Atomically Dispersed Pt on CdS Nanosheets for Photocatalytic Evolution of H2 and 1,1-Diethoxyethane from Ethanol

Efficient solar-to-H-2 conversion coupled with high-value multicarbon chemical production is an appealing strategy to meet the demands in energy and environment; unfortunately, it remains a great challenge because of insufficient effective photocatalysts and vague catalytic mechanism. Here, Pt single sites are dispersed on a two-dimensional CdS nanosheet (Pt-SS-CdS) for simultaneous photocatalytic H-2 and 1,1-diethoxyethane (DEE) evolution from ethanol. Structural characterizations elucidate that each Pt single atom is bonded with three surface S atoms in CdS, forming a Pt-S-3 tetrahedron coordination structure. The strong semiconductor (CdS) and metal (Pt) interface interaction not only endows efficient migration of photoexcited electron from CdS to Pt single atom via Pt-S bonds but also promises Pt centers with optimized H adsorption energy, thus accelerating the H-2 evolution reaction. Moreover, in situ electron spin resonance measurements reveal that the a-C-H bond rather than the O-H in ethanol prefers to be dehydrogenated by the surface holes of PtSS-CdS. Therefore, a remarkably promoted H-2 generation rate (11.5 mmol g(-1) h(-1)) is observed on Pt-SS-CdS under simulated solar light, and continuous H-2 bubbles are generated over Pt-SS-CdS thin film upon light irradiation. Meanwhile, DEE is also formed with the selectivity of 97.9%. This study affords a promising strategy to develop high-performance catalysts toward photocatalytic H-2 evolution and organic synthesis in a sustainable manner.