First-Principles Modeling of Oxygen-Deficient Anatase TiO₂Nanoparticles

TY - JOUR

T1 - First-Principles Modeling of Oxygen-Deficient Anatase TiO2Nanoparticles

AU - Quirk, James A.

AU - Lazarov, Vlado K.

AU - Mckenna, Keith P.

N1 - © 2020 American Chemical Society

PY - 2020/10/14

Y1 - 2020/10/14

N2 - First-principles calculations of the electronic structure of reduced anatase TiO2 nanoparticles are performed using a hybrid density functional theory approach for an accurate description of charge trapping. It is found that, in the bulk and at extended surfaces, electrons introduced by oxygen vacancies delocalize but, in reduced nanoparticles, electrons preferentially localize (forming Ti3+ species) at low-coordinated sites on the surface of the particle. It is favorable for nanoparticles to be oxygen-deficient in oxygen-poor conditions with the Ti33O66 nanoparticle being significantly easier to reduce than the larger Ti151O302 nanoparticle. Since low-coordinated sites are more prevalent in smaller nanoparticles, this suggests that there is a delicate balance between the number of carriers introduced by vacancies and the number of trapped electrons.

AB - First-principles calculations of the electronic structure of reduced anatase TiO2 nanoparticles are performed using a hybrid density functional theory approach for an accurate description of charge trapping. It is found that, in the bulk and at extended surfaces, electrons introduced by oxygen vacancies delocalize but, in reduced nanoparticles, electrons preferentially localize (forming Ti3+ species) at low-coordinated sites on the surface of the particle. It is favorable for nanoparticles to be oxygen-deficient in oxygen-poor conditions with the Ti33O66 nanoparticle being significantly easier to reduce than the larger Ti151O302 nanoparticle. Since low-coordinated sites are more prevalent in smaller nanoparticles, this suggests that there is a delicate balance between the number of carriers introduced by vacancies and the number of trapped electrons.

UR - http://www.scopus.com/inward/record.url?scp=85096052479&partnerID=8YFLogxK

U2 - 10.1021/acs.jpcc.0c06052

DO - 10.1021/acs.jpcc.0c06052

M3 - Article

AN - SCOPUS:85096052479

SN - 1932-7447

VL - 124

SP - 23637

EP - 23647

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 43

ER -