Catalytic nano-rattle of Au@hollow silica: Towards a poison-resistant nanocatalyst

In this work, size-controlled gold nanocatalysts (2.8 to 4.5 nm) inside monodisperse hollow silica nanospheres, Au@HSNs, have been prepared by using a water-in-oil microemulsion as a template. The size of gold nanocatalysts can be easily controlled based on the gold precursor and the chloroauric acid concentration used during synthesis. These Au@HSN nanocatalysts were characterized by transmission electron microscopy, scanning electron microscopy, N₂ adsorption-desorption isotherms, powder X-ray diffraction, and UV-vis spectrometer. Furthermore, we demonstrate their catalytic capability with respect to the 4-nitrophenol reduction reaction in the absence and presence of a thiol compound, meso-2,3-dimercaptosuccinic acid. The results show that the Au@HSNs display highly catalytic activity and resistance to other strongly adsorbing molecules in reaction solutions.