Sustainable remediation of toxic industrial pollutant  via NiO/ZrO2/Mn3O4 biomimetic nano-photocatalysts

The greener approaches for synthesis of triple junction nanostructured material consisting of  NiO/ZrO/Mn3O4 mixed oxide provided an alternative way by lowering the hazardous chemicals utilization and diminishing biological risks in the biomedical applications. Plant-assisted synthesis of mixed metal oxide nanoparticles is now bulging because of its simplicity, rate of synthesis and environmental affability. The structural and morphological properties of synthesized nanocomposite were analyzed by various spectroscopic techniques including Fourier transform infrared spectroscopy, X-ray powder diffraction, Raman and field emission scanning electron microscopy coupled with energy-dispersive spectroscopy which confirmed the formation of pure NiO/ZrO2/Mn3O4 nanocomposites. The phytochemicals found in the leaf extract for the formation of metal oxide nanocatalysts were identified using Fourier transform infrared spectroscopy and gas chromatography–mass spectrometry. The organic complex (phytocompounds of leaf extract) plays an important role in the synthesis mechanism as well as in improving the catalytic efficiency of the material, as the organic functional groups incorporate electron and proton into the reaction mechanism. The study covers the effect of triple metal oxide nanoparticles size on the rate of degradation of hazardous dye (methyl orange). The nanoparticles were proved as an efficient candidate for the catalysis of organic dyes via the electron transfer process. The removal of methyl orange increased with time depicting excellent catalytic activity of the catalyst even under dark ambient conditions (84%). Moreover, the kinetics of catalytic reaction process based on composite (NiO/ZrO/Mn3O4) follows pseudo-first-order kinetics.