Abstract

ABSTRACT Titanium dioxide (TiO2) is one of prototype, water-splitting catalysts, while its catalytic performance is strongly affected by the presence of water molecules or hydroxyl groups on the surface. The adsorption of water on the TiO2(101) and TiO2(001) surfaces at different water/hydroxyl coverages was firstly studied using density functional theory (DFT) calculations. It has been found that the surface hydroxylation state has a significant influence on water adsorption behaviour. On the basis of calculated Gibbs free surface energies as a function of temperature and hydroxylation extent, the fully dehydrated TiO2(101) and TiO2(001) surfaces will be reached at 500 and 1000 K, respectively. In the present work, BF3 and NH3 were used as probe molecules to study the Lewis acidic and Brønsted basic strengths of TiO2(101) and TiO2(001) surfaces under different hydroxylation conditions. As the hydroxyl coverage increases, the Brønsted basic strength becomes stronger while the Lewis acidic strength is weakened. Finally, it is noted that the TiO2 surface is slightly oxidised at low hydroxyl coverage but being reduced at high hydroxyl coverage.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.