Ternary TiO2/MoSe2/γ-graphyne heterojunctions with enhanced photocatalytic hydrogen evolution

Abstract

Photocatalytic water splitting for hydrogen evolution is widely considered as a clean, green, and renewable route for solar energy conversion and storage. In this work, we fabricated ternary TiO2/MoSe2/γ-graphyne nanocomposite and demonstrated its superior photocatalytic hydrogen evolution activity. The samples were investigated by transmission electron microscopy, UV–Vis diffuse reflectance spectra, electrochemical impedance spectroscopy, and photoluminescence spectra. The optimized sample exhibited a high H2 production rate of 16 μmol h−1, which was 3.2-fold as high as that of binary TiO2/MoSe2 and 6.2-fold as high as that of pristine TiO2. The enhanced photocatalytic activity is mainly because of the higher light-harvesting capacity, more active edge sites, and more charge-transfer channels induced by the multicomponent heterojunction through a cascade-driven electronic mechanism. This work presents a practical way to design noble-metal-free photocatalysts for solar energy-driven water splitting by band-engineering tailoring.