Adsorption behavior of barium ions onto ZnO surfaces: Experiments associated with DFT calculations

Abstract

This work aimed to evaluate and optimize parameters for the removal of barium (Ba2+) ions on ZnO spherical nanoparticles. Spherical ZnO nanoparticles was fabricated using over-simplistic applying arabinose sugar followed by evaporation methods. The physicochemical properties of the ZnO nanoparticles were studied using XRD, SEM, EDX, and FTIR. The maximum adsorption capacity of Ba2+ by ZnO nanoparticles was 64.6 mg/g. In isotherm studies, the Langmuir model is well-fitted to the sorption data. Kinetic pseudo-second-order models best illustrated the adsorption mechanism of barium (Ba2+) ions. Based on the density functional theory calculation, the barium (Ba2+) ion adsorption onto the ZnO surface is strong chemisorption with an exothermic adsorption energy of -291.3 kJ/mol.