Facile synthesis of CuOx-decorated TiO2 nanoparticles via oxygen-limited pyrolysis of Cu(II) complex for efficient photocatalytic hydrogen evolution

CuO x -decorated TiO 2 (CuO x /TiO 2 ) nanoparticles have been prepared by the pyrolysis of Cu(II) complex on TiO 2 in an oxygen-limited atmosphere. A solution phase deposition method combined with freeze drying was employed for depositing the 2-methylimidazole-Cu(II) complex onto TiO 2 nanoparticles . The effect of decoration of CuO x on TiO 2 nanoparticles in terms of the crystal phase, morphology, chemical compositions , surface area , surface elemental states, optical absorption and emission properties, was investigated using a series of characterization tools. The oxygen-limited pyrolysis of 2-methylimidazole resulted in the reduction of partial Ti 4+ and Cu 2+ ions into Ti 3+ , Cu + and Cu 0 species, respectively. The surface decoration of CuO x was found to improve the separation and migration of photogenerated electron-hole pairs and increase the life time of excitons. Furthermore, the photocatalytic performance of CuO x /TiO 2 nanoparticles was evaluated for hydrogen evolution in aqueous methanol solution under UV–visible light irradiation . The CuO x /TiO 2 photocatalyst with the optimal cocatalyst loading achieved hydrogen evolution rate of 4.34 mmol h −1 g −1 , with 71- and 5.5-fold enhancement in activity over neat TiO 2 and CuO x /P25, respectively. It is expected that the combination of deposition and pyrolysis of 2-methylimidazole-Cu(II) complex could be an effective approach for the decoration of Cu and its oxides on other supports.