Synthesis of Ag-SiO2 composite nanospheres and their catalytic activity

A simple, mild, and time-saving method is employed to synthesize Ag-SiO₂ composite nanospheres with Ag nanoparticles uniformly distributed on the surface of SiO₂ nanoparticles. The chemical elements and the morphology of Ag-SiO₂ composite nanospheres were analyzed with transmission electron microscopy (TEM), X-ray power diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). On the surface of Ag-SiO₂ composite nanospheres, silane coupling agent (KH-550) is introduced as an intermediary to connect the surfaces of SiO₂ nanospheres and Ag nanoparticles, which is also helpful for avoiding the aggregation of Ag nanoparticles. It is found that Ag-SiO₂ composite nanospheres have very good catalytic properties for the reduction of organic dyes, which may have potential application in wastewater treatment.