TY - JOUR
T1 - Enhanced Photocatalytic Alcohol Oxidation at the Interface of RuC-Coated TiO2Nanorod Arrays
AU - Li, Shuya
AU - Shuler, Eric Wolfgang
AU - Willinger, Debora
AU - Nguyen, Hai Tien
AU - Kim, Saerona
AU - Kang, Hyeong Cheol
AU - Lee, Jae Joon
AU - Zheng, Weiwei
AU - Yoo, Chang Geun
AU - Sherman, Benjamin D.
AU - Leem, Gyu
N1 - Funding Information:
This work is supported by the USDA National Institute of Food and Agriculture, McIntire Stennis Program project (1023017, NYZ1161219). W.Z. acknowledges support from an NSF CAREER grant (Award CHE-1944978), an NSF IUCRC Phase I grant (Award 2052611), and a Syracuse University CUSE Grant (SD-10-2020). B.D.S. thank the Welch Foundation for support of this work through Award P-2044-20200401. J.-J.L. acknowledges support from the Korean National Research Foundation, funded by the Ministry of Science, ICT & Future Planning (Grant NRF-2021R1A2C2094554).
Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/5/25
Y1 - 2022/5/25
N2 - Visible-light-driven organic oxidations carried out under mild conditions offer a sustainable approach to performing chemical transformations important to the chemical industry. This work reports an efficient photocatalytic benzyl alcohol oxidation process using one-dimensional (1D) TiO2nanorod (NR)-based photoanodes with surface-adsorbed ruthenium polypyridyl photocatalysts at room temperature. The photocatalyst bis(2,2′-bipyridine)(4,4′-dicarboxy-2,2′-bipyridine)Ru(II) (RuC) was covalently anchored onto TiO2nanorod arrays grown on fluorine-doped tin oxide (FTO) electrode surfaces (FTO|t-TiO2|RuC, t = the thickness of TiO2NR). Under aerobic conditions, the photophysical and photocatalytic properties of FTO|t-TiO2|RuC (t = 1, 2, or 3.5 μm) photoanodes were investigated in a solution containing a hydrogen atom transfer mediator (4-acetamido-2,2,6,6-tetramethylpiperidine-N-oxyl, ACT) as cocatalyst. Dye-sensitized photoelectrochemical cells (DSPECs) using the FTO|t-TiO2|RuC (t = 1, 2, or 3.5 μm) photoanodes and ACT-containing electrolyte were investigated for carrying out photocatalytic oxidation of a lignin model compound containing a benzylic alcohol functional group. The best-performing anode surface, FTO|1-TiO2|RuC (shortest NR length), oxidized the 2° alcohol of the lignin model compound to the Cα-ketone form with a > 99% yield over a 4 h photocatalytic experiment with a Faradaic efficiency of 88%. The length of TiO2NR arrays (TiO2NRAs) on the FTO substrate influenced the photocatalytic performance with longer NRAs underperforming compared to the shorter arrays. The influence of the NR length is hypothesized to affect the homogeneity of the RuC coating and accessibility of the ACT mediator to the RuC-coated TiO2surface. The efficient photocatalytic alcohol oxidation with visible light at room temperature as demonstrated in this study is important to the development of sustainable approaches for lignin depolymerization and biomass conversion.
AB - Visible-light-driven organic oxidations carried out under mild conditions offer a sustainable approach to performing chemical transformations important to the chemical industry. This work reports an efficient photocatalytic benzyl alcohol oxidation process using one-dimensional (1D) TiO2nanorod (NR)-based photoanodes with surface-adsorbed ruthenium polypyridyl photocatalysts at room temperature. The photocatalyst bis(2,2′-bipyridine)(4,4′-dicarboxy-2,2′-bipyridine)Ru(II) (RuC) was covalently anchored onto TiO2nanorod arrays grown on fluorine-doped tin oxide (FTO) electrode surfaces (FTO|t-TiO2|RuC, t = the thickness of TiO2NR). Under aerobic conditions, the photophysical and photocatalytic properties of FTO|t-TiO2|RuC (t = 1, 2, or 3.5 μm) photoanodes were investigated in a solution containing a hydrogen atom transfer mediator (4-acetamido-2,2,6,6-tetramethylpiperidine-N-oxyl, ACT) as cocatalyst. Dye-sensitized photoelectrochemical cells (DSPECs) using the FTO|t-TiO2|RuC (t = 1, 2, or 3.5 μm) photoanodes and ACT-containing electrolyte were investigated for carrying out photocatalytic oxidation of a lignin model compound containing a benzylic alcohol functional group. The best-performing anode surface, FTO|1-TiO2|RuC (shortest NR length), oxidized the 2° alcohol of the lignin model compound to the Cα-ketone form with a > 99% yield over a 4 h photocatalytic experiment with a Faradaic efficiency of 88%. The length of TiO2NR arrays (TiO2NRAs) on the FTO substrate influenced the photocatalytic performance with longer NRAs underperforming compared to the shorter arrays. The influence of the NR length is hypothesized to affect the homogeneity of the RuC coating and accessibility of the ACT mediator to the RuC-coated TiO2surface. The efficient photocatalytic alcohol oxidation with visible light at room temperature as demonstrated in this study is important to the development of sustainable approaches for lignin depolymerization and biomass conversion.
KW - TiOnanorods
KW - alcohol dehydrogenation
KW - dye-sensitized photoelectrosynthesis cell
KW - lignin conversion
KW - mild conditions
KW - photo-oxidation
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U2 - 10.1021/acsami.1c20795
DO - 10.1021/acsami.1c20795
M3 - Review article
AN - SCOPUS:85125908301
SN - 1944-8244
VL - 14
SP - 22799
EP - 22809
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 20
ER -