ZnIn2S4 nanosheets grown on biomass chitin-derived 3D carbon substrates as self-supporting high-efficiency photocatalysts for water splitting

The charge transfer within heterojunctions is a critical factor influencing the overall efficiency and stability of photocatalytic water splitting. In this context, a heterojunction of two-dimensional ZnIn 2 S 4 nanosheets grown on two-dimensional chitin-derived N-doped carbon (Chitin-NC) nanosheets was fabricated, forming an integrated three-dimensional interconnected network architecture of Chitin-NC/ZnIn 2 S 4 composite with visible light response. This well-designed stable structure exposes more catalytic active sites and promotes the separation and migration of photogenerated charges, demonstrating the excellent photocatalytic activity for hydrogen evolution and cyclic stability of the Chitin-NC/ZnIn 2 S 4 composite. Under visible light irradiation , the optimized Chitin-NC/ZnIn 2 S 4 achieved a hydrogen production rate of 0.665 mmol g −1  h −1 without the use of any co-catalysts. And the structure remained stable after multiple photocatalytic cycles. This achievement provides a new cost-effective and sustainable methodology for enhancing the efficiency of photocatalytic water splitting.