▎ 摘　　要

In this study, the adsorption of methyl violet (MV) onto biocompatible reduced graphene oxide nanocomposite was investigated. The covalent modification of GO with L-cysteine-hydrochloride in the presence of N, N-dicyclohexylcarbohydramide (DCC) obtained L-cysteine-reduced graphene oxide nanocomposite (L-cys-rGO). Fabricated nanocomposite was analyzed using standard characterization tools and techniques, viz. UV-Vis, XRD, FT-IR, and SEM. FT-IR results confirmed covalent modification of GO with L-cysteine. In adsorption dye studies, the effect of initial dye concentration, adsorbent dosage, contact time, and the temperature was investigated. 91% dye removal was performed by 20 mg/L of nanocomposite at pH 7, contact time of 5 min, MV concentration of 10 mu M at 25 degrees C. The kinetic study displayed that the adsorption data were fitted with the quasi-second-order model (0.984), and the equilibrium behavior of the adsorption followed the Langmuir model. Furthermore, the thermodynamic studies revealed that the adsorption of MV using L-cys-rGO nanocomposite is exothermic (Delta H = - 12.972 kJ/mol) and spontaneous (Delta S = - 0.027 kJ/mol.K). According to the obtained results, the synthesized nanocomposite can be used to treat industrial effluents and polluted waters.