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Preparation of TiO 2 ‐ SiO 2 composite photocatalysts for environmental applications
Author(s) -
Paušová Šárka,
Krýsa Josef,
Jirkovský Jaromír,
Prevot Vanessa,
Mailhot Gilles
Publication year - 2014
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4436
Subject(s) - materials science , photocatalysis , anatase , composite number , aqueous solution , chemical engineering , photodegradation , methyl orange , degradation (telecommunications) , amorphous solid , crystallization , aqueous two phase system , phase (matter) , composite material , catalysis , chemistry , organic chemistry , telecommunications , computer science , engineering
BACKGROUND The objective of this work is to prepare various TiO 2 / SiO 2 composites, determine their photocatalytic activity and suggest the most promising materials for further application. RESULTS TiO 2 / SiO 2 composites were successfully prepared as a powder, obtained by the heterocoagulation of mixed TiO 2 and SiO 2 aqueous colloidal suspensions. The heterocoagulation of prepared amorphous TiO 2 in the presence of SiO 2 led to the crystallization of TiO 2 with anatase structure. Photocatalytic activity was tested in the liquid phase by dye degradation and in the gas phase by hexane degradation. In aqueous phase the presence of SiO 2 increased the rate of degradation of Methylene Blue in comparison with pure TiO 2 in acidic conditions, whereas Acid Orange 7 photodegradation was faster in basic solution in the presence of TiO 2 / SiO 2 1:1 composite. In gaseous phase, composites prepared by heterocoagulation showed improved photoactivity (conversion around 35%). CONCLUSION Composites prepared by heterocoagulation with ratio TiO 2 / SiO 2 1:10 can be used as photocatalyst in self‐cleaning paints. SiO 2 partly covers the TiO 2 surface and acts as a barrier which separates the active surface of TiO 2 from contact with the binder or polymeric substrate. © 2014 Society of Chemical Industry