Reactive Oxygen Species-Mediated Photooxidation in a Full-Space Electric Field Catalyst: Selectivity and Activity Control of Intramolecular Alcohol Hydroxyl and Aldehyde Groups

The rational design of nanocatalysts with high activity and selectivity is crucial for photocatalytic selective oxidation, where reactive oxygen species (ROS) serve as the key oxidants for inducing molecular catalytic behavior. We developed a defective ZnIn2S4/Ti3C2 Schottky junction featuring a full-space electric field by chemically anchoring Ti3C2 nanoparticles onto the defects of a ZnIn2S4 nanosheet via the defect-mediated heterocomponent anchorage approach, as a photocatalyst platform for manipulating the efficient and alternative ROS generation (•OH or •O2–) to controllably oxidate the intramolecular alcohol hydroxyl or aldehyde group toward tunable oxygenates. The full-space directionally aligned electric field creates asymmetrical charge distributions, facilitating charge carrier localization and delocalized electron transportation, ultimately leading to an order of magnitude increase in ROS concentration for superhigh activity. Meanwhile, due to their thermodynamic and kinetic advantages under different atmospheres, hydroxyl radicals preferentially activate alcohols and induce two consecutive dehydrogenation reactions, whereas superoxide radicals preferentially activate aldehydes and induce oxygen insertion processes, thereby achieving selectivity control of the products. Encouragingly, several compounds with alcohol hydroxyl and aldehyde groups are compatible using the current protocol. This work provides a paradigm for programmable construction of composite photocatalysts in selective oxidation, elucidating the substantial impact of ROS generation (concentrations and types) on the efficient oxidation of specific functional groups.