Investigations on structural, textural, optical and antimicrobial properties of solvothermally tailored Ni-doped ZnO nanoparticles

Abstract Nickel-doped Zinc Oxide (Ni-ZnO) nanocomposites have a great potential in tackling of the antimicrobial resistance. In the current research, pure ZnO and a series of Ni-ZnO (1 to 10% Ni) nanoparticles are fabricated successfully via. a solvothermal route. The X-ray diffraction spectra ascertained the hexagonal wurtzite structure with effective incorporation of Ni²⁺evidenced through lattice parameter shifts and microstrain variations. The FT-IR spectra showed maintained Zn–O bonding and decreased surface hydroxyl groups on Ni doping. The SEM and TEM images revealed evolution in morphology from rod-shaped ZnO to spherical nanoparticles of Ni-ZnO. The UV-Vis spectroscopy exhibited the increasing absorbance and decreasing bandgap from 3.05 eV to 2.95 eV. The XPS established the presence of Zn²⁺, Ni²⁺, and oxygen without secondary phases. The antimicrobial screening of the materials unveiled good activity against Staphylococcus aureus and moderate against the Candida albicans, with no action on Escherichia coli bacteria. These findings validate ZnO-based nanocomposites as viable agents for biomedical and pharmaceutical applications.