High-performance Oxygen Evolution Reaction Electrocatalysts Research Articles

Substantial Electrocatalytic Oxygen Evolution Performances of Activated Carbon-Decorated Vanadium Pentoxide Nanocomposites

Developing the ecofriendly and high-fidelity electrocatalysts for the oxygen evolution reaction (OER) is essential to foster effective production of environmentally friendly hydrogen. Herein, we fabricated the highly efficient OER electrocatalysts of the activated carbon-decorated vanadium pentoxide (AC-V2O5) nanocomposites using a facile hydrothermal technique. The AC-V2O5 nanocomposites displayed an aggregated structure of the AC nano-sheet-anchored orthorhombic V2O5 nanorods. When performing the OER process in an alkaline electrolyte at 10 mA/cm2, AC-V2O5 exhibited the low overpotential (~230 mV), small Tafel slope (~54 mV/dec), and excellent stability. These substantial OER performances of AC-V2O5 could be ascribed to the synergistic effects from both the electrochemically active V2O5 nanorods and the highly conductive AC nanosheets. The results infer that the AC-V2O5 nanocomposites possess a substantial aptitude as a high-performance OER electrocatalyst for production of the future green energy source—hydrogen.

Superhydrophilic NiFe-LDH@Co9S8-Ni3S2/NF heterostructures for high-current-density freshwater/seawater oxidation electrocatalysts

Designing oxygen evolution reaction (OER) electrocatalysts with high efficiency and stability at large current densities is paramount for achieving hydrogen production through water splitting. In this study, a heterostructured NiFe-LDH coating Co9S8-Ni3S2 grown on nickel foam (NiFe-LDH@Co9S8-Ni3S2/NF) was successfully synthesized. The distinctive hierarchical structures featuring abundant heterointerfaces can effectively expose abundant active sites. The synergistic effect and strong electronic interaction between Co9S8-Ni3S2 and NiFe-LDH can enhance the intrinsic OER activity. Furthermore, the superhydrophilic characteristic of NiFe-LDH@Co9S8-Ni3S2/NF favors close contact between the electrode and electrolyte. Due to these advantages, NiFe-LDH@Co9S8-Ni3S2/NF can provide distinguished OER activity with low overpotentials of 274 mV in alkaline freshwater and 298 mV in alkaline seawater at 1000 mA cm−2, along with outstanding stability at high current density of 500 mA cm−2 over 200 h in both solutions. This study offers a valuable insight into fabricating high-performance OER electrocatalysts for seawater electrolysis in industrial applications.

Preparing iron oxide clusters surface modified Co3O4 nanoboxes by chemical vapor deposition as an efficient electrocatalyst for oxygen evolution reaction

Interface engineering is an effective way for optimizing the electronic configuration of Co3O4 to enhance the intrinsic activity of oxygen evolution reaction (OER). However, how to enrich accessible activity sites at the interface is still a challenge. Herein, Co3O4 hollow nanoboxes modified by iron oxide nanoclusters (FeOx NCs) (Fe-Co3O4 NBs) as OER electrocatalysts are prepared by a chemical vapor deposition process. Benefiting from high exposed surface area and utilization of atoms, FeOx NCs incorporation can not only regulates the spin state of Co sites, but also exposes more accessible sites for OER. Therefore, Fe-Co3O4 NBs shows excellent OER performance, manifested by the lower overpotential (η) of 265 mV at 10 mA cm−2 and smaller Tafel slope of 54.2 mV dec−1 compared to Co3O4 NBs, and many reported Co based OER electrocatalyst. Further density functional theory analysis reveals that FeOx NCs can downshift the d center of Co sites, which decreases the energy barrier of potential-determining step (PDS) for OER (*OH → *O + H+ + e−) to enhance the electroactivity. This work provides guidance for further designing high-performance OER electrocatalysts.

Biomineralization of Sulfate-Reducing Bacteria In Situ-Induced Preparation of Nano Fe2 O3 -Fe(Ni)S/C as High-Efficiency Oxygen Evolution Electrocatalyst.

Transition metal-based catalysts possess high catalytic activity for oxygen evolution reaction (OER). However, the preparation of high-performance OER electrocatalysts using simple strategies with a low cost still faces a major challenge. Herein, this work presents an innovative, in situ-induced preparation of the Fe2 O3 , FeS, and NiS nanoparticles, supported on carbon blacks (CBs) (denoted as Fe2 O3 -Fe(Ni)S/C) as a high-efficiency oxygen evolution electrocatalyst by employing biomineralization. Biomineralization, a simple synthesis strategy, demonstrates a huge advantage in controlling the size of the Fe2 O3 and Fe(Ni)S nanoparticles, as well as achieving uniform nanoparticle distribution on carbon blacks. It is found that the electrocatalyst Fe2 O3 -Fe(Ni)S/C-200 shows a good OER electrocatalytic activity with a small loading capacity, and it has a small overpotential and Tafel slope in 1 m KOH solution with values of 264mV and 42mVdec-1 , respectively, at a current density of 10mAcm-2 . Additionally, it presents good electrochemical stability for over 24h. The remarkable and robust electrocatalytic performance of Fe2 O3 -Fe(Ni)S/C-200 is attributed to the synergistic effect of Fe2 O3 , FeS, and doped-Ni species as well as its distinct 3D spherical structure. This approach indicates the promising applications of biomineralization for the bio-preparation of functional materials and energy conversion.

A novel bimetallic organic framework catalyst induced by dual-ligand for highly efficient oxygen evolution

With the continuous advancement of non-noble electrocatalysts, metal-organic frameworks (MOFs) are emerging as a promising substitute for noble metal nanomaterials in oxygen evolution reaction (OER) due to their larger pre-development and higher cost-effectiveness. However, there are still challenges in modifying the electronic structure of MOFs at the molecular level to enhance their activity of OER. Herein, bimetallic CoNi MOFs were utilized and modified with terephthalic acid (A) and 2, 5-dihydroxyterephthalic acid (B) (A2.5B-CoNi MOFs) through a straightforward hydrothermal method. By adjusting the ratio of A and B dual-ligand, the A2.5B-CoNi MOFs with the best ligand ratio exhibit significantly enhanced OER activity with an overpotential of only 300 mV at a current density of 10 mA cm−2, a low Tafel slope of 45.27 mV dec−1. In addition, A2.5B-CoNi MOFs also have better long-term stability than commercial RuO2. This study provides a research direction for the development of high-performance OER electrocatalysts based on dual-ligand MOFs.

Iron doped cobalt nickel layered double hydroxide supported on nickel foam as a robust electrocatalyst for highly efficient water oxidation in alkaline sea water

The seawater electrolysis is an economically favorable approach for water splitting application because seawater is one of the plentiful abundant natural resources on our earth. In water splitting pathway, the anodic half-cell reaction from seawater stills a challenging task due to anodic corrosion and the competitive chloride oxidation process. In the current study, we prepared flower-shaped porous nanorods of iron doped cobalt nickel layered double hydroxide supported on nickel foam (Fe0.05 CoNi LDH/NF), which require very less oxygen evolution reaction (OER) overpotential in 1M KOH (212mV) and alkaline seawater (287mV) to deliver 10 mAcm−2 current density and exhibited remarkable 14h durability. At the same time, post treated sample reveals the better OER activity after chronopotentiometry analysis, because of superior conductivity and corrosion-resistance of the electrocatalyst. The doping of Fe cation in catalysis improves the OER selectivity and kinetics. Meanwhile, CoNi LDH serves as an active OER centers and NF increase the conductivity of the catalyst. Our findings suggests that Fe-doped CoNi LDH on NF provides an effective pathway towards durable and high performance OER electrocatalysts for seawater electrolysis.

Misoriented high-entropy iridium ruthenium oxide for acidic water splitting.

Designing an efficient catalyst for acidic oxygen evolution reaction (OER) is of critical importance in manipulating proton exchange membrane water electrolyzer (PEMWE) for hydrogen production. Here, we report a fast, nonequilibrium strategy to synthesize quinary high-entropy ruthenium iridium-based oxide (M-RuIrFeCoNiO2) with abundant grain boundaries (GB), which exhibits a low overpotential of 189 millivolts at 10 milliamperes per square centimeter for OER in 0.5 M H2SO4. Microstructural analyses, density functional calculations, and isotope-labeled differential electrochemical mass spectroscopy measurements collectively reveal that the integration of foreign metal elements and GB is responsible for the enhancement of activity and stability of RuO2 toward OER. A PEMWE using M-RuIrFeCoNiO2 catalyst can steadily operate at a large current density of 1 ampere per square centimeter for over 500 hours. This work demonstrates a pathway to design high-performance OER electrocatalysts by integrating the advantages of various components and GB, which breaks the limits of thermodynamic solubility for different metal elements.

NiCo-layered double hydroxides /Co9S8 with heterogeneous structure as ultra-high performance electrocatalyst for oxygen evolution reaction

Heterogeneous interface engineering is an ideal method for designing low-cost and efficient electrocatalysts for oxygen evolution reaction (OER). NiCo-layered double hydroxide (LDH)/Co9S8 with heterogeneous structure was prepared by a two-step hydrothermal method and employed for OER. The layered structure with a spherical base exhibited the lower overpotential (151 mV) and Tafel slope (100 mV dec−1) at a current density of 10 mA cm−2, which surpass commercially available IrO2 and most reported non-precious metal electrocatalysts. The synergistic effect at the interface can increase the conductivity of the material, induce electron migration between NiCo-LDH and Co9S8, and decrease the energy barrier of the OER intermediate, thereby increasing the electrocatalytic activity. At the same time, heterostructures with rough surfaces and ultra-hydrophilic properties can provide the desired stability, promote ion penetration and the release of bubbles, improve the accessibility of the active site, and thus enhance the catalytic performance of OER. This work provides a feasible way to develop high performance OER electrocatalysts.

Melamine intercalation approach for the synthesis of C, N codoped net-like NiCo oxides composites and Its Application towards oxygen evolution reaction in alkaline solution

Electrolysis of water is a leading hydrogen production pathway with the advantages of simple technology, mature development and small environmental impact. However, the energy conversion efficiency seriously decreased due to the high overpotential produced by oxygen evolution reaction (OER). To decrease the overpotential of OER, NiCoOx particles with small sizes embedded in layered structure constituted with carbon and nitrogen composites (NiCoOx-CN) were prepared through melamine intercalation method with acetylacetonate as cobalt and nickel source. Finally, NiCoOx-CN showed excellent OER performance with an overpotential of only 326 mV to obtain current density of 10 mA cm−2 and Tafel slope of 70.8 mV·dec−1. Besides, NiCoOx-CN possessed excellent long-term durability in alkaline environments. Scanning electron microscopy (SEM), electron paramagnetic resonance (EPR) and other techniques were implemented to study the mechanism for the increased OER performance of NiCoOx-CN. The microstructure of NiCoOx-CN that the nanoparticles embedded into the interlinked layered nanosheets was helpful to expose more active sites. Meanwhile, the doping of C and N heteroatom and abundant oxygen vacancies also led to the enhanced conductivity of NiCoOx-CN and the optimized the electron transfer. Thus, the OER performance of NiCoOx-CN significantly boosted. As a result, this strategy holds great promise in preparing other high performance OER electrocatalysts with melamine.

High-Efficiency Oxygen Evolution Reaction: Controllable Reconstruction of Surface Interface.

The precatalyst undergoes surface reconstruction during the oxygen evolution reaction (OER) process, and the reconstituted material is the one that really plays a catalytic role. However, the degree of surface reconstruction seriously affects the catalytic performance. For this reason, it is important to establish the link between the degree of reconstruction and catalytic activity based on a deep understanding of the OER mechanism for the rational design of high-performance OER electrocatalysts. Here, the reaction mechanism of OER is briefly introduced, the competition between adsorbate evolution mechanism (AEM) mechanism and lattice oxygen-mediated mechanism (LOM) mechanism is discussed, and several activity descriptors of OER reaction are summarized. The strategies to realize OER controllable surface reconstruction are emphatically introduced, including ion leaching, element doping, regulating catalyst size, heterogeneous structure engineering, and self-reconstruction. A mechanistic perspective is emphasized to understand the relationship between dynamic surface reconstruction and electronic structure. Controlled reconfiguration of OER surface can break the limitation of proportional relationship brought by traditional AEM mechanism, also can realize the switching between AEM mechanism and LOM mechanism, thus realizing ultra-low overpotential. This review will provide some reference for surface controllable reconstruction of OER transition metal-based catalysts and reasonable development of ideal catalytic performance.

A Porous Perovskite Nanofiber with Reinforced Aerophobicity for High-Performance Anion Exchange Membrane Water Splitting.

Perovskite oxides stand out as emerging oxygen evolution reaction (OER) catalysts on account of their effective electrocatalytic performance and low costs. Nevertheless, perovskite oxides suffer from severe bubble overpotential and inhibited electrochemical performance in large current densities due to their small specific surface areas and structural compactness. Herein, the study highlights the electrospun nickel-substituted La0.5 Sr0.5 FeO3-δ (LSF) porous perovskite nanofibers, that is, La0.5 Sr0.5 Fe1-x Nix O3-δ (denoted as ES-LSFN-x, x=0, 0.1, 0.3, and 0.5), as high-performance OER electrocatalysts. The most effective La0.5 Sr0.5 Fe0.5 Ni0.5 O3-δ (ES-LSFN-0.5) nanofibers suggest a larger specific surface area, higher porosity, and faster mass transfer than the counterpart sample prepared by conventional sol-gel method (SG-LSFN-0.5), showing notably increased geometric and intrinsic activities. The bubble visualization results demonstrate that the enriched and nano-sized porosity of ES-LSFN-0.5 enables reinforced aerophobicity and rapid detachment of oxygen bubbles, thereby reducing the bubble overpotential and enhancing the electrochemical performance. As a result, the ES-LSFN-0.5-based anion exchange membrane water electrolysis delivers a superior stability of 100h while the SG-LSFN-0.5 counterpart degrades rapidly within 20h under a current density of 100mAcm-2 . The results highlight the advantage of porous electrocatalysts in optimizing the performance of large current density water electrolysis devices by reducing the bubble overpotential.

Effect of phosphorus vacancies on activity of Fe-doped Nickel phosphide by NaBH4 reduction for efficient oxygen evolution under alkaline conditions

The development of effective, stable, and inexpensive electrocatalysts through oxygen evolution reaction (OER) is important but also very difficult. Anion defects are used to control the active sites of electrocatalysts. In this study, we persent an easy NaBH4 reduction strategy for engineering a novel Fe-doped nickel phosphide material with phosphorus vacancies, (i.e., Fe-Ni2P (PV)) for OER. Interestingly, this easy NaBH4 reduction tactic can fulfill defects engineering (i.e., P vacancies). The P vacancies can adjust the electronic structures of electrocatalyst for OER. Fe-Ni2P (PV) has outstanding OER performance, e.g., a lower overpotential (290 mV at 10 mA cm−2), smaller Tafel slope (41.15 mV dec-1), and excellent durability (93.5% for 12 h) under alkaline condition. This work indicates the detailed structural changes of NaBH4 reduction treated-engineered materials and improves understanding of the structure-effect relationship of high performance OER electrocatalyst.

In Situ Fabrication of Mn-Doped NiMoO4 Rod-like Arrays as High Performance OER Electrocatalyst

The slow kinetics of the oxygen evolution reaction (OER) is one of the significant reasons limiting the development of electrochemical hydrolysis. Doping metallic elements and building layered structures have been considered effective strategies for improving the electrocatalytic performance of the materials. Herein, we report flower-like nanosheet arrays of Mn-doped-NiMoO4/NF (where NF is nickel foam) on nickel foam by a two-step hydrothermal method and a one-step calcination method. The doping manganese metal ion not only modulated the morphologies of the nickel nanosheet but also altered the electronic structure of the nickel center, which could be the result of superior electrocatalytic performance. The Mn-doped-NiMoO4/NF electrocatalysts obtained at the optimum reaction time and the optimum Mn doping showed excellent OER activity, requiring overpotentials of 236 mV and 309 mV to drive 10 mA cm-2 (62 mV lower than the pure NiMoO4/NF) and 50 mA cm-2 current densities, respectively. Furthermore, the high catalytic activity was maintained after continuous operation at a current density of 10 mA cm-2 of 76 h in 1 M KOH. This work provides a new method to construct a high-efficiency, low-cost, stable transition metal electrocatalyst for OER electrocatalysts by using a heteroatom doping strategy.

Two-Dimensional Materials for High-Performance Oxygen Evolution Reaction: Fundamentals, Recent Progress, and Improving Strategies

Open AccessRenewablesREVIEWS24 Jan 2023Two-dimensional materials for high-performance oxygen evolution reaction: fundamentals, recent progresses and improving strategies Xiong Yin, Yani Hua and Zhan Gao Xiong Yin Google Scholar More articles by this author , Yani Hua Google Scholar More articles by this author and Zhan Gao Google Scholar More articles by this author https://doi.org/10.31635/renewables.023.202200003 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail Oxygen evolution reaction (OER) has an essential role in many energy storage and conversion technologies, but its high overpotential and sluggish kinetics seriously astrict the energy efficiency. The development of efficient and inexpensive OER electrocatalysts is still a grand challenge. Two-dimensional (2D) materials with unique structure and electronic properties have wide application prospects toward OER. In this review, firstly introducing OER electrocatalytic mechanisms and some crucial parameters for evaluating OER electrocatalysts, the latest progresses in the design and construction of 2D materials for OER is systematically reviewed, including layered double hydroxides, 2D carbon materials, transition metal dichalcogenides, metal oxide and phosphide nanosheets, metal-organic frameworks, covalent-organic frameworks and MXenes. Emphatically, some effective design and optimization strategies to improve electrocatalytic activity and durability of 2D materials as OER electrocatalysts are comprehensively generalized. The advantages and shortcomings of these 2D materials are analyzed in detail and their practical applications are deeply understood, which is crucial for the rational design of high-performance OER electrocatalysts. Finally, the challenges and future development opportunities of 2D materials for enhanced OER are discussed. Our review is expected to provide certain guidance for the development of new low-cost 2D materials as advanced OER electrocatalysts. Download figure Download PowerPoint Previous articleNext article FiguresReferencesRelatedDetails Issue AssignmentNot Yet Assigned Copyright & Permissions© 2023 Chinese Chemical Society Downloaded 0 times PDF downloadLoading ...

Synthesis of vanadium metal-organic framework, characterization, and study of electrochemical properties for using in supercapacitor and oxygen evolution reaction

Transition-metal (V) based metal–organic framework drew a lot of attention for use in upcoming generation electrochemical energy storage devices (Supercapacitors) and energy production during oxygen evolution reaction (OER). The large surface area, the exposed metal sites, and structural controllability make MOFs preferred heterogeneous catalysts for various catalytic reactions. Due to their tunable structures and high porosity, MOFs have shown favorable applications as electrode materials for supercapacitors. This investigation synthesized V-MOF nanorods by hydrothermal and microwave methods. The NiCo2S4/V-MOF@rGO synthesized offered a maximum specific capacitance of 1844F/g at a current density of 1.0 Ag−1. Moreover, an asymmetric supercapacitor NiCo2S4/V-MOF@rGO//AC exhibits a high energy density of 800 Wh kg−1 at a power density of 61.10 W kg−1 and 98 % of its capacitance retention after 3000 cycles. In another part of this study, the V-MOF synthesized in the previous step showed an excellent electrocatalytic performance toward the OER. Furthermore, by compositing it with graphene sheets and doping it with phosphorus as a heteroatom, its electrocatalytic activity toward OER was further enhanced, showing160 mV overpotential at a current density of 10 mA cm−2 in a 3.0 M KOH after 1000 sweeps aqueous solution. This researches present a simple, efficient, and high-performance electrocatalyst for OER and active material for supercapacitors.

High-Performance Oxygen Evolution Reaction Electrocatalysts Discovered via High-Throughput Aerogel Synthesis

A combinatorial high-throughput aerogel synthesis method is developed to systematically study the synergistic catalytic effects of multiple non-noble metal elements. A large number of aerogels with different compositions were synthesized and the corresponding ternary phase diagrams of the composition–electrocatalytic performance were constructed. A batch of aerogel catalysts with outstanding catalytic performance and stability for the electrochemical oxygen evolution reaction (OER) were discovered. Amorphous Fe3Co3Ni2-(oxy)hydroxide with excellent electrocatalytic performance (Tafel slope of 49 mV dec–1 and η100 of 421.48 ± 6.41 mV) was found to achieve a mass activity of 611.23 A/gmetal at 1.63 V (vs RHE). X-ray photoemission spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) studies reveal that the incorporation of a third atom (Ni and Ce) into the binary aerogels enlarges the Co–O atomic distance and reduces the average valence state of Co, which in turn speed up the oxygen evolution reaction kinetics. This work puts forward a strategy for high-throughput synthesis and screening of electrocatalysts and provides valuable data sets for future machine learning and prediction of high-performance electrocatalysts.

Development of high-performance oxygen evolution reaction electrocatalyst with quick kinetics: Based on ultrafine Cu nanoparticles encircled by N-doped carbon

The oxygen evolution reactions (OER) in electrochemical water splitting are the chief catalytic processes to clean and sustainable energy technologies, such as water electrolysis or energy conversion system. This study presents a Mott-Schottky catalyst encircled copper nanoparticles, including the nitrogen doped carbon layers (Cu@NC). All the fabricated materials are analyzed via numerous complementary procedures and then employed under a potentiostat configured with a three-electrode system. The fabricated Cu@NC displays a lower overpotential of 101.0 mV to accomplish current density of 10.0 mA cm−2, lower Tafel slope of 42.0 mV dec−1, and extensive stability over 5000 cycles having exceptional oxygen evolution activity. The structural results reveal that adding Cu and N species in Cu@NC significantly enhances the numerous of active sites and improves electronic conductivity. Structural defects help to accelerate the oxygen evolution process and many other fields for future applications.

Perovskite-based electrocatalysts for oxygen evolution reaction in alkaline media: A mini review.

Water electrolysis is one of the attractive technologies for producing clean and sustainable hydrogen fuels with high purity. Among the various kinds of water electrolysis systems, anion exchange membrane water electrolysis has received much attention by combining the advantages of alkaline water electrolysis and proton exchange membrane water electrolysis. However, the sluggish kinetics of the oxygen evolution reaction, which is based on multiple and complex reaction mechanisms, is regarded as a major obstacle for the development of high-efficiency water electrolysis. Therefore, the development of high-performance oxygen evolution reaction electrocatalysts is a prerequisite for the commercialization and wide application of water electrolysis systems. This mini review highlights the current progress of representative oxygen evolution reaction electrocatalysts that are based on a perovskite structure in alkaline media. We first summarize the research status of various kinds of perovskite-based oxygen evolution reaction electrocatalysts, reaction mechanisms and activity descriptors. Finally, the challenges facing the development of perovskite-based oxygen evolution reaction electrocatalysts and a perspective on their future are discussed.

Self-supported AlFeNiCoMo high-entropy alloy with micropillar array structure for efficient oxygen evolution reaction

The development of low-cost and efficient electrocatalysts for oxygen evolution reaction (OER) is crucial for the application of hydrogen energy. In this work, a self-supported AlFeCoNiMo high entropy alloy with a uniformly distributed micropillar array structure on the surface is prepared by melt spinning followed by dealloying. The catalyst exhibits a low overpotential of 228, 265, and 318 mV to drive the current densities of 10, 100, and 1000 mA/cm2, a small Tafel slope of 51 mV/dec, and excellent long-term stability for 30 h in 1.0M KOH electrolyte for OER. The high catalytic activity is attributed to the unique micropillar array with rich active sites and the synergistic effect between multiple metallic elements. The good stability of the catalyst results from the steady micropillar array structure and the formation of oxyhydroxides on the surface during long-term catalysis. This work provides a facile and scalable method for the preparation of self-supported, low-cost, and high-performance OER electrocatalysts.

High efficiency of self-assembly between exfoliated MXene and layered-double-hydroxide nanosheets in exploring high-performance oxygen evolution reaction electrocatalysts

High-performance oxygen electrocatalysts have attracted tremendous research attention because of their crucial roles in diverse renewable energy technologies such as metal–oxygen batteries, fuel cells, and water electrolyzers. In this study, a novel lattice manipulation strategy for the exploration of highly active electrocatalysts was established via self-assembly between exfoliated MXene and layered double hydroxide (LDH) nanosheets (NSs). Electrostatically-driven self-assembly between cationic Co–Fe-LDH and anionic MXene NSs yielded intimately-coupled Co–Fe-LDH–MXene nanohybrids with porous stacking structures and significant interfacial charge transfer. The self-assembled Co–Fe-LDH–MXene nanohybrid delivered excellent electrocatalyst functionality with a lowered overpotential of 252 mV at 10 mA cm−2 that is much better than those of the precursor Co–Fe-LDH and MXene NSs. The outstanding electrocatalytic activity of the self-assembled Co–Fe-LDH–MXene nanohybrid highlights a high efficacy of the self-assembly methodology in exploring high-performance electrocatalysts. In situ surface enhanced Raman scattering analysis during electrocatalysis found that the enhanced redox activity of metal cations achieved by intimate electronic coupling with ultrathin conductive MXene NSs mainly contributes to the improved performance of the Co–Fe-LDH–MXene nanohybrids for oxygen evolution reaction.