Facile and Tunable Synthesis of Nitrogen- Doped Graphene with Different Microstructures for High-Performance Supercapacitors

Heteroatom-doped graphene is of great interest for energy storage applications due to its improved local electronic structures compared with undoped graphene. However, a tunable method for the preparation of heteroatom-doped graphene with a special microstructure is still worth developing. Herein, a novel nitrogen-doped graphene with different microstructures is facilely synthesized via an in situ interlamination self-assembling method that employs the in situ formed Fe3(PO4)2 and organoamine as the catalyst and carbon source, respectively. By tuning the alkyl chain length in organoamine, octylamine and dodecylamine, bubble-like and sheet-like nitrogen-doped graphene are obtained, respectively. In three-electrode supercapacitor tests, besides the double-layer capacitance, the as-prepared graphene electrode material indeed exhibits pseudocapacitance due to the N-rich feature, delivering a good rate capability (166 F g-1 at 20 A g-1) and cyclic performance (96% capacitance retention over 20,000 cycles at 20 A g-1). More importantly, the symmetrical supercapacitor studies reveal the promising practicality due to the achieved excellent energy and power densities together with long-term cyclability. Thereby, this work establishes a new milestone for the facile synthesis of heteroatom-doped graphene with a desired microstructure for energy storage and other applications.