Synthesis of Zn0.87(Fe, Al)0.065O-MO (MO = NiO, Fe2O3, CuO, and CoO) nanocomposites: Structural, vibrational, optical and antibacterial studies

One of the most effective strategies for achieving high-performance antibacterial activity is the synthesis of nanocomposites by combining different nanoparticles. Hence, Zn0.87(Fe, 0.87 (Fe, Al) 0.065 O - MO (NiO, Fe2O3, 2 O 3 , CuO and CoO) nanocomposites (NCs) with a 7:3 molar ratio were synthesized via the solution combustion method. The produced NCs structural, vibrational, and optical characteristics were investigated using XRD, FTIR, UV-Vis, and PL spectroscopies. The standard disc diffusion method was used to evaluate the antibacterial efficacy of the NCs. The lattice constant, crystallite size, bond length, dislocation density, and other relevant parameters of the NCs were also evaluated. XRD analysis revealed a well-defined mixed-phase structure for all 0.7Zn0.87(Fe, 0.87 (Fe, Al) 0.065 O - 0.3NiO (ZFA-Ni), 0.7Zn0.87(Fe, 0.87 (Fe, Al) 0.065 O - 0.3Fe2O3 2 O 3 (ZFA-Fe), 0.7Zn0.87(Fe, 0.87 (Fe, Al) 0.065 O - 0.3CuO (ZFA-Cu) and 0.7Zn0.87(Fe, 0.87 (Fe, Al) 0.065 O - 0.3CoO (ZFA-Co) NCs, indicating successful mixing of each metal oxide with the ZnO matrix. The average crystallite size within the NCs ranged from 14.21 to 18.10 nm, suggesting a degree of nanocrystallinity nature of all NCs. FTIR confirmed the presence of characteristic functional groups within the NCs. Moreover, all the synthesized NCs exhibited significant optical activation in the ultraviolet radiation range but visible light absorption was also observed when the composite formed with CuO and Fe2O3 2 O 3 nanoparticles. The band gap energy values exhibited variation between 2.72 eV for ZFA-Co NC and 2.90 eV for ZFA-Ni NC. Photoluminescence (PL) emission in the composite formation of ZnO NPs with other metal oxide were significantly influenced by the absorption range of the composite with pn-junction formation in a notable enhancement of antibacterial efficacy against bacterial strains of Escherichia coli and Staphylococcus aureus. . Particularly, ZFACo NC exhibited an excellent antibacterial performance against both bacterial strains.