ZnO nanophotocatalytic solution with antimicrobial potential toward drug-resistant microorganisms and effective decomposition of natural organic matter under UV light

Abstract This research explores the synthesis of zinc oxide nanomaterials (ZnO NMs) through the utilization of neem leaf extract, presenting an environmentally conscious and sustainable methodology. The biosynthesized ZnO NMs exhibit dual functionality, showing remarkable efficacy in the photocatalytic degradation of natural organic matter (NOM) as well as antimicrobial activity against drug-resistant microorganisms. Under low-energy UV light, ZnO effectively degraded 92 % of NOM within a span of 180 min, concurrently exhibiting substantial antimicrobial effects against Escherichia coli and Candida albicans , characterized by significant inhibition zones. The research further highlights the application of low-energy UV light to improve the photocatalytic efficiency of ZnO NMs, thereby promoting sustainability and reducing the toxicity of by-products. The characterization of ZnO NMs was conducted employing various techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV–vis), and scanning electron microscopy (SEM). At a concentration of 3 g/l, ZnO accomplished a 92 % reduction in NOM over a period of 180 min, accompanied by a 59 % reduction in organic carbon deposition (OCD). The low levels presence of OCD on the surface after the reaction further confirmed the effectiveness of the process. The findings highlight the promise of neem-extract ZnO NMs as an eco-friendly and adaptable substance for environmental cleanup and antimicrobial uses, demonstrating significant antibacterial efficacy at concentrations of 0.05 mg/ml and 0.1 mg/ml.