Photocatalytic activity of titanium dioxide coatings: Influence of the firing temperature of the chemical gel
| Autor: | C. Ducroquetz, M. Fassier, T. Voland, David S. Smith, Claire Peyratout |
|---|---|
| Přispěvatelé: | Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Centre Technique de Matériaux Naturels de Construction (CTMNC), CTMNC |
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Anatase
Materials science Mineralogy 02 engineering and technology Thermal treatment 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences [SPI.MAT]Engineering Sciences [physics]/Materials chemistry.chemical_compound Chemical engineering chemistry Rutile Specific surface area Titanium dioxide Materials Chemistry Ceramics and Composites Ultraviolet light Photocatalysis Crystallite 0210 nano-technology |
| Zdroj: | Journal of the European Ceramic Society Journal of the European Ceramic Society, Elsevier, 2010, 30 (13), pp.2757-2762. ⟨10.1016/j.jeurceramsoc.2010.05.018⟩ |
| ISSN: | 0955-2219 |
| DOI: | 10.1016/j.jeurceramsoc.2010.05.018⟩ |
| Popis: | International audience; Heterogeneous photocatalysis can be exploited for the decomposition of micro-organisms which have developed on the surfaces of building materials. In this work, the efficiency of titanium dioxide coatings on fired clay products is examined. The sol-gel method is used to synthesize a fine TiO2 powder with a specific surface area of 180 m2 g−1. Thermal treatment of the chemical gel at 340 °C leads to crystallisation in the anatase phase and with further temperature increase, crystallite growth. For thermal treatments in the range 580-800 °C, there is a progressive transition from anatase to rutile. However, despite a decrease in specific surface area of the powder attributed to aggregation/agglomeration, the coherent domain size deduced from X-ray diffraction measurements remains almost constant at 23 nm. Once the transition is completed, increase of thermal treatment temperature above 800 °C leads to further crystallite growth in the rutile phase. The thermally treated titania powders were then sprayed onto fired clay substrates and the photocatalytic activity was assessed by the aptitude of the coating to degrade methylene blue when exposed to ultraviolet light. These tests revealed that the crystallite size is the important controlling factor for photocatalytic activity rather than the powder specific surface area or the anatase/rutile polymorph ratio. |
| Databáze: | OpenAIRE |
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