Antibacterial Activity of Visible Light-Activated TiO2 Thin Films with Low Level of Fe Doping

Dan Meng,Yang Du,Yong Yang,Chao Xiao,Yun Xie,Xiuhua Liu

doi:10.1155/2019/5819805

Dan Meng, Yang Du + Show 4 more

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https://doi.org/10.1155/2019/5819805

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Abstract

Development of effective antibacterial visible light-activated photocatalytic materials in industries including wastewater treatment and food industry has attracted increasing attention. In this work, Fe-doped TiO2 thin films with different doping levels on a glass substrate were prepared by the sol-gel dip-coating method. The as-prepared films were characterized by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). Raman spectroscopy and XRD results show the crystalline phase of titanium dioxide was anatase, and the range of the crystal size for the films was 19.24–22.24 nm. XPS results indicate that iron was in the form of Fe3+ in Fe-doped TiO2 films. Regarding the antibacterial properties of TiO2 films, the order of antibacterial activity of TiO2 films was 0.1 at% Fe > 0.5 at% Fe > 1.0 at% TiO2 > bare TiO2 > 2.0 at% Fe > 3.45 at% Fe. 0.1 at% of Fe is the optimum dopant ratio related to antibacterial activity. 0.1 at% Fe-doped TiO2 film is highly efficient in inactivating E. coli under 3 h of visible light irradiation, and it remains efficient even in real dye waste water.

Highlights

Visible and solar light-active semiconductor photocatalysis has been greatly documented for antibacterial application in food industry, environmental, hospital, and wastewater treatment [1,2,3,4,5,6,7,8]
In order to explore the effect of iron content on the antibacterial properties of TiO2 thin film visible light irradiation, TiO2 films with different iron contents by the sol-gel dip-coating method on the glass substrate were prepared in our work. ese series of Fe-doped TiO2 thin films were characterized by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM)
Antibacterial Test. e antibacterial test was carried out in the aseptic room throughout the experiment. e antibacterial activity of the Fe-doped TiO2 films and bare TiO2 films was evaluated by the method of GB/T 5750.12–2006 [39]. e strain of Escherichia coli (E. coli ATCC 8739) was cultured in the solid medium and liquid medium, respectively. e lactose peptone suitable for E. coli growth was used to configure liquid medium and agar for medium configuration

Summary

Introduction

Visible and solar light-active semiconductor photocatalysis has been greatly documented for antibacterial application in food industry, environmental, hospital, and wastewater treatment [1,2,3,4,5,6,7,8]. Arellano et al [34] reported the antimicrobial activity under visible light irradiation of TiO2 thin films with 3 wt% and 5 wt% of Fe on the glass substrate by the spincoating method. In order to explore the effect of iron content on the antibacterial properties of TiO2 thin film visible light irradiation, TiO2 films with different iron contents by the sol-gel dip-coating method on the glass substrate were prepared in our work.

Results

Conclusion