Enhanced Photocatalytic Hydrogen Production via Multichannel Electron Transfer in Pairwise-Interfacially Contacted Au–Pt–CdS Heterostructures

Semiconductor-metal heterostructured nanomaterials, featuring efficient electron-transfer pathways, excellent light-harvesting capability, and effective separation of photogenerated charge carriers, have emerged as highly promising candidates for photocatalytic hydrogen production. In this study, a thin Ag transitional layer was first deposited onto the surface of Au NBPs, followed by growth to construct heterostructures featuring pairwise interfacial contact among Au, Pt, and CdS. Morphological and compositional characterizations reveal that Pt is located at the tips of the Au NBPs and CdS grows at the midsection, resulting in a unique heterostructure characterized by remarkably distinctive pairwise contacts. Experiments show that the Au-Pt-CdS heterostructures exhibit hydrogen-production efficiencies about 8 times higher than that of Au-CdS heterostructures and approximately 223 times higher than that of Au-Pt heterostructures, and also demonstrates excellent photocatalytic stability. Owing to the work function difference between the metal and the semiconductor, this heterostructure generates unique band bending and an intrinsic electric field at the interface, effectively facilitating the separation and multipath directional transport of photogenerated charge carriers, thereby significantly enhancing the rate of photocatalytic hydrogen evolution. Our study provides valuable guidance for the rational design of high-efficiency semiconductor-metal heterostructured photocatalysts and holds significant promise for advancing low-carbon energy solutions and promoting sustainable societal development.