UiO-66-NH₂ Octahedral Nanocrystals Decorated\nwith ZnFe₂O₄ Nanoparticles for Photocatalytic\nAlcohol Oxidation

Abstract

Photocatalytic\nselective oxidation of alcohols to aldehydes under\nmild conditions (atmospheric pressure and room temperature) remains\na huge challenge, especially for nanoscale catalysts without precious\nmetals. Herein, ZnFe₂O₄/UiO-66-NH₂ (ZFO/U6N) composites are fabricated via an electrostatic self-assembly\nprocess, which follows the Z-scheme interfacial charge transfer pattern.\nUltrasmall ZFO nanoparticles are anchored to the surface of U6N uniformly\ndue to the large potential difference, forming a tight heterogenous\ninterface for efficient charge transfer and separation. The optimized\nZFO/U6N composite possesses excellent conversion (68%) and selectivity\n(99%) for photocatalytic oxidation of benzyl alcohol to benzaldehyde\nin an air atmosphere with AM 1.5G as a light source at room temperature.\nThe fantabulous photocatalytic activity can be ascribed to the Z-scheme\ncharge transfer stratagem, improving the charge transfer and separation\nefficiency, which can maintain the oxidizing ability of holes in the\nhighest occupied molecular orbital energy level of U6N and the reducibility\nof electrons in the conduction band of ZFO nanoparticles. In addition,\nafter five recycles, the photocatalytic performance of ZFO/U6N nearly\nremains constant, indicating the high stability. This work provides\na strategy for the optimizing nanoscale photocatalysts for photocatalytic\nselective oxidation reactions under mild conditions.