High-efficiency solar-driven H2 generation by three-dimensionally ordered macroporous heterojunction structure

Development of high-efficiency photocatalyst for solar-driven hydrogen (H2) generation still encounters significant challenges. The biomimetic materials with a multistage structure are advantageous for enhancing light harvesting and utilization, as well as facilitating the efficient separation of photon-generated electron-hole pairs, thus play a crucial role in improving photocatalytic efficiency. Herein, the present study demonstrates the design of ZnIn2S4-TiO2 (ZIS/T) biomimetic multistage heterostructure with three-dimensionally ordered macroporous (3DOM) structure for efficient H2 generation. The optimal ZIS/T heterostructure photocatalyst by carefully regulating the interface structure exhibits the superior H2 generation rate of 9.05 mmol·h−1·g−1, surpassing the rates observed in 3DOM TiO2 and ZnIn2S4 samples by 11 and 4.1 times, respectively. The significantly improved photocatalytic efficiency was primarily attributed to the unique multistage structure that provide with abundant reactive sites and excellent mass transfer ability. Furthermore, the slow photon effect induced by the particular 3DOM multistage heterojunctions promote separation of photon-generated carriers. This resultant work provides a novel strategy for the construction of photo-confined heterojunction photocatalysts with enhanced photocatalytic performance through interfacial engineering.