Surface–interface engineering of single atom catalysts for solar hydrogen generation

Single-atom photocatalysts have rapidly emerged as a frontier in photocatalysis, offering complete atom utilization and exceptional catalytic activity while enhancing light harvesting, charge separation, and surface reaction kinetics. This perspective summarizes recent progress in surface and interface engineering of single-atom photocatalysts, achieved through strategies such as interfacial modulation, defect engineering, heteroatom doping, and related approaches. In particular, we discuss electronic interactions of single atoms on various supports, their coordination environment, and electronic structure engineering of single atoms in governing the photocatalytic hydrogen evolution reaction (HER). By highlighting recent advancements and discussing key challenges alongside potential strategies, this work aims to provide clear design principles that will guide future research on single-atom catalysts for photocatalytic energy conversion. This study supports the global transition toward clean and sustainable energy technologies, aligning with the United Nations Sustainable Development Goals (SDGs).