Fabrication of Sulfur Defect Rich ZnIn2S4/SnSe2 Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

The development of a noble‐metal‐free cocatalyst is of great significance for boosting photocatalytic H 2 evolution performance. Herein, SnSe 2 is developed as a cocatalyst to in situ attachment on the surface of sulfur defect rich ZnIn 2 S 4 (Vs‐ZIS) via a simple hydrothermal method. Owing to the intimate atomic‐level interface and the different work function between Vs‐ZIS and SnSe 2 , a particular Ohmic junction with internal electric field is formed in Vs‐ZIS/SnSe 2 , which facilitates the electrons in Vs‐ZIS transfer to SnSe 2 and participate in H 2 evolution reaction rapidly. Moreover, the abundant S vacancies also benefit the separation of photocarriers in Vs‐ZIS/SnSe 2 . The optimized Vs‐ZIS/SnSe 2 photocatalyst performs a high H 2 evolution rate of 29.34 mmol h −1 g −1 under visible light ( λ > 420 nm) and an apparent quantum efficiency of 12.25% at 420 nm. Herein, constructive model on developing effective cocatalyst is afforded, and expediting photocarriers transfer through interfacial modulating.