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

Abstract

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 CeO 2 promotes the in situ reconfiguration of Ni-X via strengthening hydroxyl adsorption, generating highly active CeO 2 -NiOOH interfaces. Moreover, rich oxygen vacancies formed after breaking Ni-S/P bonds and leaching S/P anions render Ni 3 S 2 and Ni 2 P superior to NiO with the same CeO 2 modification, highlighting another dependence on pre-catalyst materials chemistry. Theoretical analysis further confirms that the co-presence of CeO 2 -NiOOH interfaces and oxygen vacancies can harmoniously regulate intermediate chemisorption toward favorable OER kinetics. As a proof of concept, CeO 2 -modified Ni 3 S 2 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.

Fundamental Understanding of Structural Reconstruction Behaviors in Oxygen Evolution Reaction Electrocatalysts

“…Having decorated Ni–X (X = S, P) nanosheets with CeO 2 nanoparticles, Gao et al investigated the role of the CeO 2 /Ni–X interface in tuning the OER activity of the reconstruction derived oxyhydroxides. [ 69 ] The interfacial CeO 2 was demonstrated to accelerate the reconstruction of Ni–X (X = S, P) via strengthening the hydroxyl adsorption, leading to the formation of CeO 2 –NiOOH interfaces with rich oxygen vacancies (Figure 3e). DFT calculations suggested that the CeO 2 –NiOOH interfaces containing abundant oxygen vacancies exhibited intermediate binding strengths with intermediates, thereby facilitating favorable OER kinetics.…”

Crystalline–Amorphous Interface Coupling of Ni3S2/NiPx/NF with Enhanced Activity and Stability for Electrocatalytic Oxygen Evolution

“…These advanced reports often focus on a single amorphous catalyst for electrocatalytic reactions. Besides, promoting electron transport is very critical in the electrochemical OER process, whether for designing efficient OER electrocatalysts or for exploring the mechanism of catalyst surface evolution . However, the amorphous phase suffers from intrinsic poor conductivity and low stability owing to the high cation dissolving rate, while the crystalline phase just shows the advantages of high electronic conductivity and close-packed structure with remarkable corrosion resistance. , Combining the high conductivity of the crystalline phase and abundant low-coordination atoms of the amorphous phase to construct a crystalline–amorphous (c–a) coupling structure is an extremely potent strategy for achieving this target .…”

Facile Synthesis of a Nickel-Based Dopamine MOF/Multiwalled Carbon Nanotubes Nanocomposite as an Efficient Electrocatalyst for the Oxygen Evolution Reaction

“…The overall water splitting efficiency is hindered because the OER comprises of a complex three electron method which necessitates a high energy of activation for the development of the oxygen–oxygen bond (O–O) with absorption of the intermediate on the electrode that becomes difficult as compared to the HER. − Cost effective and highly active catalysts are needed to control these half reactions occurring in the water splitting process; the excellent catalysts used for the OER in basic media were noble metals (Ir/Ru based oxides, Pt based alloys), and catalytic applications of these noble metals are limited because they are very expensive and insufficient. , Therefore, the exertions have been made for the formation of competent and unexpansive electrocatalysts for the OER in current times. , Various transition metal compounds display efficient OER catalytic activity, such as carbides, oxides, , sulfides, and hydroxides. , …”