Bi2O3 deposited on highly ordered mesoporous carbon for supercapacitors

A simple route has been employed to prepare nanosized Bi2O3 deposited on highly ordered mesoporous carbon. The electrochemical measurements reveal that, by loading only 10% Bi2O3 on the mesoporous carbon, the specific capacitance of the composite is improved by 62%, with the maximum value reaching 232 F g−1 at a sweep rate of 5 mV s−1. The specific capacitance of Bi2O3 is calculated and reaches 1305 F g−1 at 1 mV s−1. It is found that the mass transfer in the framework of the crystalline oxide is still difficult in spite of its nanosize, as evidenced by the decline of the specific capacitance of the Bi2O3 with the increase of the sweep rate. The cyclic life of composite materials is also measured and the capacitance only declines 21% after 1000 cycles.