Theoretical study of the modification of the oxide-reducing capacity of titania from selected dopant elements

SCHVVAL, ANA B.; JIMÉNEZ, M. JULIA; FUENTE, SILVIA; CABEZA, GABRIELA F.; MORGADE, CECILIA I. N.

Journal of Computational Electronics

Springer

Año: 2020 vol. 19 p. 493 - 506

1569-8025

The positions of the upper edge of the valence band and the lower edge of the conduction band of semiconducting materialssuch as TiO2 are closely related to the values of the respective oxidation or reduction potentials. The modifcations suferedby a material of this type impact on the displacements of the aforementioned bands and thus on the redox potentials. Inthe present work, anatase and rutile bulk systems are analyzed for how diferent metallic and nonmetallic dopants locatedsubstitutionally where the ?@? symbol indicates that the preceding element replaces the element after it or interstitiallythis position in the network is indicated with the letter ?i? afect these potentials. From the analysis of the modifcations,consequence of the doping, it can be noted that substitutional doping of nitrogen (N) at the oxygen site (N@O) improvesthe reduction potential of anatase and doped with interstitial (Ni) that of rutile. On the other hand, for both polymorphs,interstitial iron (Fei) doping has the best oxidant properties, followed by doping with Fe in titanium (Ti) site (Fe@Ti). Thelatter also has interesting magnetic properties to facilitate the extraction of the titania from the reaction media. The otherdoping elements studied, vanadium, platinum, silver, carbon and fuorine only improve the oxidation potential but all to alesser extent than iron.