Synthesis of Birnessite-Type MnO2 by the In-Situ Electrochemical Oxidation of Mn3O4 Film for Supercapacitors 

 - Nanoscience And Nanotechnology Letters, 4(5). p.559-563, 2012 .
<br/><br/> Artículo 
<br/><br/> Here we report an in situ electrochemical oxidation method to synthesize birnessite-type MnO2 electrodes for supercapacitors from cathodically deposited Mn3O4 thin films. Mn3O4 thin films composed of nanowall arrays with a porous structure were prepared by cathodic deposition at various temperatures. Nanoparticles were formed within the nanowalls when the deposition temperature is above 50 C, building a nanoparticle/porous hierarchy architecture. Cyclic voltammogram (CV) was used to perform electrochemical oxidation on the Mn3O4 thin film. The birnessite-type MnO2 phase was successfully achieved after the electrochemical CV cyclings, which is believed to be responsible for the significant increase in the specific capacitance of the supercapacitor. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>MANGANESE OXIDE<br/>ELECTROCHEMICAL OXIDATION<br/>SUPERCAPACITOR