CuO Quantum Dots Decorated TiO2 Nanocomposite Photocatalyst for Stable Hydrogen Generation

An efficient and stable CuO-TiO2 nanocomposite photocatalyst was synthesized by using the simple molten-salt method. Characterization by HR-TEM confirmed the existence of both TiO2 and CuO in the nanocomposite, revealing hexagonal TiO2 nanoparticles (NPs) with average particles size of 23.8 nm. CuO QDs decorated on the TiO2 surface were in the range of 2.2 to 4.6 nm. Photocatalytic experiments for hydrogen (H-2) production were carried out under an LED (2, = 365 nm) lamp and natural solar light. The effect of Cu-loading in CuO-TiO2 NCs and synthesis time were studied. The optimized CuO-TiO2 NCs abbreviated as CuT-4 and CuT-3 showed 27.7- and 9.0-fold superior rate of H-2 production compared to pristine TiO2 NPs under LED and solar irradiation, respectively. At optimal conditions, CuO-TiO2 NCs demonstrated good photostability for H-2 evolution during 75 h illumination under LED light. The experimental results confirmed the cocatalytic role of CuO for improved H-2 generation by a minimized recombination of excitons.