Ni Vacancies Research Articles

Utilizing cationic vacancies to enhance nickel-cobalt layered double hydroxides for efficient electrocatalytic urea oxidation reaction

Electrocatalytic urea oxidation reaction (UOR) is a promising approach for urea-rich wastewater splitting, which benefits for reducing energy consumption in hydrogen production accompanying environmental protection and sustainable energy development. To address the limitations posed by the self-oxidation of nickel-based catalysts on the activity of UOR, we here developed a NiCo LDH nanosheet catalyst with abundant Ni vacancies to initiate the UOR process prior to nickel oxidation. Electrochemical impedance spectroscopy and In-situ spectroscopic characterizations confirm that the UOR process primarily occurs on the surface of the catalyst, rather than being driven by nickel oxidation products. The favorable electronic structure modulation induced by Ni vacancies makes the catalyst more energetically favorable for the UOR compared to nickel self-oxidation. The catalyst exhibits excellent UOR activity, only requiring 1.27 V vs. RHE at 10 mA cm−2 and 1.34 V vs. RHE at 100 mA cm−2, with no significant decay observed after over 120 h of operation. Furthermore, it can function as a bifunctional catalyst, requiring only 1.66 V to achieve 100 mA cm−2 for the UOR||HER system. This study expands the pathway for the application of cationic vacancies in UOR.

Engineering ceria oxide with nickel doping and rich oxygen vacancies for enhanced electrocatalytic degradation of aromatic organics

Aromatic dyes are widely applicable in the textile, leather, and ink industries yet receive serious contamination issues to water bodies, soil, and even air. Herein, we develop an efficient electrocatalytic oxidation method for degrading aromatic dyes via developing supportive CeO2-based electrode materials decorating with highly dispersive Ni and rich oxygen vacancies. The decorating Ni species are in situ converted from a composite of CeO2 nanocrystals and formamide-derived polyaminoimidazole (PAI)-coordinated Ni to ensure the high dispersion of Ni species. The decomposition of PAI ligands also helps to create the localized reductive atmosphere for the generation of rich surface oxygen vacancies, which further benefits the enhancement of electronic conductivity and charge transport ability. The effects of Ni doping concentrations, Rhodamine B (RhB, as a simulating aromatic dye) concentrations, pH of RhB solution, types and concentrations of electrolytes, and working current densities on the degradation performance are comprehensively investigated. Electrocatalytic measurements reveal that the CeO2 catalyst with optimal Ni concentration and fine single-crystal sizes of 5.5 ± 0.03 nm (termed as Ni0.025-CeO2-x) exhibits very promising degradation efficiency (96.9 %) and structural durability (repeated use for 5 cycles with limited activity decrease).

Spatial Control of Nickel Vacancies in Colloidal NiMgO Nanocrystals for Efficient and Stable All‐inorganic Quantum Dot Light‐Emitting Diodes

AbstractColloidal quantum dot (QD)–based light‐emitting diodes (QD‐LEDs) have reached the pinnacle of quantum efficiency and are now being actively developed for next‐generation displays and brighter light sources. Previous research has suggested utilizing inorganic hole‐transport layers (HTLs) to explore brighter and more stable QD‐LEDs. However, the performance metrics of such QD‐LEDs with inorganic HTLs generally lag behind those of organic‐inorganic hybrid QD‐LEDs employing organic HTLs. In this study, colloidal NiMgO nanocrystals (NCs) with spatially controlled Mg are introduced as HTLs for realizing efficient and stable all‐inorganic QD‐LEDs. During the co‐condensation of Ni and Mg precursors to produce valence band‐lowered NiMgO NCs, incorporating ≈2% Mg into the NiO lattice creates additional Ni vacancies (VNi) within and on the NCs, influencing the hole concentration and mobility of the NiMgO NC films. Passivating the VNi exposed on the surface with magnesium hydroxide allows for tuning the electrical properties of the NiMgO NCs relative to those of an electron transport layer, allowing for a balanced charge supply and suppressed negative charging of the QDs. Optimized all‐inorganic QD‐LEDs employing NiMgO NCs achieved a peak external quantum efficiency of 16.4%, peak luminance of 269 455 cd m⁻2, and a half‐life of 462 690 h at 100 nit.

Magnetron sputtered nickel oxide with suppressed interfacial defect states for efficient inverted perovskite solar cells

Widely used spin-coated nickle oxide (NiOx) based perovskite solar cells often suffer from severe interfacial reactions between the NiOx and adjacent perovskite layers due to surface defect states, which inherently impair device performance in a long-term view, even with surface molecule passivation. In this study, we developed high-quality magnetron-sputtered NiOx thin films through detailed process optimization, and compared systematically sputtered and spin-coated NiOx thin film surfaces from materials to devices. These sputtered NiOx films exhibit improved crystallinity, smoother surfaces, and significantly reduced Ni3+ or Ni vacancies compared to their spin-coated counterparts. Consequently, the interface between the perovskite and sputtered NiOx film shows a substantially reduced density of defect states. Perovskite solar cells (PSCs) fabricated with our optimally sputtered NiOx films achieved a high power conversion efficiency (PCE) of up to 19.93% and demonstrated enhanced stability, maintaining 86.2% efficiency during 500 h of maximum power point tracking under one standard sun illumination. Moreover, with the surface modification using (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl)phosphonic acid (DMAcPA), the device PCE was further promoted to 23.07%, which is the highest value reported for sputtered NiOx based PSCs so far.

Vacancy formation modulating the local atomic environment for remarkable Multi-functional Magnetic properties in Ni–Co–Mn–In alloy

Defect (mainly vacancy) engineering has shown its potential for modulating the functional behavior of magnetic materials. In this work, dense Ni vacancies are introduced in Ni45Mn36.5In13.5Co5 alloy and the effect of these vacancies on the magnetic properties is both theoretically and experimentally clarified. In detail, Ni vacancy with the lowest formation energy is introduced by high energy electron irradiation, which shortens the distance between adjacent Mn atoms to strengthen the interaction between them and increase the corresponding magnetic moments, leading to the dTm/dH increase from −2.89 to 6.28 KT−1. As a result, a breakthrough in the magnetocaloric performance is correspondingly achieved, i.e., the entropy change (ΔSM) increases up to an ultra-high value of 48.15 J/(kg·K), much higher than all other reported values. Moreover, the reversible magnetostrain is also improved from 80 to 200 ppm. In summary, this work provides strong guidance for optimizing the magnetic performance of Ni–Mn based Heusler alloys via vacancy modulation.

The A-Ni chemical bond in AIIINiSb (AIII=Sc, Y, Er) half-Heusler materials triggers the formation of anomalous vacancy defects

Defects exert a profound influence on thermoelectric materials by altering electronic band structures and significantly impacting their performance. Despite being a potentially promising thermoelectric material, the mechanism behind defect formation in half-Heusler (HH) compounds ABX remains unclear, impeding the enhancement of their thermoelectric properties. In this study, we investigated the intrinsic defect formation energies for AⅢNiSb (AⅢ = Sc, Y, Er) and other 9 HH compounds, namely AⅣNiSn (AⅣ = Ti, Zr, Hf), AⅤFeSb (AⅤ = V, Nb, Ta), and AⅣCoSb (AⅣ = Ti, Zr, Hf), using first-principles calculations and thermodynamics. The results reveal that AⅢNiSb (AⅢ = Sc, Y, Er) exhibits anomalous B (Ni) vacancy defects, with their formation energies being significantly lower than those of the corresponding B vacancy defects in the other 9 HH compounds. This anomaly can be attributed to the strength of the A-B bonds, where a decrease in bond strength leads to a decrease in the formation energy of B vacancies. This approach of exploring the influence of interatomic bond strength on defect formation is not only insightful for HH compounds but also holds potential applications in defect studies across various materials, offering a broader perspective on the fundamental mechanisms governing defect formation and stability.

Controlled NiOx Defect Engineering to Harnessing Redox Reactions in Perovskite Photovoltaic Cells via Atomic Layer Deposition.

Albeit the undesirable attributes of NiOx, such as low conductivity, unmanageable defects, and redox reactions occurring at the perovskite/NiOx interface, which impede the progress in inverted perovskite solar cells (i-PSCs), it is the most favorable choice of technology for industrialization of PSCs. In this study, we propose a novel Ni vacancy defect modulate approach to leverage the conformal growth and surface self-limiting reaction characteristics of the atomic layer deposition (ALD)-fabricated NiOx by varying the O2 plasma injection time (tOE) to induce self-doping. Consequently, NiOx thin films with enhanced conductivity, an appropriate Ni3+/Ni2+ ratio, stable surface states, and ultrathinness are realized as hole-transporting layers (HTLs) in p-i-n PSCs. As a result of these improvements, ALD-NiOx-based devices exhibit the highest power conversion efficiency (PCE) of 19.86% and a fill factor (FF) of 81.86%. Notably, the optimal interfacial defects effectively suppressed the severe reaction between the perovskite and NiOx. This suppression is evidenced by the lowest decay rate observed in a harsh environment, lasting for 500 consecutive hours. The proposed approach introduces the possibility of a hierarchical distribution of defects and offers feasibility for the fabrication of large-area, uniform, and high-quality films.

Iron, Tungsten Dual-Doped Nickel Sulfide as Efficient Bifunctional Catalyst for Overall Water Splitting.

Developing low-cost and highly efficient bifunctional catalysts for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) is a challenging problem in electrochemical overall water splitting. Here, iron, tungsten dual-doped nickel sulfide catalyst (Fe/W-Ni3S2) is synthesized on the nickel foam, and it exhibits excellent OER and HER performance. As a result, the water electrolyze based on Fe/W-Ni3S2 bifunctional catalyst illustrates 10mAcm-2 at 1.69V (without iR-compensation) and highly durable overall water splitting over 100h tested under 500mAcm-2. Experimental results and DFT calculations indicate that the synergistic interaction between Fe doping and Ni vacancy induced by W leaching during the in situ oxidation process can maximize exposed OER active sites on the reconstructed NiOOH species for accelerating OER kinetics, while the Fe/W dual-doping optimizes the electronic structure of Fe/W-Ni3S2 and the binding strength of intermediates for boosting HER. This study unlocks the different promoting mechanisms of incorporating Fe and W for boosting the OER and HER activity of Ni3S2 for water splitting, which provides significant guidance for designing high-performance bifunctional catalysts for overall water splitting.

Tailoring Zirconia Supported Intermetallic Platinum Alloy via Reactive Metal‐Support Interactions for High‐Performing Fuel Cells

AbstractDeveloping efficient and anti‐corrosive oxygen reduction reaction (ORR) catalysts is of great importance for the applications of proton exchange membrane fuel cells (PEMFCs). Herein, we report a novel approach to prepare metal oxides supported intermetallic Pt alloy nanoparticles (NPs) via the reactive metal‐support interaction (RMSI) as ORR catalysts, using Ni‐doped cubic ZrO2 (Ni/ZrO2) supported L10−PtNi NPs as a proof of concept. Benefiting from the Ni migration during RMSI, the oxygen vacancy concentrations in the support are increased, leading to an electron enrichment of Pt. The optimal L10−PtNi−Ni/ZrO2−RMSI catalyst achieves remarkably low mass activity (MA) loss (17.8 %) after 400,000 accelerated durability test cycles in a half‐cell and exceptional PEMFC performance (MA=0.76 A mgPt−1 at 0.9 V, peak power density=1.52/0.92 W cm−2 in H2−O2/−air, and 18.4 % MA decay after 30,000 cycles), representing the best reported Pt‐based ORR catalysts without carbon supports. Density functional theory (DFT) calculations reveal that L10−PtNi−Ni/ZrO2−RMSI requires a lower energetic barrier for ORR than L10−PtNi−Ni/ZrO2 (direct loading), which is ascribed to a decreased Bader charge transfer between Pt and *OH, and the improved stability of L10−PtNi−Ni/ZrO2−RMSI compared to L10−PtNi−C can be contributed to the increased adhesion energy and Ni vacancy formation energy within the PtNi alloy.

Tailoring Zirconia Supported Intermetallic Platinum Alloy via Reactive Metal-Support Interactions for High-Performing Fuel Cells.

Developing efficient and anti-corrosive oxygen reduction reaction (ORR) catalysts is of great importance for the applications of proton exchange membrane fuel cells (PEMFCs). Herein, we report a novel approach to prepare metal oxides supported intermetallic Pt alloy nanoparticles (NPs) via the reactive metal-support interaction (RMSI) as ORR catalysts, using Ni-doped cubic ZrO2 (Ni/ZrO2) supported L10-PtNi NPs as a proof of concept. Benefiting from the Ni migration during RMSI, the oxygen vacancy concentrations in the support are increased, leading to an electron enrichment of Pt. The optimal L10-PtNi-Ni/ZrO2-RMSI catalyst achieves remarkably low mass activity (MA) loss (17.8 %) after 400,000 accelerated durability test cycles in a half-cell and exceptional PEMFC performance (MA=0.76 A mgPt -1 at 0.9 V, peak power density=1.52/0.92 W cm-2 in H2-O2/-air, and 18.4 % MA decay after 30,000 cycles), representing the best reported Pt-based ORR catalysts without carbon supports. Density functional theory (DFT) calculations reveal that L10-PtNi-Ni/ZrO2-RMSI requires a lower energetic barrier for ORR than L10-PtNi-Ni/ZrO2 (direct loading), which is ascribed to a decreased Bader charge transfer between Pt and *OH, and the improved stability of L10-PtNi-Ni/ZrO2-RMSI compared to L10-PtNi-C can be contributed to the increased adhesion energy and Ni vacancy formation energy within the PtNi alloy.

Unveiling the Synergistic Role of Frustrated Lewis Pairs in Carbon-Encapsulated Ni/NiOx Photothermal Cocatalyst for Enhanced Photocatalytic Hydrogen Production.

The development of high-density and closely spaced frustrated Lewis pairs (FLPs) is crucial for enhancing catalyst activity and accelerating reaction rates. However, constructing efficient FLPs by breaking classical Lewis bonds poses a significant challenge. Here, this work has made a pivotal discovery regarding the Jahn-Teller effect during the formation of grain boundaries in carbon-encapsulated Ni/NiOx (Ni/NiOx@C). This effect facilitates the formation of high-density O (VO) and Ni (VNi) vacancy sites with different charge polarities, specifically FLP-VO-C basic sites and FLP-VNi-C acidic sites. The synergistic interaction between FLP-VO-C and FLP-VNi-C sites not only reduces energy barriers for water adsorption and splitting, but also induces a strong photothermal effect. This mutually reinforcing effect contributes to the exceptional performance of Ni/NiOx@C as a cocatalyst in photothermal-assisted photocatalytic hydrogen production. Notably, the Ni/NiOx@C/g-C3N4 (NOCC) composite photocatalyst exhibits remarkable hydrogen production activity with a rate of 10.7 mmol g-1 h-1, surpassing that of the Pt cocatalyst by 1.76 times. Moreover, the NOCC achieves an impressive apparent quantum yield of 40.78% at a wavelength of 380nm. This work paves the way for designing novel defect-state multiphase cocatalysts with high-density and adjacent FLP sites, which hold promise for enhancing various catalytic reactions.

Modulation of the microstructure, optical properties and electrical properties of zinc-doped nickel oxide films via direct current sputtering power

Zinc-doped NiO (NiO:Zn) films were direct-current-magnetron sputtered on the glass substrates. The modulation of the properties of the films via sputtering powers (Pspu) was especially studied. The conducting transition from p to n type was also proposed in mechanism. The NiO:Zn films are all preferentially 〈111〉 oriented. The films with high Pspu almost have small lattice distortion due to the improved crystallization caused by the thermal effect and the Zn element doping. The films begin to exhibit the n-type conduction at 90 W Pspu. The conducting transition from p to n type is mainly attributed to the occupation of Ni vacancies by Zn2+ and the interstitial Zn, and the improved n-type conduction in Pspu range of 140 W through 160 W to the increase in content of the interstitial Zn atoms. The absorption edge of the NiO:Zn films remaining at about 3.7 eV is slightly affected by the increase in Pspu, showing that the doping of the Zn element in the NiO is not mainly in the form of the Ni vacancies occupying ions.

How to Stabilize the Current of Efficient Inverted Flexible Perovskite Solar Cells at the Maximum Power Point.

Inverted flexible perovskite cells (fPSCs) have attracted much attention for their high efficiency and power per weight. Still, the steady-state output is one of the critical factors for their commercialization. In this paper, it is found that the steady-state current of inverted fPSCs based on nickel oxide nanoparticles (n-NiOx) continuously decreases under light illumination. Conversely, those based on magnetron-sputtered NiOx (sp-NiOx) exhibit the opposite result. Based on visualization of ion migration in the photoluminescence (PL) imaging microscopy tests, the discrepancies in the buried surfaces lead to the differences in ion migration in perovskite films, which triggers the temporary instability of the output current of devices during operation. The DFT theoretical calculation and experimental results reveal that NiOx films with different contents of Ni vacancies can modulate the crystallization of the perovskite films on the NiOx surfaces. Tuning the crystallization of the perovskite films is essential to stabilize the output current of fPSCs at a steady state. To demonstrate that, capsaicin is doped into the perovskite solutions to improve the quality of the perovskite buried interface. Finally, the corresponding fPSCs exhibit outstanding efficiency and stability during operation. These results provide valuable scientific guidance for fabricating fPSCs with stable operation under illumination conditions.

EVOLUTION OF STRUCTURAL, OPTICAL PROPERTIES AND ELECTRICAL TRANSPORT Of NiOXFILMS ANNEALED IN DIFFERENT ENVIRONMENT

The influence of the annealing medium of thin films of nickel oxide (NiOx) on structural, optical and electrical transport properties is studied in this paper. NiOx films were synthesized by sol-gel method and annealed at a temperature of 300 °C in air, inert nitrogen (N2), oxygen (O2) gases and vacuum. The values of the films thickness were determined from the transverse cleavage of the SEM image. The films thickness depends on the annealing medium. Measurements of the EDX spectra of NiOx films were carried out. Analysis of the quantitative O/Ni ratio showed that the film annealed in an air atmosphere is close to the stoichiometric parameters of NiO. Measurements of the EDX spectra of NiOx films were carried out. According to the Raman spectra, an increase in peak intensities is observed indicating an increase in the density of defects in the film by Ni vacancies depending on the annealing medium. Absorption spectra and Tauc plots of NiOх films were obtained. The optical density of the films depends on the annealing conditions of the films. Data analysis shows that the band gap width depends on the annealing medium and varies from Eg = 3.12 eV to Eg = 3.45 eV. The analysis of the impedance spectra allowed us to estimate the values of the resistances R1 and R2. It is shown that an increase in the resistance of R1 is associated with a decrease in the density of defects in the NiOx film, decrease in the recombination resistance of R2, and an increase in recombination processes at the interface.

Magnesium Mitigation Behavior in P2-Layered Sodium-Ion Battery Cathode.

Heteroatom incorporation can effectively suppress the phase transition of layered sodium-ion battery cathode, but heteroatom behaviors during operating conditions are not completely understood at the atomic scale. Here, density functional theory calculations are combined with experiments to explore the mitigation behavior of Mg dopant and its mechanisms under operating conditions in P2-Na0.67Ni0.33Mn0.67O2. The void formed by Na extraction will pump some Mg dopants into Na layers from TM layers, and the collective diffusion of more than one Mg ion most likely occurs when the Mg content is relatively high in the TM layer, finally aggregating to form Mg-enrich regions (i.e., Mg segregation) apart from Ni vacancies. The void-pump-effect-induced Mg segregation effectively suppresses the P2-O2 phase transition owing to the stronger Mg-O electrostatic attraction that enhances the integrate of two adjacent oxygen layers and prevents the crack growth by mitigating the lattice volume variation under high-voltage cycling. Our work provides a fundamental understanding of heteroatom mitigation behavior in layered cathodes at the atomic level for next-generation energy storage technologies.

Engineering the Crystal Facet of Monoclinic NiO for Efficient Catalytic Ozonation of Toluene.

Modulating oxygen vacancies of catalysts through crystal facet engineering is an innovative strategy for boosting the activity for ozonation of catalytic volatile organic compounds (VOCs). In this work, three kinds of facet-engineered monoclinic NiO catalysts were successfully prepared and utilized for catalytic toluene ozonation (CTO). Density functional theory calculations revealed that Ni vacancies were more likely to form preferentially than O vacancies on the (110), (100), and (111) facets of monoclinic NiO due to the stronger Ni-vacancy formation ability, further affecting O-vacancy formation. Extensive characterizations demonstrated that Ni vacancies significantly promoted the formation of O vacancies and thus reactive oxygen species in the (111) facet of monoclinic NiO, among the three facets. The performance evaluation showed that the monoclinic NiO catalyst with a dominant (111) facet exhibits excellent performance for CTO, achieving a toluene conversion of ∼100% at 30 °C after reaction for 120 min under 30 ppm toluene, 210 ppm ozone, 45% relative humidity, and a space velocity of 120 000 h-1. This outperformed the previously reported noble/non-noble metal oxide catalysts used for CTO at room temperature. This study provided novel insight into the development of highly efficient facet-engineered catalysts for the elimination of catalytic VOCs.

Effects of Point Defects on the Monoclinic Angle of the B19″ Phase in NiTi-Based Shape Memory Alloys

This study investigated the effects of a variety of point defects on the monoclinic angle of the B19″ martensite in NiTi, including Ni and Ti vacancies, Ni–Ti anti-sites in the lattice, third element substitution, and Ni and Ti enrichments in the B2 stoichiometry. Their effects were studied by density functional theory calculations on the monoclinic B19″ phase as a proxy for the experimentally observed B19′ phase. It was found that vacancies and Ni–Ti anti-sites reduce the monoclinic angle of B19″, whereas third element substitution of Ni and Ti may affect the monoclinic angle in both directions depending on the third element and the host element it replaces. Enriching Ni or Ti content to deviate from the B2 stoichiometry decreases the monoclinic angle. A change in the monoclinic angle of the B19″ phase implies variation in the characteristic strains associated with the transformation. Thus, these findings may provide a new angle on possible interpretations of the variations of recoverable transformation strains experimentally observed of NiTi shape memory alloys.

Mild oxygen plasma-treated nickel oxides for performance enhancement of hybrid perovskite light-emitting diodes

Nickel oxide (NiOx), a representative transparent p-type semiconductor, has been a promising candidate for hole transport layer (HTL) in perovskite-based photovoltaic and light-emitting diode (LED) devices due to its high chemical stability and high transparency. However, the interface between the NiOx and perovskite emission layers shows a relatively large electrical barrier for the holes to be transported, which degrades the interfacial electrical properties. To overcome these problems, we suggest a mild oxygen plasma treatment on the NiOx surface to introduce Ni vacancies while retaining its advantages. By controllably forming the Ni vacancies, the hole concentrations could be controlled, which modulated the valence band edge level. This increases the work function of NiOx from 4.979 to 5.364 eV, which facilitates the hole transport at the interface between NiOx HTL and the perovskite emission layer. Ultimately, the overall process leads to improved electroluminescence intensity, reduced driving voltage reduction, and low charge trap density at the interface between the NiOx HTL and the perovskite emission layers. These eventually improved the external quantum efficiency of the perovskite light-emitting diodes.

Transparent pn junction of Mg:NiO/ZnO/SnO2via potential regulation and carrier injection of ZnO transition layer

Transparent pn junction of Mg:NiO/ZnO/SnO2 is prepared via an approach of continuous co-sputtering-annealing method. The Mg:NiO/ZnO/SnO2 pn junction exhibits high transmittance of ∼70–85 % in visible light, obvious photovoltaic enhancement of ∼1.6 × 102 folds than that of unmodified Mg:NiO/SnO2, stable output during 9 weeks’ cycle. It’s mainly attributed to the ultrathin ZnO transition layer, obtaining appropriate Fermi level and higher intrinsic carrier concentration can optimize carrier equilibrium, meanwhile sustaining high transparency and providing interface optimization. Furthermore, the extra hole carrier caused by Ni vacancy and Ni2+/Ni3+ mixed state can take full advantage of the defects to optimize the kinetic equilibrium. Additionally, the intrinsic high physical-chemical properties of inorganic NiO, ZnO and SnO2 can increase the intrinsic stability.

Interface strain engineering of Ir clusters on ultrathin NiO nanosheets for electrochemical water splitting over 1800 hours

Strain engineering of two-dimensional (2D) material interfaces represents a powerful strategy for enhancing the electrocatalytic activity of water splitting. However, maintaining catalytic stability under various harsh conditions by introducing interface strain remains a great challenge. The catalyst developed and evaluated herein comprised Ir clusters dispersed on 2D NiO nanosheets (NSs) derived from metal organic frameworks (Ir@NiO/CBDC), which displays a high activity and stability under all pH conditions, and even a change of only 1% in the applied voltage is observed after continuous electrocatalytic operation for over 1800 h under alkaline conditions. Through combined experimental and computational studies, we found that the introduced interfacial strain contributes to the outstanding structural stability of the Ir@NiO/CBDC catalyst, arising from its increased Ir and Ni vacancy formation energies, and hence suppressing its leaching. Moreover, strain also enhances the kinetically sluggish electrocatalytic water splitting reaction by optimizing its electronic structure and coordination environment. This work highlights the effects of strain on catalyst stability and provides new insights for designing widely applicable electrocatalysts.