Characterization and photoactivity of Pt/N-doped TiO2 synthesized through a sol–gel process at room temperature

The rates of photocatalytic production of H2 by Pt/N-doped TiO2 are significantly affected by the hydrolysis temperature applied during the sol–gel process. Production rates increase as the hydrolysis temperature decreases from 40 to 20 °C. The effects of the hydrolysis temperature on the properties and water-splitting behavior of photocatalysts were investigated. Characterization results showed that hydrolysis temperatures higher than 40 °C induce the formation of the rutile phase and particle agglomeration, reduce the N-dopant content, and decrease the range of visible-light absorption. In this study, a low hydrolysis temperature of about 20 °C is optimal for the sol–gel preparation of N-doped TiO2; this temperature favors the formation of high-purity anatase, small particle size, extensive visible-light absorption, and excellent rates of photocatalytic production of H2 (about 2100 μmol h−1 g−1).