High-quality fluorographene (FG) was prepared by solvothermal exfoliation of fluorinated graphite (F-graphite) through intercalation of acetonitrile and chloroform with low boiling points. High-yield production of FG was demonstrated by wrinkled few-layered structures with disordered edges and poor regularity along the stacking direction. X-ray photo electron spectroscopy (XPS) spectra indicated that the intercalation of chloroform led to the partial transformation from covalent C-F bonds to semi-ionic C-F bonds. A lithium primary battery (Li-battery) using a FG cathode exhibited a remarkable discharge rate performance because of good Li(+) diffusion and charge mobility through nanosheets. FG nanosheets exfoliated using chloroform showed a high specific capacity of 520 mA h g(-1) and a voltage platform of 2.18 V at a current density of 1 C, accompanied by a maximum power density of 4038 W kg(-1) at 3 C, which is almost four times higher than that of F-graphite. The results indicate that the solvothermal exfoliation using a low-boiling-point solvent is a facile, efficient and high-yield approach to prepare high-purity FG nanosheets for high-performance Li-batteries.

Supplementary InformaƟon (ESI) available: FT-IR spectrum, Raman spectrum, XRD patterns, XPS survey spectra, TEM and SEM images, the first three CV curves, Cycle performance, and rate capabilities of NG and RGO See Nitrogen and fluorine co-doped graphene (NFG) with the N and F content as high as 3.24 and 10.9 at.% was prepared through the hydrothermal reaction of trimethylamine tri(hydrofluoride) [(C2H5)3N·3HF] and aqueous-dispersed graphene oxide (GO) as the anode material for lithium ion batteries (LIBs). The N and F co-doping in graphene increased the disorder and defects of the framework, enlarged the space of the interlayer, wrinkled the nanosheets with many open-edge sites, and thus faciliated Li ion diffusion through the electrode compared with sole-N or F doped graphene. X-ray photoelectron spectroscopy (XPS) analysis of NFG demonstrated the presence of active pyridine and pyrrolic types N, and highly electrical conductive graphitic N and semi-ionic C-F bond in the structure. The N and F doping content and the component types of N and F functional groups could be controlled by the hydrothermal temperature. The NFG prepared at 150°C exhibited the best electrochemical performances tested as the anode of LIBs, including the high coulombic efficiency in the first cycle (56.7%), superior reversible specific discahrge capacity (1075 mAh g −1 at 100 mA g −1 ), excellent rate capabilities (305 mAh g −1 at 5 A g −1 ), and outstanding cycling stability (capacity retention of ~95% at 5 A g −1 after 2000 cycles), which demonstrated NFG was a promising candidate for anode materials of high-rate LIBs. 18,20,25 Recently, it has been realized that doping graphene with two or more kinds of heteroatoms can further improve its electrochemical performances because Li-ion storage is not only related with the contents of heteroatoms but also with

A high functionalization density and inter-planar bundling interaction remarkably improve both the storage capacity and lifetime of solar thermal fuels using an azobenzene/graphene nano-template.

No abstract

The large-scale synthesis of atomically thin, layered MoS2/graphene heterostructures is of great interest in optoelectronic devices because of their unique properties. Herein, we present a scalable synthesis method to prepare centimeter-scale, continuous, and uniform films of bilayer MoS2 using low-pressure chemical vapor deposition. This growth process was utilized to assemble a heterostructure by growing large-scale uniform films of bilayer MoS2 on graphene (G-MoS2/graphene). Atomic force microscopy, Raman spectra, and transmission electron microscopy characterization demonstrated that the large-scale bilayer MoS2 film on graphene exhibited good thickness uniformity and a polycrystalline nature. A centimeter-scale phototransistor prepared using the G-MoS2/graphene heterostructure exhibited a high responsivity of 32 mA/W with good cycling stability; this value is 1 order of magnitude higher than that of transferred MoS2 on graphene (2.5 mA/W). This feature results from efficient charge transfer at the interface enabled by intimate contact between the grown bilayer MoS2 (G-MoS2) and graphene. The ability to integrate multilayer materials into atomically thin heterostructures paves the way for fabricating multifunctional devices by controlling their layer structure.