Synergetic interplay between metal (Pt) and nonmetal (C) species in codoped TiO2: A DFT+U study

MORGADE CECILIA I.N.; CABEZA GABRIELA F.

COMPUTATIONAL MATERIALS SCIENCE

ELSEVIER SCIENCE BV

Lugar: Bahia Blanca; Año: 2015 p. 513 - 524

0927-0256

The structural, energetic, magnetic and electronic properties of Pt?C-doped and Pt/C-codoped TiO2 havebeen studied using first-principle calculations to elucidate the effect of the metal?nonmetal interactions.Compared with other non-metals, C-doping induces the formation of complex structures on titania.From the analysis of the electronic structures of the C-doping system, band gap narrowing as well asthe formation of localized gap states are observed in it. The calculated results are in agreement withthe experimental absorptions observed in the UV?visible diffuse reflectance spectroscopy spectra.Based on our results, the main findings relating to Pt/C codoping are the formation of highly symmetriccoordination-like compounds and the formation of impurity states in the band gap that could bepropitious for the separation of photoexcited electron?hole pairs. Is especially remarkable the case ofPt/C@Ti-codoped TiO2 which could be the most effective for the redox reaction of H2O to produce H2and O2 because it presents the greatest narrowing of the band gap, the lower shift of the conduction bandand it is the only one that favorably modifies the position of valence band. All are necessary conditions forthe reaction mentioned.