Topochemical synthesis of an atomic Pt modified plasmonic yolk-shell nanostructure for enhanced photocatalytic hydrogen evolution

The combination of plasmonic metals with semiconductors, driven by the hot injection effect and enhanced electromagnetic field effects, enables the improved absorption of incident light energy and the separation of photogenerated charge carriers. Among various metal-semiconductor topological structures, yolk-shell (Y-S) architectures are ideal photocatalysts due to their light-scattering capabilities and large surface area, but with unmanageable photocarrier dynamics. Building on this, we introduced single-atom dispersed Pt sites (Pt-SA) to increase surface catalytic sites for directional migration of charge carriers in photocatalytic hydrogen evolution reactions. By employing cation exchange and galvanic replacement, Y-S nanostructures with an Au-core and a Pt-SA modified CdS shell (namely Au@Pt-SA/CdS Y-S) were synthesized. The as-prepared catalyst exhibits an enhanced photocatalytic hydrogen evolution rate of 10.9 mmol g⁻¹ h⁻¹ under visible light (λ > 420 nm) irradiation, which is twice that of Au@CdS Y-S nanostructures. This work provides new insights into the topochemical synthesis of Y-S structures and the engineering of plasmonic metals and atomic sites for enhanced photocatalysis.