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Thermo-Raman Spectroscopy (thermo-raman + spectroscopy)

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Chemistry100%

Selected Abstracts

Synthesis and Monitoring of ,-Bi2Mo3O12 Catalyst Formation using Thermo-Raman Spectroscopy

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2004
Anil Ghule
Abstract Thermo-Raman spectroscopy was used to monitor the dehydration and phase transformations of Bi2Mo3O12·5H2O. The hydrated forms Bi2Mo3O12·5H2O, Bi2Mo3O12·4.75H2O, Bi2Mo3O12·3H2O, Bi2Mo3O12·2H2O, and anhydrous Bi2Mo3O12 were observed during dehydration in the wavelength range from 200 to 1400 cm,1. Representative Raman spectra of these compounds are reported for the first time. The thermo-Raman intensity thermogram showed a systematic dehydration in four steps, and the differential thermo-Raman intensity thermogram confirmed this. Thermogravimetry, differential thermogravimetry, and differential scanning calorimetry results were in harmony with the results of the thermo-Raman spectroscopy. Additionally, the dehydration resulting in formation of anhydrous Bi2Mo3O12 (amorphous Bi2Mo3O12 phase) and the final transformation into the ,-Bi2Mo3O12 phase was observed to be a dynamic thermal process. The slow, controlled heating rate produced ,-Bi2Mo3O12 catalyst with a particle size averaging 200 nm. The catalyst formed was further characterized by Fourier transform infrared spectroscopy, X-ray diffraction, time of flight SIMS, transmission electron microscopy, and energy-dispersive X-ray analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Thermo-Raman spectroscopy of synthetic nesquehonite , implication for the geosequestration of greenhouse gases

JOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2008
Matthew C. Hales
Abstract Pure nesquehonite (MgCO3·3H2O)/Mg(HCO3)(OH)·2H2O was synthesised and characterised by a combination of thermo-Raman spectroscopy and thermogravimetry with evolved gas analysis. Thermo-Raman spectroscopy shows an intense band at 1098 cm,1, which shifts to 1105 cm,1 at 450 °C, assigned to the ,1CO32, symmetric stretching mode. Two bands at 1419 and 1509 cm,1 assigned to the ,3 antisymmetric stretching mode shift to 1434 and 1504 cm,1 at 175 °C. Two new peaks at 1385 and 1405 cm,1 observed at temperatures higher than 175 °C are assigned to the antisymmetric stretching modes of the (HCO3), units. Throughout all the thermo-Raman spectra, a band at 3550 cm,1 is attributed to the stretching vibration of OH units. Raman bands at 3124, 3295 and 3423 cm,1 are assigned to water stretching vibrations. The intensity of these bands is lost by 175 °C. The Raman spectra were in harmony with the thermal analysis data. This research has defined the thermal stability of one of the hydrous carbonates, namely nesquehonite. Thermo-Raman spectroscopy enables the thermal stability of the mineral nesquehonite to be defined, and, further, the changes in the formula of nesquehonite with temperature change can be defined. Indeed, Raman spectroscopy enables the formula of nesquehonite to be better defined as Mg(OH)(HCO3)·2H2O. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Synthesis and Monitoring of ,-Bi2Mo3O12 Catalyst Formation using Thermo-Raman Spectroscopy

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2004
Anil Ghule
Abstract Thermo-Raman spectroscopy was used to monitor the dehydration and phase transformations of Bi2Mo3O12·5H2O. The hydrated forms Bi2Mo3O12·5H2O, Bi2Mo3O12·4.75H2O, Bi2Mo3O12·3H2O, Bi2Mo3O12·2H2O, and anhydrous Bi2Mo3O12 were observed during dehydration in the wavelength range from 200 to 1400 cm,1. Representative Raman spectra of these compounds are reported for the first time. The thermo-Raman intensity thermogram showed a systematic dehydration in four steps, and the differential thermo-Raman intensity thermogram confirmed this. Thermogravimetry, differential thermogravimetry, and differential scanning calorimetry results were in harmony with the results of the thermo-Raman spectroscopy. Additionally, the dehydration resulting in formation of anhydrous Bi2Mo3O12 (amorphous Bi2Mo3O12 phase) and the final transformation into the ,-Bi2Mo3O12 phase was observed to be a dynamic thermal process. The slow, controlled heating rate produced ,-Bi2Mo3O12 catalyst with a particle size averaging 200 nm. The catalyst formed was further characterized by Fourier transform infrared spectroscopy, X-ray diffraction, time of flight SIMS, transmission electron microscopy, and energy-dispersive X-ray analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Thermo-Raman spectroscopy of synthetic nesquehonite , implication for the geosequestration of greenhouse gases

JOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2008
Matthew C. Hales
Abstract Pure nesquehonite (MgCO3·3H2O)/Mg(HCO3)(OH)·2H2O was synthesised and characterised by a combination of thermo-Raman spectroscopy and thermogravimetry with evolved gas analysis. Thermo-Raman spectroscopy shows an intense band at 1098 cm,1, which shifts to 1105 cm,1 at 450 °C, assigned to the ,1CO32, symmetric stretching mode. Two bands at 1419 and 1509 cm,1 assigned to the ,3 antisymmetric stretching mode shift to 1434 and 1504 cm,1 at 175 °C. Two new peaks at 1385 and 1405 cm,1 observed at temperatures higher than 175 °C are assigned to the antisymmetric stretching modes of the (HCO3), units. Throughout all the thermo-Raman spectra, a band at 3550 cm,1 is attributed to the stretching vibration of OH units. Raman bands at 3124, 3295 and 3423 cm,1 are assigned to water stretching vibrations. The intensity of these bands is lost by 175 °C. The Raman spectra were in harmony with the thermal analysis data. This research has defined the thermal stability of one of the hydrous carbonates, namely nesquehonite. Thermo-Raman spectroscopy enables the thermal stability of the mineral nesquehonite to be defined, and, further, the changes in the formula of nesquehonite with temperature change can be defined. Indeed, Raman spectroscopy enables the formula of nesquehonite to be better defined as Mg(OH)(HCO3)·2H2O. Copyright © 2008 John Wiley & Sons, Ltd. [source]