Efficient Charge Carriers Separation and Transfer Driven by Interface Electric Field in FeS2@ZnIn2S4 Heterojunction Boost Hydrogen Evolution

Photocatalytic H₂ evolution technology is regarded as a promising and green route for the urgent requirement of efficient H₂ production. At present, low efficiency is a major bottleneck that limits the practical application of photocatalytic H₂ evolution. The construction of high-activity photocatalysts is highly crucial for achieving advanced hydrogen generation. Herein, a new S-scheme FeS₂@ZnIn₂S₄ (FeS₂@ZIS) heterostructure as the photocatalyst was developed for enhanced photocatalytic H₂ evolution. Density function theory (DFT) calculation results strongly demonstrated that FeS₂@ZIS generates a giant interface electric field (IEF), thus promoting the separation efficiency of photogenerated charge carriers for efficient visible-light-driven hydrogen evolution. At optimal conditions, the H₂ production rate of the 8%FeS₂@ZIS is 5.3 and 3.6 times higher than that of the pure FeS₂ and ZIS, respectively. The experimental results further indicate that the close contact between FeS₂ and ZIS promotes the formation of the S-scheme heterojunction, where the interfacial charge transfer achieves spatial separation of charge carriers. This further broadens the light absorption range of the FeS₂@ZIS and improves the utilization rate of photogenerated charge carriers. This work thus offers new insights that the FeS₂-based co-catalyst can enrich the research on S-scheme heterojunction photocatalysts and improve the transfer and separation efficiency of photogenerated carriers for photocatalytic hydrogen production.