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

Efficient solar-to-H2 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 (PtSS-CdS) for simultaneous photocatalytic H2 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–S3 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 H2 evolution reaction. Moreover, in situ electron spin resonance measurements reveal that the α-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 H2 generation rate (11.5 mmol g–1 h–1) is observed on PtSS-CdS under simulated solar light, and continuous H2 bubbles are generated over PtSS-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 H2 evolution and organic synthesis in a sustainable manner.