Preparation and photophysical and photoelectrochemical properties of a covalently fixed porphyrin-chemically converted graphene composite

Tomokazu Umeyama, Junya Mihara, Noriyasu Tezuka, Yoshihiro Matano, Kati Stranius, Vladimir Chukharev, Nikolai V. Tkachenko, Helge Lemmetyinen, Kei Noda, Kazumi Matsushige, Tetsuya Shishido, Zheng Liu, Kaori Hirose-Takai, Kazu Suenaga, Hiroshi Imahori

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Chemically converted graphene (CCG) covalently linked with porphyrins has been prepared by a Suzuki coupling reaction between iodophenyl-functionalized CCG and porphyrin boronic ester. The covalently linked CCG-porphyrin composite was designed to possess a short, rigid phenylene spacer between the porphyrin and the CCG. The composite material formed stable dispersions in DMF and the structure was characterized by spectroscopic, thermal, and microscopic measurements. In steady-state photoluminescence spectra, the emission from the porphyrin linked to the CCG was quenched strongly relative to that of the porphyrin reference. Fluorescence lifetime and femtosecond transient absorption measurements of the porphyrin-linked CCG revealed a short-lived porphyrin singlet excited state (38 ps) without yielding the porphyrin radical cation, thereby substantiating the occurrence of energy transfer from the porphyrin excited state to the CCG and subsequent rapid decay of the CCG excited state to the ground state. Consistently, the photocurrent action spectrum of a photoelectrochemical device with a SnO 2 electrode coated with the porphyrin-linked CCG exhibited no photocurrent response from the porphyrin absorption. The results obtained here provide deep insight into the interaction between graphenes and π-conjugated systems in the excited and ground states.

Original languageEnglish
Pages (from-to)4250-4257
Number of pages8
JournalChemistry - A European Journal
Volume18
Issue number14
DOIs
Publication statusPublished - 2012 Apr 2
Externally publishedYes

    Fingerprint

Keywords

  • energy transfer
  • graphene
  • photophysics
  • porphyrinoids
  • time-resolved spectroscopy

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

Cite this

Umeyama, T., Mihara, J., Tezuka, N., Matano, Y., Stranius, K., Chukharev, V., Tkachenko, N. V., Lemmetyinen, H., Noda, K., Matsushige, K., Shishido, T., Liu, Z., Hirose-Takai, K., Suenaga, K., & Imahori, H. (2012). Preparation and photophysical and photoelectrochemical properties of a covalently fixed porphyrin-chemically converted graphene composite. Chemistry - A European Journal, 18(14), 4250-4257. https://doi.org/10.1002/chem.201103843