Carlos A Guerrero-Fajardo1, Liliana Giraldo1, Juan Carlos Moreno-Piraján2. 1. Departamento de Química-Grupos de Investigación Aprena y Calorimetría, Facultad de Ciencias, Universidad Nacional de Colombia-sede Bogotá, Cra. 45 No. 26-85, Edificio 451, Bogotá 111321, Colombia. 2. Facultad de Ciencias, Departmento de Química, Universidad de los Andes, Bogotá 111711, Colombia.
Abstract
A thermodynamic and kinetic study of the adsorption process of Zn (II) and Pb (II) ions from aqueous solution on the surface of graphene oxide (GO) to establish the mechanisms of adsorbate-adsorbent interaction on this surface. The effect of pH on the retention capacity was studied and adsorption isotherms were determined from aqueous solution of the ions; once the experimental data was obtained, the kinetic and thermodynamic study of the sorption process was carried out. The data were fitted to the Langmuir, Freundlich, Dubinin-Raduskevich and Temkin isotherm models. The results showed that Zn(II) and Pb(II) on the GO adsorbing surface fitted the Langmuir model with correlation coefficients (R2) of 0.996. Kinetic models studied showed that a pseudo-second-order model was followed and thermodynamically, the process was spontaneous according to the values of Gibbs free energy (ΔG°). N2 adsorption isotherms were determined and modeled with the NLDFT (nonlocal density functional theory) and QSDFT (quenched solid density functional theory) kernels.
A thermodynamic and kinetic study of the adsorption process of Zn (II) and n class="Chemical">Pb (II) ions from aqueous solution on the surface of graphene oxide (GO) to establish the mechanisms of adsorbate-adsorbent interaction on this surface. The effect of pH on the retention capacity was studied and adsorption isotherms were determined from aqueous solution of the ions; once the experimental data was obtained, the kinetic and thermodynamic study of the sorption process was carried out. The data were fitted to the Langmuir, Freundlich, Dubinin-Raduskevich and Temkin isotherm models. The results showed that Zn(II) and Pb(II) on the GO adsorbing surface fitted the Langmuir model with correlation coefficients (R2) of 0.996. Kinetic models studied showed that a pseudo-second-order model was followed and thermodynamically, the process was spontaneous according to the values of Gibbs free energy (ΔG°). N2 adsorption isotherms were determined and modeled with the NLDFT (nonlocal density functional theory) and QSDFT (quenched solid density functional theory) kernels.
Entities:
Keywords:
Graphene oxide; isotherms; metallic ions; thermodynamic study
Authors: Nguyen Van Hao; Nguyen Van Dang; Do Hoang Tung; Pham The Tan; Nguyen Van Tu; Pham Van Trinh Journal: RSC Adv Date: 2020-11-12 Impact factor: 4.036