▎ 摘　　要

Benzothiazole (Bz) molecules with excellent electrochemical stability and activity are favor of enhancing the capacitance performance of N-doped graphene (NG) by non-covalent functionalization. Herein, Bz molecules with different substituent groups (-ketone,-methoxy,-ketone and-methoxy) are used to functionalize NG nanosheets by a hydrothermal method and freeze-drying procedure. The surface chemistry and structure of as -prepared functionalized NG nanosheets are investigated through UV -vis, FTIR, SEM, AFM, XPS, TGA, XRD, Raman and BET. The electrochemical results of four functionalized NG nanosheets show that the substituent groups on Bz molecules have a great influence on their capacitive properties, among which the NG modified by the 6-methoxy benzothiazol-2-ketone (1-MhzNG) demonstrates the highest specific capacitance (420 F g-1 at 1 A g-1) and excellent cycle stability of 95.7 % after 10,000 cycles. In addition, the assembled supercapacitor based on the 1-MhzNG electrode delivers the highest energy density of 22.5 Wh kg-1 at 809 W kg-1. Our work provides a new idea to modify graphene with novel organic small molecules for high-performance SCs.