Density Functional Theory Study on the Adsorption of Fe(OH)2+ on Kaolinite Surface in Water Environment

Hongqiang Wu; Yuqi Miao; Yong Li; Huashan Yan; Jinbiao Tan; Sen Qiu; Hao Wu; Tingsheng Qiu

LAPSE

Living Archive for Process Systems Engineering

LAPSE:2023.0071

Published Article

LAPSE:2023.0071

Density Functional Theory Study on the Adsorption of Fe(OH)2+ on Kaolinite Surface in Water Environment

Hongqiang Wu, Yuqi Miao, Yong Li, Huashan Yan, Jinbiao Tan, Sen Qiu, Hao Wu, Tingsheng Qiu

February 17, 2023

Fe impurity is abundant in rare earth leaching solutions. The optimal hydrate structure of Fe(OH)2+ was calculated based on the quantum chemical in the water environment to investigate the microscopic occurrence of Fe impurity on kaolinite surfaces. The adsorption structure and bonding mechanism (including outer and inner layer) of hydrate Fe(OH)2+ on the kaolinite (001) surface were investigated. According to the results, the stable hydrate form of Fe(OH)2+ is [Fe(OH)(H2O)5]2+. Hydrated Fe(OH)2+ has a tendency to adhere to the Si-O surface in the form of outer layer adsorption. Adsorbate tends to adsorb to the Ou (deprotonated upright hydroxyl) site, where it generates a monodentate adsorption compound, and to the Ol and Ou (deprotonated lying and upright hydroxyl) sites, where it generates a bidentate adsorption compound if inner layer adsorption occurs. The Mulliken population and density of state analysis demonstrate that the ionic properties of Fe-Os in the inner layer adsorption compound are reduced and Fe-Os bonds are filled with strong bonding and weak antibonding orbitals. More chemical bonds are formed in the bidentate adsorption compound, and the bidentate adsorption has lower adsorption energy. Therefore, in the process of inner layer adsorption, bidentate adsorption is more likely to occur.

Record ID

LAPSE:2023.0071

Keywords

Adsorption, Fe, kaolinite, quantum chemistry

Subject

Environment

Suggested Citation

Wu H, Miao Y, Li Y, Yan H, Tan J, Qiu S, Wu H, Qiu T. Density Functional Theory Study on the Adsorption of Fe(OH)2+ on Kaolinite Surface in Water Environment. (2023). LAPSE:2023.0071

Author Affiliations

Wu H: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China; Sinosteel Maanshan Mining Research Institute Co., Ltd., Maanshan 243000, China
Miao Y: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Li Y: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Yan H: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China; Collaborative Innovation Center for Development, Utilization of Rare Metal Resources Co-Sponsored by Ministry of Education and Jiangxi P [ORCID]
Tan J: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Qiu S: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Wu H: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Qiu T: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China; Collaborative Innovation Center for Development, Utilization of Rare Metal Resources Co-Sponsored by Ministry of Education and Jiangxi P

Journal Name

Processes

Volume

11

Issue

1

First Page

38

Year

2022

Publication Date

2022-12-24