Dependence of photocatalytic activity on the compositions and photo-absorption of functional TiO2–Fe3O4 coatings deposited by plasma spray

Autor: Akira Ohmori, Kazuhiro Nakata, Fuxing Ye, Takuya Tsumura
Rok vydání: 2008
Předmět:
Zdroj: Materials Science and Engineering: B. 148:154-161
ISSN: 0921-5107
DOI: 10.1016/j.mseb.2007.09.057
Popis: Owing to the much concern with global environmental issues, Fe 3 O 4 added photocatalytic TiO 2 coatings were deposited using plasma spray for environmental depollution. The influence of the content of Fe 3 O 4 additive to the TiO 2 powder on the phase composition, microstructure and photo-absorption of plasma-sprayed TiO 2 coatings was systematically studied. The results showed that the TiO 2 –Fe 3 O 4 coatings consisted of anatase TiO 2 , rutile TiO 2 and Fe 2 TiO 5 pseudobrookite phase which appeared when the content of Fe 3 O 4 additive was equal to or over 10%. The content of FeTiO 3 was highest in the sprayed TiO 2 –10%Fe 3 O 4 coatings. The addition of Fe 3 O 4 improved the anatase–rutile transformation of TiO 2 –Fe 3 O 4 powders. Furthermore, it was found that TiO 2 coatings can decompose acetaldehyde under the illumination of ultraviolet rays, and the degrading efficiency was improved with an increase of FeTiO 3 content in the coatings. A two-step electron transfer model was proposed to explain the good photocatalytic activity of the sprayed coating with high content of FeTiO 3 . However, presence of large amount of Fe 2 TiO 5 compound substantially reduced the photocatalytic efficiency of the sprayed TiO 2 –Fe 3 O 4 coatings for its unfavorable photo-excited electron–hole transfer process.
Databáze: OpenAIRE
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