Vertical and lateral order in adsorbed water layers on anatase TiO2(101).
The structure and energetics of thin water overlayers on the (101) surface of TiO(2)-anatase have been studied through first-principles molecular dynamics simulations at T = 160 K. At one monolayer coverage, H(2)O molecules are adsorbed at the 5-fold Ti sites (Ti(5c)), forming an ordered crystal-like 2D layer with no significant water-water interactions. For an adsorbed bilayer, H(2)O molecules at both Ti(5c) and bridging oxygen (O(2c)) sites form a partially ordered structure, where the water oxygens occupy regular sites but the orientation of the molecules is disordered; in addition, stress-relieving defects are usually present. When a third layer is adsorbed, very limited parallel and perpendicular order is observed above the first bilayer. The calculated energetics of multilayer adsorption is in good agreement with recent temperature-programmed desorption data.
Tilocca
Antonio
A
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA. atilocca@princeton.edu
Selloni
Annabella
A
D000327:Adsorption; D003198:Computer Simulation; D010100:Oxygen / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D014867:Water; C009495:titanium dioxide; D014025:Titanium; D010100:Oxygen