Facile Fabrication of a Low-Cost Lignosulfonate– Graphene Oxide–Polyaniline Ternary Nanocomposite for the Highly Efficient Removal of Pb(II) and Cr((VI) Ions from Aqueous Solutions

In this study, we demonstrate a one-step method for fabricating a novel lignosulfonate–graphene oxide–polyaniline (LS-GO-PANI) nanocomposite aerogel, were prepared and employed for adsorption and removal of (Pb(II)) and Cr(VI) ions from aqueous solution. The results have shown that (LS-GO-PANI) nanocomposite exhibits a very high affinity and selectivity towards Pb(II) and and Cr((VI) Ions The morphology and structure of the LS-GO-PANI ternary nanocomposite were characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscope (AFM), fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS).. Furthermore, the effects of adsorption time, initial pH value, adsorbent concentration, and initial adsorbate concentration on the adsorption of Pb(II) ions in aqueous solution were investigated by batch experiments. The LS-GO-PANI ternary nanocomposite showed an adsorption capacity as high as 356.4 mg g–1 for Pb(II) ions and 282.15 mg/g mg/g for Cr(VI) ions at 30 °C. Moreover, the adsorption kinetic and equilibrium data were described well with the pseudo-second-order and Langmuir isotherm models for the Pb(II) and Cr(VI) ions adsorption process. The results showed that the LS-GO-PANI ternary nanocomposite has broad application potential in treating Pb(II) and Cr(VI) ions containing industrial wastewater.

Keywords: Graphene oxide; Lignosulfonate; Polyaniline; Heavy metals; Nanocomposites; Adsorption