Graphene has been regarded as a potential application material in the field of new energy conversion and storage because of its unique two-dimensional structure and excellent physical and chemical properties. However, traditional graphene preparation methods are complicated in-process and difficult to form patterned structures. In recent years, laser-induced graphene (LIG) technology has received a large amount of attention from scholars and has a wide range of applications in supercapacitors, batteries, sensors, air filters, water treatment, etc. In this paper, we summarized a variety of preparation methods for graphene. The effects of laser processing parameters, laser type, precursor materials, and process atmosphere on the properties of the prepared LIG were reviewed. Then, two strategies for large-scale production of LIG were briefly described. We also discussed the wide applications of LIG in the fields of signal sensing, environmental protection, and energy storage. Finally, we briefly outlined the future trends of this research direction. Since graphene was discovered in 2004, it has attracted the attention of scholars because of its excellent physical and chemical properties, such as ultra-high carrier mobility  [2/g) [Energy and environmental issues have gradually become a formidable challenge for human sustainable development. With the continuous deepening urgency of carbon peaking and carbon neutrality targets, all kinds of clean-energy and renewable-energy materials are ushering in unprecedented new opportunities for development. Graphene, a type of two-dimensional carbon nanomaterial with spcm2/V·s) , high licm2/V·s) ,4, larges) [2/g) , good mes) [2/g) , and ches) [2/g) , etc. The traditional methods for preparing graphene mainly include chemical vapor deposition, redox, mechanical stripping, and epitaxial growth, etc. Chemical vapor deposition  is a proThese above methods for preparing graphene have complex processes, low efficiency, limited choice of substrate materials, and require additional patterning processes to achieve graphene patterning. Therefore, it is necessary to develop a technology with simple operation processes, low cost, high efficiency, wide choice of raw materials, controllable graphene patterning, and a more environmentally friendly preparation process.2 carbon lattice were changed due to a large number of defects. The RGO was not completely equivalent to graphene. Therefore, there are limitations in the preparation and application of this method in graphene-based electronic devices [In recent years, with the rapid development of ultrafast optics, fiber lasers and high-power lasers, laser technology has widely been used in the fields of materials processing, biomedical, and defense industries. Laser processing technology, as an ultra-fine, non-contact, maskless, and programmed processing method, embodies the advantages of high efficiency, flexible patterning, and precise physical property regulation in the preparation and processing of graphene. GO can be converted into reduced graphene oxide (RGO) with the help of laser reduction ,23. Comp devices .2 infrared laser to directly scan on commercial polyimide (PI) films, as shown in In 2014, James M. Tour’s team  successfCompared with the traditional hexagonal honeycomb lattice of two-dimensional graphene, LIG contains a large number of crystalline structures consisting of two pentagons and one heptagon lattice. Due to these unique lattice structures, the graphene can be folded and warped . The lasLIG technology can control graphene’s micro morphology and greatly improve its light utilization and photothermal conversion efficiency . The thrIn this review, we focus on the preparation process, property control of graphene materials, and their applications in the fields of signal sensing, environmental protection, and energy storage, highlighting the latest research results, as illustrated in The surface morphology, as well as chemical, electrical, and mechanical properties of graphene, are related to the laser parameters, laser type, process atmosphere and doping. In this section, we will briefly introduce the influence of various process parameters on LIG morphology and properties during LIG preparation.2, PI was converted into graphene [It was found that the morphology pore size, and thickness of the graphene structure could effectively be tuned by adjusting the laser parameters  ,42. If ographene .2 infrared laser (wavelength 10.6 μm) and a 5 W UV laser (wavelength 355 nm). The experimental results showed that under the same UV and CO2 laser flux, the ablation of PI films formed different morphologies. The surface morphologies with micron-sized and nanometer pores were found under the UV laser, while the sheet structure with micron-sized pores and few pores was produced under CO2 laser. The laser energy density could be controlled with the laser pulse width. Garland et al. [q = 14.4 μm). The LIG produced by low pulse width had a high specific surface area and randomly formed nodule structures (Rq = 30.9 μm). It is worth noting that scanning speed, laser power, wavelength, and pulse width also play a key role in the structure formation of graphene and should be considered simultaneously in the graphene preparation process. Varying these parameters can significantly affect the electrical conductivity, composition, and morphology of LIG e 45,46,,46,47,48d et al.  tested t2 laser, respectively [Selecting appropriate laser parameters  can increase the electrical conductivity of laser carbonized structures on PI surfaces. This is because the laser increases the conductivity by reducing the level of defects within the orbit during graphitization. However, the substrate thickness limits a further increase in conductivity. Biswas et al.  also demectively ,55,56.2 laser, ultraviolet laser (UV), and visible laser.There are three types of lasers used to prepare LIG: infrared CO2 lasers  for the irradiation of PI films to prepare LIG. Laser irradiation region generates localized high temperatures that lead to C–O, C=O, and N–C bond breakage and carbon atom rearrangement, resulting in porous graphene on the film surface [Infrared laser preparation of graphene mainly stems from the photothermal effect, where the absorbed laser energy can be significantly converted into heat due to the high energy density of the laser, and the instantaneous high temperature can break and recombine the chemical bonds of the precursors , as show surface ,66,67,682 infrared lasers. For UV laser, the formation of graphene is mainly due to a photochemical reaction process. Due to the short wavelength and high energy of UV laser, especially when the photon energy is larger than the dissociation energy, the absorbed photon energy can directly break chemical bonds ,57, as sFor visible lasers, both photothermal and photochemical reactions may promote the formation of LIG . RecentlMany scholars have prepared LIG from various precursor materials, as shown in 2 laser, could achieve a lower graphitization temperature due to the ultra-short pulse duration, which is shorter than the time required for heat transfer to the surrounding environment. The results showed that this method could effectively reduce the degree of ablation of wood, and could convert wood and leaves into graphene with good electrical conductivity in an air environment without protective gas [For thermally sensitive materials containing high cellulose content, such as paper, wood, and fabrics, the addition of flame retardants to inhibit ablation and volatilization in ambient air promotes LIG formation ,49,62. Ttive gas .Using laser-induced technology to extract high-quality graphene from nature's abundant precursor materials is simple, economical, and environmentally friendly, laying a solid foundation for the large-scale application of graphene.Although the unique structure of graphene gives it excellent thermal, mechanical and electrical properties, the application of intrinsic graphene in electronics is limited by its zero-bandgap property. It is especially important to obtain graphene with a bandgap tunable within a certain range. To open the bandgap of graphene and solve the application question of graphene in electronics, researchers have explored many methods. One of the most feasible methods is to improve the performance of graphene, or obtain the properties that graphene does not have, by doping. This is because a carbon structure doped with heteroatoms can provide many active sites for electrochemical reactions, thus facilitating ion transfer during electrochemical processes ,83.2, LIG-Co3O4 and LIG-Fe3O4 were successfully prepared. The above-mentioned graphene had excellent redox catalytic activity and is expected to be applied in the electrocatalysis of fuel cells. Clerici et al. [2-LIG, which had good electrochemical properties and high surface area.From the research status of graphene doping, doping technology can be basically divided into in situ and non-in situ. In situ doping is usually achieved by changing the substrate composition or gas environment during laser ablation see . Ye et ai et al.  and Chhei et al.  deposite3BO3 solution with PAA, followed by the preparation of B-LIG using a CO2 laser under ambient conditions, resulting in B-LIG being able to be placed into active electrodes that could be used in flexible micro-supercapacitors. Due to the boron doping, the maximum area capacitance of the prepared devices reached 16.5 mF/cm2, which was three times higher than the undoped devices, and the energy density increased by 5–10 times, making this boron-doped LIG material a great potential for future microelectronics applications. Zhang et al. [In addition, heteroatoms, such as B, N, P, and S, are also important dopants. The direct use of substrate materials containing these atoms or the indirect introduction of these atoms can effectively improve the electrochemical properties of graphene. Peng et al.  first prg et al.  preparedg et al.  also preg et al.  prepared3BO3, followed by another laser irradiation, resulting in the incorporation of N and B atoms into the graphene-like structure. Due to the synergistic effect of N and B, the capacitive properties of NB-dLIG were significantly improved. This method provides a new idea for the preparation of multiple heteroatom co-doped LIGs [2, O2, and SF6 atmospheres, which effectively modulated LIG surface superhydrophobicity or superhydrophilicity [It is very noteworthy that multi-element co-doping is more effective than single element doping due to the synergistic effect of co-doped elements, which can form stronger active regions on its surface ,88. An Lped LIGs . Anotherhilicity .Non-in situ doping refers to the subsequent modification and coating treatment of the formed LIG. Various composites have been successfully prepared by electrodeposition of materials inside or on the surface of graphene. LIGs are commonly used with a variety of materials, such as commercial plastics , construction materials , to form composites with different properties and applications . Luong eLIG technology has emerged as a powerful material fabrication method. Currently, two pathways exist for large-scale production of LIG: in-plane roll-to-roll method, and 3D printing of LIG on a macroscopic scale.2 was prepared in their laboratory. This LIGP was not dependent on any substrate, and could be bent, folded, and cut into specific shapes, which gives it the characteristics of scalable size, mechanical flexibility, and customizable shape. In addition, the authors also indicated that the laboratory-scale process could be upgraded to roll-to-roll continuous fabrication in the future.The roll-to-roll production process is feasible for continuous fabrication of LIG films, as shown in Complexly-shaped graphene components with thicknesses in the micron to millimeter range can be prepared using laser-induced techniques. In some applications where thicker LIG is required, a 3D printing of LIG on a macroscopic scale has been proposed. Sha et al.  preparedSince the discovery of LIG, many scholars have carried out a large amount of research to improve the preparation process of LIG and apply it to various application fields. This section will introduce the research progress of graphene from the perspective of signal sensing, environmental protection, and energy storage.The excellent physicochemical properties and 3D porous structure of LIG make it an ideal candidate for a variety of sensors. The one-step synthesis of patterned graphene has greatly contributed to the development of smart sensors. Researchers have developed a wide variety of LIG-based sensors or sensor devices with modified LIG materials, such as strain sensors, pressure sensors, temperature sensors, humidity sensors, gas sensors, and biochemical sensors, for monitoring various physical and biochemical signals ,97,98,99−1) and good cycling stability (>4000 repetitive cycles)  c. These LIG has high thermal conductivity and low heat capacity, making it an ideal material for thermoacoustic sound sources. Moreover, its porous structure has high sensitivity to weak vibrations and is suitable for sound detection. Therefore, Tao et al.  develope−1). It was reported that the CLIG film can measure wrist pulses, swallowing, and even recognize gestures by the subtle differences in muscle contractions.Flexible wearable pressure sensors play an important role in advanced applications, such as electronic skin, real-time physiological signal monitoring, and human-computer interaction. Pressure sensors based on different mechanisms have been widely used in past decades ,112,113.−1) when the GO concentration was 4 mg/mL and the scan line spacing was 0.12 mm. In addition, this sensor was able to monitor human breathing and contactlessly unlock a combination lock. Han et al. [−1 in the range of 25–45 °C. The sensitivity of the RGO/LIG-based temperature sensor decreased with increasing laser power written to the LIG-based electrode.Temperature sensors are important tools for real-time temperature monitoring in the fields of healthcare and disease diagnosis ,116. LIGn et al.  proposed2 and CO2, which are the most abundant gas species in flue gas. Thus, LIG-based embeddable sensors can be integrated into composite materials, making electronic functional building materials possible. Yang et al. [2 and RGO/MoS2) as gas-sensitive materials to monitor gases, biomolecules, and chemicals. The platform was composed of a fine wire sensing region of LIG and a serpentine connection region of Ag/LIG. This serpentine design increased the tensile properties of the sensor to accommodate different bending variations of the body. Additionally, the platform had good selectivity at slightly higher self-heating temperatures, which allowed the sensor to detect NO2 at a concentration of 1.2 ppb. In addition, Zhang et al. [2 nanoparticles on a PI surface, and CO2 laser irradiation was then applied to both sides to convert them into LIG. The LIG, as an electrode, and the semiconductor ZnS/SnO2, in the middle, formed an ultraviolet photodetector. The lateral electrode structure reduced the total thickness of the device, thus minimizing strain and improving the flexibility of the photodetector. Due to the high flexibility and the ultra-thin characteristics of graphene, the device showed great mechanical flexibility. This simple and cheap manufacturing process is expected to be applied to the field of miniaturized flexible electronics.Due to its three-dimensional porous structure and ultra-high specific surface area, LIG provides sufficient surface locations for gas–solid interactions, making LIG also promising for gas-sensitive detection devices and gas sensing ,123,124.g et al.  developeg et al.  coated aWith the advantages of masklessness, high resolution, low cost, and high throughput, LIG technology has extended its application to biosensors ,58. The From a practical point of view, these above sensors are single-functional and cannot acquire multiple stimuli at the same time. It has been proposed to integrate multiple single-function sensors onto a single substrate, which can detect multiple stimuli simultaneously ,132. ThiDue to its large pore structure, large specific surface area, and excellent surface chemistry, LIG has tremendous potential for many environmental applications, such as anti-pollution systems for desalination and water treatment, air filtration, and generation of anti-bacterial/anti-viral surfaces.Recently, LIG has been considered as a promising candidate material for air filters due to its good microporous structure and strong adsorption of organic molecules . StanforLIG also has many applications in water treatment due to its large specific surface area, tunable surface properties, excellent antifouling activity, and high photothermal conversion efficiency. The sulfur-doped porous LIG prepared by Singh et al.  on sulfoSince the outbreak of neocoronavirus pneumonia, masks, as filters for both inhaled and exhaled air, have played a critical role in controlling the spread of the epidemic . However−2 h−1. This high efficiency was due to the efficient water pumping and high optical absorption of the porous structure. Moreover, the authors also desalinated seawater. The experimental results showed that the water with desalination treatment contained fewer electrolytes than the actual seawater or even domestic water. Thus, graphene membranes can indeed be used for seawater desalination. More importantly, these graphene membranes were self-correcting, and floated firmly at the air-water interface, making the process suitable for practical seawater desalination at the ocean surface [Desalination is a key technology to solve the global water scarcity problem. Existing desalination technologies have a high economic cost. Desalination driven by solar energy is a sustainable means of obtaining fresh water. It is important to seek a carbon material with high solar vapor generation efficiency and stable buoyancy. Li et al.  reported surface . −2 h−1 and a photothermal conversion efficiency of 85.4% at 1 solar light intensity. The evaporation performance of the LIG evaporator in high-concentration NaCl solution (10 wt%) could be maintained for up to 12 h, showing excellent stability and salt tolerance  [To meet the needs of portable and wearable electronic devices, and modern microelectronic systems, miniature energy storage devices are receiving increasing attention. Micro-supercapacitors (MSCs) are promising energy storage devices with fast response to electrochemical processes, high power density, and cyclic stability ,99,140. G layers a. They bolutions . The autolutions . To furtolutions  and pseund MnS2) ,105. Thend MnS2) ,142,143.nd MnS2)  introduc2 MSCs by the spatially shaped femtosecond laser (SSFL) method. It was reported that the SSFL technique can directly complete the processing of electronic devices in batch. The MSC fabricated by this technology had ultra-high energy density (0.23 Wh cm−3), ultra-small time constant (0.01 ms), excellent specific capacitance (128 mF cm−2 and 426.7 F cm−3), and long-term cycling performance, overcoming the current limitations of low efficiency fabrication and low energy density of micro-supercapacitors. Recently, Le et al. [−1. Finally, flexible FsLIG-MSCs were also prepared using FsLIG. After 50,000 cycles, the capacitance of the device retained about 99% of the initial capacitance with good electrochemical stability. The maximum surface energy density of the device was 1.204 μWh cm−2 and the power density was 324.39 µW cm−2, which is comparable to other advanced SCs and MSCs [Although the laser-induced technique has higher fabrication efficiency compared with the conventional method, it is still far from meeting the requirements of rapid mass production and industrialization. Yuan et al.  fabricate et al.  preparedand MSCs ,147,148.−2 and a high cycle life of 400 h. Yang et al. [2S aqueous solution cell. They used a composite of LIG mixed with sulfur as the cathode of this cell. The large specific surface area of LIG sheets (up to 294.69 m2 g−1) provided a large number of surface-active sites. The characterization revealed that the LIG was multilayered, multi-doped and defective, which facilitated the sulfur loading. Due to the synergistic effect of the new redox couple and LIG, when the current density was 0.8 A g−1, the discharge capacity of the battery reached 1654.7 mAh g−1 at the initial cycle. Moreover, 91.2% of the reversible capacity was retained after 328 cycles.With the growth of demand for Li-ion batteries, there is a need to continuously improve the coulomb efficiency, lifetime, stability, and safety factor of batteries. The high porosity, high electrochemical stability, and excellent electronic conductivity of LIG could meet the basic requirements for an ideal collector. A large specific surface area and a good electronic conductivity would reduce the local current density during lithium deposition and slow down the high-volume change of lithium during cycling. Yi et al.  laser irg et al.  proposedProton exchange membrane fuel cells have received the most attention as fuel cells in recent decades. However, production cost and lifetime limit their commercialization applications ,151. TilThis review first outlined the preparation methods of graphene, including chemical vapor deposition, redox, mechanical exfoliation, epitaxial growth, and laser-induced technology. Compared with other methods, laser-induced preparation of graphene is highly efficient, low cost, more environmentally friendly, and has a wide selectivity of precursors. Moreover, laser-induced technology can prepare graphene with controllable patterns without using any catalysts or templates. Next, we introduced the research progress of LIG in the preparation process, which has broadened its application fields by adjusting laser parameters, laser type, precursor materials, atmosphere and doping to achieve the morphology control, conductivity, hydrophilic properties, etc. Thirdly, two methods for large-scale production of LIG were briefly discussed. Finally, the applications of LIG in the fields of signal sensing , environmental protection , and energy storage  were reviewed. (1)Although there have been many kinds of graphene preparation technologies, the large-scale, low-cost, environment-friendly, high-quality, and large-size macro-preparation technologies have not yet made substantial breakthroughs, making it difficult to meet the needs of industrial mass production. Exploring new preparation methods, determining more suitable laser parameters, and finding new precursor materials will provide new possibilities for the large-scale production of high-quality graphene;(2)Single-element doping and two-element co-doping have been studied to prepare LIG, which improves the electrochemical properties to a certain extent, and provides a new idea for multi-element co-doping. Therefore, researchers can further explore other new elements and develop multi-element co-doping to endow LIG with more excellent properties, and endow LIG with broader application prospects;(3)Scientists have developed a variety of sensors, such as pressure sensors, strain sensors, temperature sensors, biosensors, gas sensors, etc. From a practical point of view, these sensors have a single function and cannot acquire multiple stimuli at the same time. Studying multifunctional LIG-based sensors that can detect multiple stimuli is a fascinating direction;(4)When LIG is used in masks, its safety is a primary concern. A Canadian research institute has indicated that the use of masks containing graphene may cause the wearer to inhale graphene particles. To the best of the authors' knowledge, there are no relevant reports on the safety assessment of LIG-based masks for this issue so far. Addressing this issue is an important goal for ongoing research.From the current state of development of LIG, researchers can focus on seeking breakthroughs in the following areas in the development of LIG in the coming years:


Devices composed of monolayer 0.5%G, partially deposited on SiO2 and h-BN were used for transport measurements. We find that the 0.5%G on h-BN exhibits ambipolar transfer behaviours under ambient conditions, in comparison to unipolar p-type characters on SiO2 for the same flake. While intrinsic defects in graphene cause scattering, the use of h-BN as a substrate reduces p-doping.The substrate effect on the electronic transport of graphene with a density of defects of about 0.5% ( Defects in graphene cause scattering and basal plane interactions shift the Dirac-point. However, the chemical structure varies and the carbon lattice may even be amorphous due to the evolution of CO2 during synthesis.4 Thus, in this study we use oxo-functionalized graphene (oxo-G), a type of GO with a more defined structure, as proven in our previous work.3 The oxygen-containing groups on the graphene basal plane and rims of flakes and holes make GO a p-type semiconductor with a typical resistance of 1010–1013 Ω sq−1 5,6 and a band gap of about 2.2 eV.7,8 The reductive defunctionalization of GO leads to a certain type of graphene (G), often named reduced GO (r-GO).4,9 Removal of oxo-groups from the surface can be achieved by chemical reduction,9,10 electrochemical methods,11,12 electron beam treatment13 and was observed in situ by transmission electron microscopy.13 Thermal processing of GO instead leads to a disproportionation reaction forming carbon with additional vacancy defects and CO2.14 In general, the reduction of GO turns r-GO from a semi-conductive material to a semi-metal. Mobility values were determined in field effect transistor (FET) devices.15,16 Generally, the quality of graphene strongly depends on the integrity of the hexagonal carbon lattice. Thus, mobility values of 10−3 and up to 103 cm2 V−1 s−1 were reported,3,17,18 with the resistance fluctuating between 103 and 106 Ω sq−1.19–21 We reported on the highest mobility values of chemically reduced oxo-G (with about 0.02% of lattice defects) of 1000 cm2 V−1 s−1,3 determined by Hall-bar measurements at 1.6 K.Wet-chemically prepared graphene from graphite can be stabilized in solution by covalently bound oxo-groups using established oxidation protocols.22 Up to now, most studies with graphene deposited on h-BN were restricted to measurements with virtually defect-free graphene.23 To the best of the authors knowledge, no studies reported transport measurements based on single layers of GO or oxo-G on h-BN substrates. No studies are reported with graphene derived from GO or oxo-G on single-layer level. Recently, we found that chemical reactions can be selectively conducted close to the rims of defects.24 However, before functionalized devices can be studied, the lack of knowledge on the ambient environment device performances of graphene with defects and the influence of substrates must be addressed. Therefore, we fabricated the devices composed of 0.5%G, partially deposited on SiO2 (SiO2/0.5%G) and h-BN (h-BN/0.5%G)  has been proved to be an excellent substrate for matching graphene-based materials owing to its atomic flatness, chemical inertness and electronic insulation due to a bandgap of ∼5.5 eV.N/0.5%G) . Areas o0.5%G, flakes of 0.5%G were deposited on HOPG surface and examined by scanning tunnelling microscopy (STM) under an ultra-high vacuum (10−10 mbar). The average height of a single 0.5%G flake was determined as 0.9 nm . I (V) spectrum of the 0.5%G surface. Compared to the tunnelling current at the dark region, there exists an apparent suppression of current at the bright region owing to a lower conductivity in the distorted graphene lattices. For the averaged I (V) spectra of the whole area, the metallic behaviour of the 0.5%G flake is found. This phenomenon is also confirmed by the differential conductivity (dI/dV) curves in I/dV curves. The Dirac point in dark region is located at 0.0 V, suggesting low impurity-related doping level. In contrast, the bright regions exhibit a positive shift of the Dirac point of about 50 mV, likely due to the presence of oxygen groups. For the entire scanned areas, the 0.5%G flake exhibits a p-type electronic doping feature with the average Dirac point at about 20 mV.Atomic scale electronic properties of 0.5%G or SiO2/0.5%G, flakes of oxo-G were first deposited on SiO2 substrate by Langmuir–Blodgett technique,29 as shown in 0.5%G flakes were prepared by reduction using vapor of HI/TFA  partially covering the h-BN. The AFM image in 0.5%G. The height profile of the single 0.5%G flake on SiO2 is shown in 0.5%G on HOPG. A major plausible reason is that e.g. water molecules are inevitably adsorbed on the hydrophilic SiO2 surface (treated by O2 plasma) leading to an approximately nanometer-thick hydrogen-bonded water layer and cleaved oxo-groups captured between SiO2 and 0.5%G.33 In contrast, although small amounts of polymer residues are likely trapped between h-BN and 0.5%G, the measured thickness of the same 0.5%G flake on h-BN is ∼1 nm as shown in 0.5%G flake on ∼6 nm thick h-BN (2 (∼1 nm). Therefore, h-BN, as a passivation layer, can not only negate the influence of trapped water on graphene, but also improves accuracy in the AFM thickness measurements of monolayer 2D flakes.ick h-BN  possesse0.5%G supported by SiO2 and h-BN, respectively, are shown in −1, the G peak near 1555–1557 cm−1 and the 2D peak near 2667 cm−1. The D peak of 0.5%G on each interface is mainly activated by defects in the carbon skeletons. The G and 2D peaks closely relate to the quality of graphene. The almost unchanged positions of the three peaks indicate that wrinkles and residual polymers induced during the transfer processes do not produce obvious doping effect on the single layer 0.5%G. We use scatter plots of ID/IGversus Γ2D to further confirm the quality of the 0.5%G in 0.5%G on h-BN, the ID/IG ratio is about 3.3, within the standard deviation of the ID/IG ratio of 3.1 determined on SiO2. Based on the model introduced by Lucchese and Cançado et al.,25,26 the density of lattice defects is related to 0.5% for the devices on h-BN and SiO2. This density of defects relates to the average distance between defects of around 3 nm. The related defect density (nD) is 4.0 × 1012 cm−2 on h-BN and SiO2, respectively, calculated from the equation nD (cm−2) = 1014/(πL2D).25 The Γ2D of the Raman 2D band is sensitive to the presence of defects. For the monolayer 0.5%G on h-BN, only a slightly smaller Γ2D of ∼70 cm−1 is observed than on SiO2 (∼72 cm−1). The same monolayer 0.5%G, partially deposited on SiO2 and h-BN, presents almost the same Γ2D. Therefore, the quality of the investigated flake is the same on SiO2 and h-BN, respectively.Average Raman spectra of the 0.5%G on SiO2 substrate  of 0.5%G on h-BN is shown in 0.5%G on h-BN is observed in ambient environment for sweeping continuously from −50 to 50 V in forward direction and then back to −50 V (backward direction). From the red dashed lines presented in μh) of 5.6 cm2 V−1 s−1 is extracted using the equation μ = (L/W) × (1/(CoxVds)) × (dIds/dVbg),34 where Cox = 1.15 × 10−8 F cm−2. As the output curves (Ids–Vds) exhibit ohmic behaviour . Obviously, electrical transport of the 0.5%G on SiO2 is completely governed by holes with hole mobility μh estimated to about 11.6 cm2 V−1 s−1. In addition, the Ids–Vbg curves exhibit an increase of hysteresis in SiO2/0.5%G device with a shift of Vbg (ΔVbg ≈ 7.3 V) between the forward and reverse sweeps, compared to the h-BN/0.5%G device with ΔVbg ≈ 2.6 V. Substrate change from h-BN to SiO2 induces trapped holes with density higher than 1.6 × 1012 cm−2 using Δnt = ΔVDirac point (Cox/q),2 where q is the elementary charge, ΔVDirac point > 43–20 = 23 V. In general, a high density of charge traps can cause hysteresis and lead to reduced mobility of graphene samples.35 However, as summarized in 2 are higher and the resistance is lower than on h-BN. The main reason for that contradictory finding is that for 0.5%G defects are the dominant scatterers reducing the carrier mobility. This is consistent with Raman results of 0.8%G on SiO2. As shown in Fig. S6,2 V−1 s−1 in ambient and 0.9 cm2 V−1 s−1 in vacuum. However, the Dirac point shifts only from 60 V in ambient to 30 V in vacuum. Those results are in agreement with the STS measurements, which indicate p-doping of 0.5%G in vacuum. It could however be expected that oxo-groups with −I and −M effects,2,3 decorating the rims of vacancy defects, may be responsible for trapping hole carriers. However, the experimental results, such as transport and AFM measurements, give evidence that p-doping is strongly induced by the SiO2 substrate and cleaved oxo-species, such as water or organosulfate, which are trapped between SiO2 and 0.5%G. Therefore, based on the AFM height determination on SiO2, the knowledge about the chemical structure and the reduction mechanism of oxo-G to 0.5%G we propose that molecules, such as water or hydrogensulfate stemming from oxo-G (2 substrate surface and 0.5%G (0.5%G. As a result, spurious dopant molecules may get squeezed out (In contrast to haracter . The poiom oxo-G  are trapnd 0.5%G . In compezed out , as is a0.5%G is a p-doped material and defects determine the scattering of charge carriers. Using h-BN as substrate leads to less trapped molecules, which are responsible for p-doping. In this regard, most likely hydrogen-bonded water and other cleaved oxo-species are captured between SiO2 and 0.5%G causing p-doping, as a consequence of chemical reduction of oxo-G. The ambipolar behaviour with VDirac point of +20 V was therefore observed for the h-BN/0.5%G structure while unipolar p-type response was shown for the same 0.5%G flake on SiO2. Transfer characteristics show a reduction of hysteresis in the h-BN/0.5%G. The mobility of the SiO2/0.5%G is determined to 7.4–14.5 cm2 V−1 s−1 and for h-BN/0.5%G to 5.6–8.5 cm2 V−1 s−1 at ambient conditions.There are no conflicts to declare.RA-009-C9RA09197A-s001


Furthermore, the neutral community model and normalized stochasticity ratio model were applied to reveal the underlying assembly process. Stochastic process and deterministic process dominated the assembly process in wet season and normal season, respectively and similar contributions of deterministic and stochastic processes were observed in dry season. Meanwhile, abundant (relative abundance >0.1%) and rare (relative abundance <0.01%) DAMO bacterial communities were found to be shaped via distinct assembly processes. Deterministic and stochastic processes played a considerable role in shaping abundant DAMO bacterial communities, while deterministic process mainly shaped rare DAMO bacterial communities. Results of this study revealed the dynamics of DAMO bacterial communities in river networks and provided a theoretical basis for further understanding of the assembly process.Denitrifying anaerobic methane-oxidizing bacteria (DAMO bacteria) plays an important role in reducing methane emissions from river ecosystems. However, the assembly process of their communities underlying different hydrologic seasons remains unclarified. In this study, the dynamics of DAMO bacterial communities in river networks of the Taihu Basin were investigated by amplicon sequencing across wet, normal, and dry seasons followed by multiple statistical analyses. Phylogenetic analysis showed that Group B was the major subgroup of DAMO bacteria and significant dynamics for their communities were observed across different seasons (constrained principal coordinate analysis,  Methane is the second most important greenhouse gas with a global warming potential 20–30 times that of carbon dioxide . In receMicrobial-mediated methane oxidation is an effective pathway to reduce methane emissions . AccordiRevealing the assembly process that shape the microbial community is one of the central topics in microbial ecology of freshwater ecosystems . DetermiRivers are typical freshwater ecosystems and serve as key transport channels for the global carbon and nitrogen biogeochemical cycles . In rece2, with the water area constituting 17% of the total area. Sampling campaign was carried out at 18 sampling sites on four crisscross rivers . The nested PCR amplification method was used to amplify the 16S rRNA gene of DAMO bacteria, consisting of an initial PCR with primers qP1mF (5′-GGGCTTGAC ATCCCACGAACCTR-3′)/1492R , and beta diversity index (“Bray-Curtis” distance) were calculated by “vegan” package (version 2.6-2) in the R software (version 4.0.2). One-way ANOVA followed by Duncan’s multiple comparison test was used to compare the alpha diversity and beta diversity across different seasons by “agricolae” package (version 1.3-3) in the R software (version 4.0.2).via constrained principal coordinate analysis (CPCoA) and permutation multivariate ANOVA (PERMANOVA). The CPCoA and PERMANOVA were performed by “amplicon” package (version 1.1.4) and “vegan” package (version 2.6-2) in the R software (version 4.0.2), respectively. The distance-decay patterns of DAMO bacterial communities were calculated as the slope of the linear regression between geographic distance and “Bray-Curtis” similarity (1- “Bray-Curtis” distance) of each pairwise sample. The habitat niche breadth (Bcom) of each ASV was calculated by “spaa” package (version 0.2.2) in the R software  from DAMO bacterial communities were selected for phylogenetic analysis. Phylogenetic analysis was performed by MEGA 7 software using the neighbor-joining method with 1000 bootstrap replicates .4+-N), nitrite nitrogen (NO2−-N), and nitrate nitrogen (NO3−-N) were extracted with 2 mol/L KCl solution for 1 h and then measured colorimetrically by a spectrophotometer  and then determined by the ICP-OES  redundancy analysis (db-RDA) and Mantel test were carried out to reveal the relationships between DAMO bacterial communities and environmental factors. The db-RDA and Mantel test were conducted using “vegan” package (version 2.6-2) and “linkET” package (version 0.0.3.3) in the R software (version 4.0.2), respectively.2 represented the fit of the entire neutral model. The 95% confidence intervals were calculated based on 1,000 bootstrap replicates.The neutral community model (NCM) was used to evaluate the potential contribution of stochastic process in community assembly by predicting the relationship between detection frequency and relative abundance of each ASV . In thisThe normalized stochasticity (NST) ratio was further applied to evaluate the relative importance of deterministic and stochastic processes in shaping DAMO bacterial communities . This moM. oxyfera, M. sinica, M. limnetica, and M. lanthanidiphyla were filtered and 2,599 ASVs  were obtained. After removing ASVs with less than 5 sequences to reduce the PCR bias  than the other seasons  and wet and dry seasons showed higher richness than normal season (p < 0.001). Meanwhile, the similarity of DAMO bacterial communities also exhibited temporal dynamics (p < 0.001).Significant temporal dynamics of alpha diversity and beta diversity of DAMO bacterial communities were observed across different seasons –C. The Sdynamics , and theTo compare the profile of abundant and rare DAMO bacterial communities, 48 ASVs with 1,688,209 (66.59%) sequences and 1,662 ASVs with 55,185 (2.18%) sequences were selected as the “abundant” and “rare” DAMO bacterial communities, respectively. The CPCoA plot and PERMANOVA showed clear differences in whole, abundant, and rare DAMO bacterial communities during wet, normal, and dry seasons . These rp < 0.001). On the contrary, the rare DAMO bacterial communities did not show significant distance-decay patterns  for variations of DAMO bacterial communities and fitted well for the DAMO bacterial communities. Similar observation was found during wet, normal, and dry seasons , which indicated that rare DAMO bacterial communities had narrower niche widths.Similar to the whole DAMO bacterial communities, both deterministic and stochastic processes played important roles in shaping abundant DAMO bacterial communities . During 4+-N, NO3−-N, pH, and Zn, exhibited significant temporal dynamics across different seasons . The db-RDA was further used to reveal the impacts of environmental factors on DAMO bacterial communities (p < 0.001). In addition, the linear regression analysis showed that these metals were significantly correlated with the NST values (p < 0.0001). These results indicated that metals  were the major driving factors affecting the structure and assembly process of DAMO bacterial communities. Meanwhile, similar to the whole DAMO bacterial communities, these metals showed strong correlations with abundant DAMO bacterial communities (r > 0.45) while their correlations with the rare DAMO bacterial communities were weak (r < 0.25), indicating that abundant and rare DAMO bacterial communities responded differently to environmental factors.In this study, most of the environmental factors, such as Cu, Cr, DOC, Mn, Ni, NHmunities . Based oin-situ activity needs to be further explored.Previous studies have confirmed the distribution of DAMO bacteria in the river ecosystem , while tIn this study, the diversity of DAMO bacterial communities was observed to exhibit temporal dynamics –C. The aThe distance-decay patterns were widely prevalent in microbial geographic distributions . In thisRevealing the assembly process was important for understanding the microbial communities . The NCMThe respective roles of deterministic process and stochastic process in shaping DAMO bacterial communities were found to be distinct in different seasons. The stochastic process dominated the community assembly process in wet season, while deterministic process was the major process in normal season . In the Abundant and rare DAMO bacterial communities were observed to exhibit distinct assembly processes. Similar to the whole DAMO bacterial communities, the abundant DAMO bacterial communities were dominated by both deterministic and stochastic processes, while deterministic process shaped the rare DAMO bacterial communities . Our resThis study explored the dynamics and assembly process of DAMO bacterial communities in river networks of the Taihu Basin across different hydrologic seasons. Our results revealed that the diversity and structure of DAMO bacterial communities exhibited significant temporal dynamics while the spatial dynamics were found to be distinct in different seasons. The NCM and NST models together showed that stochastic and deterministic processes both played a considerable role in shaping DAMO bacterial communities. In addition, the abundant DAMO bacterial communities exhibited similar spatiotemporal variations, assembly process, and environmental response with the whole DAMO bacterial communities, but distinct from the rare DAMO bacterial communities. These results provided new clues for DAMO bacterial communities while their contributions to methane reduction need further investigation.The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/SX and SG provided initial concept. RW and TZ carried out field sampling and chemical analyses. RW, SX, YZ, and SG wrote the manuscript. All authors contributed to the manuscript and approved the submitted version.This study was supported by National Natural Science Foundation of China (No. 42007302), Natural Science Foundation of Jiangsu Province (No. BK20190481), China Postdoctoral Science Foundation (No. 2020M681480), and Fundamental Research Funds for the Central Universities (No. 30922010810).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.https://www.frontiersin.org/articles/10.3389/fmicb.2022.1074316/full#supplementary-materialThe Supplementary material for this article can be found online at: Click here for additional data file.


Emerging high-entropy alloy (HEA) films achieve high strength but generally show ineludible brittle fractures, strongly restricting their micro/nano-mechanical and functional applications. Nanolayered (NL) CoCrFeNi/graphene composites are elaborately fabricated via magnetron sputtering and the transfer process. It is uncovered that NL CoCrFeNi/graphene composite pillars exhibit a simultaneous ultra-high strength of 4.73 GPa and considerable compressive plasticity of over 20%. Detailed electron microscope observations and simulations reveal that the monolayer graphene interface can effectively block the crack propagation and stimulate dislocations to accommodate further deformation. Our findings open avenues for the fabrication of high-performance, HEA-based composites, thereby addressing the challenges and unmet needs in flexible electronics and mechanical metamaterials. The dimensions of the initial model were Lx = 201.128 Å, Ly = 206.114 Å, and Lz = 201.95 Å. Before loading, the whole system was equilibrated at 1 K for 100 ps via the Nosé–Hoover isothermal–isobaric (NPT) ensemble, resulting in Lx = 199.479 Å, Ly = 205.718 Å, and Lz = 200.292 Å (a = 3.538 Å). For loading experiments, the micropillars were aligned along the Y-direction, while periodic boundary conditions were used in three axes. Simulations were performed at a constant strain rate (ε) of 109/s using the Nosé–Hoover canonical ensemble (NVT).Molecular dynamics (MD) simulations were performed to illustrate the deformation and fracture behaviors, especially in the vicinity of the CoCrFeNi/graphene interface, using LAMMPS software. Specifically, embedding atomic potential was used to display the interatomic interaction in the HEA . The TerField emission scanning electron microscope  observations were used to understand the growth and morphology of CoCrFeNi HEA films. Columnar grains with high aspect ratios were observed on the cross-sectional HEA film with a film thickness of 625 nm, as shown in The morphology and structure of the monolayer graphene were studied by TEM. 0.1CoCrFeNi HEA film pillar Gr, Y = [111]CoCrFeNi||[010]Gr, and Z = CoCrFeNi||[001]Gr, as shown in More importantly, the experimental observation on crack features indicated that the monolayer graphene interface can strongly hinder and arrest crack propagation. To better understand the effect of the graphene interface on the HEA matrix, MD simulation was employed on an interfacial model system of X = Note that sputtering and transfer might induce damages, such as holes, vacancies, delamination, etc. In this case, the atomic configuration of the CoCrFeNi/intermittent graphene/CoCrFeNi was also considered, as shown in (1)Coupled with HEA sputtering and high-quality monolayer graphene transfer techniques, nanolayered CoCrFeNi/graphene composites can be delicately fabricated;(2)The presented CoCrFeNi/graphene nanolayered composite pillars showed a superior high strength of 4.73 GPa exceeding 20% compressive strain;(3)By postmortem microscope observations and molecular dynamics simulations, the simultaneous high strength and deformability can be interpreted by nanotwins in the HEA matrix and the monolayer graphene interface as a result of confining the dislocation pathway and stimulating dislocations emission and storage.To sum up, we systematically introduced the fabrication, mechanical properties, and deformation behaviors of nanolayered CoCrFeNi/graphene composites. The main findings are as follows:Our preliminary findings not only provide insights into the mechanical properties of CoCrFeNi/graphene nanolayered composites but also offer some clues to the tunable design and feasible fabrication of high-performance, metallic-based composites.


The Raman spectra and photoluminescence properties of the GF and ZGCF were characterized before and after the sliding friction. A remarkable phenomenon was observed that after friction the GF generated a more pronounced luminescence response than it had prior, apparently due to graphene quantum dots which were found in the wear debris of the GF. Furthermore, the introduction of graphene into YSZ:Er nanoparticles (NPs) resulted in an unmistakable red-shift on the main luminescence bands of ZGCF after the applied friction. This is explained by the formation of considerable graphene scrolls in the wear debris of ZGCF due to the interaction of the graphene and the YSZ:Er NPs. It can be concluded that changes to the configuration of graphene greatly influence the tribo-induced photoluminescence response. Our findings justify further investigation into the composition and morphology of worn surfaces in order to better understand how photoluminescence relates to frictional effects. In addition, this work proposes the in situ fabrication of graphene quantum dots and nanoscale scrolls as a new potential application of the tribo-induced photoluminescence study.In the present work, a novel method was developed to study the evolving surface state of graphene film as it is subject to friction, characterized by photoluminescence properties. We prepared the graphene film (GF) and YSZ:Er (Er In the present work, a novel method was developed to study the evolving surface state of graphene film as it is subject to friction, characterized by photoluminescence properties. In the past decade, several tribological mechanisms have been proposed to explain the friction processing of freshly worn surfaces along with the associated formation and transfer of debris.5,6 However, due to limitations of the experimental tools, it remains challenging to thoroughly analyze the role of shearing reactions during the friction process. Of particular interest is the shearing phenomena within the sliding contact area in situ at the molecular-level.7 Certain weak physical and chemical effects observed on the surface or the interface of sliding partners were typically neglected in the past, but presently these phenomena become increasingly significant in regard to changing friction service conditions.8 For example, harsh friction conditions can lead to a cascade of excitation and de-excitation processes of tribological interface or fractured surfaces, producing luminescence and emitting charged particles. Consequently, several investigations on tribo-induced magnetization,9 luminescence10 and surface charges11 have been reported. Nakayama et al.12,13 studied the phenomena of triboplasma and triboemission, as well as the occurrence of shearing reactions during the friction process. They found that various solids, especially insulating solids, emit UV photons during the sliding process; they also found that the triboemission depends greatly on the electric resistivity of the sliding partners. Nevshupa14 found that energy dissipation at a tribo-contact can depend on a variety of elementary physical processes and chemical reactions; they studied several factors, such as the surrounding gas, the surface coating and the types of rubbed materials, that can influence triboluminescent behavior.Extreme external loading conditions can significantly impact the worn surfaces of many materials that are widely used in industrial and marine fields.15–17 Recently, due to its compact size and extremely thin laminated structure, the tribological properties of graphene have been intensively examined for potential applications in micro- and nano-mechanical devices.18,19 The size effect of graphene in conjunction with a surface coating of functional groups or metallic ions was proved to contribute to extraordinary optical properties.20,21 It is also known that friction may induce considerable changes in the size, defect structure, and surface adsorption of counterface materials.22 Mishina et al.23 reported an in situ observation of such effects on surface crystal grains during a sliding friction process and witnessed a wear debris generated from the solid surface. However, up to now, research has been rarely focused on how the morphologies of graphene wear-debris could affect the physical phenomena and chemical reactions on the tribological surfaces or the graphene interface, in particular regarding the tribo-induced photoluminescence during the process of sliding friction.Graphene, as a 2D-honeycomb structural carbon sheet, possesses exceptional optical, electrical and mechanical properties.In the present work, we prepared graphene film (GF) and YSZ:Er/graphene composite film (ZGCF) see  and founvia a standard metallographic procedure and then were cleaned with acetone. Subsequently, the treated stainless steels were implemented using the laser drilling technique with pulsed laser . The diameter of each hole was 150 μm and each two of the adjacent rows was evenly spaced with 350 μm.The surfaces of stainless steels (20 mm × 20 mm × 3 mm) were mechanically polished 4 as an oxidizing agent. For this purpose, 50 mL of H2SO4 (AR) was introduced into a three mouth flask with constant stirring. 1 g flake graphite  and 1.2 g KNO3 (AR) were added into the three mouth flask. After stirring for five minutes, 6 g KMnO4 (AR) was slowly added to the mixture. The reaction mixture was maintained at 40 °C for 3 h. Then, 80 mL deionized water was slowly added into the three mouth flask and the mixture was maintained at 70 °C for 30 min. After the oxidation step, the resulting mixture was added to a beaker containing 400 mL of deionized water and 20 mL of H2O2  in order to quench the reaction. 2 mol L−1 NaOH (AR) solution was slowly added into the above-mentioned solution in order to adjust the PH value to 6. After static precipitation and removing the supernatant, the precipitate was centrifuged and washed with distilled water and ethanol for three times. The product obtained was reduced by hydrazine hydrate . The obtained reduced graphene oxide (rGO) obtained via Hummers' method was dispersed in ethanol at a pre-determined ratio using the ultrasonic treatment. A spin-coating on the stainless steel was applied and dried in an oven at 80 °C. The preparation process of the GF is shown in Graphene oxide was synthesized by the Hummers method. The first step consists of the oxidation of graphite using KMnO2·8H2O (AR), ErCl3 (99.9%), Y(NO3)3·6H2O (≥99.99%), NaOH (AR), lactic acid (AR) and deionized water were used as raw materials. A procedure for the sample with 1 at% Er3+, 10 at% Y3+:ZrO2 synthesis is typically described as follows: 2.578 g ZrOCl2·8H2O, 0.3064 g Y(NO3)3·6H2O (acted as stable agent), 0.0219 g ErCl3 were first dissolved in 24 mL deionized water. Then 5 mL lactic acid was added to the above solution then mixed well with a magnetic stirrer. 10 mol L−1 NaOH solution was slowly added into the above solution to adjust the PH value to 6. After mixing evenly, the mixed solution was transferred to Teflon liner. Hydrothermal treatments were conducted at 160 °C for 24 h. After the synthesis reaction, the product obtained was centrifuged and washed with distilled water and ethanol, and dried at 80 °C during 12 h. In the last step, the dried YSZ:Er samples were annealed at 700 °C for 2 h in air. YSZ:Er NPs, rGO obtained via Hummers' method, and salicylic acid were dispersed in ethanol at a pre-determined ratio using the ultrasonic treatment. A spin-coating on the stainless steel was applied and dried in an oven at 80 °C. The preparation process of the ZGCF is also illustrated in YSZ:Er (Er-doped yttria stabilized zirconia (YSZ)) nanoparticles (NPs) were prepared by the hydrothermal synthesis method. YSZ:Er was prepared by a hydrothermal method. ZrOCl3N4) with diameter of 3 mm, and announced mean roughness of 0.02 μm were used as the stationary upper counterparts. The friction-coefficient-versus-time curves were generated automatically. All experiments were performed under ambient conditions of 25 °C and 26% relative humidity.The dry friction test at room temperature in air was conducted with a WTM-2E tribometer  in a ball-on-disc contact configuration at a load of 1 N and a speed of 200 rpm for 20 minutes. Commercially available silicon nitride balls .Raman and photoluminescence spectroscopy were performed in the wear and non-wear track by using the laser spectrometer  with 514 nm and 325 nm excitation wavelengths to assess the quality of graphene and the luminescent behavior before and after friction. The light source with excitation wavelength was used to test each sample at three random points.λex = 633 nm) of graphene and YSZ:Er/graphene nanocomposite. On the Raman spectrum of graphene, the exhibited G band (∼1605 cm−1) is corresponding to sp2-hybridized carbon while a D band (∼1350 cm−1) is corresponding to disordered carbon. The spectra of YSZ:Er/graphene shows a combination of the characteristic peaks from both the graphene sheets  and the ZrO2 (m-phase at Ag 634 cm−1 and t-phase at Eg 269 cm−1 and B1g 312 cm−1). The measured signal intensity of D and G peaks of the ZGCF sample is higher than that of GF under the same testing condition. The difference in the Raman spectra of GF and ZGCF is due to the surface enhanced Raman spectroscopy (SERS) effect caused by chemical enhancement. It is generally known that there are many functional groups on the surface of GO, which can interact with YSZ:Er NPs. The obtained ZGCF is something like charge transfer complex, which can absorb the light at the excitation frequency, consequently resulting in chemical SERS.242 in YSZ:Er NPs and ZGCF, respectively, which indicate that the characteristic peaks of both ZrO2 in YSZ:Er NPs and ZGCF are similar. The difference in the peak intensity of is attributed to the presence of graphene wrapping NPs in ZGCF, which is caused by the interaction between the graphene and YSZ:Er NPs.3N4 counterface. Owing to the fact that the graphene sheets exhibit a relatively low shear strength, the interlayer interaction is weakened and thus deceases the COF. In contrast, 3N4 counterface. The wrapping around the YSZ:Er NPs by graphene starts at the initial friction stage,25 which coincides with substantial dropping of the COF value. As the friction proceeds, graphene sheets are divided into a considerable number of patches and then the YSZ:Er NPs are exposed on the wear surface. Hence, the YSZ:Er NPs act as a nano-ball bearing and can roll between the Si3N4 counterface and substrate, which reduces the friction and provides extra mechanical strength. Therefore, the COF of ZGCF has a higher COF than that of GF, while both of them have the lower COF than the substrate.−1 of iron oxide debris besides in Raman spectrum of GF after the friction. As for the new band peak located at 667 cm−1 of GF, many researches have reported26–28 that the peaks at about 660 cm−1 exhibited existence of the magnetite (Fe3O4). The hole structure produced by laser drilling can not be filled by the graphene sheets, which affects the release of the graphene lubricant and the wear life of GF. The Raman spectra show that the intensity ratio of D band over G band (ID/IG) after the friction is higher (1.03) than that before friction (0.95), as indicated in 29 where the increase of ID/IG ratio is due to the increased number and size of sp2 clusters. The surface structure and composition of graphene sheets were greatly shown to be influenced by plastic deformation and heat transfer during the friction; these two factors play an important role in the evolution of graphene configurations.30,31 The insets of 2 shifts from 634 cm−1 (before friction sliding) into 642 cm−1 (after friction sliding). Interestingly, unlike the case of GF, the ID/IG before friction (0.97) is surprisingly higher than that after friction (0.83), indicating that the embedded YSZ:Er NPs do affect the defect structure in the graphene. Specifically, when these YSZ:Er NPs are removed from the graphene, we observed the formation of many graphene scrolls that are very similar to CNT-like structures32  from the encapsulated YSZ:Er NPs that essentially drive the motion of the rolling graphene to form into a scroll shape.35,36 During the friction, the shear stress arises and weakens the interaction between the graphene and NPs. When the wear debris is dispersed into an alcohol solution for microstructure characterization, many YSZ:Er NPs become detached from the curled graphene and the hollow graphene scrolls finally can be formed.i.e., the tribo-induced photoluminescence. 37,38 it was found that optical responses are due to the quantum confinement effect of graphene as well as the presence of defects. Consistently, in the present work this obvious photoluminescence behavior of GF is observed at the wavelengths of 430 nm and 505 nm within the spectrum, as plotted in 39 that graphene-oxide NPs can exhibit a red-shift of the band-edge and a significant reduction of the band gap. These phenomena can be explained by the photoluminescent mechanisms illustrated in 40 Meanwhile, the friction environment enables the adsorption of a little amount of oxygen on the graphene surface accompanied by the composition of the debris, which gives rise to the presence of sp3 carbon atoms covalently bonded to the oxygen-bearing functional groups in addition to the sp2 hybridization in the pristine graphene. Therefore, a finite electronic bandgap generated by the disruption of π-networks, to a certain extent, can facilitate in opening up the bandgap of graphene and thus enhance its photoluminescence quantum yield. In contrast, the changing photoluminescent behavior of ZGCF can be explained with a mechanism (see the illustration in 41 Our current study demonstrates that the tribo-induced interaction between YSZ:Er NPs and graphene nanoscrolls has a unneglectable effect on the electronic structure and bandgap, which in turn influences the luminescent emission and results in the red-shifts on the spectra.The above-mentioned wear debris of unique microstructures culminated in an unexpected physical response, In summary, we proposed and implemented a novel strategy for studying the surface state and interface phenomena of sliding contact materials during the friction process. More importantly, we report the phenomenon that GF exhibits pronounced friction-induced photoluminescent properties due to the formation of graphene quantum dots as well as the defect structures formed in the graphene sheets. Furthermore, ZGCF displayed a noticeable red-shift of luminescent bands due to the combined effects of YSZ:Er NPs and graphene scrolls during the friction process. The discovery of the presence of graphene quantum dots and graphene scrolls that are induced by friction provides a potential new approach for multi-morphology fabrication of graphene. Lastly, the tribo-induced luminescent behavior reported in current research can be served as an incentive for further inquiry into tribo-physical phenomena and tribo-chemical reactions in the near future.There are no conflicts to declare.


The interfaces in 2D hybrids of graphene and h-BN provide interesting possibilities of adsorbing and manipulating atomic and molecular entities. In this paper, with the aid of density functional theory, we demonstrate the adsorption characteristics of DNA nucleobases at different interfaces of 2D hybrid nanoflakes of graphene and h-BN. The interfaces provide stronger binding to the nucleobases in comparison to pure graphene and h-BN nanoflakes. It is also revealed that the individual dipole moments of the nucleobases and nanoflakes dictate the orientation of the nucleobases at the interfaces of the hybrid structures. The results of our study point towards a possible route to selectively control the orientation of individual molecules in biosensors. The interfaces in 2D hybrids of graphene and h-BN provide interesting possibilities of adsorbing and manipulating atomic and molecular entities. These studies indicate that the noncovalent interactions such as π–π stacking and X–π  interactions stabilize the nucleobases adsorbed on graphene and h-BN.19–25 This shows the potential of using graphene and h-BN in biosensing applications. Moreover, graphene nanoribbons have been proposed to rapidly sequence DNA by measuring the time-dependent conductance as the nucleotides of single-stranded DNA are brought sequentially in contact with the nanoribbon.26 Recently Lee et al. have studied the interaction of nucleobases with h-BN and graphene using an approach that incorporates van der Waals interactions into the density functional scheme. They found that the binding energies of the different nucleobases with two sheets (h-BN and graphene) are similar and an interfacial dipole is induced between the sheet and base molecule during adsorption.27Graphene,28 Gao et al. have explained the formation of CBN with different edges using Rh (111) substrate and they have shown that formation of zigzag edges is more favorable than that of armchair edges.29 The CBN monolayer can be used as an ultrathin solar cell with PCBM fullerene as an acceptor.30 Although, the physical properties of these CBN materials have been studied, the interaction of nucleobases with CBN surfaces has not yet been reported. It should be noted that the interaction between the dipoles in the nucleobases and hybrid nanoflakes can give rise to non-trivial properties based on the mutual orientations at the interface of dissimilar flakes. In the present study, we have carried out density functional calculations to investigate different orientations of nucleobases, namely adenine (A), guanine (G), thymine (T) and cytosine (C) adsorbed on CBN nanoflakes with different edges, namely armchair, as well as zigzag with either N- or B-termination. Specifically, we have studied the equilibrium geometries, binding characteristics, and role of dipoles in dictating the mutual orientations.Very recently, 2D hybrids (CBN) of graphene and h-BN have been prepared through chemical vapor deposition method. These hybrids are found to have unusual electronic, magnetic and transport properties including half-metallicity.31 Throughout this article, we refer to interfaces with armchair edges as Arm, to those with zigzag edges where N bonds with C as Zig-N, and to those with zigzag edges where B bonds with C as Zig-B. We have employed ab initio calculations based on Density Functional Theory32,33 (DFT) and the Linear Combination of Atomic Orbitals (LCAO) as implemented in Gaussian09 34 and SIESTA35 codes. We used two levels of calculations to validate our results and give greater confidence in the accuracy of the study: one of them was hybrid meta exchange–correlation functional M06-2X36 with 6-31+G basis set, while for the second one, we used Generalized Gradient Approximation (GGA-PBE)37 with van der Waals corrections38,39 to take into account dispersive interactions. For the SIESTA calculations, we considered a box of 30 Å3 to avoid the interactions between periodic images. Double-ζ polarized basis sets (DZP) and norm-conserving pseudopotentials40 were used. To obtain equilibrium structures, forces in three directions on each atom were minimized below 0.01 eV Å−1. From here on, meta-GGA is meant to refer to Gaussian09 calculations while GGA + vdW refers to SIESTA calculations.Structural models of CBN flakes with armchair (Arm) and zigzag (Zig) interfaces were considered from previous studies.The stability of the flakes was evaluated using the formation energy as per the following equation:ET, ni, μi, N refer to: total energy of the flake, number of each species in the flake, corresponding chemical potential, and total number of atoms in the flake, respectively. In the second equation, Eflake is the total energy of the hybrid flake . EGR flake is the total energy for the graphene reference system, μi  is the chemical potential of each species and Ni  is the number of extra or missing atoms for a particular species in comparison to the reference graphene flake. Ntot is the total number of atoms comprising of C, N and B involved in the equation.In the first equation, −1 considering GGA + vdW and 3.38 (7.34) kJ mol−1 for meta-GGA respectively. The results follow the same trend using both functionals; the cohesive energy difference between the most stable flake (Zig-N) with the least stable (Zig-B) is about two times bigger than that for the second-most stable (Arm) flake. Next, we have calculated the formation energies for the hybrid flakes with GR flake as a reference using the equation given above and the values are 384.32, 473.24, and 479.37 kJ mol−1 for the Zig-N, Arm, and Zig-B flake respectively. This result follows the same trend as that of cohesive energies. It should be noted that the positive formation energies indicate that the flakes can be metastable but still possible to form as seen in experiments. The corresponding values are calculated as −457.68, −368.77, −362.63 kJ mol−1 when a BN flake is considered as the reference. These values indicate that the hybrid flakes can be spontaneously formed. The difference in these two cases is related to the growth conditions with different reservoirs. As the flake with the B-terminated zigzag edge (Zig-B) is found to be the least stable in all the cases, we will consider only adsorption complexes involving Zig-N and Arm from now on.The cohesive energies for the three flakes are given in 41 For the flakes, we note that Zig-N possesses a total dipole moment about 1.5 to 1.7 times bigger than the Arm flake.As nucleobases and flakes possess distinct dipole moment values and orientations, an interesting question can be addressed regarding the mutual interaction and the resulting stability of the complexes formed between the nucleobases and the nanoflakes. Specifically the relative orientation between a nucleobase and a nanoflake is of primary interest to us in the present study. To explore this question, we have investigated two fundamentally different geometries for each complex, in which the dipole moments of the constituting subsystems are either parallel or antiparallel to each other.E = EP − EAP) can provide insights into the relative stabilities and are listed for all explored combinations of Zig-N and Arm flakes with the four nucleobases in vs. 1.33 kJ mol−1), whereas in meta-GGA, the reverse is true (0.54 vs. 2.50 kJ mol−1). This difference may occur due to distinct considerations of dispersion corrections in GGA + vdW and meta-GGA.Indeed it is found that for all nucleobases on either of the two studied nanoflakes, the antiparallel configuration is always more stable than the parallel one in the Arm and Zig-N flakes, as confirmed by both functionals. However, the nucleobases A and T on Arm are almost degenerate in energy for parallel and antiparallel configurations, indicating no strong preference for either orientation. However, a closer inspection reveals that for GGA + vdW, the antiparallel configuration for A is more stabilized than that for T  arrangement: G > C > T > A. It is interesting to note that these results follow the same hierarchy as that of the isolated nucleobases. For the anti-parallel (AP) orientation, the trend is reversed,  moments . The sitIflake+DNA is the total charge density for the full system and Iflake(IDNA) is for the flake (DNA), respectively. The charge density difference plots shown in i.e., the accumulation of positive charge in the graphene side and a negative one in the h-BN side.To understand in detail the interaction due to adsorption, we calculated charge density differences between the flake-DNA nucleobase complexes and the sum of the charge densities of flakes and DNA nucleobases as described in the following expression:Finally, we discuss the binding energies of the nucleobases on different interfaces of CBN flakes. For comparison, we have also calculated the binding energies on pure graphene and h-BN flakes of the same size as the hybrid systems. These calculations have been carried out using the meta-GGA approach. From the binding energies presented in e.g., for the purpose of DNA sequencing, by improving the signal-to-noise ratio due to the reduction of spatial fluctuations of the nucleobases.In the present work, we have performed first-principles calculations to study the interaction of nucleobases with 2D hybrid nanoflakes formed of graphene and h-BN, considering three different types of interfaces. Our results reveal that the dipole moment orientation of the nucleobases relative to the dipole moment of the hybrid nanoflake interface plays the decisive role in stabilizing these complexes. The antiparallel orientation of dipole moments of the nucleobases with respect to those of the nanoflake interfaces is found to be more stable than the parallel orientation in the armchair and N-terminated zigzag interfaces. Furthermore, the binding energies of the nucleobases on the hybrid flakes are found to be higher than those on both pure graphene and pure boron nitride flakes of the same size. Our study hints at the possibilities of using hybrid flakes to achieve better sensitivity in detecting and identifying specific nucleobases, There are no conflicts to declare.


How to prepare graphene@MXene hybrid through a simple, safe and eco-friendly synthetic route is highly desired. Compared with traditional synthesis technology, ultrasound synthesis strategy displays the merits of simplicity, low cost and environment protection. Herein, MXene (Ti3C2Tx) nanoflakes coupled with graphene nanosheets (graphene@MXene) were prepared in N-methylpyrrolidone (NMP) by simple ultrasound-assisted liquid-phase exfoliation method for the first time. Besides, the effect of types of solvent with different viscocity, sonication temperature and sonication duration time on the property of graphene@MXene hybrids were systematacially investigated. It is found the liquid-phase exfoliated graphene owned excellent electron transfer ability and the MXene (Ti3C2Tx) nanoflakes possessed outstanding adsorption property, the as-synthesized graphene@MXene hybrid exhibited significant signal synergistic enhancement effect toward the oxidation of hazardous veterinary drug residue compound (chlorpromazine) and food additives (rhodamine B). Based on this, a novel and sensitive electrochemical sensor was fabricated, the linear detection ranges were 5 nM to 0.5 μM for chlorpromazine with sensitivity of 1090 µA μM−1 cm−2, and 10 nM to 2.5 μM for rhodamine B with sensitivity of 440 and 102.14 µA μM−1 cm−2. Besides, the detection limits were evaluated to be as low as 1.25 nM and 2.45 nM for chlorpromazine and rhodamine B, respectively.To date, multiple graphene@MXene hybrids have been reported  For instance, the Yang group developed a highly sensitive electrochemical sensing platform for the detection of organic dye Sudan I basing on the chemically reduced graphene oxide In recent years, ultrasound-assisted synthesis method has been considered to be a kind of simple, green, low-cost and promising technology for preparing various functional nanomaterials. During the sonication process, plenty of cavitation bubbles were generated and then collapsed in the liquid environment, the collapsed cavitation bubbles can result in instantaneous high temperature and high pressure, which make it possible to actuate certain physical/chemical reaction and obtain the nanomaterials with different morphology and composition 3C2Tx) nanosheets, the as-synthesized graphene@MXene hybrid exhibited impressive signal enhancement effect toward the oxidation of chlorpromazine and rhodamine B. Chlorpromazine is a kind of common central nervous system drugs, which may be illegally added to the animal feed to reduce the animal activity and promote animal weight. Excessive intake of chlorpromazine may increase the liver damage risk of humans In this work, novel graphene@MXene hybrid was prepared through simple, green and eco-friendly ultrasound-assisted liquid-phase exfoliation approach for the first time . It is f22.13AlC2 powder was added and kept stirring for 24 h at 40 °C. Subsequently, the suspension was treated by centrifugation and the obtained solid residue was repeatedly washed by deionized water until the pH of the supernatant reached to approximately 7. The final solid product was then dried in vacuum drying oven at 60 °C for 12 h, and the obtained powder was denoted as etched Ti3AlC2 powder. After that, 0.5 g etched Ti3AlC2 powder and 0.5 g graphite powder were respectively added into 25 mL NMP with initial concentration of 20 mg mL−1, and sonicated for 5 h in an ultrasonicator  under the persistent nitrogen gas protection, and the sonication temperature was controlled at about 30 °C. At last, the obtained graphene and MXene suspensions were centrifuged at 3000 rpm for 60 min to remove the large particles, and the resulted colloidal suspensions consisted of MXene (Ti3C2Tx) nanosheets or graphene nanosheets were then separately collected. The concentrations of the MXene and graphene suspensions were then evaluated to be about 0.78 mg mL−1 and 0.18 mg mL−1 by weighing method, respectively. Besides, MXene and graphene powders were also obtained by filtrating the resulted MXene or graphene suspension. When studying the effect of types of solvents with different viscosity, sonication time and sonication temperature on the structure of graphene and MXene, similar experiment procedures were conducted.First, 1.6 g LiF powder was mixed with 20 mL HCl (9 mol/L) until the LiF powder was fully dissolved. After then, 1 g pristine Ti2.2−1) was mixed with 900 μL of graphene suspension (0.18 mg mL−1) and then sonicated for 10 min to obtain the homogeneously dispersed graphene@MXene hybrid suspension. In order to prevent the oxidation of MXene nanoflakes, the sonication mixing process of MXene and graphene nanosheets was also conducted under the persistent nitrogen protection. Basing on this, the volume ratio of MXene in the graphene@MXene suspension was 10 vol% and the total weight concentration of the as-synthesized graphene@MXene hybrid was calculated to be about 0.24 mg mL−1. Besides, the weight fractions of MXene and graphene in the hybrid were then calculated to be 32.5 % and 67.5 %, respectively. Other graphene@MXene hybrids with various composition were also prepared via changing the volume ratio of MXene suspension to 2.5 vol%, 5.0 vol%, 20 vol% and 30 vol%, the weight fractions of MXene in these hybrids were then assessed to be about 10.0 %, 18.6 %, 52.0 % and 65.0 %, respectively.Graphene@MXene hybrid was easily prepared by mixing the liquid-phase exfoliated MXene and graphene suspensions with certain volume ratio. For a typical procedure, 100 μL of MXene suspension  for further electrochemical detection. For the detection of rhodamine B in red chilli powder, 1 g red chilli powder was first dispersed into 10 mL acetonitrile and sonicated for 20 min. The mixture was then centrifuged at 5000 rpm for 10 min. The supernatant liquid was collected and another 10 mL acetonitrile was further used to extract rhodamine B from the residual solid again. When the extract solution was mixed together, 1 g NaCl and 2 mL water was added in succession, and the mixed solution was placed in a refrigerator with −20 °C for 5 h to remove the natural pigments and lipids. After that, the resulted solution was centrifuged at 5000 rpm for 10 min, and the upper acetonitrile solution was collected for the following electrochemical analysis. Spiked samples were obtained by adding a certain amount of chlorpromazine or rhodamine B standard before the pretreatment.The real pork and red chilli powder samples were purchased from the local food market. Before the detection of chlorpromazine in pork and rhodamine B in red chilli powder, the samples were treated by the following procedures 33.13AlC2, HF-etched Ti3AlC2, ultrasound-assisted synthesis of graphene, MXene (Ti3C2Tx) and graphene@MXene powders were first obtained to study their crystal structure  crystal face of the layer-like Ti3C2Tx material. This result suggested that only partial Al element was removed from the pristine MAX phase, and the HF-etched Ti3AlC2 powders were composed of bulk Ti3AlC2 and Ti3C2Tx. Compared with the pristine bulk Ti3AlC2 and HF-etched Ti3AlC2, their characteristic peaks that located at about 2θ = 39° disappeared in MXene, demonstrating the Al element was successfully removed and only the bulk Ti3C2Tx powders in the HF-etched Ti3AlC2 can be exfoliated into thin-layer of Ti3C2Tx nanosheets. Besides, the (0 0 2) diffraction peak of MXene shifted to a lower 2θ angle value relative to that of bulk Ti3AlC2, demonstrating the enlarged interlayer spacing, which could be also attributed to the effective etching of the Al layer XRD patterns of the pristine Titructure a. It is 3C2 precursors can be exfoliated into the flake-like nanostructure. High-resolution XPS spectra of the C 1 s was divided into five well-defined peaks that located at 281.8, 282.3, 284.8, 286.2 and 288.8 eV, which could be ascribed to C-Ti, C-Ti-O, C—C, C—O and O PBM data was replaced with SVG by xgml2pxml:<glyph-data id="pc-E00C" format="PBM" resolution="300" x-size="12" y-size="9">000000000000000000000000000000000000111111111111000000000000111111111111000000000000000000000000000000000000</glyph-data><svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="20.666667pt" height="16.000000pt" viewBox="0 0 20.666667 16.000000" preserveAspectRatio="xMidYMid meet"><metadata>Created by potrace 1.16, written by Peter Selinger 2001-2019</metadata><g transform="translate scale" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 480 0 480 0 0 40 0 40 -480 0 -480 0 0 -40z M0 280 l0 -40 480 0 480 0 0 40 0 40 -480 0 -480 0 0 -40z"/></g></svg>C-O bonds, respectively (3/2/Ti 2p1/2), which could be assigned to the Ti-C (455.2 eV/461.1 eV), Ti2+ (456.2 eV/462.9 eV), and Ti3+ (458.9 eV/464.7 eV) bonds (X-ray photoelectron spectroscopy (XPS) analysis was further conducted to study the surface chemical states and composition of the as-synthesized graphene nanosheets, MXene nanosheets, and graphene@MXene hybrid b. The XPectively c. In addV) bonds d [22], [3AlC2 powders, both graphite and Ti3AlC2 displayed irregular shape with size ranging from 5 to 30 μm. After etching by HF, only partial particles exhibited the accordion-like morphology , numerous nanoflakes were observed for the MXene  scanning in the absence and presence of 1 μM chlorpromazine a and 1 μ2O, ethanol (EtOH), NMP, DMSO, and their viscosity coefficient were 0.553, 0.802, 0.894, 1.07, 1.65, 1.99 mPa.s, respectively. It is seen that bulk graphite powder can be exfoliated into graphene nanosheets in DMF and NMP while bulk etched Ti3AlC2 can be exfoliated into MXene nanoflakes in H2O and NMP. Considering only NMP can be used for the synchronous exfoliation of graphene and MXene, thus NMP was selected as the optimum solvent to prepare graphene, MXene (Ti3C2Tx) and graphene@MXene nanoflakes suspensions. More importantly, both the resulted graphene and MXene nanosheets exhibited good stability in NMP. Studies showed that only when the surface energy of solvent was closed to that of the target material, bulk two-dimensional precursors can be easily transformed into the sheet-like nanomaterial through sonication-assisted liquid-phase exfoliation 2 flow. It is seen that when the sonication temperature varied from 10 °C to 40 °C, the exfoliation efficiency and morphology of graphene and MXene changed little  and volume (20 mL) were first treated by vacuum filtration on the organic porous films, we could see that compact and flat flexible films were easily obtained (R) values of MXene, graphene, and graphene@MXene hybrid were determined as 5.54 MΩ, 3.0 kΩ and 7.6 kΩ, respectively  of chlorpromazine and rhodamine B linearly raised with their continuously increased concentrations , and the corresponded linear relationships can be depicted as: i = 0.0763C − 0.0023 for chlorpromazine in the range of 5 nM to 500 nM, and i1 = 0.0308C − 0.0066 in the range of 10 nM to 250 nM and i2 = 0.00715C + 6.2647 in the range of 250 nM to 2500 nM for rhodamine B. Based on the 3σ/m criterion, where σ is the standard deviation of ten DPV tests for the blank electrolyte and m is the slope of the linear plots, the detection limits of chlorpromazine and rhodamine B were then evaluated to be as low as 1.25 nM and 2.45 nM, respectively.In order to achieve the highly sensitive detection of chlorpromazine and rhodamine B, the effect of pH of electrolytes, accumulation potential, accumulation time and amount of suspension on the current responses of chlorpromazine and rhodamine B at the surface of graphene@MXene hybrid were investigated . It is sThe reproducibility of graphene@MXene hybrid modified electrodes was then evaluated by recording the repetitive DPV curves and current responses of 0.25 μM chlorpromazine and 1 μM Rhodamine B at ten different electrodes. The relative standard deviation (RSD) was then measured to be about 3.8 % for chlorpromazine and 4.8 % for rhodamine B, confirming its good reproducibility.Stability evaluation was conducted by recording the oxidation peak currents of 0.25 μM chlorpromazine and 1 μM rhodamine B at the same sensor for every day. The fabricated sensor was used for only once for each test. After each electrochemical test, the GCE was polished with 0.05 μm alumina powder, sonicated in deionized water and ethanol, modified with 5 μL graphene@MXene suspension, and drying under an infrared lamp in the air. After that, the graphene@MXene modified GCE was stored in air at room temperature for different time for the next test. It is found that the current responses of chlorpromazine and rhodamine B at graphene@MXene hybrid modified electrode still can reached to 93.1 % and 91.2 % of their initial values after two weeks, respectively, demonstrating the long-term stability of graphene@MXene hybrid modified electrodes. For further judging the stability of graphene@MXene hybrid modified electrode in the electrolyte solution, graphene@MXene modified GCE was immersed in the blank electrolyte solution for different time and the oxidation peak signals of 0.25 μM chlorpromazine and 1 μM rhodamine B at graphene@MXene modified GCE was then recorded by DPV test . It is f+, K+, Mg2+, Ca2+, Fe3+, Cu2+, SO42−,Cl−, NO3−, 200 folds of moxifloxacin metronidazole, ofloxacin, fleroxacin, erythrocin, gatifloxacin, dinotefuran has no obvious effect on the electrochemical response of 0.25 μM chlorpromazine. 500 folds of Na+, K+, Mg2+, Ca2+, Fe3+, Cu2+, SO42−,Cl−, NO3−, 100 folds of ascorbic acid, congo red, quinoline yellow, lemon yellow, alizarin red, carmine has no obvious effect on the electrochemical response of 1 μM rhodamine B. These results manifested the as-synthesized graphene@MXene hybrid owned strong anti-interference ability for the detection of chlorpromazine and rhodamine B.Anti-interference ability of graphene@MXene hybrid modified electrodes was also investigated. The potential interference substances were severally adding into 0.25 μM chlorpromazine or 1 μM rhodamine B and the oxidation peak currents of chlorpromazine and rhodamine B were then recorded. It was found that 500 folds of NaIn order to further verify the feasibility of the electrochemical sensor, the content of chlorpromazine in pork sample and rhodamine B in red chilli powder sample were evaluated under the optimal test conditions by DPV. Each sample was parallelly detected for three times, and the content of the target analyte was measured by standard addition method. The analysis results were summarized in 4Ultrasound-assisted liquid-phase exfoliation method has been confirmed to be a simple and effective method for the preparation of novel graphene@MXene hybrid. Due to the synergistic effect, the as-synthesized two-dimensional graphene@MXene hybrid was endowed with superior electron transfer ability and physical adsorption property. Basing on this, excellent electrochemical activity toward the oxidation of chlorpromazine and rhodamine B was achieved, and a facile and sensitive electrochemical sensor was established for the simultaneous voltammetric detection of chlorpromazine and rhodamine B. Besides, the fabricated sensor displayed satisfied reproducibility, stability and practicability. Considering the diversity of MAX phase materials, the proposed liquid-phase exfoliation strategy is believed to be instructive for preparing other graphene@MXene hybrids for various applications.Shenchao Shi: Methodology, Conceptualization, Software, Visualization, Validation, Writing – original draft, Writing – review & editing. Ruizheng Zhong: Methodology, Conceptualization, Formal analysis, Writing – original draft. Lele Li: Methodology, Conceptualization. Chidan Wan: Supervision, Formal analysis, Writing – review & editing, Funding acquisition, Project administration. Can Wu: Supervision, Formal analysis, Writing – review & editing, Funding acquisition, Project administration.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.