Boosting Photocatalytic Performance of Metal Nanoclusters by Hierarchical Structure Engineering

Photocatalysis is regarded as a pivotal strategy to address the global challenges of energy shortages and environmental pollution. Metal nanoclusters (MNCs), as an emerging class of nanomaterials with atomically precise structures, provide an ideal platform for understanding and optimizing photocatalytic processes at the atomic level. Although the photocatalytic performance of MNCs has become tunable via structure engineering at diverse structural hierarchies, reminiscent of those of natural proteins, there is a lack of a systematic summary of recent development in this area. In this review, we aim to bridge the structure of MNCs with their photophysical properties in varied component steps of photocatalysis, based on a hierarchical core–shell structure scheme of MNCs. This review begins with a brief discussion of the fundamental principles and component steps of photocatalytic reactions, followed by detailed analysis of photocatalytic customization strategies at different structure hierarchies of MNCs. In particular, the mechanisms and recent advances in tailoring light absorption, charge carrier separation/migration, and catalytic active sites have been summarized at the structure hierarchies of metal core, metal–ligand interface, ligand body, and cluster–support interface. We then conclude this review by our perspectives on further development of MNC‐based photocatalysts. The methodological and mechanistic advances summarized in this review should add to understanding the photocatalytic reactions at the atomic level.