▎ 摘　　要

MnO2/graphene oxide sheet composite (MnO2/GOS) has been co-electrodeposited on the thermally treated carbon paper (TTCP) in phosphate buffer solution containing GOS and KMnO4. The resulted samples have been characterized by scanning and transmission electron microscopy, Raman, X-ray diffraction, and X-ray photoelectron energy spectroscopy. The results show that the synthesized MnO2 may be delta-MnO2 and the morphology of MnO2/GOS is very different from that of MnO2, indicating that the introduction of GOS in electrolyte can influence the morphology during the deposition. The capacitive properties of the samples are investigated by using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The specific capacitance of MnO2 for MnO2/GOS can reach about 829 F g(-1) at discharged current density of 1.0 A g(-1) in 1 M Na2SO4 aqueous solution, which is larger than that of MnO2 deposited on TTCP. The composite of MnO2/GOS also exhibits excellent cyclic stability with a decrease of 18.5 % specific capacitance after 1,500 cycles.