Dendritic branching Z-scheme Cu2O/TiO2 heterostructure photocatalysts for boosting H2 production

Abstract

Photocatalytic water splitting is a promising way for producing chemical energy from solar energy, but it is still a great challenge. Here, the dendritic branching Cu2O was prepared through a facile hydrothermal method, and the Z–scheme Cu2O/TiO2 composite was formed by electrostatic interaction in the reaction solution. Remarkably, the Cu2O coupled with 70 wt% TiO2 (labeled as CT–70) shows the highest photocatalytic hydrogen production activity of 14.020 mmol g−1 in 6 h, which was 264 and 44 times higher than that of pure Cu2O (0.053 mmol g−1) and TiO2 (0.315 mmol g−1), respectively. The enhanced photocatalytic activity was ascribed to the wide light absorption and effective charge separation. Moreover, the Z–scheme mechanism was elucidated and confirmed by electron paramagnetic resonance (EPR) investigations and density functional theory (DFT) calculation. These results might provide guidance on the rational construction of efficient Z–scheme photocatalysts for solar fuel production.