Zinc-Imidazole Metal-Organic Nanocomposite for High-Efficiency Crystal Violet Removal and Antibacterial Applications for Environmental Remediation

The development of multifunctional materials capable of simultaneously removing toxic dyes and providing antibacterial protection is critical for sustainable environmental remediation. In this study, a zinc-imidazole ([Zn-Im]) metal-organic nanocomposite was synthesized and evaluated for its dual role in removing Crystal Violet (CV) dye from aqueous systems and inhibiting bacterial growth. Characterization by FT-IR, XRD, SEM-EDX, and elemental mapping confirmed successful coordination between ZnO and 2-methylimidazole, yielding a porous and well-structured nanocomposite. Adsorption studies demonstrated that [Zn-Im] achieved 95% CV removal within 5 h under optimal conditions, following pseudo-second-order kinetics and fitting well to the Langmuir isotherm. The presence of competing ions reduced efficiency due to site blocking, but high removal rates were maintained for both tap water and pond water. Antibacterial assays revealed strong inhibitory effects against Bacillus cereus, Bacillus amyloliquefaciens, and multiple Burkholderia cepacia strains, with tolerance varying by species. Molecular docking suggested favorable π-π and π-alkyl hydrophobic interactions between CV and [Zn-Im], supporting the observed adsorption performance. The nanocomposite retained 60% efficiency after four reuse cycles, highlighting its reusability potential. Overall, [Zn-Im] offers an effective, reusable, and multifunctional solution for integrated sustainable environmental remediation.