Interfacial Synthesis of δ-MnO2 Nano-sheets with a Large Surface Area and Their Application in Electrochemical Capacitors

Birnessite-type MnO2 (delta-MnO2) nano-sheets were successfully synthesized by an interfacial synthesis method in this work. The properties and electrochemical performance of the as-prepared delta-MnO2 were analyzed and evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption measurement and electrochemical tests. This facile synthesis method enables delta-MnO2 nano-sheets to show a large specific surface area (257.5 m(2) g(-1)). The electrochemical test results show that the specific capacitance is 272 F g(-1) and the specific capacitance retention is over 96.7% after 1000 cycles at a scan rate of 10 mV s(-1). All results demonstrate that delta-MnO2 has a great potential application in high-performance electrochemical capacitors, and this interfacial synthesis method will be a very promising method to synthesize highly active MnO2 materials in a large scale. Copyright (C) 2015, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved.