Enhanced simultaneous sequestration of Cd(II) and Pb(II) ions from industrial wastewater samples based on poly-(2-aminothiophenol) functionalized graphene oxide

Heavy metals sequestration from industrial discharges has aroused increasing attention worldwide to cleaner and sustainable water production by developing fast, effective eco-friendly nanosorbents. This study aimed to design a robust and fast nanocomposite to remove heavy metal ions, mainly Pb(II) and Cd(II). To this end, poly-(2-aminothiophenol); PATP was incorporated into graphene oxide; GO to fabricate PATP@GO nanocomposite. The structure and morphology of the novel nanocomposite were evaluated by FTIR, TEM, XRD, Raman, EDX, and TGA. Integrating PATP improved the adsorption efficiency of the GO from 61.3% to 98.6% for Pb(II) and 34.6% to 87.3% for Cd(II). Furthermore, the impact of pH, the mass of nanocomposite, metal ions concentrations, and coexisting ions were thoroughly investigated and optimized. The potential efficiency and adsorption capacity of PATP@GO nanocomposite toward Pb(II) was 98.6.00%, 142.9 mg.g(-1) for Pb(II) at pH 5 and 87.3%, 125.0 mg.g(-1) for Cd(II) at pH 7 within 25 minutes, respectively. This behavior was explained in terms of strong complex formation with the thiol groups of PATP, as well as the hydroxyl and carboxyl groups in GO. Kinetic studies were based on pseudo-second order (R-2 > 0.99) and the adsorption data are best fitted with the Langmuir model. The excellent stability of PATP@GO nanocomposite enabled effective extractions for seven successive runs (98.6%-95.3% for Pb(II) and 87.3-85.1% for Cd(II)). The developed PATP@GO nanocomposite is believed to show fast and high potential in detoxifying of heavy metal ions from different environmental samples in aquatic life.