Abstract
•A promising Fe3O4@GO–DS nanosorbent was fabricated for MSPE of MG from aqueous solutions.•The novel nanosorbent has special structure with high surface area and high hydrophilicity.•Three different electrostatic interactions were proposed for the adsorption mechanism.•The extraction efficiency is decreased from 98.75% to 95.6% after 5 sorption–desorption cycles.•The adsorption data was best-fitted to 2nd order kinetic model and Langmuir isotherm.
In this study, the ease of magnetic separation was hybridized with the excellent hydrophilicity of both graphene oxide (GO) and dodecyl sulphate (DS) to synthesize a novel nanosorbent (Fe3O4@GO–DS; 10–25nm) for simple, fast and efficient remediation of malachite green (MG) from aqueous media. The structure and morphology of Fe3O4@GO–DS were elucidated by FTIR, HRTEM, XRD and TGA techniques. Different analytical parameters including medium acidity, equilibration time, Fe3O4@GO–DS dose, initial MG concentration and temperature were optimized for maximum percentage MG removal efficiency. The experimental results indicated that Fe3O4@GO–DS had excellent sorption capacity (714.3mgg−1 at pH 7.0 and 25°C) which decreased from 98.75% to 95.60% after five sorption–desorption cycles. The adsorption isotherm data best-fitted to Langmuir model and the sorption reactions follow second order rate equations. Thermodynamic study is inspected and different mechanistic pathways are proposed for the sorption process.
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