Toggle Main Menu Toggle Search

Open Access padlockePrints

Photogreying of TiO2 nanoparticles

Lookup NU author(s): Dr Terry Egerton, Ian Tooley


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Photogreying, the change in brightness on UV irradiation in the absence of oxygen, of TiO2 nanoparticulate dispersions is shown to depend on the nature of the liquid, consistent with a surface reaction. Measurements on a series of TiO2 particles (mainly 75×10 nm) dispersed in, e.g., alkyl benzoate correlate well with those on the same TiO2's dispersed in a second liquid (e.g. propan-2-ol). Photogreying in propan-2-ol is paralleled by photocatalytic-oxidation activity, indicating a common origin - UV-generation of charge carriers. Further, photogreying parallels Ti 3+ formation. Hence, although appearance and the visible spectra of photogreyed particles both differ from those of Ti3+ in ≤ 10 nm colloidal TiO2, we suggest that photogreying is caused by capture of UV excited electrons to form Ti3+. Surface treatment reduces photogreying, and we speculate that differences between uncoated samples reflect differences in the number of potentially reducible Ti's. © 2006 Springer Science+Business Media, Inc.

Publication metadata

Author(s): Egerton TA, Kessell LM, Tooley IR, Wang L

Publication type: Article

Publication status: Published

Journal: Journal of Nanoparticle Research

Year: 2007

Volume: 9

Issue: 2

Pages: 251-260

ISSN (print): 1388-0764

ISSN (electronic): 1572-896X

Publisher: Springer Netherlands


DOI: 10.1007/s11051-006-9195-1


Altmetrics provided by Altmetric