Theoretical study of water decomposition on TiO2 surface

Density functional theory and pseudopotential method were employed to investigate one water molecule decomposition on perfect TiO2 rutile (110) surface. First we build up a surface, which is large enough to simulate this reaction as under the real condition. Then we put a water molecule on the top of one five-fold-coordinate Ti atom on the surface as the reactant; we put two OH radicals at the corresponding position of the surface as the product. At,last we simulate the reaction from the reactant to the product to get the reaction free energy, which is about 15.562 kJ/mol. This free energy,can fit well with the experimental results.