Aqueous CO2 Reduction on Si Photocathodes Functionalized by Cobalt Molecular Catalysts/Carbon Nanotubes
Photoelectrochemical reduction of CO2 is a promising approach for renewable fuel production. We herein report a novel strategy for preparation of hybrid photocathodes by immobilizing molecular cobalt catalysts on TiO2‐protected n+‐p Si electrodes (Si|TiO2) coated with multiwalled carbon nanotubes (C...
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Published in | Angewandte Chemie International Edition Vol. 61; no. 24; pp. e202201086 - n/a |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
Wiley Subscription Services, Inc
13.06.2022
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Edition | International ed. in English |
Subjects | |
Online Access | Get full text |
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Summary: | Photoelectrochemical reduction of CO2 is a promising approach for renewable fuel production. We herein report a novel strategy for preparation of hybrid photocathodes by immobilizing molecular cobalt catalysts on TiO2‐protected n+‐p Si electrodes (Si|TiO2) coated with multiwalled carbon nanotubes (CNTs) by π–π stacking. Upon loading a composite of CoII(BrqPy) (BrqPy=4′,4′′‐bis(4‐bromophenyl)‐2,2′ : 6′,2′′ : 6′′,2′′′‐quaterpyridine) catalyst and CNT on Si|TiO2, a stable 1‐Sun photocurrent density of −1.5 mA cm−2 was sustained over 2 h in a neutral aqueous solution with unity Faradaic efficiency and selectivity for CO production at a bias of zero overpotential (−0.11 V vs. RHE), associated with a turnover frequency (TOFCO) of 2.7 s−1. Extending the photoelectrocatalysis to 10 h, a remarkable turnover number (TONCO) of 57000 was obtained. The high performance shown here is substantially improved from the previously reported photocathodes relying on covalently anchored catalysts.
A hybrid photocathode prepared by attaching a molecular cobalt catalyst on a n+‐p Si film coated with multiwalled carbon nanotubes (CNTs) exhibits 100 % selectivity and 100 % Faradaic efficiency towards CO2‐to‐CO conversion in aqueous media under simulated sunlight irradiation. The high performance benefits from CNTs as both a support platform for highly dispersed molecular active sites and an efficient mediator for charge transfer. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1433-7851 1521-3773 1521-3773 |
DOI: | 10.1002/anie.202201086 |