fulltext.study @t Gmail

Low temperature synthesis, characterization and substrate-dependent photocatalytic activity of nanocrystalline TiO2 with tailor-made rutile to anatase ratio

Paper ID Volume ID Publish Year Pages File Format Full-Text
43461 45971 2008 9 PDF Available
Title
Low temperature synthesis, characterization and substrate-dependent photocatalytic activity of nanocrystalline TiO2 with tailor-made rutile to anatase ratio
Abstract

TiO2 photocatalysts with predetermined phase composition (anatase-to-rutile ratio) have been prepared from strongly acidic aqueous HCl/TiCl4 mixtures with 0.1 M ≤ [HCl]TOT ≤ 5 M and 0.05 M ≤ [TiCl4]TOT ≤ 3 M (where the subscript TOT denotes total or analytical concentration). During the syntheses, TiCl4 was added to a cold-HCl solution. The initially precipitate free reaction mixture was boiled, resulting in the formation of large amount of solid, nanocrystalline (particle size 4–12 nm) TiO2 particles with large specific surface area (up to ∼240 m2/g). We found from the XRD patterns that at constant [HCl]TOT, the anatase content of the crystallized solid systematically increases with decreasing [TiCl4]TOT, while at constant [TiCl4]TOT, the rutile content was found to systematically increase with increasing [HCl]TOT. Thus the phase composition of the photocatalysts prepared was possible to be fine-tuned with the aid of these two simple initial parameters. The photocatalytic activity of the as-prepared catalysts was found to strongly correlate with the phase composition. In phenol decomposition the samples’ photocatalytic performance gradually and significantly increases with their anatase content: photocatalysts containing only anatase as crystalline phase were up to three times more efficient than rutile ones. Interestingly, in salicylic acid decomposition, rutile-only catalysts were found to show no activity at all, but some of our catalysts (both anatase-only and rutile–anatase mixtures) at pH ∼3 (but not at pH ∼7) displayed photocatalytic activity commensurable to that of Degussa P25. This can be explained in terms of the efficient surface chemisorption of salicylate ion on large specific surface area TiO2 particles in acidic solutions.

Graphical abstractTiO2 photocatalysts with predetermined phase composition (anatase-to-rutile ratio) have been prepared from strongly acidic aqueous HCl/TiCl4 mixtures. The phase composition of the photocatalysts was fine-tuned with systematically changing the concentration of HCl and TiCl4 in the reaction mixture. In phenol decomposition the photocatalysts containing only anatase were up to three times more efficient than rutile ones.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Titania; Rutile; Anatase; Titanium tetrachloride; Hydrolysis; X-ray diffraction; Heterogeneous photocatalysis; Photocatalytic activity; Nanocrystals
First Page Preview
Low temperature synthesis, characterization and substrate-dependent photocatalytic activity of nanocrystalline TiO2 with tailor-made rutile to anatase ratio
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 340, Issue 2, 1 June 2008, Pages 153–161
Authors
, , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us