Sensitive efficiency of photoinduced electron transfer to band gaps of semiconductive single-walled carbon nanotubes with supramolecularly attached zinc porphyrin bearing pyrene glues

Eranda Maligaspe, Atula S.D. Sandanayaka, Taku Hasobe, Osamu Ito, Francis Dsouza

Research output: Contribution to journalArticle

96 Citations (Scopus)

Abstract

Photoinduced electron transfer in self-assembled single-walled carbon nanotube (SWNT)/zinc porphyrin (ZnP) hybrids utilizing (7,6)- and (6,5)-enriched SWNTs has been investigated. Toward this, first, zinc porphyrin was covalently functionalized to possess four pyrene entities (ZnP(pyr)4). Exfoliation of the semiconducting nanotube bundles occurred due to π-π-type interactions with the pyrene and porphyrin entities in organic solvents. The nanohybrids thus formed were isolated and characterized by TEM, UV-visible-near-IR, and Raman spectroscopy. Free-energy calculations suggested the possibility of electron transfer in both the (7,6)- and (6,5)-possessing ZnP(pyr)4/SWNT nanohybrids. Accordingly, fluorescence studies revealed efficient quenching of the singlet excited state of ZnP in the nanohybrids, originating from the charge separation, as confirmed by observation of a ZnP π-cation radical in transient absorption spectra. The rates of charge separation were found to be slightly higher for (7,6)-SWNT-derived hybrids compared to the (6,5)-SWNT-derived hybrids. Charge recombination revealed an opposite effect, indicating that the (7,6)-SWNTs are slightly better for charge stabilization compared to the (6,5)-SWNTs. The present nanohybrids were further utilized to photochemically reduce the hexyl viologen dication in the presence of a sacrificial electron donor in an electron-pooling experiment, offering additional proof for the occurrence of photoinduced charge separation and potential utilization of these materials in light-energy-harvesting applications. Finally, solar cells constructed using the ZnP/SWNT hybrids revealed higher efficiency for the ZnP(pyr)4/(7,6)-SWNT hybrid with narrower nanotube band gap compared with the ZnP(pyr)4/(6,5)-SWNT having a relatively wider band gap.

Original languageEnglish
Pages (from-to)8158-8164
Number of pages7
JournalJournal of the American Chemical Society
Volume132
Issue number23
DOIs
Publication statusPublished - 2010 Jun 16

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Sensitive efficiency of photoinduced electron transfer to band gaps of semiconductive single-walled carbon nanotubes with supramolecularly attached zinc porphyrin bearing pyrene glues'. Together they form a unique fingerprint.

  • Cite this