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

Abstract

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@TiO 2 hybrid (Cu nanoparticles encapsulated in TiO 2 ) has been successfully prepared by Cu 2 O self-template reduction through solvothermal treatment in ethylene glycol-water mixed solvent. When octahedral Cu 2 O is involved in the reaction system, the Cu 2 O@Ti-precursor octahedral structure is first formed and subsequently the Cu@TiO 2 hybrid is prepared with the reduction of ethylene glycol (EG). The Cu@TiO 2 hybrid derived with different mass of Cu exhibits improved photocatalytic hydrogen production performance compare to pure TiO 2 and P25. Among those photocatalysts, the Cu@TiO 2 -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 TiO 2 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 H 2 evolution upon the Cu@TiO 2 hybrid. When replacing octahedral Cu 2 O with cubic and truncated octahedrons ones, the Cu@TiO 2 hybrid photocatalysts are also obtained and they also display superior solar-to-hydrogen evolution than pure TiO 2 and P25. It is expected this work could develop an approach to design Cu-encapsulated hybrid photocatalysts for hydrogen generation. •Cu@TiO 2 hybrid photocatalyst was prepared by a facile solvothermal method. •Different structured Cu 2 O were employed to prepare Cu@TiO 2 hybrid nanostructures. •The formed Schottky junction between Cu and TiO 2 facilitated the charge separation. • The Cu@TiO 2 hybrid Schottky junction showed enhanced photocatalytic hydrogen evolution.