Adsorption Characteristics of Chlorophenols from Aqueous Solution onto Graphene

The adsorption of chlorophenols (CPs) on pristine graphene was investigated. The adsorption capacities of graphene were 88.1 mg g(-1) for 2-chlorophenol (2-CP), 114.2 mg g(-1) for 4-chlorophenol (4-CP), 155.3 mg g(-1) for 2,4-dichlorophenol (DCP), and 175.8 mg g(-1) for 2,4,6-trichlorophenol (TCP), respectively. The equilibrium was attained during 20 min. There was no significant effect on the adsorption amounts in the pH range of pH 1.01-8.09 for 2-CP, 1.08-8.01 for 4-CP, 1.04-7.03 for DCP, and 2.86-5.63 for TCP. The Langmuir and pseudo-second-order models supplied good fitting of the experimental data. Thermodynamic constants demonstrated that the process was endothermic and spontaneous.