Synthesis Photocatalytic TiO<sub>2</sub>/ZnO Nanocomposite and Investigation through Anatase, Wurtzite and ZnTiO<sub>3</sub> Phases Antibacterial Behaviors

Abstract

Titanium dioxide is prepared by sol gel method from titanium tetraisopropoxide (TTIP) as precursor and likewise zinc oxide is prepared by sol gel method from zinc acetate dehydrate (ZAD) as precursor. The composite sols are prepared in three different molar ratios 90TiO2:10ZnO, 70TiO2:30ZnO and 50TiO2:50ZnO. Thin film deposition is carried out by dip coating technique. Crystal structure, surface morphology and photocatalytic activity of the prepared nanocomposite thin films are investigated. The antibacterial activity of the prepared nanocomposite thin film against E-coli ATCC 25922 bacteria is examined by placing the thin film in standard aqueous E-coli medium under UV light for 1, 2, 3 and 4 hours and then counting the bacteria with Standard Plate Count Agar (SPC) technique. The prepared thin films have shown strong antibacterial activity in the presence of UV light and by increasing the ZnO molar ratio from 10 to 50, antibacterial activity of the thin films decreases because of decreases in the anatase phase of the TiO2. In the dark conditions by increasing the molar ratio of ZnO, the antibacterial activity of the thin films increases and this phenomenon is related to increasing the zinc ions in the thin films.