Seeded growth of wavy Au@PdAu core-shell nanoplates with tunable thickness for visible light-assisted reduction of 4-nitrophenol

Wavy gold@palladium-gold (Au@PdAu) core-shell nanoplates are successfully prepared via seeded growth. Starting with the use of plate-like Au nanocrystals with the thickness of ~10 nm as seeds, the preferential deposition of Pd atoms vertical to the upper/bottom surface plane allows the formation of the core-shell structure with tunable thickness, where the shell thickness can be limited to sub-10 nm. As confirmed by X-ray diffraction (XRD) analyses, further atomic diffusion allows the generation of PdAu alloy phase in the products, leading to the formation of Au@PdAu core-shell nanostructure. With the strong absorbance in near-infrared (NIR) region, they could work as efficient catalysts towards reduction of 4-nitrophenol under visible light irritation. In particular, the enhancement factor (the ratio of apparent rate constant in light to that in dark) reaches as high as 6.76 arising from the plasmonic-enhancement effect. The current work provides a feasible strategy to fabricate Pd-based bimetallic nanocrystals with plasmonic properties and validates their promising application in the plasmonic-enhanced catalysis. Graphical abstract: [Figure not available: see fulltext.]