Low Temperature Synthesis of Se2+ Doped TiO2 Nanoparticles for Inhibition of Escherichia coli

Nanocrystalline TiO2 powder with and without Se2+ doping were successfully synthesized at low temperature by a microwave-assisted sol-gel method. The synthesized TiO2 powders were characterized by XRD, UV-vis, FT-IR and SEM. It was found that anatase and brookite phase was formed after refluxed at 80 degrees C using a domestic microwave oven. The study also investigated the efficiency of this compound to inhibit the growth of Escherichia coli with various concentrations of 0, 0.5, 1.0 and 2.0 mole % doping Se2+. The antibacterial activity against Escherichia coli was investigated with a vitro test, from which the mixture of conidial suspension and Se2+ doped TiO2 powder was added to Macconkey Agar plates under fluorescent light irradiation. It was found that Se2+ doped TiO2 nanoparticles enhance photocatalytic activity and bacterial inactivation efficiency. In addition, 1.0 mole % Se2+ doped TiO2 nanoparticles can destroy the bacteria within 10 min. Furthermore, the disinfection efficiency of Se2+ doped TiO2 is good activity is mainly related to the high OH radicals on its surface. The absorption threshold of the Se2+ doped photocatalyst shifted to the visible region of the spectrum.