We present density functional calculations of H2O interacting with the (101) and (001) surfaces of TiO2 anatase at various coverages θ. On the (101) surface, nondissociative molecular adsorption at fivefold coordinated Ti sites is favored at both low and monolayer coverage. On the (001) surface, for θ≤0.5, H2O is adsorbed dissociatively, with an adsorption energy ΔHH, OH∼1.6 eV. At θ = 1, H2O can be adsorbed molecularly (ΔHH2O = 0.82eV/molecule), but a state with half of the H2O adsorbed dissociatively and the other half H bonded in a “second layer” is energetically more favorable. These results are discussed in the context of the available experimental information.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)