Spatially Adjacent Cu Single Atoms and Au Clusters for Photocatalytic Selective Oxidation of Ethylene Glycol Coupled with Hydrogen Generation

The photocatalytic oxidation of ethylene glycol (EG) and water splitting to glycolic acid (GA) coupled with H2 evolution is promising for solar-to-chemical conversion but suffers from poor selectivity and activity. Herein, we construct a TiO2-based photocatalyst with spatially adjacent Cu single atoms (CuSA) and Au clusters (AuC) via an in situ adsorption-pyrolysis and subsequent photodeposition strategy. Electron microscopy and X-ray absorption fine structure spectroscopy confirm the atomically dispersed Cu sites with spatially adjacent Au clusters. The electron microscopy, X-ray photoelectron, and in situ Raman spectroscopy reveal that CuSA modulates the electronic and geometric structures of AuC sites. The optimized AuC-CuSA/TiO2 exhibits excellent performance for EG oxidation to GA coupled with H2 production. Mechanistic studies demonstrate that AuC activates interfacial water to generate reactive oxygen species for selective EG oxidation, while adjacent CuSA facilitates electron enrichment and proton reduction for H2 evolution. This work provides a dual-active-site interfacial synergy strategy for efficient photocatalytic redox coupling.