▎ 摘　　要

Nitroaromatic pollutants with unusually strong adsorption affinity are highly attractive candidates for creating 2D molecular assemblies on the surface of graphene, which is crucial to prepare high-quality N-doped graphene by post-treatment. Herein, the few-layered crumpled N-doped graphene (5-NIGN) with high N content is successfully prepared by mixing 5-nitroindole (5-NI), ammonia, and graphene oxide (GO) and using a simple hydrothermal method followed by the post-treatment process of vacuum freeze-drying and annealing. It is found that the rapid assembly of 5-NI effectively suppresses the aggregation of the products in the reduction process of GO, so that the thickness of as-prepared 5-NIGN is 4.21 nm, very close to that of GO (4.01 nm). Compared with the N-doped graphene (GN) derived from the system of GO containing ammonia (341 F g(-1)), 5-NIGN exhibits higher capacitance of 457.4 F g(-1) at 1 A g(-1) and prominent long-term life (115% of capacitance maintenance upon 10,000 cycles) within the voltage window of 1.0 V. Furthermore, the supercapacitor assembled by 5-NIGN electrodes can deliver the energy density of 15.5 Wh kg(-1) 18.5 Wh kg(-1) at the power density of 8000 W kg(-1) 800 W kg(-1). These results indicate that the 5-NIGN material will have potential advantages in the realm of electrochemical energy storage. (C) 2020 Elsevier Ltd. All rights reserved.