A nitrogen-superdoped graphene with diamond-like interlayer bonds is obtained via the radical chemistry of fluorographene, affording a symmetric supercapacitor with an energy density of 200 W h L−1 at a power of 2.6 kW L−1 and 143 W h L−1 at 52 kW L−1.
The nitrogen doping of graphene via mild and low energy processes to afford homogeneous product composition and topology with high nitrogen content (>10 at. %) remains a challenge of contemporary 2D materials chemistry. Here, we report a previously unexplored route to synthesize N-doped graphene (NG) with exceptionally high N content (up to 18.2 at. %) by reaction of fluorographene (FG) with NaNH 2 in N,N-dimethylformamide (at 130°C) or acetonitrile (at 70°C). The N content can be tuned by changing the reaction time, temperature, and/or solvent, ranging from 6.6 to 18.2 at. %, mainly in the form of pyridinic and pyrrolic configurations. With thermal annealing, the N content remained constant up to 400°C but then decreased by ∼50% upon being further annealed to 1000°C. Density functional theory (DFT) calculations showed that nitrogen incorporation into the carbon lattice mostly occurred at vacancies present in the starting material. We also conducted a thorough rationalization of sidereaction pathways leading to byproducts, which were confirmed by GC-MS analysis. This is the highest yet recorded N content for a wet chemical doping procedure and at such a low temperature of 70°C. The reported synthetic approach thus offers a sustainable and cost-effective way to prepare NG with a broad tunability window of N content for potential applications related to energy storage and catalysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.