Nanostructured Mn-doped CeO2 thin films with enhanced electrochemical properties for pseudocapacitive applications

Abstract

Cerium oxides with variable oxidation states, high interfacial charge transfer rate have demonstrated to be a potential pseudocapacitive material. In this paper, we present the structural and electrochemical properties of undoped and Mn-doped CeO2synthesized using successive ionic layer adsorption and reaction(SILAR) method. The structural results as obtained from x-ray diffraction (XRD) confirmed the cubic fluorite structure of CeO2 which was unaltered despite the doping concentration. However, a tensile strain of ~2.3% was observed due to ionic radii difference. The topography showed a porous network of nanograins, accounting for strong redox interfacial charge transfer. A specific capacitance of 690 Fg−1 was obtained for 5 wt% Mn-doped CeO2, from cyclic voltammetry curve at a scan rate of 10 mV/s. This value is considerably higher than what was obtained for the undoped ceria, indicating that doping with Mn improved the electrochemical performance of the ceria films.