Stability Investigation of Scandium Adsorption Configuration on Anatase TiO<sub>2</sub>(101) Surface

Titanium dioxide is a stable photocatalytic material, for improving surface photocatalytic performance, this study employs first-principles calculations based on density functional theory to investigate the adsorption stability of rare-earth scandium atoms on three distinct anatase TiO₂ (101) surfaces: pristine, subsurface oxygen vacancy-containing, and surface oxygen vacancy-containing configurations. Scandium atoms exhibit the most stable adsorption configuration when located between two three-coordinated oxygen atoms on a defect-free surface, with an adsorption energy of -7.25 eV. When adsorbed on a surface containing a subsurface oxygen vacancy, scandium atoms achieve optimal stability at sites between two adjacent three-coordinated oxygen atoms near the vacancy, with an adsorption energy of -6.66 eV. Scandium atoms exhibit the highest adsorption stability above the four-coordinated titanium atoms adjacent to surface oxygen vacancies, with an adsorption energy of -7.63 eV. The aforementioned results indicate that rare-earth scandium atoms can be stably adsorbed on the anatase TiO₂ (101) surface, thereby providing a theoretical foundation for further investigations into the influence of Sc atoms on photocatalytic reactions at the TiO₂ surface.