Abstract:

Nanoporous gold (NPG) was prepared on Ni foam through electrodeposition of Au-Sn alloy and chemical dealloying. MnO2 was electrodeposition NPG/Ni foam to obtain the MnO2@NPG/Ni foam electrode material. The surface morphology and composition of the MnO2@NPG/Ni foam electrode were characterized by means of scanning electron microscopy (SEM)，energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The as-prepared electrode was employed as the supercapacitor electrode material, and its charge-discharge characteristics and cyclic stability were tested. The results show that the MnO2@NPG/Ni foam electrode exhibits a greatly enhanced specific capacitance, better rate capability and cyclic stability compared to the MnO2@Ni foam electrode. The MnO2@NPG/Ni foam composite electrode provides a specific capacitance of 377.9 F·g1 at a current density of 1 A·g1. The capacitance retention of the MnO2@NPG/Ni foam composite electrode remains 99% after 2500 cycles at a scan rate of 50 mV·s1.

Key words:  supercapacitor, nanoporous gold, manganese dioxide, nickel foam, dealloying, electrodeposition