Investigation of structural, optical properties Zn0.96(Fe, Al)0.02O – MO (MO = NiO, Fe2O3, CuO, and CoO) nanocomposites for antibacterial application

This study investigates the effect of doping and nanocomposite formation on the optical and structural properties of Zn₀.₉₆(Fe,Al)₀.₀₂O-based nanocomposites (NCs) with NiO, Fe₂O₃, CuO, and CoO, synthesized via solution combustion. Characterization through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy confirmed successful integration within the ZnO matrix, with no peak shifts indicating stable phase mixing. Crystallite sizes ranged from 10.99 to 22.42 nm, and band gaps from 2.77 to 3.11 eV, indicating a visible-range absorption shift. FTIR spectra evidenced functional groups, while particle size analysis revealed broad distribution for ZFA-Cu and narrower, more uniform sizes for ZFA-Ni and ZFA-Co. Antibacterial efficacy, assessed via disc diffusion, demonstrated significant activity against both Gram-positive and Gram-negative bacteria: ZFA-Cu exhibited maximum zones of inhibition (ZOI) against E. coli , whereas ZFA-Ni showed superior activity against S. aureus . These findings suggest the potential of these nanocomposites for antibacterial applications, especially in combating antibiotic-resistant pathogens.