Au@Pd nanorods with a suitable shell thickness of titanium dioxide can improve its catalytic performances

The localized surface plasmon resonances (LSPRs) in plasmonic nanoparticles have been used in accelerating photocatalytic reactions under light illumination. To improve the catalytic performances, bimetallic nanoparticles composed of a plasmonic core and a catalytic shell, where LSPR-excited hot electrons and the intrinsic catalytically active sites work synergistically, have attracted much attention. Bimetallic nanostructures are a promising material for the fabrication of a novel type of photo-enhanced nanoreactor. This work presents a photoreactor based on gold–palladium (Au@Pd) nanorods with an optimized photothermal conversion and localized surface plasmon effect. Au@Pd nanorods were fabricated via a seed-mediated growth method using the surfactant hexadecylpyridiniumbromide monohydrate, making the Au@Pd surface rough, which can provide more active sites than smooth surfaces. The photothermal conversion of Au@Pd nanorods was improved with a titanium dioxide shell. Through the titanium dioxide shell, under the same light irradiation, its efficiency in catalyzing methylene blue is at most five times that of gold nanorods and at most two times that of Au@Pd nanorods.