Pt decorated hierarchical Sb2WO6 microspheres as a surface functionalized photocatalyst for the visible-light-driven reduction of nitrobenzene to aniline

Abstract

Optimizing the structure of semiconductor materials and introducing functional metal clusters have emerged as an effective strategy to improve the photocatalytic performances of catalysts through the synergistic effect between metals and supports. In this work, Pt nanocluster decorated hierarchical Sb₂WO₆ microspheres which are assembled from ultra-thin nanosheets with only 3.3 nm thickness (Pt/SWO-NS) jointly achieve an efficient photocatalytic reduction of nitrobenzene to aniline and show 10 times higher activity than Pt decorated bulk Sb₂WO₆ (Pt/SWO-bulk). More importantly, the respective roles of SWO-NS and Pt nanoclusters are deeply studied. SWO-NS with a unique 2D structure, abundant unsaturated surface sites and good visible light response would be favorable for stabilizing Pt nanoclusters, adsorbing and activating more nitrobenzene molecules and providing abundant photo-generated electrons. Meanwhile, Pt nanoclusters serve as electron enrichment centers to decompose HCOONH₄ to produce rich ·CO₂⁻ and active H for reducing the activated nitrobenzene molecules. In addition, on combining coordination chemistry, a possible synergistic mechanism for hierarchical Sb₂WO₆ microspheres and Pt nanoclusters is proposed to elucidate the efficient reduction of nitrobenzene to aniline. We believe that this work would provide an effective strategy to optimize catalytic performance by the design of applicable nanocomposites with synergistic effects.