Ceria-Promoted Reconstruction of Ni-Based Electrocatalysts toward Efficient Oxygen Evolution

Modulating the dynamic change of catalysts is significant for understanding the mechanism and exploiting better electrocatalysts but remains challenging in oxygen evolution reaction (OER). Herein, ceria-promoted reconstruction of Ni-X (X = S, P, and O) is investigated to unravel the correlation between the reconstructed surface and the OER performance, which further guides the design of prominent electrocatalysts. Interfacial CeO2 promotes the in situ reconfiguration of Ni-X via strengthening hydroxyl adsorption, generating highly active CeO2-NiOOH interfaces. Moreover, rich oxygen vacancies formed after breaking Ni-S/P bonds and leaching S/P anions render Ni3S2 and Ni2P superior to NiO with the same CeO2 modification, highlighting another dependence on pre-catalyst materials chemistry. Theoretical analysis further confirms that the co-presence of CeO2-NiOOH interfaces and oxygen vacancies can harmoniously regulate intermediate chemisorption toward favorable OER kinetics. As a proof of concept, CeO2-modified Ni3S2 exhibits low overpotentials of 251 and 364 mV at the current densities of 10 and 100 mA cm–2 in 1.0 M KOH, respectively, performing among the best of recently reported Ni-based counterparts.