Preparation of Ag/SiO2 powder with light color and antibacterial performance

•Ag NPs are in a non-oxidized state.•Air isolation is an effective way to prevent discoloration of Ag/SiO2 powder.•The powder prepared has little change when it is exposed to air.•The Ag/SiO2 powder displays light color and good antibacterial performance.

Ag/SiO2 powder was prepared by chemical reduction method. By changing the Ag+ concentration and air isolation, the color of Ag/SiO2 powder was altered. The results show that Ag NPs are in a non-oxidized state, as revealed by X-ray photoelectron spectroscopy, and dispersed in SiO2 with an average particle size of about 30 nm, as measured using electron microscopy. Air isolation is an effective method to prevent oxidation and discoloration during the preparation of Ag/SiO2 powder. The Ag/SiO2 powder displays light color and good antibacterial performance, and has little change when it is exposed to air. This will significantly expand the application of the silver-doped silica products.

Graphical abstractThe color of Ag/SiO2 powder samples becomes shallow gradually from samples 1# to 9#. Sample 1# is black and finally sample 9# displayed almost white color. Both reducing Ag+ concentration and air isolation are effective measures in the preparation of Ag/SiO2 powder with light color. And air isolation caused no damage to the antibacterial performance of Ag/SiO2 powder.Figure optionsDownload full-size imageDownload as PowerPoint slide