Harnessing atomically precise metal nanoclusters as next-generation photocatalysts for CO₂ reduction

Photocatalytic CO₂ conversion using solar energy offers a sustainable route to value-added fuels and chemicals. Atomically precise metal nanoclusters (NCs), with discrete electronic states, abundant active sites, and well-defined structures, are promising photocatalysts for this process. This Minireview summarizes recent advances in gold, silver, copper, and bimetallic NCs for photocatalytic CO₂ reduction, focusing on their reaction products, selectivity, and catalytic mechanisms. Strategies to enhance charge separation, migration, and catalytic performance are critically discussed. Finally, key challenges and future directions toward efficient, stable, and practically viable NC-based photocatalysts are highlighted.