Universal pseudo-fluctuation engineering induces local free radical surface confinement effect to enhance photocatalytic oxidation of toluene

Breaking the trade-off between activity and selectivity has always been a long-standing challenge in the field of catalysis. In this study, we introduce an innovative universal pseudo-fluctuation strategy utilizing surface-uncoordinated In(OH) 3-x -ZnIn 2 S 4 heterojunctions (ZIO) to achieve local free radical confinement. Notably, the low-coordination and contraction of In−O bonds generate disordered and loosely hydrogen-bonded chains, which enhances the adsorption and activation of toluene. Meanwhile, the dynamic transformation of In−O bonds regulates the d‐band center while restructuring a dense hydrogen bonding network. This process locally confines highly reactive oxygen species and facilitates the desorption of benzaldehyde, effectively inhibiting the over-oxidation of the product. Ultimately, after 48 h of irradiation, the photocatalytic toluene oxidation rate of ZIO-2 reached 100.59 mmol g −1 without generating excessive oxidation by-products. Our work delineates a clear surface reaction pathway and introduces a novel design paradigm for atomic-scale photocatalysis in multi-state interfaces, paving the way for advanced catalysts that harness interfacial microenvironments to achieve enhanced performance. • A water-mediated free radical surface confinement strategy to enhance photocatalytic toluene oxidation. • The low-coordination structure modulates the d‐band center of ZIO-2. • The dynamic transformation of In−O bonds reorganizing the chain hydrogen bonding into a hydrogen bonding network. • ZIO-2 demonstrated excellent activity and long-term selectivity.