Design and performance assessment of novel Fe3O4 decorated nanoblend of guar gum/graphene oxide flakes and CuO for mitigation of fluoroquinolones from wastewater

Abstract

Organic-inorganic nanoblends particularly, polysaccharide-blended-inorganic ones, possess interesting properties and hence versatile applications, due to which they have become the focus of much research attention, lately. The present study reports the fabrication of magnetic guar gum/graphene oxide nanocomposite blended with CuO to obtain a novel nanoblend, mGG/GO/CuO NB, through a two-stepped synthesis route: preparation of GO via Improved Hummers technique followed by mGG/GO/CuO NB preparation using co-precipitation method. The nanocomposite was subsequently investigated for its capacity for adsorptive elimination of ciprofloxacin from aqueous medium. It was identified using typical physico-chemical techniques, such as XRD, Raman, and FTIR spectroscopy; EDX and FESEM for morphological investigation; as well as VSM, pHZPC and TGA. The Langmuir isotherm model and the pseudo second order model are obtained as the isotherm model and kinetic model that can best depict the adsorption behaviour. The Langmuir isotherm model provided an outstanding maximum adsorption capacity value of 769.23 mg g−1 for CPX removal. Thermodynamics studies witness a spontaneous adsorption with an exergonic behaviour supported by a ΔGo value of −11.74 kJ mol−1 and ΔHo value of −49.976 kJ mol−1 as well as an increase in ΔSo value (+189.32 mol−1). Columbic/electrostatic interactions, hydrophobic interactions, hydrogen bonds, and electron-donor-acceptor (EDA) interactions are the main interacting forces predicted to be pivotal in the adsorption mechanism.