High-performance photocatalytic and antibacterial properties of WO3/ZnO honeycomb structures: synthesis and mechanistic insights

Abstract

A hexagonal honeycomb-structured WO₃-loaded ZnO catalyst was synthesized using a solvothermal method and characterized through various techniques, including FT-IR, XRD, FE-SEM, TEM, UV-Vis, DRS, PL, XPS, and BET measurements. The work novelty for WO₃-loaded ZnO photocatalysts refers to the innovative aspects and new contributions to the field of photocatalysis that come from the combination of tungsten oxide (WO₃) with zinc oxide (ZnO). This composite material is being studied to enhance photocatalytic activity under various conditions, including UV, visible and solar light irradiation. Furthermore, it will increase enhanced photocatalytic efficiency, charge carrier separation, synergistic effect, tuning band gap and energy aligment, durability and stability, etc. The influence of tungsten concentration on the surface morphology, structure, and optical properties was thoroughly investigated. XRD analysis confirmed the hexagonal wurtzite structure, with crystallite size decreasing from 36.95 to 28.11 nm as the WO₃ loading increased. Surface morphology revealed irregularly shaped grains, including chain-like, hexagonal, and spherical nanoparticles with slight size variations. The introduction of tungsten notably altered the properties of ZnO nanoparticles, with the grain size playing a key role in these modifications. Additionally, the band gap decreased with 5 wt% WO₃ loading. Photoluminescence spectra showed an emission at 482 nm, corresponding to blue-green emission bands. Additionally, the synthesized WO₃/ZnO catalyst has also a wonderful photocatalytic performance in the degradation of three azo dyes: NBB, RR 120, and AR 27, when exposed to sunlight. Moreover, WO₃-loaded ZnO nanoparticles exhibited enhanced antibacterial effectiveness against E. coli, S. typhimurium, and P. mirabilis strains.