Single-atom catalysts for photocatalytic energy conversion

Artificial photocatalytic energy conversion represents a highly intriguing strategy for solving the energy crisis and environmental problems by directly harvesting solar energy. The development of efficient photocatalysts is the central task for pushing the real-world application of photocatalytic reactions. Due to the maximum atomic utilization efficiency and distinct advantages of outstanding catalytic activity, single-atom catalysts (SACs) have emerged as promising candidates for photocatalysts. In the current review, recent progresses and challenges on SACs for photocatalytic energy conversion systems are presented. Fundamental principles focusing on charge separation/transfer and molecular adsorption/activation for the single-atom photocatalysis are systemically explored. We outline how the isolated reactive sites facilitate the photogenerated electron–hole transfer and promote the construction of efficient photoactivation cycles. The widespread adoption of SACs in diverse photocatalytic reactions is also comprehensively introduced. By presenting these advances and addressing some future challenges with potential solutions related to the integral development of photocatalysis over SACs, we expect to shed some light on the forthcoming research of SACs for photocatalytic energy conversion.