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.