The adsorption and reactions of SiClx (x = 0–4) on hydroxylated TiO2 anatase (1 0 1) surface: A computational study on the functionalization of titania with Cl2Si(O)O adsorbate

The adsorption and reactions of the SiClx (x = 0–4) on the hydroxylated TiO2 anatase (1 0 1) surface have been investigated by using periodic density functional theory calculations in conjunction with the projected augmented wave (PAW) approach. The adsorption and reactions tend to occur more readily on the ‘Ow’ site derived from water than the ‘Os’ site from TiO2 as revealed by the potential energy profiles and adsorption energies. The stepwise reactions of SiClx can be achieved by dehydrochlorination taking place by three paths: Ow-path, cross-path, and Os-path. The Ow-path is the lowest energy path, in which Cl3Si–Ow(a) and Cl2Si–(Ow)Ow(a) are the main products formed by spontaneous reactions. The ready formation and the high stability of Cl2Si–(Ow)Ow(a) suggest that it can be employed as a molecular linker for Si and other semiconductor quantum dot growth on titania through its high reactivity towards SiHx radicals and metal alkyls, respectively.