Atomistic simulation of the surface structure of the TiO2 polymorphs rutile and anatase

Atomistic simulation has been used to calculate the surface structures and stability of the rutile and anatase polymorphs of TiO2. The surface and attachment energies were used to evaluate the equilibrium and pseudo-kinetic morphologies. The surfaces expressed in rutile were {011}, {110}, {100} and {221} with surface energies of 1.85, 1.78, 2.08 and 2.02 J m(-2) respectively. For anatase the {011} and {001} surfaces were dominant in the morphology with relaxed surface energies of 1.40 and 1.28 J m(-2). The predicted equilibrium forms were largely in good agreement with the reported experimental morphologies of rutile and anatase and showed the importance of surface relaxation.