Synthesis and capacitive property of hierarchical hollow manganese oxide nanospheres with large specific surface area

• Published in: Journal of power sources 2009-09, Vol.193 (2), p.939-943
• Main Authors: Tang, Xiuhua, Liu, Zong-huai, Zhang, Chengxiao, Yang, Zupei, Wang, Zenglin
• Format: Article
• Language: English
• Subjects: Applied sciences; Capacitance; Capacitors. Resistors. Filters; Concentration (composition); Core-shell material; Core-shell structure; Electrical engineering. Electrical power engineering; Etching; Exact sciences and technology; Layered manganese oxide; Manganese oxides; Mesoporous material; Nanospheres; Silicon dioxide; Specific surface; Various equipment and components
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2009.04.037

The hierarchical hollow manganese oxide nanospheres with both a large surface area and a layered structure have been successfully prepared by a templating-assisted hydrothermal process at 150 °C for 48 h. SiO 2 template spheres are dispersed in KMnO 4 solution, and then followed by hydrothermal treatment to forming silica/manganese oxide nanospheres with a core-shell structure. The core-shell nanospheres are etched in a NaOH solution (20 wt.%), so that the SiO 2 core is removed, and the hierarchical hollow manganese oxide nanospheres are obtained. The as-synthesized hierarchical hollow manganese oxide nanospheres present a birnessite-type manganese oxide phase with a chemical composition of Na 0.38MnO 2.14·13H 2O, and a specific surface area of 253 m 2 g −1. The prepared materials exhibit an ideal capacitive behavior and good cycling stability in a neutral electrolyte system and the initial capacitance value is 299 F g −1. Some preparation conditions including the hydrothermal temperature, dwell time and concentration of template have been also investigated.