TY - JOUR
T1 - Band gap effect on the photocatalytic activity of supramolecular structures obtained by entrapping photosensitizers in different inorganic supports
AU - Cojocaru, Bogdan
AU - Neau, Tefan
AU - Pârvulescu, Vasile I.
AU - Dumbuya, Karifala
AU - Steinrück, Hans Peter
AU - Michael Gottfried, J.
AU - Aprile, Carmela
AU - Garcia, Hermenegildo
AU - Scaiano, J. C.
PY - 2009
Y1 - 2009
N2 - Different metallophthalocyanines and 2,4,6-triphenylpyrylium (TP +) ions were entrapped in different inorganic supports such as Y zeolite, mesoporous MCM-41, TiO2-SiO2 and SiO2 following a specific protocol. The resulting supramolecular structures were characterized by chemical analysis and diffuse reflectance UV-Vis measurements. The determination of the band gap on the basis of UV-Vis measurements showed that the host is not a spectator in this process and an electronic interaction occurs that lowers the band gap of the support. The XPS measurements were performed with an in situ X-ray photoelectron spectrometer, which can be operated at pressures of up to 1 mbar at the sample. They indicated that the formation of the supramolecular structure generates a stable environment, in which the oxidation state of the metal can still be influenced by reaction of the metal center with gas molecules. The photocatalytic tests carried out in photodecomposition of dipropyl sulfide showed a good correlation between the band gap values and the photocatalytic activity for metallophthalocyanine complexes. It is remarkable that the triphenylpyrylium ion follows the same trend observed for metallophthalocyanines, although it is a different type of photosensitizer.
AB - Different metallophthalocyanines and 2,4,6-triphenylpyrylium (TP +) ions were entrapped in different inorganic supports such as Y zeolite, mesoporous MCM-41, TiO2-SiO2 and SiO2 following a specific protocol. The resulting supramolecular structures were characterized by chemical analysis and diffuse reflectance UV-Vis measurements. The determination of the band gap on the basis of UV-Vis measurements showed that the host is not a spectator in this process and an electronic interaction occurs that lowers the band gap of the support. The XPS measurements were performed with an in situ X-ray photoelectron spectrometer, which can be operated at pressures of up to 1 mbar at the sample. They indicated that the formation of the supramolecular structure generates a stable environment, in which the oxidation state of the metal can still be influenced by reaction of the metal center with gas molecules. The photocatalytic tests carried out in photodecomposition of dipropyl sulfide showed a good correlation between the band gap values and the photocatalytic activity for metallophthalocyanine complexes. It is remarkable that the triphenylpyrylium ion follows the same trend observed for metallophthalocyanines, although it is a different type of photosensitizer.
UR - http://www.scopus.com/inward/record.url?scp=67651085079&partnerID=8YFLogxK
U2 - 10.1039/b902348h
DO - 10.1039/b902348h
M3 - Article
AN - SCOPUS:67651085079
SN - 1463-9076
VL - 11
SP - 5569
EP - 5577
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 27
ER -