Removal of toxic hexavalent chromium <i>via</i> graphene oxide nanoparticles: study of kinetics, isotherms, and thermodynamics

Abstract

In this study, graphene oxide (GO) was prepared by the Hummers' method from graphite material. The adsorption potential of GO-200 nm for the removal of Cr(vi) ions was investigated. Fourier transform infrared (FTIR) spectroscopy was used to analyze Cr(vi) before and after adsorption. The adsorption isotherm was fitted by the Langmuir model and the maximum adsorption capacity of the GO was 41.27 mg g^-1 at 25 °C. Thermodynamic parameters (Δ<i>G</i>°), (Δ<i>H</i>°), and (Δ<i>S</i>°) were calculated and exhibited as +2.63 kJ mol^-1 K^-1, +4.30 kJ mol^-1 K^-1, and +5.56 kJ mol^-1 K^-1 at 30 mg L^-1 of Cr(vi) solution, respectively.