▎ 摘　　要

This study reports the preparation of nitrogen and sulfur co-doped graphene by hydrothermal synthesis using methionine as doping agent and GO as precursor. The structure, morphology, mechanical property and surface chemistry of the as-prepared co-doped graphene were investigated though XRD, N-2 adsorption-desorption, SEM, XPS, dynamic mechanical analyzer and Raman characterizations. The material was tested for supercapacitive and oxygen reduction reaction behaviors. It was found that the obtained co-doped sample NS-Gm05 with 3D porous structure and the highest specific surface area (260 m(2) g(-1)) exhibited good mechanical properties, excellent capacitive performance and ORR performance. When used as free-standing electrode in supercapacitor, the specific Capacitance of NS-Gm05 reached 431 F g(-1) at 0.5 A g(-1), which might be due to its highest specific surface area and the pseudocapacitance that N and S provided. Furthermore, the better ORR activity of the as prepared samples can be attributed to its high specific surface area and heteroatom doping contents.