Precursor self-derived Cu@TiO2 hybrid Schottky junction for enhanced solar-to-hydrogen evolution

Solar-to-hydrogen production has attracted increasing attention since it possesses great potential in alleviating energy and environmental crises to some extent. The key issue is to develop efficient photocatalysts exhibiting superior hydrogen production capability. In this work, Cu@TiO2 hybrid (Cu nanoparticles encapsulated in TiO2) has been successfully prepared by Cu2O self-template reduction through solvothermal treatment in ethylene glycol-water mixed solvent. When octahedral Cu2O is involved in the reaction system, the Cu2O@Ti-precursor octahedral structure is first formed and subsequently the Cu@TiO2 hybrid is prepared with the reduction of ethylene glycol (EG). The Cu@TiO2 hybrid derived with different mass of Cu exhibits improved photocatalytic hydrogen production performance compare to pure TiO2 and P25. Among those photocatalysts, the Cu@TiO2-10% (the copper content is 10 wt%) shows the highest hydrogen evolution rate of 4336.7 μmol g−1 h−1, and it is twice as much as the pure TiO2 and 1.9 times as much as P25, respectively. Based on the photo/electrochemical results, an efficient photo-generated electron-hole separation contributes to the enhancement of photocatalytic H2 evolution upon the Cu@TiO2 hybrid. When replacing octahedral Cu2O with cubic and truncated octahedrons ones, the Cu@TiO2 hybrid photocatalysts are also obtained and they also display superior solar-to-hydrogen evolution than pure TiO2 and P25. It is expected this work could develop an approach to design Cu-encapsulated hybrid photocatalysts for hydrogen generation.