Non-precious metal MoO2 co-catalysts efficiently enhance hydrogen production of ZnIn2S4 under visible light

Photogenerated electron-hole separation and transfer and band gap modulation are the main reasons for the performance of semiconductor catalysts. These problems can be effectively solved by the proper use of co-catalysts. However, the current co-catalysts are generally noble metal co-catalysts, which cannot be used industrially because of their high cost. Therefore, it is important to use non-noble metal co-catalyst to solve these problems. In this study, MoO₂ with localized surface plasmon resonance (LSPR) effect loaded onto ZnIn₂S₄ (ZIS) by primary hydrothermal method and structured to form type II heterojunctions. The formation of the heterojunctions not only tunes the band gap to improve the light absorption intensity, but also reduces the charge transfer resistance and promotes electron-hole directed movement to improve the electron-hole separation efficiency. The tuning of the band gap and the increase in the electron-hole separation rate lead to improved performance of all ZIS/MoO₂ heterojunctions under visible light (λ ≥ 420 nm). Among them, ZIS/MoO₂-4% has the best photocatalytic performance of 2.757 mmol g^?1 h^?1, which is 3.75 times higher than that of pure ZIS (0.736 mmol g^?1 h^?1). This study provides a new strategy for the preparation of high performance catalysts without precious metals.