2D slab models of TiO2 nanotubes for simulation of water adsorption: Validation over a diameter range
Date
2020
Authors
Lisovski, Oleg
Piskunov, Sergei
Bocharov, Dmitry
Kenmoe, Stéphane
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier B.V.
Abstract
Currently a lot of attention is paid to 1D nanomaterials due to their advantages in comparison to bulk materials. They offer broad possibilities of application, including photocatalytic water splitting. Simulations of water adsorption on such materials with computationally costly theoretical methods, such as ab initio molecular dynamics, are needed for improvement of such photocatalysts’ efficiency. Still, it is very problematic to treat a real-size nanotube at available computational power. The existing nanotube surface approximations are not accurate and universal enough. We have already proposed methods for 2D model construction out of TiO2 nanotubes of (101) and (001) configuration at the moderately expensive DFT level. The idea behind was to provide a partial description of nanotubular strain by applying lattice constants from nanotubes to slab models, and preserving geometry motifs. We use water adsorption energy, valence band maximum and conduction band minimum positions, as well as DOS shape as criteria for model validation. Our previous work was limited only to specific variants of nanotubes and water adsorption. In this work we establish these novel approaches along a wide nanotube diameter range, in particular for water adsorption studies. We demonstrate that the 2D models do not impose critical compromises in terms of accuracy, and therefore allow calculations of much larger nanotubes than common approaches do.
Description
Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2019/2 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART 2 .
Keywords
Research Subject Categories::NATURAL SCIENCES:Physics , DFT , Nanotubes , Slab model , TiO2 , Water adsorption , Water splitting