Tailored rGO@Fe3O4 and rGO@Co3O4 Nanocomposites for Treatment of Organic Toxic Effluents: Modeling, Optimization, Kinetics, and Recyclability Evaluation

Water pollution has emerged as an important concern because polluted water damages the whole ecosystem. In order to prevent the loss of contaminated water, reduced graphene oxide-based materials i.e rGO@Fe3O4 and rGO@Co3O4 have been synthesized. Synthesized nanomaterials were characterized by different techniques like UV-visible spectroscopy, EDX, and XRD spectroscopy, which confirmed the synthesis of rGO@Fe3O4 and rGO@Co3O4 with average size of 3.34 and 3.07 nm, respectively. Functional groups involved in synthesis and stabilization of nanocomposites were identified by FTIR spectrophotometry, while crystalline structure was depicted by SEM. By optimizing different factors maximum % removal of dyes i.e 96% and 94% by rGO@Fe3O4 for rhodamine B and alizarin R, respectively, and 94% and 92% by rGO@Co3O4 for rhodamine B and alizarin R, respectively, within contact time of 20 min were observed under tungsten lamp. Kinetics study revealed adsorption mechanism followed by pseudo 2nd order reaction as R2 values of both dyes were 0.98 and 0.99 with synthesized nanomaterials. Freundlich isotherm was best-fitted isotherm, and thermodynamics study described the spontaneity and endothermic nature of adsorption mechanism. Reusability of synthesized materials was analyzed about 5 times, and hydroxyl radicals involved in photocatalytic degradation, was examined through different types of scavengers.