Effective adsorption of antimony(III) from aqueous solutions by polyamide-graphene composite as a novel adsorbent

Graphene was modified with polyamide by using a facile interfacial polymerization method to obtain an effective composite. The produced polyamide-graphene (PAG) was characterized by Fourier transform infrared spectroscopy (FTIR), Scanning Electron microscopy (SEM) equipped with Energy-Dispersive X-ray spectroscopy (EDX), Thermogravimetric analyzer (TGA), and Brunauer–Emmett–Teller (BET) analysis methods. The adsorption efficiency of the adsorbent for the removal of Sb(III) was evaluated under the effects of concentration, temperature, contact time, medium pH, and re-usability. The results of the study showed very good adsorption performance and high regeneration efficiency. The Langmuir modeling results revealed that the synthesized PAG sorbent had a considerably high adsorption capacity (158.2 mg/g) for Sb(III) ions from aqueous solution. The adsorption data fitted well into pseudo-second order model. The exothermic enthalpy change of −65.6 kJ/mol and negative Gibbs free energy change assured the viability of the adsorption process under the considered temperature conditions. Moreover, by taking into account all results it was concluded that the PAG composite material leverages its cheap source and ease of regeneration in combination with its high and fast uptake capacities to offer a great promise for the remediation of Sb(III) ions from aqueous solutions.