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Photoelectrochemical Reduction of Carbon Dioxide with a Copper Graphitic Carbon Nitride Photocathode
Author(s) -
Yu Huijun,
Cohen Hagai,
Neumann Ronny
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202101820
Subject(s) - photocathode , faraday efficiency , electrochemical reduction of carbon dioxide , graphitic carbon nitride , x ray photoelectron spectroscopy , materials science , oxide , copper , nitride , electrode , carbon dioxide , photocatalysis , inorganic chemistry , chemistry , anode , carbon monoxide , nanotechnology , chemical engineering , layer (electronics) , electron , catalysis , quantum mechanics , metallurgy , engineering , biochemistry , physics , organic chemistry
Research on the photoreduction of CO 2 often has been dominated by the use of sacrificial reducing agents. A pathway that avoids this problem would be the development of photocathodes for CO 2 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 CO 2 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 CO 2 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 CO 2 .