Improved suitability as catalyst support and more efficient charge carrier separation of native air-formed TiO2 films by mild laser treatment

The possibility of using native air-formed TiO2 films (N–TiO2) as substrate for platinum deposition and the extent to which the effectiveness of such Pt/TiO2 systems can be improved by a mild laser treatment of the TiO2 support was investigated. Laser-treated titania (LT-TiO2) exhibited homogeneous rough surface and allowed much efficient separation of photogenerated charge carriers. Both N–TiO2 and LT-TiO2 were used as substrates for platinum electrochemical deposition and it was found that the use of the latter enables more uniform distribution and much lower average size of the Pt particles, leading to an enhancement of the electrochemically active specific surface area of ca. 75%. Moreover, the use of a laser-treated titania substrate not only facilitates methanol anodic oxidation overall process but also improves the resistance of the electrocatalyst to deactivation by strong adsorption of intermediates. Upon UV irradiation, Pt/LT-TiO2 electrodes exhibit a strong enhancement of the methanol oxidation current and, importantly, a much better resistance to poisoning.