Fabrication of a novel graphene oxide/β-FeOOH composite and its adsorption behavior for copper ions from aqueous solution.

A graphene oxide (GO)/β-FeOOH composite was prepared by the liquid insert method and was characterized by XRD, FT-IR, SEM and TEM. The adsorption capacity of the composite was evaluated by the removal of copper ions (Cu(2+)) from aqueous solution. The effect of initial pH, contact time and absorbent dose on the removal efficiency of Cu(2+) was investigated by batch experiments. Langmuir and Freundlich models were employed to describe the adsorption equilibrium. The adsorption kinetics was investigated by both the pseudo-first-order and pseudo-second-order kinetics models. The results showed that the GO/β-FeOOH composite exhibited excellent adsorption capacity for Cu(2+) and under the optimum experimental conditions, the removal rate of Cu(2+) can reach ca. 93.8%. The adsorption isotherm was a good fit with the Langmuir model and the adsorption process was described by the pseudo-second-order kinetics model.