Jump to main content
Jump to site search

Issue 4, 2012

Experimental and computational studies of nitrogen doped Degussa P25 TiO2: application to visible-light driven photo-oxidation of As(iii)

Author affiliations

Abstract

Degussa P25 TiO2 doped with nitrogen via NH3 treatment at 400–600 °C was found to be capable of catalyzing the photo-oxidation of aqueous As(III) to As(V) under visible light. Substitutional doping of N for O creates N–Ti–O surface linkages, as confirmed by XPS. Kinetic studies have been performed in batch systems with 40 μM As(III) and 0.05 g L−1 TiO2. Photocatalytic oxidation of As(III) in the presence of N-doped TiO2 annealed at 500 °C was complete within 4 hours of irradiation at λ > 435 nm. The presence of titanium oxynitride (or similar surface moieties) is linked with the good photooxidation catalytic activity toward As(III). Zeta potentials of the N-doped TiO2 showed negative shifts at low pH values, which became more pronounced when measured after photocatalytic testing, suggesting at least partial retention of As(V). First principles DFT calculations were also carried out for a model anatase (101) surface, in both the pristine and N-doped condition. Dissociation of water is energetically favoured over the N-TiO2 surface. This surface activation mechanism provides the rationale for increased As(V) retention. Enhanced adsorptive properties in TiO2 would render it a more versatile remediation agent.

Graphical abstract: Experimental and computational studies of nitrogen doped Degussa P25 TiO2: application to visible-light driven photo-oxidation of As(iii)

Article information


Submitted
25 Nov 2011
Accepted
17 Dec 2011
First published
19 Dec 2011

Catal. Sci. Technol., 2012,2, 784-793
Article type
Paper

Experimental and computational studies of nitrogen doped Degussa P25 TiO2: application to visible-light driven photo-oxidation of As(III)

X. Wang, S. O. Pehkonen, J. Rämö, M. Väänänen, J. G. Highfield and K. Laasonen, Catal. Sci. Technol., 2012, 2, 784 DOI: 10.1039/C2CY00486K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements