Zn-doped NiO nanocomposites for efficient solar light-assisted wastewater treatment and its profound for low phytotoxic and antibacterial applications

The present research aims to eradicate methylene blue toxins (test effluent) in aquatic environments using photocatalytic Zn-doped NiO nanoparticles. Ultrasonic-assisted co-precipitation process was adopted to synthesize Zn-doped NiO nanoparticles. The prepared samples were characterized by XRD, SEM, in vitro antibacterial, phytotoxicity, and photocatalytic analysis. XRD patterns exhibited a solitary phase of Fm3m space-group-cubic-structured Zn-doped NiO crystallites with a preferred orientation along the (200) plane. SEM analysis explored the formation of nanorods with hexagonal ends. Zn-doped NiO is capable of rendering significant antibacterial efficacy against Staphylococcus aureus (MTCC 25923) and Escherichia coli (MTCC 25922) bacterial strains. Zn-doped NiO nanocomposites are appropriate for decomposing methylene blue (MB) contaminants in 120 minutes under direct sunlight irradiation. Hydroponically grown Vigna radiata seedlings and Mentha piperita L plants in dye-deprived water show minimal phytotoxicity and enhanced physiological aspects of plants. The outcome of the current research encouraged bringing new ideas for further utilization of textile MB effluent after photocatalytic treatment to non-domestic applications, such as irrigating roadside plants, public parks, and gardens.