Synthesis and Catalytic Performance of Multiple Gold Nanodots Core-Mesoporous Silica Shell Nanoparticles

Abstract

Multiple gold (Au) nanodots core-mesoporous silica shell nanoparticles (multi-Au@mesoporous-SiO2 NPs) were successfully synthesized in solution through a soft-etching methodology. Thermal treatment of the multi-Au@SiO2 NPs in water without adding any other additives lead to generation of mesopores over the silica shell without any change in the size and number of the Au nanodots. The multi-Au@mesoporous-SiO2 NPs showed much higher catalytic activity in the reduction of 4-aminophenol than multi-Au@SiO2 NPs and other single Au nanodot core-silica shell nanoparticles with york-shell morphologies, which were also effectively fabricated (single-Au@SiO2 NPs and single-Au@mesoporous-SiO 2 NPs). The enhanced catalytic activity is mainly due to the efficient diffusion of reactants onto the multiple Au nanodots through mesopores within the silica shell as well as the higher surface area of multiple Au nanodots.