Argentina
| info:eu-repo/semantics/article
Theoretical analysis of band alignment and charge carriers migration in mixed-phase TiO2 systems
Fecha
2018-08-10Registro en:
Morgade, Cecilia Ines Nora; Castellani, Norberto Jorge; Cabeza, Gabriela Fernanda; Theoretical analysis of band alignment and charge carriers migration in mixed-phase TiO2 systems; Springer New York LLC; Journal of Computational Electronics; 17; 4; 10-8-2018; 1505-1514
1569-8025
1572-8137
CONICET Digital
CONICET
Autor
Morgade, Cecilia Ines Nora
Castellani, Norberto Jorge
Cabeza, Gabriela Fernanda
Resumen
Photocatalysts based on mixtures of rutile and anatase forms of titania usually show a better catalytic performance than each individual component. In order to understand this behavior, several experimental and theoretical approaches have been proposed in the past, looking for an adequate reference frame for aligning energy bands, and arriving sometimes to opposite results. In this work, the theoretical results obtained for the band alignment applying a modified common anion rule for different possibilities of mixed-phase (anatase–rutile) interaction are presented. According to our results, mixed-phase systems involve the transfer of electrons from rutile to anatase and holes from anatase to rutile. This analysis would be applicable to real samples of mixed phase of titania with large particle size. However, for heterogeneous size particulate systems, it is not only necessary to consider the alignment of bands of the bulk system, but also those of the corresponding surfaces. In keeping with the analysis performed, the best mixed systems are those composed by large particles of both polymorphs or by small particles of anatase dissolved in rutile. Our results could explain the disagreement found in the literature regarding the experimental works.