TY - JOUR
T1 - Poly(1,4-di(2-thienyl))benzene Facilitating Complete Light-Driven Water Splitting under Visible Light at High pH
AU - Oka, Kouki
AU - Noguchi, Kanako
AU - Suga, Takeo
AU - Nishide, Hiroyuki
AU - Winther-Jensen, Bjorn
N1 - Funding Information:
This work was partly supported by Grant-in-Aids for Scientific Research (16K05922, 15H00766, and 18H03921), Research Fellowship of Japan Society for the Promotion of Science, and the Top Global University Project from MEXT, Japan. K.O. acknowledges support from the Leading Graduate Program in Science and Engineering, Waseda University from MEXT, Japan. T.S. acknowledges the Grants-in-Aids for Scientific Research on Innovative Areas (New Polymeric Materials Based on Element Blocks, 15H00766 and 25102541).
Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/2/7
Y1 - 2019/2/7
N2 - The recent discovery that metal-free polyterthiophene (PTTh) prepared by iodine-vapor-assisted polymerization (IVP) can catalyze the hydrogen evolution reaction (HER) when illuminated, and this light-enhanced electrolysis expresses a non-Nernstian relation with pH, provides the foundation for further improvement of the photovoltage of the reaction by engineering the band structure of the light-absorbing polymer. Deviating from an all-thiophene backbone, using poly(1,4-di(2-thienyl))benzene (PDTB) lowers the highest occupied molecular orbital level by ≈0.3 eV compared with polythiophene, and PDTB simultaneously maintains the photoelectrocatalytic properties without an all-thiophene backbone, resulting in very high conversion rate of 600 mmol(H2) h−1 g−1 at 0 V versus the reversible hydrogen electrode (RHE) at pH 11. PDTB shows the same non-Nernstian behavior as PTTh with increasing onset potential (versus RHE) at higher pH, and the open circuit potential on PDTB under visible light reaches 1.4 V versus RHE at pH 12. The PDTB photocathode thus produces a photovoltage above the theoretical potential for the complete water-splitting (1.229 V) and is indeed able to produce hydrogen in a one-photon-per-electron light-driven water splitting setup with MnOx as the anode at a rate of 6.4 mmol h−1 gPDTB −1.
AB - The recent discovery that metal-free polyterthiophene (PTTh) prepared by iodine-vapor-assisted polymerization (IVP) can catalyze the hydrogen evolution reaction (HER) when illuminated, and this light-enhanced electrolysis expresses a non-Nernstian relation with pH, provides the foundation for further improvement of the photovoltage of the reaction by engineering the band structure of the light-absorbing polymer. Deviating from an all-thiophene backbone, using poly(1,4-di(2-thienyl))benzene (PDTB) lowers the highest occupied molecular orbital level by ≈0.3 eV compared with polythiophene, and PDTB simultaneously maintains the photoelectrocatalytic properties without an all-thiophene backbone, resulting in very high conversion rate of 600 mmol(H2) h−1 g−1 at 0 V versus the reversible hydrogen electrode (RHE) at pH 11. PDTB shows the same non-Nernstian behavior as PTTh with increasing onset potential (versus RHE) at higher pH, and the open circuit potential on PDTB under visible light reaches 1.4 V versus RHE at pH 12. The PDTB photocathode thus produces a photovoltage above the theoretical potential for the complete water-splitting (1.229 V) and is indeed able to produce hydrogen in a one-photon-per-electron light-driven water splitting setup with MnOx as the anode at a rate of 6.4 mmol h−1 gPDTB −1.
KW - high pH
KW - hydrogen evolution
KW - photocathodes
KW - poly(1,4-di(2-thienyl))benzene
KW - water splitting
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U2 - 10.1002/aenm.201803286
DO - 10.1002/aenm.201803286
M3 - Article
AN - SCOPUS:85059304157
VL - 9
JO - Advanced Energy Materials
JF - Advanced Energy Materials
SN - 1614-6832
IS - 6
M1 - 1803286
ER -