Abstract
Research on the photoreduction of CO2 often has been dominated by the use of sacrificial reducing agents. A pathway that avoids this problem would be the development of photocathodes for CO2 reduction that could then be coupled to a photoanodic oxygen evolution reaction. Here, we present the use of copper-substituted graphitic carbon nitride (Cu−CN) on a fluorinated tin oxide (FTO) electrode for the photoelectrochemical two-electron reduction of CO2 to CO as a major product (>95 %) and formic acid (<5 %). The results show that at a potential of −2.5 V versus Fc\Fc+ the CO2 reduction activity of Cu−CN on FTO electrode improves by 25 % upon illumination by visible light with a faradaic efficiency of nearly 100 %. Independently, X-ray photoelectron spectroscopy conclusively shows a pronounced increase in the electrical conductivity of the Cu−CN upon white light illumination under vacuum and a contactless measuring configuration. This photo-assisted charge mobility is shown to play a key role in the increased reactivity and faradaic efficiency for the reduction of CO2.
Original language | English |
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Pages (from-to) | 13513-13517 |
Number of pages | 5 |
Journal | Chemistry - A European Journal |
Volume | 27 |
Issue number | 54 |
State | Published - 24 Sep 2021 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2021 Wiley-VCH GmbH
Keywords
- CO reduction
- copper-carbon nitride
- electrochemistry
- photochemistry
- XPS