Exploration of the interaction between Fe-doped kaolinite surface and H2O based on DFT simulation and experiment

[Display omitted] •Reveal the adsorption mechanism of single H2O on Fe-doped kaolinite surface by DFT method.•The adsorption of single H2O on Fe-doped kaolinite surface was mainly through hydrogen bonding.•We successfully synthesized Fe-doped kaolinite by hydrothermal synthesis.•Fe doping enhanced the surface hydration characteristics of kaolinite. To research the adsorption mechanism of single H2O on the surface of Fe-doped kaolinite (named Fe-kao), the adsorption process was simulated using the density functional theory (DFT) method. The analysis demonstrated that the adsorption of a single H2O on the Fe-kao surface is more stable than that on the ideal kaolinite surface. Additionally, it can be deduced that the most stable H2O adsorption occurs on the Fe(III)-Na-doped kaolinite(named Fe(III)-Na-kao) (001) surface. The adsorption of single H2O on Fe-kao surfaces relies heavily on hydrogen bonding and electrostatic attraction. Simultaneously, Fe-kao samples were synthesized by hydrothermal synthesis, and synthesized samples were tested by the Mössbauer spectrum and capillary ascent method. The results show that the Fe element is successfully doped into the kaolinite lattice, and Fe doping heightens the surface hydration characteristics of kaolinite, which is similar to the simulation results. The outcomes will offer theoretical backing for slime water ensuing dewatering and sedimentation.