Ethyl acetate-induced formation of amorphous MoSx nanoclusters for improved H2-evolution activity of TiO2 photocatalyst

Abstract

Amorphous MoSx has been demonstrated to be a high H2-production cocatalyst towards various photocatalytic materials, and the facile synthetic route of MoSx cocatalyst with a small size is highly required to further improve its H2-evolution performance. In this study, amorphous MoSx nanoclusters (a-MoSx) with a very small size of 0.4–0.7 nm have been successfully loaded on TiO2 surface by an ethyl acetate-induced hydrolysis route. Herein, the MoS42− ions can be gradually and homogeneously transformed into amorphous MoSx nanoclusters on the TiO2 surface to prepare the highly efficient a-MoSx/TiO2 photocatalysts via the gradual hydrolysis of ethyl acetate. The photocatalytic hydrogen-production experimental results reveal that the resulting a-MoSx/TiO2 (5 wt%) photocatalyst achieves the maximum H2-evolution rate (1106 μmol h−1 g−1), which is apparently higher than that of crystalline MoSx-modified TiO2 (94 μmol h−1 g−1) by a factor of 11.71 times. The markedly enhanced H2-evolution rate of the a-MoSx/TiO2 photocatalyst can be attributed to the formation of more unsaturated S atoms in the amorphous MoSx nanoclusters, which can work as effective active sites to boost the interfacial H2-production rate. The present facile method may provide rational ideas for preparing other nanocluster materials for energy and environmental applications.