Photocatalytic antimicrobial and photostability studies of TiO2/ZnO thin films

A nanothin film-based antimicrobial coating has been attractive in response to the rise and spread of pathogenic microbes, which led to the development of low-cost, effective, and rapid disinfection methods for coating material. TiO2/ZnO bilayer thin films have been developed through magnetron sputtering and thermal oxidation. The influence of oxidation temperature on structural, optical, photocatalytic, photostability, and antimicrobial properties of Ti/ZnO thin films has been addressed. X-ray diffraction (XRD) analysis has shown the presence of hexagonal wurtzite ZnO, Ti0.895O.77, and anatase TiO2 in the bilayer films. Increasing the oxidation temperature reveals a certain degree of crystallization and transforms Ti0.895O.77 into the anatase/rutile TiO2 phase. The bottom layer of ZnO provides sufficient oxygen to improve TiO2 crystallinity and prevent trans-forming anatase to rutile during thermal oxidation process. Moreover, Ti/ZnO thermally oxidized at 550 & DEG;C exhibit excellent photocatalytic performance under UV irradiation with high photostabil-ity. The inhibition rate increased (p < 0.05) with irradiation time for E. coli, S. aureus, and C. albi-cans with effectiveness values reaching approximately 97 & PLUSMN; 3.408, 98 & PLUSMN; 2.409, and 95 & PLUSMN; 3.105 %, respectively. This work reveals that magnetron sputtering through a thermal oxidation approach could generate stellar TiO2/ZnO thin films as photocatalysts and antimicrobial agents with cost-effectiveness and efficiency. & COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

A TiO2/ZnO bilayer thin film was prepared using magnetron sputtering and thermal oxidation. The oxidation temperature was found to affect the structural, optical, photocatalytic, photostability, and antimicrobial properties of the film. Increasing the oxidation temperature led to the transformation of Ti0.895O.77 into the anatase/rutile TiO2 phase and improved the crystallinity of TiO2. The resulting Ti/ZnO thin film exhibited excellent photocatalytic performance and antimicrobial properties when thermally oxidized at 550°C.