Kinetic studies of NiO-rGO hybrid nanocomposite for the treatment of organic toxic effluents and oxidative stress

Abstract

ABSTRACT The extensive use of aromatic compounds in industries is increasing the contamination of the water. Treatment of wastewater by environment friendly and financially effective methods has become a research hotspot. In the current study, graphene-based nanocomposite was found as effective nano-adsorbent due to π–π interaction and large surface area of graphene to interact with organic pollutants. Nickel oxide–reduced graphene oxide nanocomposite (NiO-rGO ncp) was synthesised by using the extract of Cordia myxa leaves as a reducing agent. The characterisation of nanocomposite was carried by using UV-Vis spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and scanning electron microscopy (SEM) which revealed the size (6.16 nm) and morphology (spherical) of the synthesised nanocomposite. The antioxidant potential of nanocomposite was also evaluated using DPPH radical scavenging potential, total antioxidant potential and total phenolic content (TPC) which was found to be good. The ability of nanocomposite to catalyse the removal of methylene blue dye, rhodamine B dye and phenol was also assessed. NiO-rGO ncp showed 99% removal for methylene blue, 90% removal for rhodamine B using a tungsten bulb and 88% phenol elimination. Thermodynamic investigations validated the adsorption process’s spontaneity. Adsorption isotherm and kinetic models were also applied. A novel nanocomposite was demonstrated to be an effective antioxidant and a potential adsorbent for the extraction of organic pollutants from aqueous contaminated waste.