Electrodeposition of mesoporous manganese dioxide films from lyotropic liquid crystalline phases

Mesoporous manganese dioxide (MnO2) films have been successfully electrodeposited from hexagonal structured lyotropic liquid crystalline phases with polyoxyethnlene surfactant. The liquid crystalline templates are characterized by low-angle X-ray diffraction (XRD) and polarized-light optical microscopy (POM). The mesoporous MMO2 films are characterized by low-angle XRD, wide-angle XRD, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mesoporous MnO2 films heat-treated at 200 degrees C were characterized by cyclic voltammetry (CV) in 0.5 M Na2SO4 electrolyte for supercapacitor application. The mesoporous MnO2 films exhibit ideal capacitive behavior between -0.1 and 0.9 V, and a specific capacitance of 460 Fg(-1) is obtained at the scan rate of 10 mV s(-1). These results indicate that mesoporous MnO2 films electrodeposited from lyotropic liquid crystalline phases provide promising applications in supercapacitors. (C) 2007 Elsevier Inc. All rights reserved.