As the experimental data shown in Figure J–V curves have illustrated that graphene/QWs/GaAs heterostructure solar cell still exhibit well stability in the low temperature environment. Additionally, the variation of potential difference is rather apparent, when the temperature of environment gradually decreases. Simultaneously, comparing with the J–V curve of graphene/GaAs heterostructure solar cell  was spin‐coated on the front surface of cooper to be a supporting and protective layer. Then, hydrochloric acid and CuSO4 mixed solution was prepared to etch the copper and obtained monolayer graphene for about 2 h. After that, the graphene was transferred to deionized water to clean up.Graphene was grown on a cooper foil with chemical vapor deposition (CVD) technique using CHN‐type GaAs substrate was doped with silicon at a density of Nd = 2 × 1017 cm−3. 10 nm Ti was thermally evaporated on back surface of GaAs to form an ohmic contact, followed by a 50 nm Au rear electrode. Then, graphene was transferred onto GaAs substrate and the PMMA of the surface of graphene was removed later by acetone, isopropanol and deionized water in turn for 15 min, individually. Silver paste was pasted onto graphene as a front contact electrode and annealed at 105 °C for about 15 min on the hot plate.The N‐type GaAs substrate was doped with silicon at a density of Nd = 2 × 1018 cm−3. QWs are epitaxial growth on the GaAs substrate with alloy layers are designed as 5 nm GaAs0.75P0.25 and 3 nm In0.15Ga0.85As layers, forming a combination of 10 periods. 10 nm Ti was thermally evaporated on back surface of GaAs to form an ohmic contact, followed by a 50 nm Au rear electrode. Then, graphene was transferred onto In0.15Ga0.85As layers and the PMMA of the surface of graphene was removed later by acetone, isopropanol and deionized water in turn for 15 min, individually. Silver paste was pasted onto graphene as a front contact electrode and annealed at 105 °C for about 15 min on the hot plate.The N‐type GaAs layer with the doping density of Nd = 2 × 1018 cm−3 and a 3 µm P‐type GaAs layer of Na = 1 × 1017 cm−3 was used as a control group. The rear contact of the PN GaAs solar cell was made of Au–Ge–Ni alloy, and the front electrode was made into grid structure with Au.A conventional single‐junction GaAs solar cell with N on P structure consisting of a 100 nm I–V characteristics were measured under the standard spectrum of AM 1.5 at temperatures ranging from 90 to 300 K with a step length of 30 K and an error of ± 0.2 K in the low temperature optical measurement system. The effective working area of the solar cells were measured and calculated with Image Pro software. EQE tests were measured by Enlitech QE‐R system. After transferring to SiO2/Si substrate (oxide layer thickness was 270 nm), monolayer graphene was characterized by Raman spectroscopy (Renishaw inVia Reflex) with the excitation wavelength of 532 nm and the sampling interval of 1 nm.The The authors declare no conflict of interest.S.L. designed the experiments, discussed the results, and conceived the study. X.Y. carried out the experiments, discussed the results, and wrote the paper. Y.D., Y.L., C.L., Y.Y., R.S., Z.Y., L.F., L.S., and Y.L. discussed the results and assisted with experiments. All authors contributed to the preparation of the manuscript.Supporting InformationClick here for additional data file.


Optical microfibers find new applications in various fields of industry, which in turn require wear resistance, environmental friendliness and ease of use. However, optical microfibers are fragile. Here we report a new method to prolong the microfiber lifetime by modifying its surface with green-extracted graphene overlayers. Graphene films were obtained by dispergation of shungite mineral samples in an aqueous medium. For this, we tapered optical fibers and sculptured them with graphene films mixed with gold nanoparticles. We observed that due to the surface modification the lifetime and survivability of the microfiber increased 5 times, as compared to the bare microfiber. The embedded gold nanoparticles can also be utilized for enhanced sensitivity and other applications. Optical fibers are dated back to 1880 when William Wheeler transmitted light through a glass pipe and referred to it as ’light piping’. It took until 1966 when the optical fibers with a higher guiding medium as compared to the cladding were proposed for light transmission . FurtherThese days, optical microfibers are widely used for the determination of various substances with low concentrations. Namely, in biomedicine  and biolWith such wide uses of microfibers, there are also different methods for modifying them, depending on the required parameters. One of the simplest methods is the method of chemical modification when various materials are deposited on the microfiber surface . The useμm . Howeverμm . While uμm . These aμm ,44,45.Here, we report the use of graphene films with gold nanoparticles to increase the lifetime of microfiber as illustrated in In our work, we used tapered fiber as our sensing device. A single-mode fiber (SMF-28) was tapered using a commercial Vytran GPX-3000 tapering system. In the first step, we removed the acrylate coating from the fiber section where the tapering was carried out. After the removal of the coating, the fiber narrowed from a diameter of 125 For obtaining the composite material, 0.01 mL of nanoparticles of gold with a diameter of 30 nm was added to plastic eppendorf with a capacity of 5 mL and 4.5 mL of distilled water was added. Dispersion of nanoparticles was carried out using a Sony ultrasonic bath in a solution of distilled water. Plastic tubes with the obtained suspensions were placed in an ultrasonic bath. Having dispersed the nanoparticles, we broke up the microagglomerates, increasing the specific surface area of the nanoparticles. In flasks with a capacity of 50 mL, 25 mL of distilled water and 4.51 mL of dispersed gold nanoparticles were added. Then, 1 g of shungite powder was placed in each flask and placed in an ultrasonic bath for 1 h. The resulting solutions were stored at room temperature.For applying the composite material on the microfiber region, we applied 6 micro liters of composite material (graphene films + gold nanoparticles) to the microfiber region of the tapered fiber with an automatic pipette. Then, the laser was coupled to the tapered fiber and turn on. Under the thermal action of the laser, the water from the composite evaporated and the particles settled on the surface of the microfiber. The process of physical adsorption on the surface of graphene films and addition to OH groups also took place.To increase the lifetime of the microfiber while in contact with metals and caustic materials, we used graphene films, which prevent the microfiber from contacting with gold but do not change the peaks of gold nanoparticles during research. We obtained graphene films from the natural mineral shungite by the method of sonication in an aqueous solution without the addition of surfactants. We studied the surface of shungite samples before and after dispergation treatment to determine how the surfaces of the samples changed by scanning and transmission electron microscopy.For the chemical modification of the fiber surface, we use graphene films with gold nanoparticles coating. We added gold nanoparticles with a diameter of 30 nm to the graphene samples obtained during sonication. The concentration ratio of graphene and gold was 1:1. Gold particles are adsorbed on the surface of graphene layers by physical sorption and chemical reaction due to the replacement of OH groups in graphene layers by gold. To investigate the interaction between the graphene films and the gold nanoparticles, we studied samples of graphene with gold nanoparticles and investigate them using transmission electron microscopy (TEM).Next, we study the samples of graphene with gold nanoparticles via UV-VIS spectrometry and Raman spectroscopy to determine the spectra of graphene and gold and how they affect each other in a composite material.Next, we studied the samples using X-ray photoelectron spectrometry to determine the composition of the samples, characterize the carbon, and check how the oxygen concentration changes after the addition of gold nanoparticles. The data are presented in Comparing the data given in Here, we used the microfiber region of a tapered fiber as the sensing device. A commercial single-mode fiber was tapered to a diameter of 2.5 For verifying the optimal concentration of gold nanoparticles, we measured graphene with gold nanoparticles with different concentrations using a cuvette. We measured samples with ratios of graphene to gold nanoparticles of 1:1, 1:2, 1:3, 1:4, 1:5 and 1:6. Since it is known that microfibers are fast to break when interacting with metals and caustic substances in water ,51, we iWe examined the use of graphene films from the natural mineral shungite with the addition of gold nanoparticles of gold to increase the lifetime of microfiber (SMF-28). From the data obtained, we can conclude that the presence of graphene particles on the surface of microfiber increases its lifetime by 4.57 times. This method opens up the prospect of utilizing microfibers with graphene for sensing and for the studies of corrosive substances and metals.We conducted a study of graphene composites and selected the optimal ratio of gold nanoparticles to graphene , biotechnology and biology , chemical industry (determination of new substances with low concentrations), pharmacology (study of new drugs with low concentrations), chemical industry , construction industry , stratigraphy  and manufacturing of smart materials; it can also be used to capture sound waves.


A general strategy of fabricating thickness-controllable hydrogel films with diverse polymer networks for humidity sensing is proposed. The hydrogel film humidity sensor displays an unprecedented sensitivity up to 13,462.1%/%RH.The stretchable humidity sensor can work normally under large tensile strains with even enhanced sensitivity, which makes the humidity responding property of hydrogel mechanically programmable.A wireless respiratory interruption detection mask with Bluetooth transmission function is developed based on the sensor, enabling the real-time, wireless and accurate acquisition of user's breathing state, such as the interval and breathing frequency and apnea.The online version contains supplementary material available at 10.1007/s40820-022-00934-1. Respiratory monitoring plays a pivotal role in health assessment and provides an important application prospect for flexible humidity sensors. However, traditional humidity sensors suffer from a trade-off between deformability, sensitivity, and transparency, and thus the development of high-performance, stretchable, and low-cost humidity sensors is urgently needed as wearable electronics. Here, ultrasensitive, highly deformable, and transparent humidity sensors are fabricated based on cost-effective polyacrylamide-based double network hydrogels. Concomitantly, a general method for preparing hydrogel films with controllable thickness is proposed to boost the sensitivity of hydrogel-based sensors due to the extensively increased specific surface area, which can be applied to different polymer networks and facilitate the development of flexible integrated electronics. In addition, sustainable tapioca rich in hydrophilic polar groups is introduced for the first time as a second cross-linked network, exhibiting excellent water adsorption capacity. Through the synergistic optimization of structure and composition, the obtained hydrogel film exhibits an ultrahigh sensitivity of 13,462.1%/%RH, which is unprecedented. Moreover, the hydrogel film-based sensor exhibits excellent repeatability and the ability to work normally under stretching with even enhanced sensitivity. As a proof of concept, we integrate the stretchable sensor with a specially designed wireless circuit and mask to fabricate a wireless respiratory interruption detection system with Bluetooth transmission, enabling real-time monitoring of human health status. This work provides a general strategy to construct high-performance, stretchable, and miniaturized hydrogel-based sensors as next-generation wearable devices for real-time monitoring of various physiological signals.The online version contains supplementary material available at 10.1007/s40820-022-00934-1. Portable or wearable electronic devices with good shape-conformability and specific stimuli-responsiveness are currently attracting extensive attention and have a widespread employment in soft robots, healthcare, artificial intelligence, and human–machine interaction –6. To beGenerally, traditional flexible humidity sensors are constructed by integrating non-stretchable humidity sensing materials, such as graphene oxide (GO), reduced graphene oxide (rGO), single-walled carbon nanotube (SWCNT), micro/nanostructured metal oxides, conductive polymer, etc., onto flexible substrates, which always bear limited deformability and struggle to meet the requirements of wearable devices –29. For Recently, hydrogels consisting of three-dimensional networks and numerous water molecules have emerged as a promising stretchable material for the fabrication of wearable electronics, thanks to its intrinsic stretchability and ionic conductivity –41. AttrIn this work, ultra-high-performance, stretchable, transparent, and cost-effective humidity sensors and corresponding wireless sensing system are developed, enabling real-time respiration monitoring even under stretching Fig. a. Import−1. A rubber stopper was deployed to seal the mouth of the flask to prevent moisture from evaporation. After heating and stirring, a flowable PAM/Carrageenan hydrogel precursor solution was obtained, which was poured into a glass petri dish, and then placed in a refrigerator at 6 °C for 1 h. After refrigeration, the first network of carrageenan was formed. The samples were then irradiated with UV light for 2 h. Under the combined action of MBA, photoinitiator, and UV light, AM was induced to polymerize to form the second network of PAM, leading to the formation of PAM/Carrageenan DN hydrogel. A piece of hydrogel with the size of 2 × 1 × 1 cm3 hydrogel was then soaked in glycerol solution with controlled concentrations for 2 h.Chemicals including acrylamide (AM), N,N-methylene bisacrylamide (MBA), and potassium chloride (KCl) were purchased from Sigma-Aldrich. Carrageenan and irgacure2959 (photoinitiator) were purchased from Aladdin. The PAM/Carrageenan hydrogel was prepared via a one-pot sol–gel process. Firstly, 7.5 g AM, 1.5 g carrageenan, 0.005 g MBA, 0.09 g KCl, 0.1 g photoinitiator, and 41 mL deionized water were added to a flask. To disperse the chemicals uniformly, the solution was stirred at 95 °C for 5 h at 550 rpm min2 aluminum (Al) sheets to facilitate tearing off the film hydrogel after synthesis . The transmittance spectra were acquired using the ultraviolet spectrophotometer . The Fourier transform infrared (FTIR) spectra were acquired on a Thermo Scientific Nicolet 6700 FT-IR Spectrometer.The differential scanning calorimetry (DSC) spectra were obtained on a Netzsch DSC-204-F1 at a cooling rate of 5 °C min3COOK), magnesium chloride (MgCl2), potassium carbonate (K2CO3), sodium bromide (NaBr), sodium chloride (NaCl), KCl, and potassium sulfate (K2SO4), respectively. During the testing, changing the RH around the sensor was achieved by rapidly transferring the hydrogel sensor from one sealed glass bottle into another bottle with a different RH. Both the conductance and capacitance of the sensor were measured using an LCR meter  at 200 Hz. To measure the humidity-sensing properties at different strains, two binders were utilized to fix the stretched hydrogel sensor on a glass slide after applying certain tensile strains such as 10, 15, and 20%.A homemade static humidity characterization system was deployed for the RH sensing test at room temperature. Taking advantage of the characteristic that the RH of the air above the saturated salt solution is constant under specific temperature and pressure, a sealed glass bottle with a specific RH in the internal air was created using specific salt and further used as the humidity testing chamber. The RH of 11, 22, 33, 43, 59, 75, 85, and 98% were obtained using the saturated solutions of lithium chloride (LiCl), potassium acetate .PAM hydrogel is an outstanding candidate for the fabrication of flexible wearable electronics due to its excellent stretchability up to 1500% strain) and ion transport ability . In part0% strainWhereafter, a series of PAM/Carrageenan organohydrogels were prepared by soaking the hydrogel in different mass ratios of Gly aqueous solutions , and their moisturizing ability was compared with that of original hydrogel. Figure ΔG/G0, where ΔG is the change in the conductance of the sensor at the target RH compared to the initial conductance (G0) at 11% RH. Figure e is the unit charge [Utilizing this organohydrogel with excellent environmental stability as a humidity-sensing material, a flexible humidity sensor was constructed by attaching two copper electrodes to its two ends. By supplying an alternating current (AC)  to the sensor, its humidity-sensing properties were tested by monitoring the conductance change when alternately exposing it to 11% RH and a specifically different RH environment. Testing with AC is to exclude the interference of gases in the external environment. If a stable direct current (DC) is used, redox gases, such as oxygen, will electrochemically react at the interface between the organohydrogel and the electrodes. As such, the varied concentration of these gases will interfere with the humidity sensor, while utilizing the AC will not have this problem. Also, different quantitative RH around the sensor can be changed by quickly placing the sensor in a sealed bottle with different saturated salt solutions, since the RH above their liquid level is different and stable, which is determined by the type of salt . As showt charge . When ex−1, which is much larger than that of the bulk counterpart (0.0005 μm−1) . As such, the adsorption and desorption of water molecules by the hydrogel film are more efficient than that of the bulk hydrogel, as the relative weight variation of the hydrogel film is much higher than that of the bulk hydrogel under the same humidity variation . Furthermore, the hydrogel film-based sensor possesses an extremely low initial conductance under 11% RH due to the desorption of more water molecules in this dry environment, which can also improve its sensitivity to humidity due to the low baseline. Specifically, the initial conductance can be as low as 2.75 × 10–8 S when the thicknesses of the film is 54.61 μm, which is four orders of magnitude lower than that of the bulk hydrogel (5 × 10–4 S) . Moreover, we notice that the response of the hydrogel film-based sensor does not increase linearly with RH. Within 11% to 37% RH, the response grows slowly and has a low sensitivity calculated from the slope of the response versus RH curve. Whereas in the range of 37% to 98% RH, the sensor has greater sensitivity, and there must be two distinct conductance change mechanisms here that enable the piecewise response . As demonstrated above, the thin-filmization of the hydrogels can greatly improve their sensitivity to humidity, demonstrating its feasibility of optimizing the humidity sensing performance by structural engineering.To further explore the sensing mechanism of hydrogel film-based humidity sensor, its EIS spectra under different RH were tested, and the corresponding equivalent circuit was also analyzed . Under trve Fig. d, S1 and1, S2) of the hydrogel sensor continued to increase significantly with decreasing thickness  but also certain self-adhesive properties due to the presence of more functional groups, this allows it to be directly adhered to human skin without the need for tape-like items . Also, its mechanical properties are better than that of PAM/Carrageenan hydrogel films, alleviating the requirement of using PDMS as a substrate (free-standing hydrogel film) , making the preparation process simpler and faster.ΔC/C0, where ΔC is the change in the capacitance of the sensor at the target RH relative to the initial conductance (C0) at 11% RH. For the bulk PAM/Tapioca hydrogel, the sensor exhibits only a small sensitivity of 0.2%/%RH. In stark contrast, the response of the PAM/Tapioca hydrogel film-based sensor is unprecedentedly boosted even compared to previous PAM/Carrageenan hydrogels  chip, and which is applied to the humidity sensor. The trans-impedance amplifier (TIA) converts and amplifies the current signal output by the sensor into a voltage signal, which is then collected by the analog-to-digital converter (ADC) of the STM32F103RCT6 after passing through a first-stage voltage amplifier. The STM32F103RCT6 is used as the Microcontroller Unit (MCU) to analyze the signal output by the humidity sensor, extract the waveform, frequency, and cycle of the respiration, and send the data to the mobile terminal in real-time through Bluetooth. At the same time, when the MCU detects that the breathing interval exceeds 10 s, the mobile phone and the circuit board trigger the sound and light alarms simultaneously to warn the user and the guardian to take action Fig. c-d. As sIn summary, stretchable and transparent humidity sensors were constructed using PAM-based hydrogels as the transducing materials, boosting humidity sensing performance is achieved through synergistic regulation of structure and composition. On one hand, a general hydrogel film preparation method is proposed, and the resulting hydrogel films have thicknesses of tens of micrometers, high transparency in the visible light range, and more importantly, the boosted humidity sensing performance. This is attributed to the large specific surface area and small diffusion distance of water molecules in the hydrogel film, and the consequent more efficient adsorption and desorption of moisture. The improvement in humidity sensitivities brought by this method is much greater than that of ordinary micropatterns and wrinkled surfaces , etc. The reduction in initial conductance also contributes to the increased sensitivities. On the other hand, the humidity sensitivity of the hydrogel films was further improved by introducing natural tapioca as the second cross-linked network instead. Thanks to the more polar hydrophilic groups and self-supporting double-sided exposed film structure, the free-standing PAM/Tapioca hydrogel film possesses excellent moisture adsorption capacity, and its sensitivity reaches unprecedented 13,462.1%/%RH.Benefiting from the inherent stretchability of the sensing material, these humidity sensors are able to work properly under large tensile strains with even boosted sensitivity, which can meet the requirements of wearable devices. Also, the sensor exhibits excellent repeatability and broad detection range. By soaking the hydrogels with polyols or LiBr, their environmental tolerance is greatly improved, which is beneficial to the stability and reliability of the sensor. Notably, the in-depth humidity sensing mechanism of ion-conducting hydrogel is understood by the complex impedance spectrum. We have also attached the film humidity sensor to the inside of the mask to detect human breathing and uploaded the detected breathing interval and frequency to the APP on the mobile phone through the Bluetooth transmission module and specially designed circuit, which shows its great potential in wireless, real-time, continuous and accurate healthcare monitoring, such as the early detection and alarm of apnea in a facile way. This work provides a universal strategy to enhance the performance of hydrogel-based humidity sensors to adapt to practical wearable applications, which is of great significance for the development of advanced wearable electronics.Supplementary file1 (MP4 63868 kb)Supplementary file2 (PDF 1034 kb)Below is the link to the electronic supplementary material.


Herein, we have investigated the performance of B3+ on monolayer (MG), bilayer (BG), trilayer (TG), and tetralayer (TTG) graphene sheets using first-principles calculations. The findings reveal significant stabilization of the HOMO and the LUMO frontier orbitals of the graphene sheets upon adsorption of B3+ by shifting the energies from −5.085 and −2.242 eV in MG to −20.08 and −19.84 eV in 2B3+@TTG. Similarly, increasing the layers to tetralayer graphitic carbon B3+@TTG_asym and B3+@TTG_sym produced the most favorable and deeper van der Waals interactions. The cell voltages obtained were considerably enhanced, and B3+/B@TTG showed the highest cell voltage of 16.5 V. Our results suggest a novel avenue to engineer graphene anode performance by increasing the number of graphene layers.Advanced battery materials are urgently desirable to meet the rapidly growing demand for portable electronics and power. The development of a high-energy-density anode is essential for the practical application of B The past two decades have witnessed impressive improvements in lithium-ion battery (LIB) technologies for portable consumer electronics, electrical devices, and energy storage ,2. LIBs 3 with efficient rate capability. Similar improved electrode properties, such as enhanced conductivity and voltage capacities via carbon anode N/S-codoped hierarchy for SIBs, have also been reported [The developmental process of ion batteries in the past few decades has advanced since the discovery of nanotechnology and nanomaterials, which provide excellently performing electrodes ,20,21,22reported . Commonl2-hybridized carbon atoms. The sp2-hybridized bonds offer excellent structural reliability and outstanding mechanical properties, which are important for anodic material applications [4C6 [2/g [Graphene is a 2D nanosheet comprising spications ,47,48,49ications . Graphenications ,52,53,54ications . More spications ,55,56. Hons [4C6 , while H4C6 [2/g . Lian et4C6 [2/g . Further4C6 [2/g . It has Despite these efforts, there are limited reports on the intercalation of elements such as boron within the layers of high-quality graphene nanosheets for improved anodic boron-ion batteries (BIBs). Hence, in the present study, we report a theoretical investigation of the anodic performance of graphene nanosheets for boron-ion batteries. Previous reports ,51,57 haad) were calculated according to the following equation [complex, Eadsorbate, and Esubstrate represent the energies of the absorbate and boron ion(s), graphitic layer(s), and the substrate, respectively. Likewise, the final cell voltages (Vcell) were calculated utilizing the Nernst equation:Gcell stands for the Gibbs free energy of the overall cell reactions ascell) [All structural optimizations and electronic properties calculations were performed employing Density Functional Theory (DFT) as implemented on Gaussian 09 suite. The Perdew–Burke–Ernzerhof (PBE) functional belonging to the generalized gradient approximation (GGA) functional was used to account for the exchange–correlation energy because it provides reasonable accuracy without prolonged computational times, while the 6–311 G basis set was adopted ,59,60,61equation :(1)Ead=E (Vcell) .Pristine graphene nanosheets: The optimized electronic structures of the graphene sheet and the different multilayer orientations of the sheets are shown in Boron-intercalated and boron-free graphene nanosheets: 3+) adsorbed on the monolayer graphene sheets (MG) (3+ preferred the edges of the multilayer sheets after optimization. The reduced density gradient (RDG) maps for the complexes imply weak van der Waals interactions predominantly among the boron species and the graphene sheets. It may offer explanations for the preferred arrangements of the complexes. As shown in 3+) alternatively intercalated within two layers of the graphene sheets.ets (MG) a,b,i,j. 3+). As shown in 3+). The monolayer graphene arrangement results from the “α-layer”-B/B3+ arrangement with the subsequent multilayer arrangements resulting from the successive addition of two or more graphene layers in the α- and/or β-layered direction(s). The “α-layer”-B/B3+ distances (the green bars) are generally shorter than the “β-layer”-B/B3+ distances (the red bars), probably due to stronger interaction between the α-layer and the boron species before the subsequent addition of the β-layer(s) to generate the multilayers. The β-layer distances from the boron atoms (B) are also longer than their corresponding distances from the ionic boron species (B3+), which further amplifies the ionic interaction effect of the boron with the graphene layer(s).We examined the distances between the layers of the graphene (α-layer and β-layer) and the boron species  of the graphene sheets is reduced significantly to about 99.89%, and the same trend is observed with adsorbed neutral boron , colors are used as indicators for different electrostatic potential values: blue demonstrates high positive (electron-deficient) regions of the species, while green displays the region of zero potential [3+ form of B3+@MG, B3+@BG, B3+@TG, B3+@TTG_asym, B3+@TTG_sym, 2B3+@TG, and 2B3+@TTG reveal predominantly more electropositive regions (blue color). This is more severe with B3+@MG, B3+@BG, 2B3+@TG, and 2B3+@TTG configurations. However, with the addition of layers, a slightly neutral region with B3+@TG, B3+@TTG_asym, and B3+@TTG_sym was observed.The observed order with adsorbed neutral boron could be due to the existence of unpaired electrons in the valence shell of the neutral boron; the HOMO level of the graphitic layer is largely impacted by altering to higher energies, suggesting a considerable destabilization . Similarotential . As illu3+ ions on the wall of the solid host is considered an alternative B3+-storage mechanism. The model sheets studied with adsorbed B3+ ions are depicted in 3+ ions are examined. We studied the adsorption characteristics of graphitic carbon sheets by intercalating B3+ ions between the bilayer, trilayer, and tetralayer  for the singly intercalated B3+ ions were calculated as 3.987, −320.1, −477.0, −638.4, and −637.6 kcal/mol for B3+@MG, B3+@BG, B3+@TG, 2B3+@TTG_asym, and B3+@TTG_sym, respectively  isosurfaces of the interactions are shown in ectively . RDG isoectively . The RDG 3+ ions . Except form BC6 a,b, all ne layer .3+/B atom and the numbers of graphene sheets, we calculated the density of states (DOS) and the projected density of states (PDOS) of the B3+/B atom adsorbed graphene sheets as displayed in g from 2.843 eV in MG to 2.472 eV with TTG, which is likely due to an increase in the number of graphene sheets  is generated, which mainly comes from the contribution of 2p unpaired electrons of the B atom  population analysis was conducted to estimate the charge transfer in the complexes and is presented in 3+ is the boron atom/ion and “sheet” is the monolayer graphene sheet (MG), bilayer graphene sheet (BG), trilayer graphene sheet (TG), and tetralayer graphene sheet (TTG). The cell voltage (Vcell) and the cell energy are computed according to Equations (2) and (3).The graphene sheets (single and multilayers) were considered as anodic electrodes for the boron-ion batteries with the half-cell reactions taking place at the cathode and anode shown in Equations (4)–(7). Equation (8) also shows the overall cell reaction.3+) adsorption being more negative than the atomic counterparts. The monolayer graphene sheet (B3+/B@MG) has the least negative adsorption energy, while the tetralayer graphene sheet (B3+/B@TTG) showed the highest negative adsorption energy. The complexes with more negative adsorption energies express more favorable and deeper van der Waals interactions [cell) and the corresponding voltages of the cells. The cells’ energy increases with an increasing number of graphene sheets. However, for the intercalation of two atoms/ions of boron, the overall cell adsorption energy is higher. This can be attributed to the increased weak interactions between the graphene sheets and the two boron ions, which still permit free movement of the boron ions within the graphene layers during the charging and discharging processes.As depicted in ractions ,77. Tabl3+/B@TTG showed the highest cell voltage of 16.5 V, which indicates that in addition to the complexes being efficient alternatives for the anodic electrode of boron-ion batteries, increasing the number of the graphene layers also improved the electrochemical performance of the storage system. Generally, the boron-graphene sheets have shown excellent voltage outputs, hinting at their suitability as anodic material(s) for enhancing the energy storage performance of boron-ion batteries (BIBs) if extensively studied.Moreover, compared to sodium and lithium-ion batteries (SIBs and LIBs)  and othe3+@MG and from −20.08 eV to −19.84 eV for 2B3+@TTG were recorded. The predominant interaction force for the graphene layers was van der Waals, as predicted by the reduced density gradient isosurface analyses, with the B3+@TTG_asym and B3+@TTG_sym configurations showing the most favorable interactions. We have studied the high-energy-density anodic compartment for boron-ion batteries as an alternative to lithium-ion and sodium-ion batteries using the first-principles calculations within the framework of Density Functional Theory. We investigated the electrochemical performance of the boron ion(s) on the monolayer, bilayer, trilayer, and tetralayer graphene sheet electrodes. Significant decreases in the HOMO–LUMO energy gap from −5.085 eV to −2.242 eV for B3+/B@MG) and/or multilayer  graphene sheets were significantly improved, with B3+/B@MG (13.7 V) showing the least voltage. On the contrary, B3+/B@TTG (16.5 V) showed the highest voltage. The results revealed that increasing the number of graphene layers improves the electrochemical performance of the anodic electrode of the boron-ion battery. Therefore, the number of layers or the thickness of the graphene nanosheets is another effective parameter to tune the anode performance for boron-ion batteries. This might suggest an additional dimension to further engineer the graphene anode performance by increasing the number of graphene layers. Our theoretical investigations demonstrate the suitability of the graphene-based anodic electrodes for boron-ion batteries when extensively investigated for large-scale application as a highly efficient energy storage substitute for lithium- and sodium-based ion batteries, which could be beneficial to the material design of ion batteries.Furthermore, the electrochemical cell voltages obtained with the single-layer (B