TY - JOUR
T1 - Structure and Reactivity of Pristine and Reduced Spinel CoFe2O4(001)/(100) Surfaces
AU - Rushiti, Arjeta
AU - Hättig, Christof
AU - Wen, Bo
AU - Selloni, Annabella
N1 - Funding Information:
This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, project number 388390466–TRR 247). A.R. acknowledges financial support by the Ruhr University Research School PLUS, funded by Germany’s Excellence Initiative [DFG GSC 98/3]. B.W. and A.S. were supported by DoE-BES, Division of Chemical Sciences, Geosciences and Biosciences under Award DESC0007347. We used resources of the TIGRESS High Performance Computer Center at Princeton University.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/5/13
Y1 - 2021/5/13
N2 - Cobalt ferrite, CoFe2O4 (CFO), nanocrystals are efficient and competitive anode materials in the field of electrochemical water splitting. Using density functional theory with on-site Hubbard U corrections (DFT+U), we have investigated the structural, electronic, and magnetic properties of CFO (001)/(100) surfaces, as well as their reactivities toward water adsorption. Special attention has been focused on the formation of oxygen vacancies (VO), due to their key role in the oxidation activity of metal oxides, often based on the Mars-van Krevelen mechanism. Our results show that vacancy formation is easiest at oxygen sites that are not bound to tetrahedrally coordinated Fe. Water adsorbs mainly in molecular form on the Co/Fe metal cations, whereas it dissociates at defects. In comparison to other spinels, CFO is similar to NiFe2O4, exhibiting relatively low energy cost of VO formation and a strong affinity of the vacancies toward water. These findings suggest that CFO may be a more promising oxidation catalyst than NiCo2O4 and Co3O4.
AB - Cobalt ferrite, CoFe2O4 (CFO), nanocrystals are efficient and competitive anode materials in the field of electrochemical water splitting. Using density functional theory with on-site Hubbard U corrections (DFT+U), we have investigated the structural, electronic, and magnetic properties of CFO (001)/(100) surfaces, as well as their reactivities toward water adsorption. Special attention has been focused on the formation of oxygen vacancies (VO), due to their key role in the oxidation activity of metal oxides, often based on the Mars-van Krevelen mechanism. Our results show that vacancy formation is easiest at oxygen sites that are not bound to tetrahedrally coordinated Fe. Water adsorbs mainly in molecular form on the Co/Fe metal cations, whereas it dissociates at defects. In comparison to other spinels, CFO is similar to NiFe2O4, exhibiting relatively low energy cost of VO formation and a strong affinity of the vacancies toward water. These findings suggest that CFO may be a more promising oxidation catalyst than NiCo2O4 and Co3O4.
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U2 - 10.1021/acs.jpcc.1c01881
DO - 10.1021/acs.jpcc.1c01881
M3 - Article
AN - SCOPUS:85106457196
SN - 1932-7447
VL - 125
SP - 9774
EP - 9781
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 18
ER -