Effect of Halide Impregnation on the Structure and Surface Characteristics of Rutile
Titanium dioxide (TiO 2 , rutile) subjected to fluoride (1 M and 2 M NH 4 F) and iodide (1 M KI) treatment has been investigated by combining several approaches: structural and textural characterization as well as surface acidity and basicity. Fluorination reduces the crystallinity at both concentra...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SAGE Publications
1996-08-01
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| Series: | Adsorption Science & Technology |
| Online Access: | https://doi.org/10.1177/026361749601300405 |
| _version_ | 1797283462093209600 |
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| author | Christine A. Philip Anwar Amin Nabawia A. Moussa |
| author_facet | Christine A. Philip Anwar Amin Nabawia A. Moussa |
| author_sort | Christine A. Philip |
| collection | DOAJ |
| description | Titanium dioxide (TiO 2 , rutile) subjected to fluoride (1 M and 2 M NH 4 F) and iodide (1 M KI) treatment has been investigated by combining several approaches: structural and textural characterization as well as surface acidity and basicity. Fluorination reduces the crystallinity at both concentrations studied, the higher concentration being more effective. Iodination has the same effect. Fluoride ions replace all basic OH groups whereas iodination does not lead to full replacement due to competition with the Ti 4+ substrate. A distinct exotherm is observed at 228°C and 235°C, respectively, for the F − and I − treated samples, resulting from energetic changes leading to the activated dissociation of water and restoration of the basic OH groups. A surface compound is apparently formed on fluorination and iodination, and this decomposes endothermally at 270–275°C. In addition, impregnation with I − appears to increase the photosensitivity of the TiO 2 leading to the formation of a carbonate with atmospheric CO 2 which generates an endotherm at 285°C and whose existence has been confirmed by IR spectral analysis. Specific surface areas and pore structure analyses demonstrate differences not only upon increasing the F − concentration but also between the F − and I − treated samples, where the addition of the latter markedly reduced the surface parameters. Two groups of pore sizes could be recognized with most samples. Increasing the F − concentration increased the sintering temperature to 550°C, the value for the low F − sample being 400°C. |
| first_indexed | 2024-03-07T17:31:02Z |
| format | Article |
| id | doaj.art-5d6d5d97d32547428f72127810d2ce2b |
| institution | Directory Open Access Journal |
| issn | 0263-6174 2048-4038 |
| language | English |
| last_indexed | 2024-03-07T17:31:02Z |
| publishDate | 1996-08-01 |
| publisher | SAGE Publications |
| record_format | Article |
| series | Adsorption Science & Technology |
| spelling | doaj.art-5d6d5d97d32547428f72127810d2ce2b2024-03-02T17:54:28ZengSAGE PublicationsAdsorption Science & Technology0263-61742048-40381996-08-011310.1177/026361749601300405Effect of Halide Impregnation on the Structure and Surface Characteristics of RutileChristine A. Philip0Anwar Amin1Nabawia A. Moussa2 Chemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt Chemistry Department, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt Chemistry Department, Faculty of Science, Ain Shams University, Cairo, EgyptTitanium dioxide (TiO 2 , rutile) subjected to fluoride (1 M and 2 M NH 4 F) and iodide (1 M KI) treatment has been investigated by combining several approaches: structural and textural characterization as well as surface acidity and basicity. Fluorination reduces the crystallinity at both concentrations studied, the higher concentration being more effective. Iodination has the same effect. Fluoride ions replace all basic OH groups whereas iodination does not lead to full replacement due to competition with the Ti 4+ substrate. A distinct exotherm is observed at 228°C and 235°C, respectively, for the F − and I − treated samples, resulting from energetic changes leading to the activated dissociation of water and restoration of the basic OH groups. A surface compound is apparently formed on fluorination and iodination, and this decomposes endothermally at 270–275°C. In addition, impregnation with I − appears to increase the photosensitivity of the TiO 2 leading to the formation of a carbonate with atmospheric CO 2 which generates an endotherm at 285°C and whose existence has been confirmed by IR spectral analysis. Specific surface areas and pore structure analyses demonstrate differences not only upon increasing the F − concentration but also between the F − and I − treated samples, where the addition of the latter markedly reduced the surface parameters. Two groups of pore sizes could be recognized with most samples. Increasing the F − concentration increased the sintering temperature to 550°C, the value for the low F − sample being 400°C.https://doi.org/10.1177/026361749601300405 |
| spellingShingle | Christine A. Philip Anwar Amin Nabawia A. Moussa Effect of Halide Impregnation on the Structure and Surface Characteristics of Rutile Adsorption Science & Technology |
| title | Effect of Halide Impregnation on the Structure and Surface Characteristics of Rutile |
| title_full | Effect of Halide Impregnation on the Structure and Surface Characteristics of Rutile |
| title_fullStr | Effect of Halide Impregnation on the Structure and Surface Characteristics of Rutile |
| title_full_unstemmed | Effect of Halide Impregnation on the Structure and Surface Characteristics of Rutile |
| title_short | Effect of Halide Impregnation on the Structure and Surface Characteristics of Rutile |
| title_sort | effect of halide impregnation on the structure and surface characteristics of rutile |
| url | https://doi.org/10.1177/026361749601300405 |
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