Preparation of titanium dioxide/silver sulfate powder and its antibacterial activity

摘要

Antibacterial powders of titanium dioxide/silver sulfate were produced by heat-treatment of the metatitanic acid, as precursor, into which the silver nitrate was added. The influences of heating temperature on the structure and composition of the product were investigated through XRD and SEM. The results show that the powder is spherical in the phase of TiO_2-Ag_2SO_4. The granularity of the particles increases from 10. 7 nm to 28. 7 nm with the temperature of heat-treatment increasing from 300 deg C to 800 deg C. The antibacterial activity of the powder was judged in the way of the minimum inhibitory contents (MiCs). When the content of silver sulfate is less than 2 percent , the photocatalysis of titanium dioxide and silver ions cooperate to kill bacteria. And the MiCs decrease and keep around 1. 0 X 10~(-4)- 1. 5 X 10~(-4) constantly with the increase of silver content. Furthermore, the MiCs decrease with the increase of temperature of heat-treatment when the temperature is lower than 500 deg C. But when the temperature is beyond 600 deg C the MiCs increase quickly, which shows the inferior antibacterial performance.