C–doped TiO2(B): A density functional theory characterization

RICARDO FACCIO; HERMAN HEFFNER; IGNACIO LÓPEZ CORRAL

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Año: 2021 vol. 551

0169-4332

Calculations based on the Density Functional Theory(DFT) were applied to study structural, electronic and optical properties ofpure and C-doped TiO2(B) taking into account five different types ofsubstitutional impurities. Our calculations indicate that the substitution of aC atom at an O site (C@O) is not only thermodynamically more favorable, butalso independent of the growing conditions. The presence of impurity states inthe band gap, along with a great reduction of the gap energy (Eg) wereobtained after C@O doping, which leads to an enhancement of the absorbance inthe visible and IR spectrum caused partially by trapped holes and electronsthat the introduction of the impurity induces. Additionally, our results showedthat the substitution of a C atom at a Ti site (C@Ti) originated a significantchange not only in the structural arrangement of the neighborhood of theimpurity, but also on its electronic and optical behavior compared to the pureTiO2(B) model.