The photocatalyst sorbic acid (SA)/titanium dioxide (TiO2) was successfully synthesized by sol-gel method and characterized. The composite exhibited regularly spherical particles with the size of 50 nm and the specific surface area of 90.3 m2 g-1, furthermore, it showed mesoporous structure and significantly improved dispersion. SA was grafted on TiO2 surface by -COOTi and TiO2 existed as pure anatase phase in the composite. The addition of SA made the band gap of TiO2 increased from 3.03 to 3.35 eV, which indicting that the composite exhibited a strong response to the ultraviolet light. The optimum preparation parameters of the catalyst were as follows: n(Ti):n(SA) = 1:0.05, ethanol 60 mL, glacial acetic acid 40 mL, hydrothermal temperature 180 °C, hydrothermal time 12 h. The composite could reach the 4.31 log reduction of E. coli, with the optimum catalyst dosage of 0.7 g L-1, irradiated by UV light for 60 min. SA/TiO2 was an environmentally friendly, non-toxic and safe sterilized nanocomposite material appropriate for future bactericidal applications, providing a new way to effectively increase the dispersion of TiO2 particles to achieve superior photocatalytic sterilization efficiency.
Keywords: E. coli; In situ modification; Sorbic acid; Sterilization activity; TiO2.
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