TY - JOUR
T1 - A carbon nanohorn-porphyrin supramolecular assembly for photoinduced electron-transfer processes
AU - Vizuete, María
AU - Gómez-Escalonilla, Maria José
AU - Fierro, José Luis G.
AU - Sandanayaka, Atula S.D.
AU - Hasobe, Taku
AU - Yudasaka, Masako
AU - Iijima, Sumio
AU - Ito, Osamu
AU - Langa, Fernando
PY - 2010/9/17
Y1 - 2010/9/17
N2 - A supramolecular assembly of zinc porphyrin-carbon nanohorns (CNHs) was constructed in a polar solvent. An ammonium cation was covalently connected to the CNH through a spacer (sp) (CNH-sp-NH3+) and bound to a crown ether linked to a zinc porphyrin (Crown-ZnP). Nanohybrids CNH-sp-NH 3+;Crown-ZnP and CNHsp-NH3+ were characterized by several techniques, such as high-resolution transmission electron microscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy. The photoinduced electron-transfer processes of the nanohybrids have been confirmed by using time-resolved absorption and fluorescence measurements by combining the steady-state spectral data. Fluorescence quenching of the ZnP unit by CNH-spNH3+ has been observed, therefore, photoinduced charge separation through the excited singlet state of the ZnP unit is suggested for the hybrid material, CNH-sp-NH3+;Crown-ZnP. As transient absorption spectral experiments reveal the formation of the radical cation of the ZnP unit, electron generation is suggested as a counterpart of the charge-separation on the CNHs; such an electron on the CNHs is further confirmed by migrating to the hexylviologen dication (HV2+). Accumulation of the electron captured from HV+ is observed as electron pooling in solution in the presence of a hole-shifting reagent. Photovoltaic performance with moderate efficiency is confirmed for CNH-sp-NH3+;CrownZnP deposited onto nanostructured SnO2 films.
AB - A supramolecular assembly of zinc porphyrin-carbon nanohorns (CNHs) was constructed in a polar solvent. An ammonium cation was covalently connected to the CNH through a spacer (sp) (CNH-sp-NH3+) and bound to a crown ether linked to a zinc porphyrin (Crown-ZnP). Nanohybrids CNH-sp-NH 3+;Crown-ZnP and CNHsp-NH3+ were characterized by several techniques, such as high-resolution transmission electron microscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy. The photoinduced electron-transfer processes of the nanohybrids have been confirmed by using time-resolved absorption and fluorescence measurements by combining the steady-state spectral data. Fluorescence quenching of the ZnP unit by CNH-spNH3+ has been observed, therefore, photoinduced charge separation through the excited singlet state of the ZnP unit is suggested for the hybrid material, CNH-sp-NH3+;Crown-ZnP. As transient absorption spectral experiments reveal the formation of the radical cation of the ZnP unit, electron generation is suggested as a counterpart of the charge-separation on the CNHs; such an electron on the CNHs is further confirmed by migrating to the hexylviologen dication (HV2+). Accumulation of the electron captured from HV+ is observed as electron pooling in solution in the presence of a hole-shifting reagent. Photovoltaic performance with moderate efficiency is confirmed for CNH-sp-NH3+;CrownZnP deposited onto nanostructured SnO2 films.
KW - Carbon nanohorns
KW - Electron transfer
KW - Photovoltaic cells
KW - Porphyrinoids
KW - Supramolecular chemistry
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U2 - 10.1002/chem.201000299
DO - 10.1002/chem.201000299
M3 - Article
C2 - 20687144
AN - SCOPUS:77956642457
SN - 0947-6539
VL - 16
SP - 10752
EP - 10763
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 35
ER -
