Effect of cathodic polarization of n-TiO2 thin films on their photoresponse towardswater splitting reactions

Abstract

Cathodic reduction of Titanium oxide (n-TiO2) thin films was investigated as an alternative approach to customary hydrogen modification of n-TiO2 under hydrogen gas stream at high temperature. Hydrogen modification of n-TiO2 was carried out electrochemically under cathodic polarization. The photo-response of the electrochemically hydrogen modified n-TiO2 (HM-n-TiO2) exhibited a fourfold enhancement in their photoresponse compared to n-TiO2 during water splitting under solar simulated light. The photoactivity of HM-n-TiO2 suffers a substantial decrease after heat-treatment at 200 °C, remarkably the photoactivity of these samples was fully repaired after re-hydrogenation under similar conditions. The electrodes were characterized using electrochemical and spectroscopic techniques.