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Photoelectron Spectroscopy at the Graphene–Liquid Interface Reveals the Electronic Structure of an Electrodeposited Cobalt/Graphene Electrocatalyst
Author(s) -
VelascoVelez Juan J.,
Pfeifer Verena,
Hävecker Michael,
Weatherup Robert S.,
Arrigo Rosa,
Chuang ChengHao,
Stotz Eugen,
Weinberg Gisela,
Salmeron Miquel,
Schlögl Robert,
KnopGericke Axel
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201506044
Subject(s) - graphene , x ray photoelectron spectroscopy , cobalt , electrocatalyst , materials science , catalysis , chemical engineering , electronic structure , nanotechnology , chemistry , electrode , electrochemistry , organic chemistry , computational chemistry , engineering , metallurgy
Electrochemically grown cobalt on graphene exhibits exceptional performance as a catalyst for the oxygen evolution reaction (OER) and provides the possibility of controlling the morphology and the chemical properties during deposition. However, the detailed atomic structure of this hybrid material is not well understood. To elucidate the Co/graphene electronic structure, we have developed a flow cell closed by a graphene membrane that provides electronic and chemical information on the active surfaces under atmospheric pressure and in the presence of liquids by means of X‐ray photoelectron spectroscopy (XPS). We found that cobalt is anchored on graphene via carbonyl‐like species, namely Co(CO) x , promoting the reduction of Co 3+ to Co 2+ , which is believed to be the active site of the catalyst.