Recyclable removal of bisphenol A from aqueous solution by reduced graphene oxide–magnetic nanoparticles: Adsorption and desorption

• rGO-MNPs with tunable MNPs were synthesized for adsorption of BPA.
• rGO-MNPs with lower density of MNPs showed better adsorption ability for BPA.
• Adsorption kinetics fitted to a pseudo-second-order model.
• Thermodynamics revealed the adsorption process was spontaneous and exothermal.
• rGO-MNPs could be used as recyclable adsorbents for BPA due to superparamagnetism.

Reduced graphene oxide (rGO) nanosheets decorated with tunable magnetic nanoparticles (MNPs) were synthesized by a simple co-precipitation method and employed for recyclable removal of bisphenol A (BPA) from aqueous solution. The morphological characterization shows that Fe3O4 nanoparticles are uniformly deposited on rGO sheets. The magnetic characterization demonstrates that composites with various amounts of Fe3O4 nanoparticles are superparamagnetic. Due to the superparamagnetism, rGO-MNPs were used as recyclable adsorbents for BPA removal in aqueous solution. The kinetics of the adsorption process and the adsorption isotherm were investigated. The results indicate that the adsorption process is fitted to Langmuir model and the composites with lower density of MNPs represent better adsorption ability. In addition, its kinetics follows pseudo-second-order rate equation. Moreover, the adsorbents could be recovered conveniently by magnetic separation and recyclable used because of the easy desorption of BPA.

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