Preparation Of TiO₂/ZnO Composite And Its Antibacterial Activity

With more attention paid to public health, antibacterial materials have been widely used in daily life. The research on the high antibacterial activity and purification of composites has become a hotspot, especially the antibacterial of TiO2 composites. In this study, TiO2/ZnO composite was prepared by hydrothermal synthesis method. The crystal structure and morphology of the TiO2/ZnO composite were characterized by XRD, SEM and EDX method. The antibacterial activity of the TiO2/ZnO composite was performed by the bacterial inhibition ring test and bacteria suspensions exposure test, respectively. The antibacterial activity of TiO2/ZnO composite in different concentrations of bacteria and the effect of temperature on TiO2/ZnO composite during the research were investigated. In addition, the preliminary exploration of the carrier of TiO2/ZnO composite materials –had been conducted.The results show that the TiO2/Zn O composite prepared by hydrothermal synthesis method was consisted of Ti, O and Zn and composed of anatase, rutile and hexagonal wurtzite. There is great amount of tiny lamellar structure on the surface of composite. The median particle sizes of TiO2 and TiO2/ZnO composite were 1.411 ?m and 1.504 ?m. Thus, the composite had achieved a combination of anatase and rutile TiO2 heterostructure with wurtzite structure of ZnO, while the particle size had little change.Antibacterial activity of TiO2/ZnO composite was significantly better than TiO2. Under the dark condition, TiO2/ZnO composite could produce 17 mm inhibition zone diameter to Escherichia coli. Under the visible light irradiation, TiO2/Zn O composite could produce 22 mm inhibition zone diameter to Escherichia coli. Exposure to bacteria suspensions, the inactivation rate difference of the TiO2/ZnO composite between visible light and dark conditions was mainly reflected in the initial stage. In 0.5 h, the inactivation rate of TiO2/ZnO composite could achieve approximately 16.99% under visible light irradiation and 8.45% under dark conditions; In 1 h, the inactivation rate of TiO2/ZnO composite could achieve approximately 32.17% under visible light irradiation and 22.60% under dark conditions; The inactivation rate of TiO2/Zn O composite achieved 99.90% in 4 h under the visible light and dark conditions, the visible light irradiation improved the early inactivation rate of TiO2/ZnO composite, which provided a guidance for the applications of the TiO2/ZnO composite. In the range from 4 oC to 30 oC, higher temperature could promote the antibacterial activity of TiO2/ZnO composite. Under the condition of fully conntacting with 100 mL water sample,(0.5 ± 0.05) g of TiO2/ZnO composite had good antibacterial effect to the sample in which the concentration of bacteria was below 107 CFU/m L.t 30 oC inactivationA, the rate of culturable heterophic bacteria in the secondary effluents could achieve 90.40% by TiO2/ZnO composite. And there was no effect on activity-of Ti O60 g of antibacterial 2/ZnO composite when SS was below 20 mg/L. haydite could load approximately 1 g of TiO2/ZnO composite, which was significantly higher than the quartz sad. The inactivation rate of haydite loaded with TiO2/ZnO tocould reach 99.58% in the contact time of 4 h. bacterial suspension...