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Semiempirical computational study of oxygen vacancies in a decahedral anatase nanoparticle
Author(s) -
Vorontsov Alexander V.,
Smirniotis Panagiotis G.
Publication year - 2019
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.25806
Subject(s) - anatase , facet (psychology) , oxygen , band gap , energetics , materials science , nanoparticle , enthalpy , chemical physics , chemistry , computational chemistry , catalysis , nanotechnology , thermodynamics , photocatalysis , physics , optoelectronics , biochemistry , organic chemistry , psychology , social psychology , personality , big five personality traits
Formation of oxygen vacancies ( V O ) is an important step of many catalytic reactions following the Mars van Krevelen mechanism. High rate of oxidation is associated with low energy of V O formation while high selectivity requires an optimal energy of V O formation. In the present computational study, enthalpy of V O formation (Δ H OVF ) is studied in a decahedral anatase nanoparticle (TiO 2 ) 121 (H 2 O) 6 using PM6 method. Δ H OVF shows large variations for oxygen atoms in different locations on facets, edges and vertices. V O are much more stable in the (101) facet compared to the (001) facet, while internal V O are more stable for (101) but equally stable for (001) facet compared to surface vacancies on average. Comparison with literature DFT methods results reveals good consistency and high computational efficiency of the PM6 method for vacancies formation energy. Pm6 also correctly predicts admixture states of the Ti 3+ within the band gap, but absolute values of electronic band gap and position of admixture states is overestimated and needs scaling factors.