Preparation, Characterisation, and Photocatalytic Behaviour of Co-TiO2 with Visible Light Response

The preparation of cobalt-modified TiO2 (Co-TiO2) was carried out by the incipient impregnation method starting from commercial TiO2 (Degussa, P-25) and cobalt acetate. XPS data show that cobalt is incorporated as divalent ion, and it is likely present within few subsurface layers. No appreciable c...

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Bibliographic Details
Main Authors: Rossano Amadelli, Luca Samiolo, Andrea Maldotti, Alessandra Molinari, Mario Valigi, Delia Gazzoli
Format: Article
Language:English
Published: Wiley 2008-01-01
Series:International Journal of Photoenergy
Online Access:http://dx.doi.org/10.1155/2008/853753
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Summary:The preparation of cobalt-modified TiO2 (Co-TiO2) was carried out by the incipient impregnation method starting from commercial TiO2 (Degussa, P-25) and cobalt acetate. XPS data show that cobalt is incorporated as divalent ion, and it is likely present within few subsurface layers. No appreciable change in structural-morphologic properties, such as surface area and anatase/rutile phase ratio, was observed. Conversely, Co addition brings about conspicuous changes in the point of zero charge and in surface polarity. Diffuse reflectance spectra feature a red shift in light absorption that is dependent on the amount of cobalt. The influence of cobalt addition on the performance of TiO2 as a photocatalyst in the degradation of 4-chlorophenol and Bisphenol A is investigated. The results show that the modified oxide presents a higher photoactivity both for illumination with UV-visible (λ>360 nm) and visible light (λ>420 nm; λ>450 nm), and that this enhancement depends on the amount of the added species and on the final thermal treatment in the preparation step. We also show that Co-TiO2 is a more active catalyst than pure TiO2 for the reduction of O2 in the dark, which is an important reaction in the overall photocatalytic processes.
ISSN:1110-662X
1687-529X