Infrared Spectroscopic Study of the Adsorption Forms of Cyanuric Acid and Cyanuric Chloride on TiO2
Autor: | Tzu En Chien, Po Yuan Lin, Kun Lin Li, Jong Liang Lin |
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Rok vydání: | 2016 |
Předmět: |
Cyanuric chloride
02 engineering and technology Surfaces and Interfaces 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Tautomer Chloride 0104 chemical sciences chemistry.chemical_compound Hydrolysis Adsorption chemistry Electrochemistry medicine Organic chemistry General Materials Science Triol 0210 nano-technology Cyanuric acid Melamine Spectroscopy medicine.drug |
Zdroj: | Langmuir. 32:5306-5313 |
ISSN: | 1520-5827 0743-7463 |
Popis: | Cyanuric acid is often found to be the end product in the hydrolysis of waste melamine and in the TiO2-mediated photocatalytic decomposition of s-triazine-containing compounds used as herbicides or dyes. The photocatalytically recalcitrant nature of cyanuric acid on TiO2 may be closely related to its adsorption properties, including the tautomeric forms present on the surfaces and their bonding structures, which remain to be determined. In this paper, we present the optimized adsorption structures of the four tautomeric isomers (triketo, diketo, monoketo, and triol) of cyanuric acid on a model rutile-TiO2(110) surface and their vibrational absorptions. Experimentally, the adsorption structures of cyanuric acid and chloride on powdered TiO2 are analyzed on the basis of the theoretically obtained, characteristic infrared information. Cyanuric acid on TiO2 at 35 °C exists in triketo and hydroxylated forms, but the diketo becomes the predominant form on the surface at 250 °C, being bonded to a titanium site via one of its carbonyl groups and with a N-H···O hydrogen bonding interaction. Hydroxylation of cyanuric chloride occurs as it is adsorbed on TiO2 at 35 °C. Upon being heated to 200 °C, the surface is mainly covered with the diketo form of cyanuric acid after the adsorption of cyanuric chloride. |
Databáze: | OpenAIRE |
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