Diffusivity and Mobility of Adsorbed Water Layers at TiO2 Rutile and Anatase Interfaces

Crystals

Niall J. English¹  Sᐪwomir Grabowski¹ 

[1] School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland

关键词: molecular dynamics;    titania;    water;    diffusivity;   

DOI  :  10.3390/cryst6010001

来源: mdpi

【 摘 要 】

Molecular-dynamics simulations have been carried out to study diffusion of water molecules adsorbed to anatase-(101) and rutile-(110) interfaces at room temperature (300 K). The mean squared displacement (MSD) of the adsorbed water layers were determined to estimate self-diffusivity therein, and the mobility of these various layers was gauged in terms of the “swopping” of water molecules between them. Diffusivity was substantially higher within the adsorbed monolayer at the anatase-(101) surface, whilst the anatase-(101) surface’s more open access facilitates easier contact of adsorbed water molecules with those beyond the first layer, increasing the level of dynamical inter-layer exchange and mobility of the various layers. It is hypothesised that enhanced ease of access of water to the anatase-(101) surface helps to rationalise experimental observations of its comparatively greater photo-activity.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.