Highly enhanced photocatalytic H₂ evolution of Cu₂O microcube by coupling with TiO₂ nanoparticles

A Cu₂O/TiO₂ p-n heterojunction composite was created via a facile, controllable, one-pot hydrothermal method based on cubic Cu₂O and TiO₂ nanoparticles in the presence of dioctyl sulfosuccinate sodium salt (AOT) surfactant. The TiO₂ nanoparticles with an average edge length of ∼10.1 nm were uniformly distributed on the crystal surface of a Cu₂O cube {100}. The photocatalytic performance of the composite was effectively tuned by controlling the amount of TiO₂. The Cu₂O/TiO₂ (60 wt%, labeled as CT-60) exhibits the highest enhanced photocatalytic activity in hydrogen production with H₂ evolution of 3002.5 μmol g^-1. The yield remained around 92.6% after three cycles. Hydrogen production of the CT-60 is 103 and 8.5 fold higher than the cubic Cu₂O and TiO₂ nanoparticles, respectively. The improvement in photocatalytic performance could be attributed to the formation of p-n heterojunction. Furthermore, the interface effect of Cu₂O and TiO₂ caused a broader absorbance in the visible-light region and the lower recombination of photogenerated electron-hole pairs. It is believed that the Cu₂O/TiO₂ p-n heterojunction composites could provide an alternative method to design highly efficient photocatalysts for solar energy.