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• Al/B/CF microspheres have been prepared through self-assembly in emulsion. • Spherical Al/B/CF fuel exhibits high energy density and superior reactivity. • The combustion reaction of single Al/B/CF microsphere are studied for the first time. • The CF content and Al/B mass ratio have significant effects on combustion behaviors. Aluminum (Al) is one of the most widely used metal fuels in the fields of automotive airbags, solid propellants, explosives and pyrotechnics. Unfortunately, it is hard to meet further demand of practical applications owing to the comparatively low calorific value. Herein, graphite fluoride (CF) and boron (B) are employed to construct Al/B/CF microspheres through self-assembly in emulsion to obtain high energy density and significantly improved combustion performance resulted from synergistic reaction between Al and B reacted with fluorine. The Al/B/CF microspheres with pore structure have uniformly distribution of components and the average size range from 60 to 600 μm. Based on the experimental results, CF content and Al/B mass ratio have significant important effects on the combustion behavior and pressure output. The highest burning rate (301.74 m/s) and pressurization rate (77.78 MPa/s) are obtained for the Al/B/CF microspheres with CF content of 50 wt% and Al/B mass ratio of 3 to 1, respectively. Furthermore, the combustion reaction process of single Al/B/CF microsphere are studied for the first time to understand the synergistic reaction between high reactivity of Al and high energy of B reacted with fluorine. This work demonstrates that introducing CF and B to construct Al/B/CF microspheres is an efficient strategy to achieve high energy density and reactivity for the practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nitrogen doped sub-fluorinated graphite with larger layer spacing material. • Simple and effective modified method without high temperature or pressure. • Fluorinated graphite can obtain a power density of 40.23 kW kg−1. • The dependence of cathode material structure, LiF and cathode swelling is provided. Lithium/carbon fluorides batteries own a high theoretical energy density of 2180 Wh kg−1 and exceptional shelf life, but poor electrode kinetics, low electronic conductivity of cathode, and cathode swelling during discharge. In this work, fluorinated graphite is modified by a controllable solvent treatment using N-methyl-2-pyrrolidone at medium temperature (50 ∼ 90 °C). The modified fluorinated graphite is doped with nitrogen atoms and owns increased interlayer spacing and electrochemical active semi-ionic C F bonds, providing a higher conductivity and facilitating the diffusion of Li+ or solvent Li+. The maximum power density of the modified fluorinated graphite is 40.23 kW kg−1 at 25C. To elucidate the cathode swelling of the fluorinated graphite, in-situ confocal optical microscope and in-situ X-ray diffraction are conducted for the first time. It is found that the formation and accumulation of crystalline LiF during discharge, as well as the interlayer spacing of fluorinated graphite, are related to the cathode swelling in liquid electrolyte. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • High-quality fluorographene nanosheets are fabricated by microwave-assisted liquid phase exfoliation. • The as-prepared fluorographene nanosheets are comprised of no more than four monolayers. • No other side reaction and impurity elements are introduced during the exfoliation process. • Fluorographene nanosheets exhibit excellent thermal stability and remarkable lubrication behavior in oil. Abstract Fluorographene (FG), as an important class of graphene derivatives, has shown great promise in high-performance devices and lubricating materials. However, the large-scale fabrication of high-quality and impurity-free FG nanosheets still remains a main challenge. Herein, a simple liquid-phase exfoliation approach to prepare thin FG nanosheets through the preliminary intercalation of raw graphite fluoride (GrF) particles by N,N-dimethyl formamide molecules, followed by a short-time microwave treatment is reported. Atom force microscopy measurements demonstrate that as-prepared FG nanosheets are comprised of no more than four monolayers after the microwave irradiation. After exfoliation, a small amount of aromatic C C groups in the FG nanosheets are restored, which slightly lowers the F content in FG as compared with the raw GrF. Besides, no other side reaction and impurity elements are introduced during the exfoliation process as revealed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The resultant high-quality FG nanosheets exhibit excellent thermal stability and remarkable lubrication behavior in oil, and thus can be used as a new class of graphene derivatives with the capability of large-scale fabrication for the future device and various other applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • New concept of graphene oxide preparation via graphite fluoride hydrolysis. • Well-defined and unambiguous chemical structure of graphene oxide. • Less-defective lattice and higher electrical properties and energy-storage performances. • Efficient and versatile post-functionalization by active hydroxyl reactions. Graphene oxide was universally acknowledged to be a very important precursor to prepare graphene or the relative derivatives, but it was criticized sharply due to its quite inferior electrical properties and many structural defects arising out of strong oxidation process. Non-oxidation synthetic strategy of graphene oxide was expected a good solution to mitigate the disadvantages. Inspired by this concept, we attained a totally new, well-defined graphene oxide, that is , G(C 4)–OH, in which hydroxyl was the unique oxygen-containing group and the hexagonal honeycomb carbon lattice was less-defective, by successfully challenging the hydrolysis of ultra-inert, commercially-available graphite fluoride feedstock. An advantaged structure made G(C 4)–OH greatly outperforming traditional graphene oxide both in fundamental electrical properties, such as conductivity, carrier mobility, and in electrochemical performances when applied in supercapacitors and lithium-ion batteries. As convenient as traditional graphene oxide, G(C 4)–OH was pretty reactive to versatile electrophiles and allowed tremendous post-functionalization opportunities to customize graphene functions and orientate its applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydration process had been visualized on the fluorinated graphite (FG) layer for the first time. • By building a hydrate formation platform, FG made the hydrate grow upward. • Gas storage rate of FG + SDS system was 20.84 cm3·g−1·min−1, far higher than other materials. • Excellent stability of FG made the performance remain at about 90% after 10 cycles. Achieving rapid and high gas storage is the primary goal of solidified natural gas storage (SNG) using hydrate. In this study, the formation and decomposition process of hydrate were visualized on the fluorinated graphite (FG) layer for the first time by sapphire visible vessel. The results show that, the addition of FG alone can promote the formation of hydrate. After adding fluorinated graphite into SDS system, the gas storage capacity can be further increased to 165.2 cm3 STP/g H 2 O, and the average gas storage rate can be further increased to 20.84 cm3·g−1·min−1, which were 154.7% and 507.7% of SDS system, respectively. Meanwhile, the decomposition speed was faster than SDS system. After optimizing the experimental conditions, it was found that FG-1 with superhydrophobicity could stably exist in the gas–liquid interface and cover it when the dosage reached 1 wt% (13.95 mg·cm−2), and the combination with 300 ppm SDS could greatly promote the growth of hydrate. In addition, the excellent stability of FG made the performance of FG + SDS system remain at about 90% after 10 cycles. The unique growth phenomenon of hydrate in fluorinated graphite system was interesting. By building a hydrate formation platform, FG made water pumped from below to the gas phase and hydrate grow upward continuously. In comparison with other reported carbon nanoparticles, FG system maintained similar gas storage and had excellent gas storage speed, which was 1.35 ∼ 40.67 times faster under similar conditions. Therefore, the reusable FG + SDS system with high gas storage capacity and fast growth rate without induction time and mechanical agitation was a promising alternative to hydrate-based SNG technology. [ABSTRACT FROM AUTHOR]