Molecular Simulation of NaF Chemisorption on Lepidocrocite for Water Purification

Abstract

NaF chemisorption onto lepidocrocite (LEP) was examined by experimental, molecular dynamics and DFT approach. DFT theoretical calculations suggest that the Fe and O atoms (OH species, for that matter) are the dominant active sites for the subsequent reaction on the LEP (0 0 1) surfaces. The adsorption of F onto LEP was relatively more favorable in acidic media compared to basic and neutral media and validated by experimental findings. The NaF adsorption sites vary in different media. The preferential adsorption of F onto LEP surfaces in acidic media was because of stable and strong interaction and/or thermodynamic stability between F adsorbate and the surface Fe and O atoms of LEP substrate.