Fabrication of Sulfur Defect Rich Znin2s4/Snse2 Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

The development of noble-metal free cocatalyst is of great significance for boosting photocatalytic H2 evolution performance. Herein, SnSe2 was developed as a cocatalyst to in-situ attach on the surface of sulfur defect rich ZnIn2S4 (Vs-ZIS) via a simple hydrothermal method. Owing to the intimate atomic-level interface and the different work function between Vs-ZIS and SnSe2, a particular Ohmic contact was formed in Vs-ZIS/SnSe2, which facilitated the electrons in Vs-ZIS transfer to SnSe2 and participate in H2 evolution reaction rapidly. Moreover, the abundant S vacancies also benefited the separation of photocarriers in Vs-ZIS/SnSe2. The optimized Vs-ZIS/SnSe2 photocatalyst performed a high H2 evolution rate of 29.34 mmol·h−1·g−1 under visible light (λ>420 nm), and an apparent quantum efficiency (AQE) of 12.25 % at 420 nm. This work affords a constructive model on developing effective cocatalyst and expediting photocarriers transfer through interfacial modulating.