▎ 摘 要
A facile approach for the fabrication of NiO/sulfonated graphene composites (NiO/sGNS) using ammonium carbamate as a precipitating agent was developed. With an enhanced specific surface area and a desirable surface chemical environment, the NiO/sulfonated graphene composites exhibit excellent electrochemical performance. The results from cyclic voltammetry (CV) demonstrate that traditional electrical double-layer capacitive processes contribute to improving the storage energy capabilities of the NiO/sGNS composites. Galvanostatic charge-discharge tests show that the specific capacitance of the NiO/sulfonated graphene composites increased to 530 F g(-1) at a current density of 1.0 A g(-1) in comparison with specific capacitances of 382 F g(-1) for NiO/thermal reduced graphene composites (NiO/TRG) and 238 F g(-1) for pristine NiO. Moreover, electrochemical impedance spectroscopy (EIS) indicates the considerable effect of sulfonated graphene on building electron and ion transport channels for faradaic reaction processes of the NiO/sGNS composites.