Incorporation of Non-metal Impurities at the Anatase TiO$_2$(001)-(1$ imes$4) Surface

摘要

We use first-principles calculations to investigate the adsorption andincorporation of non-metal impurities (N, C) at the anataseTiO$_2$(001)-(1$\times$4) reconstructed surface. We analyze in detail theinfluence of the surface structure and local strain on the impurity bindingsites and incorporation pathways and identify important intermediates whichfacilitate impurity incorporation. We find various subsurface interstitialbinding sites and corresponding surface $\rightarrow$ subsurface penetrationpathways on the reconstructed surface. This surface also favors the presence ofsubsurface oxygen-vacancies, to which adsorbed species can migrate to formsubstitutional impurities. Most notably, we show that the non-exposed oxygensites just below the surface have a key role in the incorporation of nitrogenand carbon in TiO$_2$(001).