NiO co-catalyst modification ZnIn2S4 driving efficient hydrogen generation under visible light

Abstract

Photocatalytic hydrogen production is considered as a good countermeasure to solve the energy crisis, but the existing photocatalysts have very slow electron-hole separation efficiency. How to design a photocatalyst with high photogenerated carrier separation efficiency has become a difficult rproblem. The efficiency of photogenerated carrier separation can significantly improve by precious metal co-catalyst, but its further development is limited by high cost. In this work, non-precious metal NiO is used as a co-catalyst and formed heterojunction with ZnIn2S4 (ZIS) as a cocatalyst, which significantly enhances the efficiencies of photogenerated carrier separation. According to the results of transient photocurrent (TPR) and Photoluminescence (PL), ZnIn2S4/NiO (ZIS/NiO) has the fastest photogenerated carrier separation rate when the mass fraction of NiO is 3%, which is about 5 times than pure ZIS. At the same time, the highest photocatalytic hydrogen production rate of 5 mmolg−1 h−1 was achieved under visible-light (λ ≥ 420 nm), which was 6.2 times more than pure ZIS (0.804 mmolg−1 h−1). This work offers a new option for low cost, high performance co-catalyst.