DFT Investigation on the Electronic and Water Adsorption Properties of Pristine and N-Doped TiO2 Nanotubes for Photocatalytic Water Splitting Applications

Authors

John Isaac G. Enriquez, De La Salle University-Manila
Joaquin Lorenzo V. Moreno, De La Salle University-Manila
Melanie Y. David, De La Salle University-Manila
Nelson B. Arboleda, De La Salle University-Manila
Ong Hui Lin, Universiti Malaysia Perlis
Al Rey C. Villagracia, De La Salle University-Manila

College

College of Science

Department/Unit

Physics

Document Type

Article

Source Title

Journal of Electronic Materials

Volume

46

Issue

6

First Page

3592

Last Page

3602

Publication Date

6-1-2017

Abstract

© 2017, The Minerals, Metals & Materials Society. Experimental studies have shown the production of hydrogen through a photocatalytic water splitting process using a titanium dioxide nanotube (TiO2NT) as a photoelectrode. In this study, a theoretical model of pristine and nitrogen-doped TiO2NT based on a TiO2 anatase (101) surface is presented. Spin unrestricted density functional theory calculations were performed to provide a detailed description of the geometries, electronic properties, and adsorption of water (H2O) on pristine and N-doped TiO2NT. The calculations show that doping with N will improve the photocatalytic properties of TiO2NT in two ways: First, the energy barrier of the dissociation reaction of water into hydroxyl radical and hydrogen atom is reduced; and second, the defect-induced states above the valence band lowers the band gap which will result in enhanced visible-light-driven photoactivity. Based on the position of the Fermi level relative to the defect induced energy levels, an optimal doping concentration of around 1.4% is proposed, which is in good agreement with experimental results. This study provides an atomic/molecular level understanding of the photocatalytic water splitting process and may serve as a groundwork for the rational design of more efficient photocatalysts.

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Digitial Object Identifier (DOI)

10.1007/s11664-017-5342-y

Recommended Citation

Enriquez, J., Moreno, J., David, M., Arboleda, N., Lin, O., & Villagracia, A. C. (2017). DFT Investigation on the Electronic and Water Adsorption Properties of Pristine and N-Doped TiO2 Nanotubes for Photocatalytic Water Splitting Applications. Journal of Electronic Materials, 46 (6), 3592-3602. https://doi.org/10.1007/s11664-017-5342-y

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