Open AccessRelevance of Dispersion and the Electronic Spin in the DFT + U Approach for the Description of Pristine and Defective TiO2 Anatase
Author(s) -
Ana E. Torres,
Janatan Rodríguez-Pineda,
Rodolfo Zanella
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c02761
Subject(s) - anatase , density functional theory , electronic structure , dopant , materials science , doping , atom (system on chip) , hybrid functional , ferromagnetism , spin (aerodynamics) , chemical physics , computational chemistry , condensed matter physics , chemistry , catalysis , thermodynamics , physics , photocatalysis , organic chemistry , optoelectronics , computer science , embedded system
A density functional theory + U systematic theoretical study was performed on the geometry, electronic structure, and energies of properties relevant for the chemical reactivity of TiO 2 anatase. The effects of D3(BJ) dispersion correction and the Hubbard U value over the energies corresponding to the TiO 2 /Ti 2 O 3 reduction reaction, the oxygen vacancy formation, and transition-metal doping were analyzed to attain an accurate and well-balanced description of these properties. It is suggested to fit the Hubbard correction for the metal dopant atom by taking as reference the observed low spin-high spin (HS) energy difference for the metal atom. PBEsol-D3 calculations revealed a distinct electronic ground state for the yttrium-doped TiO 2 anatase surface depending upon the type of doping and interstitial or substitutional defects. Based on the calculations, it was found that a HS state explains the observed ferromagnetism in cobalt-substituted TiO 2 anatase. The results presented herein might be relevant for further catalytic studies on TiO 2 anatase using a large surface model that would be worthwhile for heterogeneous catalysis simulations.