Green Synthesis of Nickel Oxide Nano particles from Lawasonia inermis leaf extract for promising Methyl red Uptake and Efficient Iodine Adsorption

Abstract

Water pollution is the threat to the survival of life on mother earth but due to industrialization clean reservoirs of water deteriorated day by day which demands eco-friendly, cheap and highly efficient methods to counter this issue. So due to this pressing ultimatum nickel oxide (NiO) nanoparticles are synthesized with Lawasonia inermis as a reducing and capping agent. Green-synthesized NiO-NPs are analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and energy dispersive x-ray (EDX). In this study, synthesized NiO-NPs are used to remove methyl red (MR) and radioactive iodine from polluted water. The maximum adsorption efficiency of methyl red is 89% at contact time 120 minutes, pH 5.0, temperature 10 ⁰C and adsorbent dose of 1 g. The percentage adsorption by weight of NiO nanoparticles for radioactive iodine is 225%. The adsorption capacity was calculated 4.58 mgg^− 1 for methyl red at optimum conditions. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich adsorption isotherms are studied, and the experimental data suggests that Langmuir isotherms are best fit with R² = 0.996. According to a kinetic analysis, the pseudo 2^ND order kinetic model best fits the adsorption mechanism having R² = 0.993 A thermodynamic study shows the current process is spontaneous and endothermic, where Gibbs free energy (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were − 5.9461 kjmol^− 1, 33.04 kjmol^− 1 and 0.00338 kjmol^− 1K^− 1, respectively. NiO NPs contribute to the degradation of methyl red with minimal resource utilization with promising efficiency. Additionally, in the future, it may be used for the degradation of other environmental contaminants. Graphical abstract of synthesis and application of NiO-NPs