Role of Silver Nanoclusters in the Enhanced Photocatalytic Activity of Cerium Oxide Nanoparticles

We have designed a silver‐nanocluster‐supported cerium oxide nanoparticle composite (AgNC/CeO 2 ) to overcome the inapplicability of CeO 2 as a photocatalyst due to a large band gap. A hydrothermal‐based synthetic strategy was followed to prepare spherical cerium oxide nanoparticles (CeO 2 NPs). The AgNCs were synthesized separately. In the final step, silver‐nanocluster‐supported CeO 2 nanoparticle composites were fabricated by simply mixing CeO 2 and various concentrations of AgNC and stirring for 48 hours. The as‐prepared AgNC/CeO 2 nanocomposites were employed as photocatalysts to study the degradation of the dye Acridine Red (AR) under UV light illumination. The results showed that the photocatalytic activities of the AgNC/CeO 2 were enhanced several times compared with pure CeO 2 NPs, even with a very low loading of AgNC (ca. 3 %). The increased catalytic activity of the AgNC/CeO 2 nanocomposites was interpreted mechanistically by including the participation of reactive oxygen species, and corroborated experimentally. Thus, the AgNCs provide a convenient approach to improving the photocatalytic activity of CeO 2 NPs.