“Ship-in-a-Bottle” Approach to Synthesize Ag@hm-SiO₂ Yolk/Shell Nanospheres

An e ective protocol is presented for the synthesis of Ag@hm-SiO₂ yolk/shell nanostructures (YSNs) via a facile “ship-in-a-bottle” method. TEM observations show that the as-obtained Ag@hm-SiO₂ YSNs have a single silver core in the interior of hollow mesoporous silica (hm-SiO₂) nanospheres, in which the thickness of hm-SiO₂ outer shell is about 14 nm and the silver core has an average size of about 43 nm. And the content of silver in Ag@hm-SiO₂ YSNs is about 10.29% based on the inductively coupled plasma measurement. The as-synthesized Ag@hm-SiO₂ YSNs exhibited signi cantly enhanced catalytic performance compared with the pure Ag nanoparticles toward the reduction of 4-nitrophenol to 4-aminophenol in the presence of Na₄.