Applied Surface Science, Vol.287, 478-483, 2013
Adsorption characteristics of Th(IV) ions on reduced graphene oxide from aqueous solutions
Reduced graphene oxide (RGO) prepared by the reduction of graphene oxide (GO) using thiourea dioxide (TUD) was examined for the adsorption of Th(IV) from aqueous solutions. The adsorption of Th(IV) on RGO as a function of pH, contact time, adsorbent dosage, the Th(IV) initial concentration and temperature was investigated through batch adsorption experiments. The results showed that the adsorption behavior of Th(IV) on RGO followed the pseudo-second order kinetic and the Langmuir isotherm models. The maximum theoretical adsorption capacity was calculated to be 0.21 mmol Th/g RGO at 298.15K. Moreover, the thermodynamic parameters (Delta AH = 4.32 kJ/mol, Delta S = 69.47 J/mol K and Delta G = -16.39 kJ/mol at 298.15K) indicated that the adsorption process was a feasible, spontaneous and endothermic in nature. (C) 2013 Elsevier BY. All rights reserved.