Influence of different alkaline actuators in synthesis of NiO NPs: A comparative green approach on photocatalytic and in vitro biological activity

Nickel oxide nanoparticles (NiO NPs) were produced by employing a sonochemical approach with the use of three distinct alkaline activators, namely sodium hydroxide (NaOH), potassium hydroxide (KOH), and ammo-nium hydroxide (NH3OH) and as well as extract of Moringa oleifera leaves. The physiochemical and optical characteristics of sonochemically synthesized nanoparticles were examined comparatively with green synthe-sized NiO NPs. The comparison rendered the high-yield production of NiO nanoparticles achieved in the green synthesis process that includes 63.29 % of the total nickel precursor employed. The prepared samples were further investigated for their photocatalytic activity for safranin and methyl orange dye. Thus, the Moringa oleifera mediated NiO NPs have achieved the highest degradation efficiency of 92.75 % and 98.02 % against the corresponding dyes. Including NiO NPs in DPPH antioxidant activity have higher free radical scavenging effi-ciency of 95.3 %. The reduction of growth against specific S. aureus and E. coli bacteria at low concentrations of NiO-NPs was coined for various in-vitro biological and clinical applications.