Photoelectrochemical Water Splitting on Hydrogen Modified Titanium Oxide (HM-n-TiO2) Thin Film Electrode

Hydrogen modified titanium oxide (HM-n-TiO₂) thin films were synthesized by thermal oxidation of Ti metal substrate. The hydrogenation of n-TiO₂ was carried out electrochemically under cathodic polarization at −1.6 V vs SCE in 2.5 KOH electrolyte under dark condition. The photoactivity of HM-n-TiO₂ thin films was assessed by measuring the rate of the water splitting reaction under solar simulated light in terms of photocurrent density, J_p (mA cm^-2). The HM-n-TiO₂ photoelectrodes exhibited a fourfold enhancement in their photocatalytic activity compared to n-TiO₂ prior to hydrogenation. The HM-n-TiO₂ photoelectrodes were characterized using X-ray diffractions and the change in the valence band induced by the hydrogenation of n-TiO₂ was examined by XPS measurements.