TH) in power dissipation was studied using a combination of electrical breakdown thermometry and infrared (IR) imaging. A simple lumped thermal model  graphene interconnects. The electrical performance of aerosol-jet printed (AJP) graphene was characterized using the Transmission Line Method (TLM). The electrical resistance decreased with increasing printing pass number (n); the lowest sheet resistance measured was 1.5 kΩ/sq. for n = 50. The role of thermal resistance (R Conventional fabrication processes such as vacuum deposition, photolithography, and epitaxial growth of electronic materials tend to be complex, expensive, and incompatible with rapid prototyping7. Additive manufacturing techniques, such as inkjet printing, aerosol jet printing (AJP), and extrusion printing, are being explored as alternative fabrication methods for such sensor systems12. Direct write techniques offer a low-cost fabrication alternative due to the reduced material consumption while allowing for rapid customization and prototyping14.Wearable technology is an emerging multi-billion-dollar industry that is made possible, in part, by advances in flexible and wearable electronic devices9. While conductive polymer inks provide low cost printing, their performance is limited by their low conductivities, and poor thermal and chemical stabilities. Carbon nanotubes (CNTs), have shown promise as an AJP compatible ink with significant mechanical flexibility and high mobility making them attractive for AJP applications16. Nevertheless, due to poor dispersion of CNTs in AJP compatible inks and the high cost of monodispersed solutions, the applications of CNTs remain limited for AJP printable devices18. One of the more promising nanomaterials for such applications is graphene, a two-dimensional (2D) hexagonal carbon structure with sp2 hybridized carbon atoms19. Due to its high specific surface area, high carrier mobility, and unique band structure, graphene has shown many promising properties and demonstrated breakthroughs in electronic related applications23. Graphene is also a promising sensor electrode material due to its flexibility and high electrochemical activity at defect sites26.Despite the rising popularity of printing techniques, there is a growing need for ink formulations and materials to meet the demand of the electronics industry. Printable, conductive metals like Ag and Cu have been widely studied, but their applications are restricted by their high cost and the rapid oxidation of Cu28, and several groups have demonstrated inkjet printed graphene chemical29 and biological30 sensors. Graphene inks are typically produced through liquid phase exfoliation of graphite or chemical and/or thermal reduction of graphene oxide32. These processes typically result in submicron graphene crystal domains, and give rise to numerous point defects within the lattice, and closed-contour defects around the flake’s edge33. Under applied electrical bias, these defects result in highly localized electric fields which can be modified by absorbed molecules/target analytes. Combined with the high electrical conductivity and specific surface area of graphene, these defects enable highly sensitive graphene based sensors able to detect target molecules with parts per billion sensitivity in controlled environments33. Furthermore, as inkjet is typically a drop-on-demand process, the microstructure of inkjet printed graphene typically results in a well layered structure with varying amounts of porosity, depending on annealing conditions, ink properties, and the number of print passes. In this regard, graphene’s compatibility with AJP is less understood34.Inkjet printing of graphene has been well established39. Substrate properties, microstructure, and thermal interfaces are likely to play a key role in limiting reliability and power dissipation in such applications. Previous studies have reported on power dissipation processes for mechanically exfoliated, chemical vapor deposition (CVD), and epitaxial grown graphene-based devices. However, power dissipation in printed graphene-based devices has yet to be explored45. This work, therefore, investigates the roles of microstructure and the substrate properties on power dissipation in AJP graphene interconnects. The information gained from this study is expected to provide new fundamental insights that will impact low-power and high-power applications of AJP graphene devices, as device models for both will require understanding the physical properties of such materials systems and printed devices.While additive manufacturing is rapidly advancing the low-power sensor applications of graphene, the high-power and high-temperature applications of additively manufactured graphene based devices have received less attention. Such applications include temperature sensors, resistive heaters, thermal heat spreaders, high-current carrying interconnects, and ordnance fuze technologyet al. and Secor et al.28. Bulk graphite powder was sonicated in ethanol and the stabilizing polymer ethyl cellulose to obtain suspended graphene flakes. The graphene flakes were then dispersed in a mixture of 92.5% cyclohexanone and 7.5% terpineol, which has been shown to be compatible with AJP  and characterized with both TEM and Raman spectroscopy. Raman spectroscopy revealed the characteristic D, G and 2D peaks for graphene at 1350 cm−1, 1580 cm−1 and 2700 cm−1, respectively. The ratio of the D/G peak intensities (ID/IG) determines the quality (defect/disorder) of the graphene flakes. The ID/IG peak ratio of 0.24 is lower than previously reported values (0.33–0.7), suggesting the exfoliated flakes are of higher quality with fewer defects46. TEM images show the graphene flakes vary in lateral size from ~50–200 nm. To correlate the TEM and Raman data, the ID/IG peak ratio and 532 nm excitation wavelength was used in Cancado’s general equation47 to extract the crystal size (La ≈ 80 nm) of the graphene flakes. AFM characterization of the flakes shows the thickness (tg) ranges from monolayer to flakes with an average thickness of tg = 16 nm +/− 15 nm  were printed with an Optomec AJ-300 aerosol jet printer using the UA-max ultrasonic atomizer. The graphene print passes were varied from n = 5 to n = 50 and were deposited on SiOcts Fig. 48. A rec2O3 substrates remains constant as the peak height increases with increasing pass number  as expected. Based on the TLM measurements the lowest sheet resistance was calculated as 1.5 kΩ/sq. for n = 50 at room temperature. Similar conductance profiles are seen for Kapton and Al2O3  and TLM technique was used. As seen in Fig. 50. To study this effect, a simple lumped model was developed that uses a combination of infrared (IR) thermal imaging and electrical breakdown thermometry supported by finite element modeling (FEM) using COMSOL multiphysics software53.The overall power dissipation of a graphene device is dependent on the effective thermal conductivity and total thermal resistance of the system. Substrate material, interface thermal resistances, graphene quality, and device structure are a few of the factors that directly impact the total device thermal resistance2 × REL is the dissipated power and RTH is the total thermal resistance of the device. Here ΔT is comparable to ΔV, P is comparable to I, and RTH = L/(κEFF × A) is the total thermal resistance and depends on the device dimensions and an effective thermal conductivity for the system (κEFF). We note, that REL is the inverse of the device conductance , the thermal interface resistance between graphene and the substrate (RINT = 1/(g × A)), and the thermal resistance of the substrate (RSub). For the SiO2/Si substrate RSub is the sum of the oxide thermal resistance (ROX = tOX/(κOX × A)) and the silicon thermal resistance (RSi = 1/(2 × κSi × A1/2). Here, tOX = 90 nm, κOX = 1.4 Wm−1 K−1, κSi = 100 Wm−1 K−1, g is the graphene – SiO2 boundary thermal boundary conductance taken as 108 Wm−2 K−1, and A is the area of the printed graphene interconnect (A = L × W)55. For samples printed on Kapton and Al2O3 the ROX term is negligible and the substrate thermal resistances are simply (RSub = 1/(2 × κSub × A1/2), where κSub is the substrate thermal conductivity taken as 0.12 Wm−1 K−1 and 32 Wm−1 K−1 for Kapton and Al2O3 (sapphire), respectively57. Based on this model, a combination of IR microscopy and electrical breakdown thermometry can be used to quantify the heat spreading and estimate the “missing” RGTOT associated with the printed graphene interconnects.Simple lumped model: Similar to Ohm’s law , the high temperature rise at low power for Kapton results in a total thermal resistance of 9285 K/W compared to 350 K/W for SiO2/Si and 185 K/W for Al2O3.IR Microscopy: The thermal profiles of the graphene devices were characterized under varying bias conditions. The background temperature Tton Fig.  measured mW Fig. , and the mW Fig. . These dGTOT contributions to RTH a combination of electrical breakdown thermometry and COMSOL Multiphysics was used. Figure o) of 85 °C exceeds the breakdown temperature (TBD), which is either the decomposition temperature of Kapton or the oxidation temperature of the graphene on SiO2/Si or Al2O3  in order to observe where the maximum power dissipation is taking place. The total thermal resistance of the interconnect on SiO2/Si was calculated to be 372 K/W, with the highest temperature value of 520 °C being reached within the graphene interconnect. From these calculations it can be concluded that the power dissipation is dominated by the graphene interconnect. The high thermal resistance of the graphene interconnects is likely due to several factors: the porosity of the printed interconnect, the high thermal resistance between graphene layers, and the general disorder of the constituent graphene nanoflakes that make up the interconnect58. Cross-sectional TEM imaging was used to quantify the porosity of the printed graphene interconnects on SiO2/Si and better understand the structure of AJP deposited graphene. Analysis of the TEM images seen in Fig. COMSOL multiphysics was used to further analyze the thermal spreading in these systems. Figure −1 K−1)59 and high charge carrier mobility 60, which makes it a desirable material for device applications. Nevertheless, the overall performance of graphene devices can be limited by power dissipation and the thermal resistance of the system40. Understanding the details of heat spreading (or Joule heating) in the system is important as it can limit the carrier mobility of graphene and the overall current density41. Effects of Joule heating are influenced by device structure, thermal transport across material interfaces, and the choice of substrate material41. While several studies have examined the impact of Joule heating in graphene devices fabricated using graphene obtained by various synthesis techniques such as mechanical exfoliation, epitaxial growth on SiC, and CVD growth on transition metal substrates, this is the first to do so for AJP printed graphene interconnects64. Our studies of power dissipation in AJP printed graphene interconnects indicate that power dissipation in AJP graphene is dominated by the graphene interconnect morphology for high thermal conductivity substrates, but can be limited by the substrate properties in the case of low thermal conductivity polymer substrates typically used for flexible and wearable electronics applications.Graphene is known to have extremely good thermal conductivity 2/Si used in this study. In both cases we find a breakdown pattern parallel to the direction of current flow. This type of breakdown pattern is likely due to the high porosity causing trapped gasses and solvents within the interconnect, as well as weak interlayer bonding of graphene flakes. As the device undergoes Joule heating, these trapped gases and fluids expand or vaporize, resulting in physical expansion and mechanical failure of the interconnect. This is particularly well captured in Fig. 2O3 was catastrophic with the substrate completely melting and destroying the graphene interconnect (for Kapton) and a complete oxidation and disintegration of the interconnect (Al2O3).  in ethanol using a Qsonica (Q125) probe tip sonicators for 90 min28. To remove the larger graphite flakes, the dispersion was centrifuged (Heraeus Megafuge 8 Centrifuge) at 4500 RPM for 30 min and the supernatant was collected immediately. In a 1:2 volume ratio, the collected supernatant and 0.04 g/ml aqueous solution of NaCl  was centrifuged for 15 min at 4500 RPM, to facilitate the flocculation of graphene flakes. The resulting graphene/EC dispersion was dried overnight on a PTFE plate. To tailor the concentration and viscosity of ink to the AJP, the dried graphene/EC paper was then dispersed by sonication for 30 min, in a mixture of 92.5% cyclohexanone and 7.5% terpineol solution, followed by centrifugation at 4500 rpm for 15 min. The resulting ink concentration, as seen in Fig. Similar to the processes described in Jabari The graphene interconnects were printed using an AJ-300 Aerosol Jet printer manufactured by Optomec. The atomizer utilized was the UA-Max ultrasonic atomizer. A recirculating bath temperature of 15 °C was used to help stabilize the ink temperature and prevent the output from being too solvent rich. The tool platen was heated to 65 °C to help ensure rapid drying of the ink once on the substrate. The printing nozzle was a 100 μm inner diameter ceramic and the mist tube material was polyethylene. The power applied to the atomizer was 48 W (48 volts at 1 amp). The sheath and atomizer flows were 50 and 20 sccm nitrogen respectively. The tool translation speed used was 1 mm/sec and the resulting single pass line width was measured to be ~50 μm. After printing any remaining solvent was driven out of the lines with a 100 °C bake for 10 min followed by a ramp to 200 °C bake under a nitrogen purge for 30 min to maximize conductivity of the printed features.2 Si/SiO2 wafers we used for AFM and Raman characterization. The TEM grid and SiO2/Si wafers were then annealed on a hotplate at 250 °C for 10 min, to remove the ethanol/EC residuals. AFM images were obtained using a Bruker Multimode 8 system. The images were collected with 1 µm × 1 µm scans, and particle characteristics were determined using Nanoscope Analysis software. TEM images were obtained using a JOEL JEM 2100 system, and the particles were characterized by ImageJ software. Lastly, the Raman peaks were obtained using Horiba LabRAM HR Evolution Raman microscope, with an excitation wavelength of λ = 532 nm. The spectrum was collected at a laser power of 25%, with magnification of 100x with 30 s exposure time, and between the range of 1000–3000 cm−1. Baseline subtraction was employed to clearly deduct the peak intensities. Cancado’s general equation47: a axis (La) of the graphene flake from the Raman spectrum.For AFM, TEM and Raman characterization, the formulated graphene dispersion in ethanol/EC was diluted 1:10 volume ratio graphene/EC flakes in ethanol. The diluted dispersion was then drop-casted on to a TEM lacey carbon grid and tripled rinsed in isopropyl alcohol and dried with Ngl, where A is the (absorbance), α (absorption coefficient), Cg (concentration of graphene), and l is (path length of the spectroscopy), a graphene concentration of 3.5 mg/ml was measured. The previously reported absorption coefficient at wavelength of 660 nm (α660 = 2460 L/g-m) was used in the calculations8.Ultraviolet-Visible (UV-VIS) absorption spectroscopy (Cary 5000 G) was used to measure the optical absorbance of the graphene inks and quantify the graphene concentration. Using the Lambert-Beer law, A = αCIn order to find the annealing temperature and oxidation temperature of the graphene, Thermogravimetric Analysis (TGA) was employed. A Netzsch TGA instrument was used to obtain the spectra of mass percent versus temperature. The mass of the dried graphene flakes (black) was analyzed as the temperature increased from 25 °C to 1000 °C at a heating rate of 5 °C/min in air. TGA analysis revealed the decomposition peak of surfactant, ethyl cellulose, is around 250 °C and oxidation/decomposition of the graphene is 550 °C . All other external boundaries were under the adiabatic boundary conditions, if they are thermally insulating. Thermal properties of the substrates are κOX = 1.4 Wm−1 K−1, κSi = 100 Wm−1 K−1, κKapton = 0.12 Wm−1 K−1, and κAl2O3 = 32 Wm−1 K−1. Thermal conductivities of graphene interconnect are assumed at κ⊥ = 2 Wm−1 K−1 and κ|| = 50 Wm−1 K−1 for cross-plane and in-plane directions, respectively. These values are significantly lower than those of pristine graphene because of the nature of printed graphene. The thermal interface resistance between graphene interconnect and substrates Rint were fitted to be between 1.0 × 10−7 m2 K/W to 1.0 × 10−8 m2 K/W.In order to understand the heat dissipation and temperature distribution in our devices, we performed finite element simulations using COMSOL Multiphysics. In our thermal model, the bottom boundary of the substrate and the outmost surface of the silver pad (which were in contact with the probe) were kept at the ambient temperature under the isothermal boundary condition (The data generated and analyzed as part of this study are available from the corresponding authors upon reasonable request.Supplementary Information


A stretchable optical sensor can quantify the strain generated by human movement, which has been widely studied in the development of health monitoring systems, human–machine interfaces and wearable devices. This paper reports a graphene-added polydimethylsiloxane (PDMS) fiber, which has high tensile properties and good light transmittance suitable for detecting human movement. When the graphene-added PDMS fiber is stretched, the concentration of graphene per unit volume is constant, and the sensor uses the optical loss of the beam through the graphene PDMS fiber to detect the tensile strain. The fiber has excellent strain-sensing performance, outstanding sensitivity, a tensile property of 150%, and an excellent waterproofing performance. The linear response and repeated response in large dynamic range could reach 100% stability. The results show that the sensor can be used to detect human motion detection. These excellent properties indicate that the fiber has potential applications in wearable devices, soft robots and electronic skin. In recent years, flexible, stretchable and wearable sensor devices have received widespread attention ,6,7,8,9.In order to meet these needs, many studies have reported flexible, stretchable and highly sensitive strain or pressure sensors made of graphene polymer ,18,19,20This paper reports a graphene-added PDMS fiber with high tensile properties and good light transmittance. We studied the beam attenuation after passing through the graphene-added PDMS fiber to detect tensile strain. The optical loss is mainly caused by the absorption and scattering of graphene. The sensor can easily reach 150% strain, which shows the large range of human joint detection capabilities, including finger bending, wrist bending, elbow bending and knee bending. The muscle detection of human movement also exhibits excellent sensitivity including arm muscle relaxation and tension, the exhalation and inhalation of the human body. In addition, we demonstrated waterproof properties and tested the sensor changes in different environments. According to the results of this research, it is expected that people will be able to cost-effectively manufacture sensors that meet a variety of human needs.Single-layer graphene  with a purity of over 99% was acquired from Suzhou Tanfeng Materials Tech. Co. Ltd.  and was prepared by a chemical method. Poly tetra fluoroethylene (PTFE) tubes with different diameter sizes were bought from Oudelixin . Polydimethylsiloxane  was supplied by Dow Corning Co. Ltd.  The medical rubber gloves and the injection syringe were all purchased from a local hospital .A simple two-step method was used to prepare the graphene-added PDMS fiber. Firstly, the graphene powder was dispersed (5 mg/ml) in chloroform . After ultrasonic treatment for 6 hours, a well-dispersed solution was mixed with polydimethylsiloxane. Subsequently, the mixing solute on was mixed with a vortex and dried at 90 °C for 12 h in order to completely evaporate the chloroform. The mixing prepolymer was prepared by polydimethylsiloxane and a curing agent at a ratio of 10:1  by weight. The uniformly stirred PDMS mixture was degassed in a vacuum box. The High Power UV–Vis Fiber Light Source , which outputs 200 nm to 1600 nm light through a light guide, was used as the light source. The emission wavelength was 441.6 nm helium-cadmium laser. The sensor was coupled with two UV resistant quartz fibers (core: 600 μm) at each end, encapsulated with fixture equipment. Digital light power and an energy meter (PM100D) were used to measure the light intensity variation of the fiber optic sensor. The Laser Star Dual Channel (P/N 7Z01601) is a laser power meter, which is driven by window software. An Ocean Optics USB4000 spectrometer  measured the transmission spectrum and the spectral range was 200–1100 nm.c = We investigated the stretchability of the graphene-added PDMS fiber with a length of 3 cm and a diameter of 1 mm. The digital optical of graphene-added PDMS fiber is shown in In order to detect the optical properties of PDMS fibers, the optical properties of graphene-added PDMS materials were characterized by optical attenuation spectroscopy. We measured the transmission loss of PDMS fiber and graphene-added PDMS fibers in air, as shown in c = As shown in A represents the absorbance, k is the molar absorption coefficient, and the absorption property of graphene does not rely on the incident wavelength λ of visible light. ε is the strain, c is the concentration of graphene, and, under strain conditions, as, due to the constant volume, with absorption per unit length unchanged, c remains constant. T is the transmittance. The absorption of graphene leads to the attenuation of transmitted light intensity, and the change in strain attenuation can be expressed as:c is constant, the optical loss is proportional to the strain ε; when the strain ε is constant, the optical loss and the concentration c are linearly proportional.The absorption of graphene was linearly proportional to the length of the light passing through the PDMS fiber, as shown in The sensitivity of the sensor response is affected by the concentration of graphene and the length of the PDMS fiber. In our experimental test, the details of fiber fixation were as shown in Accompanied with the action of strain, the optical loss changed, as shown in In order to study the dynamic response of the sensor during stretching and releasing, we performed a cyclic test on a sensor with a graphene concentration of Due to its high flexibility, sensitivity and large strain range, the sensor can be directly attached to the human body to monitor its movement in real time. Because the graphene material has no wavelength selectivity in a visible light band, we can measure the optical loss through PDMS fibers with a single wavelength laser. Combined with the practical application of the sensor, we have improved the process of the optical fiber as shown in For large-strain detection of human motion, we attached sensors to human joints, as shown in −1.In addition, we also did some tests for smaller strains such as muscle movements, as shown in The stability of the sensor is necessary for practical applications. We soaked the sensor in water to monitor its optical response to water. In conclusion, we have demonstrated a simple, efficient and low-cost way to manufacture strain sensors with high tensile properties and sensitivity, made from graphene and polymer elastomers. Compared to the pure PDMS fiber, the composite fiber significantly enhances the optical sensing signal of the sensor, showing excellent sensitivity in the case of strain sensing. The tensile property of the sensor is 150%. This strain sensor was applied to practical applications to detect finger bending, wrist bending, elbow bending, knee bending and other motions of the human body in an all-round way. In addition, the optic fiber sensors could be used to monitor muscle movements and breathing. Moreover, we also researched the sensing capacity (bending strain) of this fiber sensor in water, and found that it has certain waterproof function. This study shows that the sensor fibers have a wide range of potential applications in flexible and stretchable devices.


Conversely, graphene has a 2D layered structure, possessing an exceptionally large specific surface area and high carrier mobility. Likewise, other emerging graphene‐analogous 2D nanomaterials, such as graphitic carbon nitride (g‐C3N4), transition‐metal dichalcogenides (TMDs), hexagonal boron nitride (h‐BN), and black phosphorus (BP), show unique electronic, physical, and chemical properties, which, however, exist only in the form of a monolayer and are typically anisotropic, limiting their applications. Upon hybridization with fullerenes, noncovalently or covalently, the physical/chemical properties of 2D nanomaterials can be tailored and, in most cases, improved, significantly extending their functionalities and applications. Here, an exhaustive review of all types of hybrids of fullerenes and 2D nanomaterials, such as graphene, g‐C3N4, TMDs, h‐BN, and BP, including their preparations, structures, properties, and applications, is presented. Finally, the prospects of fullerene‐2D nanomaterial hybrids, especially the opportunity of creating unknown functional materials by means of hybridization, are envisioned.Fullerene has a definite 0D closed‐cage molecular structure composed of merely sp In particular, g‐C3N4, with a moderate band gap and indirect‐semiconductor nature, has become a promising metal‐free catalyst for water splitting and the degradation of pollutants due to the advantages of low cost and high specific surface area (2500 m2 g−1 for the monolayer) and has been applied in organic solar cells.3N4 exhibits a poor electrical conductivity and low photocatalytic activity owing to the rapid recombination of photogenerated electron–hole pairs. Thus, improvements in the photocatalytic activity of g‐C3N4 to extend this material to further applications are highly desired. To this end, the hybridization of g‐C3N4 with other functional materials, including fullerenes, has been developed in recent years and appears feasible since the polymeric nature of g‐C3N4 renders the chemical structure flexible.During the last decade, several other types of emerging graphene‐analogous 2D nanomaterials have been discovered.2, consisting of hexagonal rings with Mo and S atoms alternately located at the hexagon corners, is the most representative TMD with a direct band gap in monolayer form and high in‐plane carrier mobility, thus being suitable for versatile applications in electro and photocatalysis, photovoltaics, and photoelectric devices.2 in photocatalytic H2 production, since only its edges have a high catalytic activity, whereas its basal plane is inactive, a low photocatalytic activity has been achieved, even for single‐layer MoS2. Consequently, MoS2 is generally applied as a cocatalyst loaded on conventional metal‐based semiconductor photocatalysts, such as TiO2, CdS, and ZnO, to reduce the energy barrier of water splitting and to increase the stability of the photocatalysts. To enhance the photocatalytic H2 production activity of MoS2 itself, the construction of nanocomposites composed of MoS2 and other functional materials, such as graphenes and fullerenes, provides a practical solution.3N4 and the TMD MoS2, no Review has reported their hybridization with fullerenes, which is crucial for understanding such intriguing 0D–2D hybrid systems.The inorganic transition‐metal dichalcogenides (TMDs) represent another type of emerging 2D semiconducting nanomaterial and have been attracting widespread attention due to their intriguing electronic, optical, and mechanical properties.3N4, TMDs, h‐BN, and BP, all types of hybrids of fullerenes and 2D nanomaterials reported to date are exhaustively reviewed, with emphasis on the exclusive impact of fullerenes with unique electronic and chemical properties on the electronic and band structures of 2D nanomaterials. Upon attachment of fullerene molecules, noncovalently or covalently, the physical/chemical properties of 2D nanomaterials can be tailored, and in most cases, improved, and the mechanisms responsible for such improvements are discussed in detail. Furthermore, fullerene incorporation may induce new properties in 2D nanomaterials as a result of strong intermolecular interactions, thus extending the functionalities and applications of 2D nanomaterials. At the end, we envision the prospects of fullerene‐2D nanomaterial hybrids, especially the opportunity of creating unknown functional materials by means of hybridization.In this Review, we focus on the hybrids of 0D fullerenes and 2D nanomaterials, including their preparations, structures, properties, and applications. Based on known 2D nanomaterials, such as graphene, g‐C22.1TableNoncovalent hybridizations of fullerenes and graphenes have been fulfilled by depositing fullerene onto a graphene layer to form a graphene/fullerene bilayer film and by physically blending pristine fullerenes or fullerene derivatives and graphenes see Table1.2.1.160 onto a graphene film to form a bilayer hybrid; in this way, the interfacial electronic interactions and charge transfer between C60 and graphene can be investigated. In 2015, Heinz et al. fabricated a C60/graphene hybrid by depositing C60 onto single‐layer graphene and studied the ground and excited‐state charge transfers at the C60/graphene interface by using Raman spectroscopy and THz time‐domain spectroscopy. The authors concluded that at equilibrium the C60 layer functioned as an electron acceptor affording hole doping of the graphene with an injection of ≈0.04 holes per interfacial C60 molecule at the surface of the bilayer hybrid, as well as a downshift of the graphene Fermi level by 160 meV , which provided a unique surface with humps and valleys facilitating the assembly of Cop Figure2.23 Th60 films onto graphene sample surfaces using a spray coating method and investigated the electrical interaction and charge transfer kinetics at the graphene/adsorbate interface by using flicker noise, as an insightful probe, in combination with Raman spectroscopy and DC‐transport measurements.60 deposition, which was attributed to the carrier trapping/detrapping processes in the hybrid system, finally leading to an enhanced charge noise. Meanwhile, the charge exchange process was significantly suppressed with decreasing temperatures, indicating that the flicker noise acted as a powerful probe to elucidate the nature of the charge transfer in the graphene–fullerene hybrid device. Furthermore, the authors fabricated graphene field‐effect transistors to quantitatively evaluate the charge transfer between C60 molecules and graphene and found that a large number of carriers with a high Fermi energy for n‐doped graphene may overcome the energy barrier to occupy the LUMO of C60 molecules compared to that of p‐doped graphene.60 was estimated to be 0.6–1.3 × 1012 cm−2, ≈0.01 electrons captured by a single C60 molecule.In 2013, Qiu and co‐workers constructed a fullerene/graphene hybrid device by depositing self‐assembled C60 onto FLG films prepared by a chemical vapor deposition (CVD) technique. The electrical conductance of the C60/FLG system decreased when the system was under illumination and was attributed to a kind of negative photoconductivity.60/FLG system varied, FLG exhibited p‐type doped characteristics under low light intensities and presented n‐type doped behavior for high light intensities.Likewise, in 2014, Mendoza et al. constructed a fullerene/few‐layer graphene (FLG) bilayer system by thermally evaporating C60–graphene vertical heterostructure with a well‐ordered film morphology on the graphene, as confirmed by transmission electron microscopy (TEM).60 crystal and graphene lattice directions. The preferential growth of C60 crystals is prone to graphene's zigzag and armchair directions. Moreover, the C60–graphene vertical junction‐based transistors showed n‐type transport behavior. The energy barrier modulation at the C60–graphene Schottky junction can achieve a high on/off ratio above 3 × 103, which is difficult to obtain for conventional graphene transistors. Thus, graphene is demonstrated to offer an excellent substrate for the epitaxial assembly of organic semiconductors toward electronics applications.Later, in 2015, Bao et al. fabricated a C60 molecules at the graphene/Cu interface by annealing led to amorphous and crystalline structures.60 molecules imprinted a local strain/deformation on the graphene layer with various magnitudes controlled by the intermolecular distance.In the same year, Reinke and co‐workers reported that the intercalation of C60 molecules were encapsulated by two layers of graphene  results in the Fermi‐level energy of the system to align inside the broadened LUMO. When the gate voltage is changed, the charge transfer to the molecule increases through the Dirac  point of graphene to the electron‐doped side , resulting in a Fermi level deeper inside the LUMO.Bilayer films comprised of graphene and fullerene derivatives have also been studied. In 2011, Lofwander and co‐workers constructed a single‐molecule device consisting of graphene and a fullerene derivative, where the graphene was patterned to form a nanogap and can be used as electrodes for gate‐tunable molecular electronics, and a dumbbell fulleropyrrolidine consisting of a central wire of 1,4‐phenylenediamine attached to C60 end‐capped molecular wire comprised of two styrene units covalently connected via a paracyclophane moiety in the center, Weber and co‐workers fabricated graphene–fullerene–graphene junctions with ultraflat, transparent, and robust graphene nanogaps. The single‐molecule contacts were confirmed according to the measured I–V curves, which were similar to those obtained with the mechanically controlled break junction technique. Additionally, nonlinear I–V curves were obtained in a very low yield when molecules were applied at low concentration, thus ruling out the possibility of larger numbers in the junction.Similar single‐molecule junctions employing a fullerene derivative were later constructed by several other groups. In 2015, using a C60 bisadduct used as the junction and observed the redox‐dependent Franck–Condon blockade and avalanche transport phenomena. The C60 bisadduct was synthesized through a 1,3‐dipolar cycloaddition reaction between C60, 1‐pyrene carboxaldehyde, and N‐methylglycine.60 with pyrene anchor groups was verified to effectively modify the electron delocalization and energy levels, leading to HOMO‐dominated transport.f) to the microheater and measuring the thermovoltage (Vth) drop across the device at a frequency (2f) for different back gate voltages (Vg),kBT0 at the operating temperature, and (3) the tunnel couplings to the left and right electrodes need to be equal to achieve a maximum power factor.In 2016, Mol and co‐workers studied a similar graphene–fullerene–graphene single‐molecule transistor with a pyrene‐functionalized C2.1.260 into graphene nanosheets prepared by the exfoliation of a bulk graphite crystal and followed by a reassembling process.60 physical blend increased from 540 to 784 mAh g−1 after the incorporation of C60.60 hybrid, in 2015, Lee and co‐workers carried out DFT studies and found that charge transfer from the graphene to the C60 took place in the graphene–C60 hybrid system, leaving the graphene positively charged (+0.095 e) and the C60 negatively charged (−0.095 e). As a result, Li ions preferentially adsorbed on the C60 side, particularly in the midway region between graphene and C60 or between two C60 molecules.60 hybrid system (−2.285 eV) was higher than that on bare graphene (−1.375 eV), indicating that the Li adsorption on the graphene–C60 hybrid system is more stable.Noncovalent hybrids of fullerenes with graphene have also been facilely prepared by physically blending both components. In 2008, Honma and co‐workers reported a graphene–fullerene physical blend by incorporating C60, pristine single walled carbon nanotubes (SWCNTs), and GO sheets.60/SWCNTs/GO exhibited a surface roughness of only a few nanometers. After the thermal reduction of GO, the as‐prepared C60/SWCNTs/rGO composite was utilized as the active layer of a photovoltaic device  of 1.23 mA cm−2, an open‐circuit voltage (Voc) of 0.59 V, a fill factor (FF) of 0.29, and a power conversion efficiency (PCE) of 0.21%. Such a decent PCE was attributed to the presence of numerous clean p–n junctions distributed throughout the all‐carbon hybrid, facilitating the spontaneous dissociation and subsequent separation of the photogenerated excitons along the bicontinuous heterojunctions.60 with C70 in both the active layer and blocking layer, a nearly fourfold increase in Jsc from 1.23 to 4.95 mA cm−2 was achieved, leading to a dramatic increase in PCE from 0.21% to 0.85%.In addition to pristine graphene (pG) sheets, exfoliating graphite flakes to few‐layer graphene via chemical functionalization is currently commonly used as the most cost‐effective method of obtaining graphene due to its easiness, reliability, and scalability.ce Figure4, affo60 with rGO by the liquid–liquid interfacial precipitation method, resulting in rGO‐wrapped C60 wires.π–π interactions between rGO and C60. FET devices fabricated with rGO/C60 wires exhibited a p‐type semiconducting behavior both in vacuum and in air, indicating that the rGO, as a shell layer, can transport holes effectively. However, the pure C60 wires and rGO sheets showed n‐type and ambipolar behaviors, respectively, in vacuum. Furthermore, the photovoltaic devices based on rGO/C60 wires as the active layer exhibited a significant enhancement in short‐circuit current (JSC) from 0.07 to 0.19 mA cm−2 compared to the devices based on a pure rGO active layer. This result can be interpreted as the photoinduced electron transfer from rGO to C60 under light irradiation.Several efforts have since been made to prepare hybrid materials based on GO or reduced graphene oxide (rGO). In 2011, Shin and co‐workers reported the preparation of hybrids of C60/C70 with GO by a simple grinding method, and the material exhibited a solubility of 5.0 mg mL−1 in water when the weight ratio of the fullerenes to GO was 1:3 , a PTA–GO–fullerene nanofilm was further fabricated by a one‐step electrodeposition. Compared to either PTA or PTA–GO‐modified electrodes, the PTA–GO–fullerene composites showed improved catalytic activity for the oxidation of a variety of small biomolecules, including dopamine (DA), with enlarged peak currents and an apparent negative shift of peak potentials  were found to be sensitive to the direct oxidation of CJ and provided a short analysis time, convenience, and good accuracy.60–GO/GE was because the partially reduced C60 in the electropolymeric process exhibited a favorable conductivity as an effective electron‐transfer medium compared to that of the pure GO film.In 2013, Hu and co‐workers prepared a noncovalent hybrid of C:3 Figure5A.84 T60 composite by electrochemical reduction of a GO–C60 composite, which was then used as an immobilization matrix for GOx.i–t response of an rGO–C60/GOx‐modified electrode to different concentrations of glucose and in constantly stirred oxygen‐saturated phosphate buffer saline (PBS) with a working potential of −0.42 V showed that the amperometric reduction current decreased with the increase in glucose concentration up to 14.6 × 10−3m.i–t response current for the biosensor exhibited a linear pattern against the concentration of glucose in a range of 0.1–12.5 × 10−3m. Hence, the rGO–C60/GOx‐modified electrode showed good analytical ability when used as a sensor for glucose over a wide response range with a low limit of detection, fast response time (3 s), and high sensitivity.60‐wrapped GO by using a simple sonication method, and the material was used to modify a glassy carbon electrode.60 hybrid showed a good sensitivity with a lower oxidation overpotential toward DA than did those of the pristine GO and C60. The as‐prepared sensor for DA detection exhibited a linear response in a range of 0.02–73.5 × 10−6m and a detection limit of 0.008 × 10−6m (based on 3σ) with a sensitivity of 4.23 µA µm−1cm−2. The GO–C60 hybrid‐based sensor also showed a wide linear response and high selectivity along with good practicality toward the detection of DA in rat brain and commercial DA injection samples.Electrochemical sensing applications of noncovalent hybrids of fullerene–graphene have also been reported by other groups. Given that the direct electron transfer properties of enzymes are helpful for studying key biological reactions and for the construction of biosensors and biofuel cells,60/graphene hybrid by using a simple solution reaction of GO and C60 in a lithium hydroxide (LiOH) saturated solution.60 particles on the GO surface served as spacers in the C60/graphene hybrid to support the graphene sheets. The noncovalent C60/graphene hybrid was employed as electrodes in a supercapacitor affording a capacitance of 135.36 F g−1 at a current density of 1 A g−1, which was higher than that based on pure graphene electrodes (101.88 F g−1). Furthermore, a remarkable retention rate of 92.35% after 1000 charge/discharge cycles was obtained, indicating the potential of the C60/graphene hybrid as a supercapacitor electrode.In addition to the applications of fullerene–graphene hybrids in solar cells and electrochemical sensors, fullerene–graphene hybrids have also been applied in supercapacitors. In 2014, Qin and co‐workers constructed a C60 molecules by self‐assembly and the Langmuir–Schaefer deposition technique.60–GO hybrid deposited on hydrophobic substrates was characterized by X‐ray diffraction, Raman and X‐ray photoelectron spectroscopies, atomic force and scanning electron microscopies, and conductivity measurements, confirming that C60 indeed existed in the hybrid multilayer system and that intercalation of fullerene into the interlayer space of the organo‐GO nanosheets did not affect the structure of GO itself. More importantly, a considerable improvement of an order‐of‐magnitude increase in the electrical conductivity for the C60–GO hybrid was achieved because of the presence of C60 intercalated between the graphene layers.Apart from physical blending, a new approach for constructing fullerene–graphene noncovalent hybrids was developed by Gournis and co‐workers in 2015. The approach was based on a bottom‐up layer‐by‐layer process, which proceeded via the formation of a hybridized organo‐GO Langmuir film, followed by the intercalation of C2.1.360–graphene hybrid in which alkylated C60 molecules self‐organized into nanoscale flake‐like films on a CVD‐grown graphene layer.60–graphene hybrid devices exhibited a clear and highly reproducible change in conductance upon visible‐light illumination due to the hole generation in the alkylated C60 molecules and the transfer of the holes to the graphene, as deduced from the upshift in the Dirac point and the broadening of the resistance. Moreover, a hole‐doping effect was observed in the C60–graphene hybrid devices, with carrier mobility decreasing from 286 to 208 cm2 V−1 s−1 upon illumination with visible light.Different from the pristine fullerenes, fullerene derivatives bear versatile functional groups grafted via chemical functionalization, facilitating their assembly on different substrates, including graphene films. In 2012, Kim, Lee and co‐workers constructed a C60 derivative based on ‐phenyl‐C61‐butyric acid methyl ester (PCBM) to rGO via the noncovalent approach in which pyrene was used as an anchoring bridge to link the rGO and PCBM components  owing to the intramolecular π–π stacking interactions between the graphene sheet and pyrene–PCBM. Importantly, according to the proposed geometric configuration of rGO–pyrene–PCBM, the C60 moiety was far from the graphene sheet and was bridged to the graphene sheet via the pyrene anchor. The rGO–pyrene–PCBM hybrid was then applied as an electron‐extraction material in P3HT:PCBM bulk heterojunction polymer solar cell (BHJ‐PSC) devices . The configurations of the fullerene–graphene hybrids were studied by molecular mechanics/molecular dynamics (MD) calculations, predicting that fullerene derivatives favorably interacted with graphene through both the pyrene base and the C60 moiety  matrix for improved thermal and mechanical properties. By using GO as the starting material, they prepared the C60@graphene hybrid (C60: ≈47.9 wt% and graphene: ≈35.1 wt%) via a three‐step reaction, with highly active amino groups introduced to react with C60 and contribute to the subsequent in situ reactive compatibilization reaction to improve the dispersion of the hybrid. The incorporation of 2.0 wt% C60@graphene (relative to PP) remarkably increased the initial degradation temperature by ≈59 °C and simultaneously enhanced the tensile strength and Young's modulus by 67% and 76%. The improvement in the thermal stability of PP was speculated to be due to the free‐radical‐trapping effect of C60 and the thermal barrier effect of the graphene layers, while the mechanical enhancement was mainly attributed to the reinforcing effect of the graphene nanosheets and the effective load transfer from the polymer matrix to the graphene sheets.Guo and co‐workers developed a new strategy to synthesize a C2.1.460, endohedral fullerenes (EMFs) with metal ions or metallic clusters entrapped in the carbon cage have been attracting considerable attention during the last two decades due to the charge transfer from the internal species to the outer carbon cage.3N@hI‐C80 is so far the most abundant and has an excellent stability superseding other conventional EMFs.3N)6+@(C2n)6−, resulting from the six‐electron transfer from the endohedral species to the carbon cage, renders an enhanced chemical reactivity and adsorption energy on surfaces compared with that of hollow fullerenes.3N@C80 absorbed on pristine graphene nanoflakes (GNFs). The Sc3N@C80–graphene noncovalent hybrid model was constructed, for which the simulated graphene nanoflake, composed of 96 C and 24 H atoms (C96H24) with symmetric hexagonal units, served as a support for the deposition of fullerenes in the center.60, which adsorbed on GNFs with an energy of 0.76 eV, Sc3N@C80 adsorption on the GNF resulted in a higher binding energy of 1.00 eV for nearly degenerate isomers that have a pentagon and a hexagon facing the single‐layer graphene (SLG). Such a large binding energy was explained in terms of a higher dispersion interaction between Sc3N@C80 and the GNF, and the fact that charge separation in Sc3N@C80 favored binding with the GNF.Different from hollow fullerenes, such as C2.2TableAlthough the noncovalent approach has been extensively used to construct fullerene–graphene hybrids, being facile and effective in achieving improved properties relative to the single components of fullerene and graphene, the determination of their chemical structures is difficult, making the manipulation of their structures and properties unrealistic. Additionally, the noncovalent nature renders relatively weak intermolecular interactions between fullerenes and graphenes. Thus, the covalent hybridization of fullerene and graphene is highly desired to construct hybrids in a controllable manner.2.2.160–graphene, termed as periodic graphene nanobuds (PGNBs) in which C60 molecules covalently attach to a graphene monolayer and form a periodic lattice structure  hybrid, termed as NanoBuds, prepared in continuous aerosol  reactors by using particles grown in situ via ferrocene vapor decomposition or by using premade iron‐catalyst particles produced by a hot‐wire generator. The authors proposed that fullerenes were formed on the iron‐catalyst particles together with SWNTs during CO disproportionation.re Figure8.17 Si54 structure was proposed by removing a six‐membered ring from C60. Four different kinds of connection positions for the C54 structure on graphene were investigated. In two cases, where six carbon atoms of graphene formed covalent bonds with the fullerene, the graphene–fullerene nanobuds were ferromagnetic at their ground states with magnetic moments of nearly 6 μB; whereas, for the other two cases, nonmagnetic states were found since the connections of two atoms in different sublattices of graphene could not generate unpaired spins.Likewise, in 2011, Li et al. designed four kinds of all‐carbon graphene–fullerene nanobuds and studied their magnetic properties by spin‐polarized DFT.60 hybrid.60 onto the carbons at the edges of the defect did not have priority over attaching to a pristine graphene sheet because the distortion of the ideal π system in graphene perturbed the π–π stacking interactions with the fullerene and forced the fullerene to avoid the defective surface of graphene.Deymier et al. adopted the self‐consistent charge density functional tight‐binding (DFTB) and DFT methods to evaluate energy barriers for the formation of a single‐layer graphene−C180, C320, C540, and C720) as sandwich cores. According to their calculation results, dangling bonds on the reciprocal locations of both graphene and fullerenes promoted the formation of covalent bonds between the fullerene and graphene layers. Moreover, the thermodynamic stability of the fullerene–graphene hybrid was evaluated with potential energy profiles, and the total configuration energies for all systems were minimized and remained stable over a long period of time, suggesting good thermodynamic stability.In 2015, Kirca designed a novel fullerene–graphene hybrid composed of fullerene covalently sandwiched between parallel graphene sheets by using MD simulations.60 onto graphene nanosheets  was attributed to the improved electron transport because the introduction of the C60–graphene covalent hybrid could provide a direct conduction path for electron transport via percolation through the highly conducting 2D graphene sheets.The experimental synthesis of a fullerene–graphene covalent hybrid was not reported until 2011, when Dai et al. developed a simple lithiation method to covalently attach monosubstituted Cts Figure9A. In 60–graphene hybrid by ball milling in which C60 was directly bonded to the edges of graphene nanoplatelets via two C—C single bonds, as confirmed by high‐resolution transmission electron microscopy (HR‐TEM) , showing improved ORR electrocatalytic activity over the pristine graphite in terms of a higher limiting current (−3.4 mA cm−2) than those of the pristine graphite (−1.8 mA cm−2) and C60 (−2.2 mA cm−2). This was interpreted as the charge transfer from graphene to C60 enabling the graphene basal plane to be positively charged and thus to be more electrocatalytically active toward the ORR than the pristine graphite  Figure10A.104e Figure , I–IV.1060. After heating the pG/C60 mixture composed of a saturated solution of C60 in 1‐chloronaphthalene mixed with pG nanosheets at 300 °C for 2 h, C60 was impregnated into pG nanosheets with the evaporation of the solvent, affording the formation of the pG–C60 covalent hybrid , thermal gravimetric analysis (TGA), and HR‐TEM  onto the GO‐CCH scaffold ‐ethynylaniline via an aryl diazonium salt reaction, followed by cleavage of the trimethylsilyl groups using tetra‐ld Figure14.34 RFigure9 s−1 for C60•−, suggesting the efficient charge separation and formation of long‐lived charge separated species.Later, by using hydrolyzed PCBM as a fullerene precursor via a very mild process without the use of metal catalysts, Kumar et al. synthesized a novel fullerene–GO covalent hybrid (PCBGO) by grafting PCBM onto GO via flexible linkages Figure15.112 60 reacted with 2,5‐bis(trimethylsilyl)‐1,4‐phenylene bis(triflate) via a [2 + 2] cycloaddition yielding a C60‐aryne precursor  phthalocyanine (ZnPc), acting as electron donor, and fulleropyrrolidine, acting as electron acceptor, were covalently linked onto single‐layer graphene oxide (SLGO) simultaneously , as evidenced by the appearance of the cation (ZnPc•+) and anion (C60•−) radicals in the visible to near‐infrared (NIR) regions. In contrast, for the control samples, GO and binary hybrids ZnPc–GO and GO–C60, no cation and anion radicals were observed. Thus, the formation of the ternary hybrid is crucial for such a photoinduced electron transfer phenomenon.In addition to above‐mentioned binary fullerene–graphene hybrids, the inclusion of another functional material to form ternary hybrids with fullerene and graphene as building blocks has also been reported. In 2013, Souza and co‐workers reported a novel ternary covalent fullerene–graphene hybrid ZnPc–SLGO–Cly Figure17.19 T60 hybrid lubricating film by a multistep self‐assembly method on silicon surfaces.60, the GO films assembled on the silicon wafers were amine‐functionalized by (N‐[3‐(trimethoxysilyl)‐propyl]‐ethylenediamine) molecules, which contained primary and secondary amino groups capable of undergoing N—H addition reactions across the C=C bonds in C60. The successful grafting of C60 chemically to the amine‐functional GO by nucleophilic addition reactions was verified by FTIR, X‐ray powder diffraction (XRD), TGA, Raman spectroscopy and XPS. Colloidal probe measurements show that APTES‐a‐graphene–C60 exhibited a low nanofriction coefficient due to the existence of a more ordered C60 outer layer, which facilitated microsphere sliding because of the small contact area between the microspheres and films, in addition to the presence of the few‐layer graphene with excellent nanolubrication properties. Furthermore, the conclusion pointed out that the strong bonds, with stable and not easily damaged characteristics, between the carbon atoms of C60 facilitated the long‐lasting and effective lubrication.In 2014, Wang and co‐workers fabricated a graphene–C60 or graphene, rendering them stable in solution with the free movement of C60 coated on the graphene restricted.60 covalent hybrid incorporating folic acid (FA) and polyethylene glycol (PEG) onto GO via an imide linkage  effect of 44.4% compared with that for the Au nanoparticles of 30%. Furthermore, when the FA–GO–PEG/C60 is taken by tumor cells, it caused heating and significant intracellular reactive oxygen species (ROS) production under light irradiation, leading to a marked decrease in cell survival and to the elevation of oxidative stress  efficacy against cancer cells. FA–GO–PEG/C60 showed a combined PDT and PTT treatment with remarkably improved and synergistic effects compared to that of PTT or PDT alone, having potential for a synergistic phototherapy of cancer.Graphenes have been reported to act as an excellent drug carrier and photothermal agent, which can efficiently convert NIR light into heat and thus induce hyperthermia to cells and surrounding tissues.ge Figure18A. Th33N4 is the most stable allotrope of carbon nitrides under ambient conditions with the 2D, π‐conjugated plane of polymeric tri‐s‐triazine connected via tertiary amines  and the existence of contact resistance between the nanosheets.3N4 needs to be improved so as to extend its photocatalytic applications.g‐Ces Figure19.115 60, which is beneficial for a rapid photoinduced charge transfer with donor molecules and a relatively slow charge recombination, hybridizing g‐C3N4 with C60 has been implemented, and the effectiveness of such a strategy in improving the photocatalytic activity of g‐C3N4 has been examined. In 2014, Chai et al. prepared a g‐C3N4/C60 composite by simply blending g‐C3N4 powder into a C60 solution in toluene.3N4/C60 composites were characterized by XRD, scanning electron microscope (SEM), TEM, and FTIR. The photocatalytic activity of the g‐C3N4/C60 composite in the degradation of rhodamine B was further evaluated, indicating that the g‐C3N4/C60 composite with the optimal amount of C60 of 1 wt% had the highest photocatalytic performance. The improved photocatalytic performance of the g‐C3N4/C60 composite was attributed to the synergetic effect of g‐C3N4 and C60, which facilitated the separation of photogenerated electrons and holes.Considering the excellent electron‐accepting ability of C60/g‐C3N4 composite was prepared by Zhu et al. via the thermal treatment of dicyandiamide, a precursor for synthesis of g‐C3N4, at 550 °C in atmosphere in the presence of C60.60 into a matrix of g‐C3N4, the valance band of g‐C3N4 shifted to a lower energy position, affording a strong photooxidation capability under visible light. Under the optimal loading amount of C60 of 0.03%, the photocatalytic activity of the C60/g‐C3N4 composite for the degradation of phenol and methylene blue under visible light was found to be ≈2.9 and 3.2 times higher than that of pristine g‐C3N4. The enhanced photocatalytic activity of the C60/g‐C3N4 composite was attributed to the promoted generation of holes, and •OH originated from the strong interaction of the conjugated π‐bond between C60 and g‐C3N4, leading to a rapid photogenerated electron transfer rate and high charge separation efficiency of C60 in the C60/g‐C3N4 composite  remained at the interface between them. Interestingly, for different stacking patterns, g‐C3N4 and C60 were always linked by vdW forces and formed type‐II heterojunctions in most cases. The valence band maximum and conduction band minimum of these heterostructures were dominated by the unsaturated nitrogen (N2) atoms and C60 molecules, respectively, which strongly interacted with each other and resulted in a strong charge transfer between g‐C3N4 and C60 and a clear bending of the g‐C3N4 sheets. The unsaturated N2 atoms included at the interfaces have a significant influence on promoting the photocatalytic performance, while the existence of saturated nitrogen (N1 and N3) atoms lying at the interfaces would weaken the interfacial interactions between C60 molecules and the g‐C3N4 monolayers.A fundamental understanding of the corresponding mechanism behind the greatly enhanced photocatalytic activity of g‐C3N4 before and after C60 adsorption by using a larger model with 25 different adsorption configurations.60 preferred to stay upon the “junction nitrogen” with the carbon atom of fullerene being nearest to the monolayer. The adsorption of fullerene resulted in a change in the geometrical morphology of g‐C3N4 from flat to wrinkled via an irreversible process. The wrinkled structure was more stable by ≈5.6 eV compared with that of the flat one. The shortest distance between g‐C3N4 and C60 for all configurations was ≈3 Å, indicating the existence of vdW interactions. Furthermore, the analysis of the electronic properties indicated that the adsorption of C60 onto g‐C3N4 did not result in efficient carrier separation at interface. In fact, C60 in these systems mainly induced the geometrical distortion of g‐C3N4 monolayers, thus leading to the improved photocatalytic performance.Dai et al. reported a systematic theoretical study on the changes in the structure, stability, electronic properties, and light absorption of g‐C60/g‐C3N4 and C70/g‐C3N4 hybrids via a hydrothermal process.3N4. The photocatalytic disinfection activity of these hybrids on the inactivation of Escherichia coli (E. coli) O157:H7 showed that the bacterial cell could be damaged by the active oxygen radicals (•O2− and •OH) produced from the fullerene/g‐C3N4 hybrids under visible‐light irradiation.70/g‐C3N4 composite exhibited a higher photocatalytic inactivation activity for completely inactivating all E. coli O157:H7 cells within 4 h under visible‐light irradiation. The high catalytic performance was attributed to the effective transfer of the photoinduced electrons from the fullerene/g‐C3N4 hybrids under visible‐light irradiation.In 2017, Cai et al. synthesized C3N4 hybrids are based on noncovalent hybridization, for which C60 was blended physically into the pristine g‐C3N4 or its precursor in a low blending ratio (<2.0 wt%), and a large number of unreacted C60 are retained in the composites. On the other hand, the photocatalytic activity of the C60/g‐C3N4 composite was examined only via the degradation of dyes. These limitations were not broken until the recent success of our group in synthesizing the first fullerene–g‐C3N4 covalent hybrid via a facile solid‐state mechanochemical route by ball‐milling g‐C3N4 and C60 in the presence of LiOH as a catalyst . Under the optimized conditions, the g‐C3N4/C60‐12 wt% hybrid exhibited the highest H2 production rate of 266 µmol h−1 g−1, which was ≈4.0 times higher than that for the pristine g‐C3N4 photocatalyst )  to g‐C3N4 due to the lowering of the conduction band of g‐C3N4 and the inhibited recombination of photoinduced electron–hole pairs owing to the fast photoinduced electron transfer process from g‐C3N4 to C60  is the most representative TMD, consisting of hexagonal rings with Mo and S atoms alternately located at the hexagon corners. Monolayer MoS2 has the direct band gap of ≈1.8 eV and a high in‐plane carrier mobility, enabling broad applications in electro and photocatalysts, photovoltaics and photoelectric devices.As another type of emerging inorganic 2D semiconducting nanomaterials, TMDs have been attracting widespread attention due to their intriguing electronic, optical, and mechanical properties. Molybdenum disulfide  method  and RESET (−5.5 V) voltages and a high ON/OFF resistance ratio (≈4 × 103)  with exposed catalytically active edge sites, yielding a 3D architecture with a high surface‐to‐volume ratio beneficial to electrocatalytic applications.2 nanosheets were interfaced with nC60 clusters by a facile solution‐deposition method via immersing the MoS2/CFP samples into a C60 solution in chlorobenzene, and the nC60/MoS2 hybrid showed greatly improved hydrogen evolution reaction activity with an overpotential value of 172 mV at 10 mA cm−2, a Tafel slope of 60 mV dec−1, and a turnover frequency value of 2.33 H2/s per active site at −0.2 V versus RHE at a C60 deposition concentration of 0.5 mg mL−1. The improved activity of the nC60/MoS2 hybrid catalyst was explained by the interfacial doping of MoS2 induced by charge transfer from the nC60 clusters to MoS2, resulting in the relative positioning of their valence and conduction band edges.In 2016, Fang, Banerjee and co‐workers reported a stepwise sulfidation approach for the direct integration of vertically aligned high edge‐density MoS2–C60 hybrid onto a semiconducting SnO2 electrode via a two‐step methodology.2 and C60 yielded MoS2–C60 hybrid aggregates via self‐assembly, followed by electrophoretic deposition onto the SnO2 electrode in the second step. The time‐resolved microwave conductivity measurements for the MoS2–C60 hybrid revealed substantially increased transient conductivities under photoexcitation in comparison with the single components of MoS2 and C60, indicating that the nanosized heterojunction structure of MoS2 and C60 promoted charge separation. Furthermore, the C60 molecules on the surface of MoS2 effectively hindered the undesirable charge combination between an electron in the electrode and a hole in the MoS2 nanosheets. Moreover, the authors fabricated a WS2–C60 hybrid for comparison and found that, despite a more suppressed charge recombination in WS2–C60 than in MoS2–C60, the incident photon‐to‐current efficiency value of the device with WS2–C60 was smaller than that with MoS2–C60 owing to its inhomogeneous film structure.In 2018, Imahori et al. fabricated a MoS60 on WSe2, which served as a weakly interacting organic/2D vdW heterostructure system.60 molecules formed a monolayer that extended uniformly over WSe2 with large grain sizes (≈5 µm). The interplay and balance between the adsorbate–adsorbate and adsorbate–substrate interactions resulted in the formation of rotational arrays of self‐assembled 2 × 2 molecules. According to vdW‐corrected ab initio DFT simulations, the C60 molecules tended to be electronically coupled with a long‐range orientational ordering, as reflected in the high crystallinity of C60 on WSe2. Meanwhile, the electronic structure of the hybrid system showed a spatial delocalization of the molecular orbitals throughout the 2 × 2 superlattice.To thoroughly understand the basic physical and chemical phenomena that rule highly crystalline architectures comprised of crystals of organic molecules and 2D materials, Wang and co‐workers fulfilled the growth of high‐quality self‐assembled monolayers of C2–fullerene hybrid can promote the photocatalytic H2 production activity of MoS2 remains intriguing. In 2016, Huang et al. carried out first‐principles calculations based on density functional theory to investigate the effects of vdW interactions on changes in the electronic structure, charge transfer and photoactivity of three typical monolayer MoS2/fullerene  hybrids. For the MoS2/fullerene vdW heterostructures, strong noncovalent interactions between the MoS2 and fullerene were concluded. The band gap of the MoS2/fullerene vdW heterostructure was smaller than that of monolayer MoS2, and thus, the visible‐light absorption and photoinduced electron transfer can be enhanced. Furthermore, the amount of charge transfer at interface induced by vdW interactions was found to be dependent on the size of the fullerene.Whether the formation of a MoS2–C60 hybrid featuring a vdW heterostructure, as well as its application in photocatalytic H2 production. The MoS2–C60 hybrid was prepared via a facile and ecofriendly solid‐state mechanochemical route by ball‐milling a mixture of bulk MoS2 and C60. In the process of ball‐milling, the bulk MoS2 was exfoliated to few‐layer MoS2 nanosheets, and the basal plane was reduced into significantly smaller nanosheets; while the C60 molecules bonded to the edge of the cut MoS2 nanosheets in the form of vdW heterostructures  was revealed  in the raw mixture, the MoS2–C60 hybrid containing 2.8 wt% C60 exhibited a visible light photocatalytic H2 production rate of 6.89 mmol h−1 g−1 in the presence of the photosensitizer EY. This value was 9.5 times higher than that of the obtained MoS2 nanosheets. This result was because the C60 bonding resulted in the fast photoinduced electron transfer from MoS2 to C60, and this action was beneficial for the separation of electron–hole pairs by inhibiting their recombination.Experimentally, our group recently reported the first MoSes Figure24.67 U60/MoS2 and C60/WS2 hybrids were also studied theoretically by Cheng and co‐workers.60/MoS2, C60/WS2, C59B/MoS2, C59B/WS2, C59N/MoS2, and C59N/WS2, C60 preferred to sit at the S‐top site with a hexagon parallel to the monolayer. All of the interfacial interactions were found to be weak, such that the main electronic features of the components were preserved. Although both the C60/MoS2 and C60/WS2 systems behaved as type‐II heterojunctions, the built‐in potential in the C60/MoS2 hybrid was too small to achieve an efficient electron–hole separation, whereas the latter system had a large built‐in potential and was thus predicted to yield an excellent photovoltaic performance.The photovoltaic applications of C55.12‐hybridized wide band‐gap semiconductor with a structure analogous to graphene and belonging to a hexagonal system with sublattices occupied by equal numbers of boron and nitrogen atoms alternatingly arranged in a honeycomb configuration. Similar to graphene, the different h‐BN planes are dominated by weak van der Waals interactions, while the in‐plane nitrogen and boron atoms are combined by sp2 orbitals to form strong σ‐bonds, which are highly polarized because of the high asymmetry of the sublattices, resulting in the large band gap (5–6 eV) of h‐BN.2D h‐BN is a sp60 has a narrower band gap, hybridizing h‐BN with C60 has been regarded as an effective strategy for modulating the electronic properties of h‐BN. In 2005, Greber and co‐workers grew a C60 monolayer film on one monolayer of h‐BN on Ni(111), providing an atomically flat metal‐insulator interface. They observed that, between 150 and 250 K, the work function of C60 decreased, while the binding energy of the HOMO increased by ≈100 meV along with a strong charge in the LUMO of C60 by 0.4 ± 0.1 electrons. Such a charge redistribution was induced by the onset of a molecular rocking motion, and the magnitude of the charge transfer was an indication of strong electron–phonon interactions.Given that C5.22 V−1 s−1, makes BP an emerging member of 2D nanomaterials and renders its potential for application in transistors, biomedicine, and energy conversion and storage.3‐orbital hybridization, as well as the armchair and zigzag‐configurations along the x and y‐axial directions, respectively.BP with a century‐long history did not draw significant attention until the recent recognition of its anisotropic 2D layered structure.60 composite via a mechanochemical ball‐milling route in a comparative study with a BP–graphite composite synthesized under the same conditions. Prior to blending with BP, C60 or graphite was ball‐milled. Then, the mixture of BP and C60 (graphite) was sealed in an argon‐filled glove box, and high‐energy mechanical milling was performed under a 1.2 MPa Ar atmosphere with a rotation rate of 700 rpm for 12 h. According to their detailed characterizations of the BP–graphite composite, phosphorus–carbon bonds formed after ball‐milling and remained stable during lithium insertion/extraction. As a result, an excellent electrical connection between BP and the carbon material was established, contributing to a high initial discharge capacity of 2786 mAh g−1 at 0.2 C and an excellent cycle life of 100 cycles with 80% capacity retention. For comparison, within the BP–C60 composite, the content of the as‐formed phosphorus–carbon bonds was significantly lower than that for the BP–graphite composite, resulting in an inferior capability. Hence, the authors concluded that the carbon structures played essential roles in the formation of stable phosphorus–carbon bonds.Despite extensive reports on hybrids of BP with other 2D nanomaterials, especially graphenes, studies on hybrids of BP and fullerene have rarely been reported. In 2014, Cui and co‐workers made an attempt to synthesize a BP–C660 as the first fullerene in 1985 marks a milestone in nanoscience due to its unique spherical molecular structure merely composed of sp2‐hybridized carbon atoms. As the only soluble species among all known nanocarbons derived from the 0D structure, fullerenes have been popularly used as important building blocks useful for constructing versatile noncovalent/covalent nanohybrids with a variety of functional materials, including 2D nanomaterials, as elaborately reviewed in this paper.The discovery of C3N4, TMDs, h‐BN, and BP, which all exhibit similar electronic properties. Meanwhile, their intrinsic differences in lattice composition and interlayer distance bring about a clear diversity in specific functionalities and applications, greatly accelerating the field of 2D nanomaterials. Despite the tremendous progress in investigating the 2D nanomaterials themselves during the past decade, enhancing the existing properties for better performance and even exploring unknown functionalities toward extended applications are definitely necessary. To this end, hybridizing 2D nanomaterials with 0D fullerenes has been well established as a successful and powerful protocol based on the detailed analyses of versatile fullerene‐2D nanomaterial hybrid systems in this Review.In 2004, the paradigm‐shifting disclosure of graphene as the first and most representative 2D layered nanomaterial opened up a new era of nanoscience because of the material's exceptionally large specific surface area and high carrier mobility, which are achievable only in the 2D layered structure. The exceptional structure and property of graphene soon stimulated the recognition of other graphene‐analogous 2D nanomaterials, such as g‐CThere are yet considerable challenges in the emerging field of fullerene‐2D nanomaterial hybrids. First, most fullerene‐2D nanomaterial hybrids that have been reported so far were synthesized in the noncovalent style via the simple blending of two components, whereas only limited reports involved the successful construction of fullerene‐2D nanomaterial covalent hybrids, which are more promising in terms of strong intermolecular interactions between fullerene and 2D nanomaterial moieties. Clearly, the natural divergence in dimensions between 0D fullerene and 2D nanomaterials makes their covalent connection difficult. Therefore, prior to hybridization, chemically functionalizing the components of fullerene and/or the 2D nanomaterial appears critical. While the chemical derivatization of fullerenes has been well developed, chemical derivatizations of 2D nanomaterials are still in their infancy, and the development of novel derivatization approaches, especially for such less studied 2D nanomaterials as h‐BN and BP, is highly desired.Another pending problem is how to determine precisely the chemical structures of fullerene‐2D nanomaterial hybrids at the molecular level. In particular, for fullerene‐2D nanomaterial covalent hybrids, the additional pattern of covalent bonding between fullerene and the 2D nanomaterial, i.e., single‐bond addition or cycloaddition onto the fullerene cage, is essential for the disruption of the π‐conjugated system of the fullerene cage. Furthermore, since the properties of 2D nanomaterials are typically anisotropic, the addition site (surface vs edge) where fullerene bonds onto a 2D nanomaterial strongly affects the difficulty of the hybridization and the modulation extent of the 2D nanomaterial within the fullerene‐2D nanomaterial hybrid. For the latter point, the direct visualization of the fullerene addition sites within the hybrid is undoubtedly needed, and thus, further improvement of the resolution of HR‐TEM/scanning tunneling microscope (STM) for clearer morphological characterizations of the geometric structure of the hybrids is of high importance.As mentioned above, hybridizing 2D nanomaterials with fullerenes may not only fulfill the modulation of the physical/chemical properties of 2D nanomaterials but also induce new properties in the 2D nanomaterials, thus significantly extending the functionalities and applications of 2D nanomaterials. An intriguing question is whether the hybridization strategy can be used to further create unknown functional materials. For instance, on the basis of binary fullerene‐2D nanomaterial hybrids, by involving one or two other functional materials, which are either another 2D nanomaterial or even a 1D nanomaterial (such as a carbon nanotube or boron‐nitride nanotube), ternary or even quaternary hybrids are expected to form. However, due to a lack of experimental reports, whether the properties of such hybrids can surpass their binary counterparts is unknown. With the foreseeable development of chemical derivatizations of 2D nanomaterials, the syntheses of such unknown complex hybrids will likely come true in the near future, making the emerging fullerene‐2D nanomaterial hybrids even more exciting and promising for vast applications.The authors declare no conflict of interest.