Abstract
Alkoxyphenyl-substituted carbazole-based metal-free organic dyes were synthesized and effectively used for dye-sensitized, visible-light-driven, photocatalytic hydrogen production. Photocatalytic hydrogen production was investigated using a TiO2/dye/Pt structure with triethanolamine as the sacrificial reagent. The dye-loaded TiO2 photocatalyst exhibited a high yield of hydrogen production when the length of the alkoxy chain was long enough to sufficiently improve the hydrophobicity at the interface between the dye-loaded TiO2 and the water medium. In the alkoxyphenyl-substituted carbazole dyes, the dye with the longest alkoxy chain (C22) exhibited the best hydrogen production performance, but it had a yield only slightly better than that of the dye with the second longest chain length (C16). The dye C22 displayed a turnover number (TON) of 3094 after 24 h of visible light irradiation (>420 nm). However, the compound with no hydrophobic substituent (C1), exhibited the lowest hydrogen production performance with a TON of 1497. Thus, a 207% increase in the hydrogen production yield was observed when hydrophobic substituents were present. Analysis of time-resolved absorption spectra, impedance spectra and incident photon conversion efficiency spectra revealed that the alkoxy chain has a hydrophobic effect at the interface between the dye-loaded TiO2 and the water. Specifically, the hydrophobicity of the dye improved the charge-recombination lifetime for electron injection from the dye into the TiO2 surface in the water for hydrogen production.
| Original language | English |
|---|---|
| Pages (from-to) | 21713-21721 |
| Number of pages | 9 |
| Journal | Journal of Materials Chemistry A |
| Volume | 3 |
| Issue number | 43 |
| DOIs | |
| Publication status | Published - Jan 1 2015 |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
Cite this
Impact of alkoxy chain length on carbazole-based, visible light-driven, dye sensitized photocatalytic hydrogen production. / Watanabe, Motonori; Hagiwara, Hidehisa; Ogata, Yudai; Staykov, Aleksandar; Bishop, Sean R.; Perry, Nicola H.; Chang, Yuan Jay; Ida, Shintaro; Tanaka, Keiji; Ishihara, Tatsumi.
In: Journal of Materials Chemistry A, Vol. 3, No. 43, 01.01.2015, p. 21713-21721.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Impact of alkoxy chain length on carbazole-based, visible light-driven, dye sensitized photocatalytic hydrogen production
AU - Watanabe, Motonori
AU - Hagiwara, Hidehisa
AU - Ogata, Yudai
AU - Staykov, Aleksandar
AU - Bishop, Sean R.
AU - Perry, Nicola H.
AU - Chang, Yuan Jay
AU - Ida, Shintaro
AU - Tanaka, Keiji
AU - Ishihara, Tatsumi
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Alkoxyphenyl-substituted carbazole-based metal-free organic dyes were synthesized and effectively used for dye-sensitized, visible-light-driven, photocatalytic hydrogen production. Photocatalytic hydrogen production was investigated using a TiO2/dye/Pt structure with triethanolamine as the sacrificial reagent. The dye-loaded TiO2 photocatalyst exhibited a high yield of hydrogen production when the length of the alkoxy chain was long enough to sufficiently improve the hydrophobicity at the interface between the dye-loaded TiO2 and the water medium. In the alkoxyphenyl-substituted carbazole dyes, the dye with the longest alkoxy chain (C22) exhibited the best hydrogen production performance, but it had a yield only slightly better than that of the dye with the second longest chain length (C16). The dye C22 displayed a turnover number (TON) of 3094 after 24 h of visible light irradiation (>420 nm). However, the compound with no hydrophobic substituent (C1), exhibited the lowest hydrogen production performance with a TON of 1497. Thus, a 207% increase in the hydrogen production yield was observed when hydrophobic substituents were present. Analysis of time-resolved absorption spectra, impedance spectra and incident photon conversion efficiency spectra revealed that the alkoxy chain has a hydrophobic effect at the interface between the dye-loaded TiO2 and the water. Specifically, the hydrophobicity of the dye improved the charge-recombination lifetime for electron injection from the dye into the TiO2 surface in the water for hydrogen production.
AB - Alkoxyphenyl-substituted carbazole-based metal-free organic dyes were synthesized and effectively used for dye-sensitized, visible-light-driven, photocatalytic hydrogen production. Photocatalytic hydrogen production was investigated using a TiO2/dye/Pt structure with triethanolamine as the sacrificial reagent. The dye-loaded TiO2 photocatalyst exhibited a high yield of hydrogen production when the length of the alkoxy chain was long enough to sufficiently improve the hydrophobicity at the interface between the dye-loaded TiO2 and the water medium. In the alkoxyphenyl-substituted carbazole dyes, the dye with the longest alkoxy chain (C22) exhibited the best hydrogen production performance, but it had a yield only slightly better than that of the dye with the second longest chain length (C16). The dye C22 displayed a turnover number (TON) of 3094 after 24 h of visible light irradiation (>420 nm). However, the compound with no hydrophobic substituent (C1), exhibited the lowest hydrogen production performance with a TON of 1497. Thus, a 207% increase in the hydrogen production yield was observed when hydrophobic substituents were present. Analysis of time-resolved absorption spectra, impedance spectra and incident photon conversion efficiency spectra revealed that the alkoxy chain has a hydrophobic effect at the interface between the dye-loaded TiO2 and the water. Specifically, the hydrophobicity of the dye improved the charge-recombination lifetime for electron injection from the dye into the TiO2 surface in the water for hydrogen production.
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U2 - 10.1039/c5ta04991a
DO - 10.1039/c5ta04991a
M3 - Article
AN - SCOPUS:84946028816
VL - 3
SP - 21713
EP - 21721
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
SN - 2050-7488
IS - 43
ER -