CINDECA   05422
CENTRO DE INVESTIGACION Y DESARROLLO EN CIENCIAS APLICADAS "DR. JORGE J. RONCO"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Effects of the modification with tungstosilicic acid on the physicochemical properties of mesoporous titania
Autor/es:
FUCHS, V.M; BLANCO M.N,; PIZZIO L.,R.
Lugar:
San Francisco, EEUU
Reunión:
Congreso; 21st North American Catalysis Society Meeting; 2009
Resumen:
The specific surface area (SBET) decreased and the mean pore radius slightly increased when increasing the TSA content . SBET also decreased when increasing the calcination temperature. The drop of SBET is lower for the samples with higher TSA amount. The XRD patterns of all the samples only exhibited the characteristic peaks of anatase phase at 2¥è = 25.3¨¬ (101), 37.9¨¬ (004), 47.8¨¬ (200) and 54.3¨¬. The particle size (DC) of samples treated at 100 ¨¬C, estimated by XRD using the Scherrer equation, seems to be independent of the TSA content. The crystallinity and DC increased when the calcination temperature is raised. However, the increment was lower for the samples with higher TSA content. According with FT-IR results, the Keggin structure of TSA was preserved during the synthesis and the thermal treatment. The UV-visible DRS spectra of the samples displayed an absorption threshold onset that continuously shifts to the visible region with the increment of both TSA content and temperature. The band gap energy (Eg) of TiTSA00 (estimated from UV-Visible DRS spectra) was similar to that reported for anatase. Eg decreased as a result of the introduction of TSA into the TiO2 matrix, and also with the raise of the calcination temperature. The XRD patterns of all the samples only exhibited the characteristic peaks of anatase phase at 2¥è = 25.3¨¬ (101), 37.9¨¬ (004), 47.8¨¬ (200) and 54.3¨¬. The particle size (DC) of samples treated at 100 ¨¬C, estimated by XRD using the Scherrer equation, seems to be independent of the TSA content. The crystallinity and DC increased when the calcination temperature is raised. However, the increment was lower for the samples with higher TSA content. According with FT-IR results, the Keggin structure of TSA was preserved during the synthesis and the thermal treatment. The UV-visible DRS spectra of the samples displayed an absorption threshold onset that continuously shifts to the visible region with the increment of both TSA content and temperature. The band gap energy (Eg) of TiTSA00 (estimated from UV-Visible DRS spectra) was similar to that reported for anatase. Eg decreased as a result of the introduction of TSA into the TiO2 matrix, and also with the raise of the calcination temperature.
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