Jinzhen Huang^1*, Adam H. Clark², Natasha Natasha Hales¹, Camelia Nicoleta Borca², Thomas Huthwelker², Thomas J. Schmidt^1,3, Emiliana Fabbri^1*

1 Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland

2 Photon Science Division, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland

3 Institute for Physical Molecular Sciences, ETH Zürich, CH-8093 Zürich, Switzerland

* Corresponding authors emails: jinzhen.huang@psi.ch, emiliana.fabbri@psi.ch

DOI10.24435/materialscloud:16-ac [version v1]

Publication date: Mar 26, 2024

How to cite this record

Jinzhen Huang, Adam H. Clark, Natasha Natasha Hales, Camelia Nicoleta Borca, Thomas Huthwelker, Thomas J. Schmidt, Emiliana Fabbri, Spectroscopic investigations of complex electronic interactions by elemental doping and material compositing of cobalt oxide for enhanced oxygen evolution reaction activity, Materials Cloud Archive 2024.51 (2024), https://doi.org/10.24435/materialscloud:16-ac

Description

Doping and compositing are two universal design strategies used to engineer the electronic state of a material and mitigate its disadvantages. These two strategies have been extensively applied to the design of efficient electrocatalysts for water splitting. Using cobalt oxide (CoO) as a model catalyst, we prove that the oxygen evolution reaction (OER) performance could be progressively improved, first by Fe-doping to form Fe-CoO solid solution, and further by the addition of CeO2 to produce a Fe-CoO/CeO2 composite. X-ray adsorption spectroscopy (XAS) reveals that distinct electronic interactions are induced by the processes of doping and compositing. Fe-doping of CoO can break down the structural symmetry in the pristine material, changing the electronic structure of both Co and O species at the surface and decreasing the flat-band potential (Vfb). In comparison, subsequent compositing of Fe-CoO with CeO2 induces negligible electronic changes in the as-synthesized Fe-CoO (as seen in ex-situ characterizations), but significantly modifies the oxidative transformations of both Co and Fe under OER conditions. Our spectroscopic investigations reveal that Fe-doping and CeO2 compositing play different roles in modifying the electronic properties of CoO in its pristine state and during OER catalysis, respectively, in return, providing useful guidance for the design of more efficient electrocatalysts using these two strategies.

Materials Cloud sections using this data

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File name	Size	Description
raw data for CoFeCe project.xlsx MD5md5:7cb482c7b3361644101ecd0ddda41319	2.4 MiB	The raw data for the Figure 1-5 in the main text

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Keywords

Oxygen evolution reaction electronic interaction Doping Compositing X-ray adsorption spectroscopy