Advancing Photocatalytic Overall Water Splitting with Z-Scheme Heterojunctions by Interfacial Manipulation

Photocatalytic overall water splitting (POWS), as a promising technology for large-scale solar hydrogen production, has propelled the development of advanced photocatalysts. Z-scheme heterojunctions are believed to be ideal candidates for efficient POWS due to the reconcilable benefits of broad solar spectrum absorption and sufficient redox potentials. POWS by Z-scheme heterojunctions involves multiple-step charge transfer processes happening at the interfaces, thereby making interfacial manipulation crucial to improving the photocatalytic performance. This review delves into the intricate details of interfacial manipulation in Z-scheme heterojunctions with an emphasis on the semiconductor-semiconductor interfaces and the semiconductor-water interfaces. First, the basic charge transfer processes are explored at the interfaces, and then summarize and explore the effective manipulation strategies to promote the interfacial charge transfer processes for enhanced POWS performance. Further, the advanced characterization techniques are introduced for understanding these interfacial processes. Finally, the current challenges and future directions are provided for the development of efficient Z-scheme heterojunctions for POWS.