Enhancing photocatalytic and antibacterial performance through compositional optimization of NiO–CdO heterogeneous nanocomposites

This research focuses on the optimization of NiO–CdO heterogeneous nanocomposites to enhance their photocatalytic and antibacterial properties. Through the ball milling method, we synthesized the nanocomposites with varying weight percentage ratios of NiO and CdO powders and extensively characterized them using multiple analytical techniques. Our systematic investigation examined the impact of different NiO and CdO compositions on the structural, morphological and optical properties of the nanocomposites. Rietveld refinement confirmed the presence of desired phases in the NiO–CdO nanocomposites. Furthermore, we evaluated the antibacterial efficacy of these nanocomposites against Escherichia coli and B. subtilis, as well as the inhibition zone diameter against yellow 28 dye. Our results demonstrated that the NiO–CdO nanocomposites with a molar ratio of 1:1 exhibited the highest photocatalytic activity and antibacterial efficacy. These superior properties can be attributed to the synergistic effect between NiO and CdO, which promoted the efficient separation of photo induced charge carriers and the generation of reactive oxygen species. Importantly, our cytotoxicity assessment indicated the non-toxic nature of CdO. Overall, our findings highlight the promising potential of NiO–CdO nanocomposites in biomedical applications, specifically for their exceptional antibacterial and anti-biofilm activities.