Promoting solar-to-hydrogen evolution on Schottky interface with mesoporous TiO 2 -Cu hybrid nanostructures.

Developing a highly efficient photocatalysis system based on a photocatalyst-cocatalyst host for the hydrogen evolution reaction has potential but is still challenging. Herein, we report enhanced splitting of water achieved by loading copper metal particles on mesoporous TiO2 microrods through involving of dual ligand agents into the reaction system. The composition, structure, and surface characteristics of the TiO2 -Cu hybrid were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy, and nitrogen adsorption. The formation of a Schottky contact in the interface between the Cu metal and the n-type semiconductor TiO2 was confirmed experimentally by photo/electrochemical measurements. This Schottky junction, the TiO2 -Cu hybrid photocatalyst, exhibited superior hydrogen evolution capability with rate of 6046 μmol g-1  h-1 , which is 23 times higher than that of pristine TiO2 (260 μmol g-1  h-1 ). The experimental results demonstrated that efficient separation and transfer of photo-induced electron-hole pairs greatly contributed to the enhanced photocatalytic H2 evolution. The Schottky contact between Cu and TiO2 as well as cocatalyst characteristic of Cu play significant roles in preventing the recombination of electron-hole pairs and enhancing water splitting to form hydrogen. This study demonstrates a rational design to construct Schottky contacts in metal-semiconductor junctions to significantly boost their photocatalytic capacity.