MOF-Derived Oxygen-Vacancy-Rich ZrO2/UiO-66-NH2 for Efficient Visible-Light-Driven Oxidation of Benzyl Alcohol
Yan‐Yan Song, Zhichao Sun, Jiamin Sun, Ying‐Ya Liu, Anjie Wang, Chong Peng
Abstract
Abstract The development of efficient photocatalysts for selective organic transformations under visible light remains a major challenge in sustainable chemistry. In this study, we present a straightforward solvothermal strategy for fabricating a defect-engineered ZrO 2 /UiO-66-NH 2 hybrid material with abundant oxygen vacancies, enabling the visible-light-driven oxidation of benzyl alcohol to benzaldehyde. By optimizing the solvothermal treatment duration, the composite (UiO-66-NH 2 -2 h) achieves a 74.1% conversion of benzyl alcohol with > 99% selectivity toward benzaldehyde under mild conditions, substantially outperforming pristine UiO-66-NH 2 . Structural and mechanistic studies reveal that the solvothermal process induces the in situ formation of ultrasmall, uniformly dispersed ZrO 2 nanoparticles (~ 2.3 nm) within the MOF matrix, while simultaneously generating abundant oxygen vacancies, as confirmed by XPS, EPR, and HRTEM analyses. The defect-mediated electronic structure of the ZrO 2 /UiO-66-NH 2 hybrid enhances visible-light absorption, facilitates charge carrier separation, and promotes efficient activation of O 2 into superoxide radicals (·O 2 − ), the primary reactive species. Transient photocurrent measurements and electrochemical impedance spectroscopy further verify the improved charge separation efficiency. The synergistic interplay between oxygen vacancies and the intimate ZrO 2 /UiO-66-NH 2 interface provides a unique defect-mediated charge transfer pathway, distinguishing this system from conventional heterojunctions. This study demonstrates a facile, one-step approach to integrate defect engineering with interfacial hybridization in MOF-based photocatalysts, offering a scalable route for solar-driven organic synthesis. Graphical Abstract