All-Solid-State Z-Scheme CsPbBr₃/Au/g-C₃N₄ Heterojunctions for Enhanced Photocatalytic C-H Oxidation

Z-scheme heterojunctions have emerged as a novel type of environmental and energy photocatalysts owing to their unique charge separation and transfer pathways as well as robust redox capabilities. Herein, this paper reports a straightforward technique for fabricating an anisotropic all-solid-state Z-scheme CsPbBr₃/Au/g-C₃N₄ heterojunction, wherein CsPbBr₃, g-C₃N₄, and the electron-transfer system (Au) are spatially immobilized. This three-component system presented high photocatalytic activity for the oxidation of C-H bonds to carboxylic acids, ketones, and alcohols, respectively. Notably, metallic Au species, functioning as solid-state electron mediators, can significantly accelerate the transfer rate of the photogenerated electrons and holes between the photocatalysts. As verified by trapping experiments and electron paramagnetic resonance, the results indicate that h⁺ and ·O₂^- serve as the primary active species in this process. This study provides novel perspectives on the development of high-performance perovskite-based Z-scheme heterojunctions in the field of organic synthesis.