RT journal article
T1 Understanding the potential-induced activation of a cobalt MOF electrocatalyst for the oxygen evolution reaction
A1 Gutiérrez Tarriño, Silvia
A1 Portorreal Bottier, Arismendy
A1 Calvente, Juan José
A1 Olloqui Sariego, José Luis
A1 Oña Burgos, Pascual
A1 Trasobares Llorente, Susana
A1 Calvino Gámez, José Juan
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
K1 2D-Cobalt-MOF
K1 Electrocatalytic oxygen evolution reaction
K1 Electrochemical activation
K1 MOF-electrode interface
K1 Structural evolution
AB Metal–organic frameworks (MOFs) are attractive porous materials for electrocatalytic applications associated with carbon-free energy storage and conversion. This type of material usually requires a post-treatment to be used as electrocatalyst. The present work comprehensively investigates the electrochemical activation of a cobalt-MOF@Nafion composite that produces outstanding electrocatalytic performance for the water oxidation reaction at neutral pH. A detailed electrochemical characterization reveals that the electroactivation of the composite requires the participation of the oxygen evolution reaction (OER) and leads to a significant increase in the electroactive population of cobalt centers. It is shown that an increase of the applied activation potential in the OER region results in a faster electroactivation of the Co-MOF without affecting the intrinsic electrocatalytic properties of the active cobalt centers, as evidenced by the unique linear correlation between the electrocatalytic OER current and the population of electroactive cobalt. In addition, at structural level, it is shown that the electrochemical activation causes the partial disruption of the Nafion adlayer, as well as morphological changes of the Co–MOF particles from a compact, rounded morphology, before electrochemical activation, to a more open and expanded structure, after electroactivation; with the concomitant increase of the number of surface–exposed cobalt centers. Interestingly, these cobalt centers retain their coordinative chemistry and their laminar distribution in the nanosheets at the nanoscale, which is consistent with the preservation of their intrinsic electrocatalytic activity after potential–induced activation. In this scenario, these results suggest that only the electroactivated cobalt centers with good accessibility to the electrolyte are electrochemically active. This work provides a better understanding of the processes and structural changes underlying the electrochemical activation at neutral pH of a Co–MOF for boosting the electrocatalytic water oxidation reaction
PB Elsevier
SN 0169-4332
YR 2023
FD 2023-03-13
LK http://hdl.handle.net/10498/29405
UL http://hdl.handle.net/10498/29405
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 15-nov-2026