Unveiling the potential of NiO–ZnCo 2 O 4 nano-composites: Electrical, optical, electrochemical and antibacterial investigation

Zinc Cobaltite (ZCO) and Nickel Oxide (NiO) nanoparticles (NPs) were synthesized using a sol-gel technique, and their composites with different weight ratios were prepared using a straightforward sonication method. The NiO and ZCO NPs had small crystallite size of 10 nm and 18 nm, respectively. According to the ultraviolet–visible (UV–Vis) spectra, pure NiO and ZCO NPs exhibited band gaps of ∼3.5 eV and 3.3 eV. Antibacterial activity against gram-positive ( Staphylococcus aureus ) and gram-negative ( Escherichia coli ) bacterial strains was also tested for the composite counterpart and its equivalents. Compared to pure NPs, the composite of 30 % ZCO-NiO (NZ3) had higher antibacterial activity with zone of inhibition of ∼13 mm against E. coli. The electrical and electrochemical properties were also explored and it was found that the composite of 50 % ZCO-NiO (NZ5) shows high specific capacitance of 188 F/g.