Facile approach to synthesize uniform Au@mesoporous SnO₂ yolk–shell nanoparticles and their excellent catalytic activity in 4-nitrophenol reduction

Monodispersed and uniform Au@mesoporous SnO₂ yolk–shell nanoparticles (Au@mSnO₂ yolk–shell NPs) composed of the moveable Au NP cores and mSnO₂ shells have been successfully fabricated via a facile and reproducible approach. The outside mSnO₂ shells of Au@mSnO₂ yolk–shell NPs not only prevent Au NPs from aggregating and corroding by the reaction solution but also allow the Au NPs to contact with reactant molecules easily through the mesoporous channels. The obtained Au@mSnO₂ yolk–shell NPs are characterized by means of transmission electron microscope, scanning electron microscopy, X-ray powder diffraction, X-ray photoelectron spectrum, and UV–vis absorption spectroscopy. The synthesized materials exhibit excellent catalytic performance and high stability towards the reduction of 4-nitrophenol with NaBH₄ as a reducing agent, which may be ascribed to their high specific surface area and unique mesoporous structure. Moreover, the synthetic strategy reported in this paper can be extended to fabricate a series of multifunctional noble metal@metal oxide yolk–shell nanocomposite materials with unique properties for various applications.