Electron Dynamics of Solvated Ti(OH)4. Issue 1647 (22nd January 2014)

• Record Type: Journal Article
• Authors: Vogel, Dayton J.; Kilin, Dmitri S.
• Is Part Of: MRS proceedings. Issue 1647:(2014)
• Publication Date: 2014-01-22
• Subjects: Ti, -- electrical properties, -- photochemical; Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/opl.2014.91
• Languages: English
• ISSNs: 0272-9172

Abstract

ABSTRACT: Increasing interest in the photocatalytic activity of TiO2 has led to considerations of using TiO2 nanoparticles in energy generation. In order to better understand the electron-hole relaxation of nano scale TiO2 structures, it is important to start with an understanding of TiO2 synthesis building blocks. The solvated titanium (IV) ion is a precursor found in synthesis methods of colloidal TiO2 nanostructures. This simplest test compound may reflect some common basic electronic features for larger structures composed of Ti(IV) coordinated with oxygen. For this computational study, a model of Ti(OH)4 with tetrahedral coordination was created. To simulate the electronic properties of a solution of Ti(IV), the model was surrounded with 27 H2 O molecules. The model was explored by means of standard density functional theory (DFT) molecular dynamics (MD) followed by nonadiabatic electron dynamics computed with Reduced Density Matrix approach combined with "on-the-fly coupling". Results were generated with Vienna ab initio Simulation Package (VASP) using the Perdew-Burke-Ernzerhof (PBE) functional, plane wave basis set, and projector augmented wave (PAW) potentials. The absorption spectra, MD, and electron-hole relaxation rates are presented for the Ti(OH)4 model at various ambient temperatures. The electron-hole relaxation rates show a non-linear dependence on temperature and were found to be near the same order of magnitude as electron-hole relaxation rates in bulk TiO2 calculations. A video of the geometry optimization can be found online.[1]