120th General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for Young Scholars in Physical Chemistry
Room No. Room 208+209+210
Time THU 10:30-:
Code PHYS.O-8
Subject A series of DFT studies on TiO2 nanoparticles with a modified hybrid functional
Authors Kyoung Chul Ko, JIN YONG LEE*
Department of Chemistry, Sungkyunkwan University, Korea
Abstract It is well known that conventional local-density approximation (LDA) and generalized gradient approximation (GGA) based functionals severely underestimate the band gap of oxides including TiO2 materials. The broadly used hybrid functionals such as PBE0 and B3LYP give too large calculated band gap values for TiO2. To avoid so-called band gap problem in DFT and to describe the electronic structure of TiO2 materials properly, we proposed a modified hybrid functional containing 12.5 % of non-local Fock exchange called as PBEx. [1] In this talk, a series of DFT studies on TiO2 nanoparticles using this PBEx functional will be briefly presented to introduce examples of its practical application. The properties of single oxygen vacancies of (TiO2)35 as a prototype of reduced nanoparticle, [2] the properties of anatase nanoparticles in the 1-6 nm size range [3] and the prediction of size dependent band alignment in anatase and rutile nanoparticles [4] will be discussed. The present approach may provide a sufficiently accurate way to study the electronic structure of large TiO2 nanoparticles which consist of hundreds or thousands of atoms where GW techniques are unaffordable. References [1] K. C. Ko, O. Lamiel-García, J. Y. Lee and F. Illas Phys. Chem. Chem. Phys. 2016, 18, 12357. [2] S. Kim, K. C. Ko, J. Y. Lee and F. Illas Phys. Chem. Chem. Phys. 2016, 18, 23755 [3] O. Lamiel-García, K. C. Ko, J. Y. Lee, S. T. Bromley and F. Illas J. Chem. Theory. Comput. 2017, 13, 1785 [4] K. C. Ko, J. Y. Lee, S. T. Bromley and F. Illas, manuscript preparation.
E-mail kcko1982@gmail.com