Atomistic Simulations of Metal-Oxide Interface with Water: Theoretical studies on systems of TiO2 and Fe2O3

In this thesis, various systems containing interfaces of titanium dioxide (TiO2) and haematite (a-Fe2O3) with water are examined using a number of atomistic simulation methodologies. These systems include large-scale anatase (101) and rutile (110) surface slabs modelled using force-field molecular dynamics (MD); smaller haematite (001) and rutile (110) surface slabs modelled using density functional theory MD; and a large scale anatase nanoparticle and smaller anatase (101) and rutile (110) surface slabs, modelled using density functional tight-binding MD. As part of these studies a variety of analyses are presented, aimed at providing a quantitative understanding of the effects that each surface or nanoparticle has on the properties of water molecules near the interface; and thereby assessing, in a qualitative way, how these effects are manifested using the different methodologies. These analyses include established techniques in the field of atomistic simulations, such as hydrogen bond analysis and electronic density of states calculations. Also employed are techniques novel to the field of atomistic simulation, such as the coherence spectrum. Two points of emphasis are present throughout this thesis: firstly, to improve the understanding of the materials examined towards the development of photoelectrochemical catalysts; and secondly, to explore the current state-of-the-art in atomistic simulations, and "push the boundaries" of the available techniques.