Diffusivity of individual adsorbed water molecules at an Fe2O3 − Hematite/Water interface under external electric-field conditions.

[Display omitted] • External electric fields shift dipole moment distribution of hematite-adsorbed water. • Significant doubling in the adsorbed-water self-diffusion constants, including at individual molecular level. • Marked field-induced shift in infrared-vibrational properties. • Underlying "dipole-locking" mechanism at play for water-dipole alignment with applied field. The dynamical properties of physically and chemically adsorbed water molecules at a pristine hematite-(0 0 1) surfaces have been studied by non-equilibrium ab-initio molecular dynamics in the constant-volume, constant-temperature ensemble at room temperature, under externally-applied, uniform static electric fields of increasing intensity. Significant alterations in the dipole moment and self-diffusion constant were found vis-à-vis zero-field conditions, as well as shifting of the probability distribution of individual molecular self-diffusivities. For instance, application of static fields was found to increase the self-diffusion of water molecules at the α-hematite Fe 2 O 3 surface, effectively due to some extent of 'dipole-locking' in the direction of the applied field. [ABSTRACT FROM AUTHOR]