Minimized Pt deposition on CdS simultaneously maximizes the performance of hydrogen production and aromatic alcohols oxidation

Constructing coupling reaction system is an effective strategy to simultaneously improve the utilization of photoexcited electrons and holes. Herein, a series of Pt/CdS photocatalysts with minimized Pt were developed by a novel method and used for the coupling system of hydrogen production and aromatic alcohols oxidation. The optimized 0.045%-Pt/CdS exhibits enhanced production rates of H-2 and aromatic aldehydes of 4.87 and 5.54 mmol.g(cat)(-1).h(-1) respectively, which is 325 and 277 times higher than those of pure CdS. Furthermore, the apparent quantum efficiency (AQE) of hydrogen production is up to 28.9% at 450 nm without palpable decrease in photoactivity during 18 h continuous testing. The enhanced photocatalytic activity is mainly attributed to the synergistic roles of Pt and CdS: (1) the larger interfacial area formed by the tight anchorage of Pt on CdS is more favorable for transferring photoexcited electrons (e(-)) to Pt, while metallic Pt ensures outstanding e(-) mobility and offers more active sites for reducing H+ to H-2; (2) the photoexcited holes (h(+)) left on CdS oxidize aromatic alcohols into corresponding aldehydes, thereby achieving the simultaneous utilization of photoexcited h(+) and e(-) in one reaction system. The anchoring design can also be expanded to other coupling systems.