Synthesis of micron-SiO2@nano-Ag particles and their catalytic performance in 4-nitrophenol reduction

Ag nanoparticles (Ag NPs) were deposited on the surface of micron silica spheres. The structure of the composite was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscope (TEM) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) method. The as-prepared micron-SiO 2 @nano-Ag particles were used as a catalyst in the borohydride reduction reaction of 4-nitrophenol (4-NP), which was detected by UV–vis absorption spectroscopy. The result showed that the composite particles presented a comparable catalytic activity with that of spherical silver nanoparticles.