Facile fabrication of Z-scheme TiO2/ZnO@MCM-41 heterojunctions nanostructures for photodegradation and bioactivity performance

Designing Z-scheme heterojunction materials as a highly efficient photocatalyst is essential in environ-mental remediation. Herein, a new type of TiO2/ZnO@MCM-41 (TZM-41) heterojunction photocatalyst was designed for degrading organic dyes from wastewater and antibacterial activity on Staphylococcus (S. aureus). First, mesoporous MCM-41 silica material was fabricated with the sol-gel method and then calcinated under 550 ? to form porous material. Subsequently, ZnO and TiO2 crystals were grown onto the MCM-41 surface to obtain a TZM-41 heterojunction photocatalyst. TZM-41 nanocomposite with visible light excitations revealed a maximum degradation of methylene blue (MB) and methyl orange (MO) under visible light irradiation. The reusability tests, reaction mechanism, reaction kinetics as well as TOC and COD tests were investigated on the photocatalytic performance. The findings obtained from the reaction mechanism, quenching radical test, and electron spin resonance (ESR) technique indicated that hydroxyl radicals ('OH) and superoxide anion ('O2?) play an essential role in organic dyes degradation. Furthermore, the antibacterial properties of ZnO and TZM-41 nanocomposite were evaluated on S. aureus. The current study provides new horizons to develop Z-scheme heterojunction materials for improvement in water treatment and remediation. (c) 2022 Elsevier B.V. All rights reserved.