The unexpectedly rich reconstructions of rutile TiO 2 (011)-(2 × 1) surface and the driving forces behind their formation: an ab initio evolutionary study

• Published in: Physical chemistry chemical physics : PCCP 2016, Vol.18 (29), p.19549-19556
• Main Authors: Wang, Qinggao, Oganov, Artem R., Feya, Oleg D., Zhu, Qiang, Ma, Dongwei
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/C6CP01203E

In this paper, we employ state-of-the-art theoretical approaches to elucidate the structures of the (011) surface of rutile (R-)TiO 2 . An unexpectedly rich chemistry has been uncovered. Titanyl-TiO 2 and titanyl-Ti 2 O 3 reconstructions can be used for rationalizing the experimental findings, matching the STM images and the changes in the band gap. From the viewpoint of thermodynamics, the predicted MF(111)-TiO reconstruction is more reasonable than the previously proposed MF(111)-TiO 3 model, although there is a structural similarity. The richness of surface phases, the formation of which is driven by thermodynamic conditions and surface stress release, implies the multifunctionality of the R-TiO 2 (011) surface. After the clarification of TiO 2 (011) and TiO 2 (110) surface structures { PRL , 2014, 113 , 266101} (the most important surfaces of rutile), the origin of the Brønsted acidity of R-TiO 2 , which has remained a mystery at the atomic level, can also be addressed in the near future.