Gold Nanorods Coated with Palladium‐Platinum Alloy Shell Superstructures for Enhanced Plasmon‐Driven Photocatalysis

ABSTRACT Bimetallic and trimetallic nanostructures offer unique physicochemical properties for enhancing photocatalytic performance. In this work, a facile and reproducible method of preparing palladium‐platinum (PdPt) alloy shell on gold nanorods (AuNRs) is designed for enhancing the catalytic reactions under light irradiation. Specifically, Pd and Pt shells are sequentially deposited on the surface of AuNRs, forming well‐defined core‐shell Au@PdPt superstructures (Au@PdPt SSs). Photocatalytic activity is evaluated through the NaBH 4 ‐mediated reduction of methyl blue (MB), demonstrating that Au@PdPt SSs exhibit significantly enhanced photocatalytic performance under light irradiation compared to bimetallic counterparts or single‐component analogs. Finite‐difference time‐domain simulations reveal that the spatial distribution of the enhanced electric field closely correlates with the structural characteristics of the Au@PdPt SSs, confirming the influence of morphology on plasmonic behavior. The localized surface plasmon resonance (LSPR) of Au promotes hot electron generation and transfer to the catalytic PdPt alloy shell surface. The results highlight the synergistic interaction between plasmonic Au core and catalytic PdPt shells, where plasmon‐induced charge separation and migration play a pivotal role. This work provides a rational design strategy for constructing high‐efficiency plasmon‐mediated photocatalysts based on multi‐metallic nanostructures, with potential applications in green chemistry and environmental remediation.