Thin films of vanadium-cerium mixed oxides (molar ratio of V2O5 and CeO2 = 1:2) were deposited at room temperature by varying the RF power in RF magnetron sputtering in a pure argon atmosphere. The XRD patterns reveal that the prepared thin films are amorphous. With increase in RF power, the transmittance and the optical bandgap of the prepared thin films increase. The structural and optical properties were studied by analyzing XRD patterns and transmittance and absorption spectra. The growth of CeVO4 phase on the surface of the prepared thin films is enhanced by increasing the RF power during deposition and this is confirmed by analyzing the photoluminescence, laser Raman and FT-IR spectra. A three electrode electrochemical cell was designed with these mixed oxide thin films as the working electrode, platinum mesh as counter electrode and the saturated calomel as the reference electrode with 0.01 M HCl solution diluted in distilled water as electrolyte. The variation in the electrochemical and the in situ optical properties of the prepared thin films over H+ ion intercalation and de-intercalation with respect to the RF power during deposition are elaborately discussed in this study. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.