Revealing Spatially Resolved Exciton Dynamics of Dual Active Centers for Dehydrogenation Oxidation of Benzyl Alcohol...

Photooxidation of biomass alcohols coupling H₂ evolution has received increasing attention due to its higher economy. However, the insufficient photoexciton utilization has become a bottleneck restricting its practical application, thereby precisely regulating the microstructure of photocatalysts is crucial for achieving efficient photoactivity. Strategically introducing functional active centers has been proven to be a valid strategy for optimizing the exciton dynamics of photocatalysts. Herein, the cobalt (Co) clusters and single-atom Co─O sites were co-decorated on the heterostructured MoS₂/CdS composite to integrate the merits of heterojunction and non-precious metal cocatalysis, which was demonstrated by the x-ray absorption fine structure spectroscopy and spherical aberration-corrected transmission electron microscope techniques. Remarkable collaborative photoactivity for benzyl alcohol (BA) oxidation (181.8 mmol_BAD·g^-1·h^-1) coupling H₂ evolution (64.6 mmol_H2·g^-1·h^-1) was achieved under artificial sunlight. Femtosecond transient absorption spectroscopy and Kelvin probe force microscopy techniques proved the improved spatial separation/transfer kinetics and hindered recombination kinetics of photoexcitons. Based on density functional theory, the Co clusters act as the oxidation sites for BA, and the Co─O sites serve as the H₂ evolution reduction centers, enabling the synergistically enhanced REDOX half-reactions due to more effective spatial separation of photoexcitons. This study proposes a strategic catalyst construction insight for highly efficient collaborative REDOX photocatalysis.