Zinc oxide derived from zinc(II)/acetoxime system: formation pathway and solar-driven photocatalytic and antimicrobial applications

Zinc(II)/acetoxime system, [ZnCl₂.2{HONC(CH₃)₂}] has been synthesized and studied by single-crystal X-ray diffraction and thermogravimetric analyses. This coordinated complex has been utilized as a potential precursor for photocatalytic and antibacterial zinc oxide nanoparticles (ZnO NPs) by sol–gel method. The powder XRD patterns of the formed ZnO particles suggest formation of a hexagonal phase with an average crystallite size of ~15 nm, which corroborates with TEM analysis. The photocatalytic activity of the synthesized ZnO NPs was examined for the degradation of methylene blue and methyl orange dyes under sunlight. In total, 99.8% of MB and 55.42% of MO were degraded within 160 min of irradiation. The formed ZnO was also explored for its potential to reduce the viability of the Gram-negative bacteria, Escherichia coli and Gram-positive bacteria, Staphylococus aureus. ZnO was found to be a promising antibacterial agent against both the bacteria; however, in the case of E. coli, higher concentration was required (2.5 mg·mL⁻¹) as compared with the S. aureus, where inhibition occurred at low concentration (0.005 mg·mL⁻¹).