3D network mesoporous beta-manganese dioxide: Template-free synthesis and supercapacitive performance

Sponge-like mesoporous beta-manganese dioxide (beta-MnO2) with a high specific surface area and narrow pore size distributions has been successfully synthesized at room temperature by a template-free approach. As a supercapacitor electrode, the as-prepared 3D network beta-MnO2 exhibits greatly improved electrochemical performance: not only its specific capacitance enhances from similar to 15 F g(-1) (traditionally hydrothermal synthesized hollow beta-MnO2 nanorods) to similar to 180 F g(-1) in 1 M Na2SO4 aqueous solutions, but also similar to 99% of its initial specific capacitance can retain after charge/discharge for 10000 cycles. In addition, its rate retention can maintain at similar to 65% as the scan rate increasing from 2 mV s(-1) to 50 mV s(-1). These results demonstrate that, through modification or improvement, beta-MnO2 can also be a promising electrode material for supercapacitors. (C) 2014 Elsevier B.V. All rights reserved.