Metal nanoclusters: emerging materials for environmental applications.

Metal nanoclusters (NCs) have emerged as promising materials for environmental applications due to their atomically precise structures and tunable physicochemical properties. Controlled synthetic strategies-including bottom-up methods, and post-synthetic modifications such as ligand and metal exchange-enable precise regulation of their size, composition, and surface chemistry. These features impart unique optical and catalytic properties, making metal NCs highly effective for environmental monitoring and remediation. Their strong and tunable photoluminescence enables sensitive and selective detection of pollutants such as heavy metal ions, toxic anions, organic contaminants, and volatile compounds. In addition, metal NCs exhibit excellent catalytic activity in processes such as CO2 reduction, nitrate conversion, pollutant degradation, and photocatalytic hydrogen production. This review highlights recent advances in the synthesis of metal NCs and emphasizes their growing role in addressing critical environmental challenges through sensing and catalytic applications.