Spatially confined growth of ultrathin NiFe layered double hydroxide nanosheets within carbon nanofibers network for highly efficient water oxidation

The rational design of catalysts with low cost, high efficient and robust stability toward oxygen evolution reaction (OER) is greatly desired but remains a formidable challenge. In this work, a one-pot, spatially confined strategy was reported to fabricate ultrathin NiFe layered double hydroxide (NiFe-LDH) nanosheets interconnected by ultrafine, strong carbon nanofibers (CNFs) network. The as-fabricated NiFe-LDH/CNFs catalyst exhibits enhanced OER catalytic activity in terms of low overpotential of 230 mV to obtain an OER current density of 10 mA cm^?2 and very small Tafel slope of 34 mV dec^?1, outperforming pure NiFe-LDH nanosheets assembly, commercial RuO₂, and most non-noble metal catalysts ever reported. It also delivers an excellent structural and electrocatalytic stability upon the long-term OER operation at a large current of 30 mA cm^?2 for 40 h. Furthermore, the cell assembled by using NiFe-LDH/CNFs and commercial Pt/C as anode (+) and cathode (?) ((+)NiFe-LDH/CNFs||Pt/C(?)) only requires a potential of 1.50 V to deliver the water splitting current of 10 mA cm^?2, 130 mV lower than that of (+)RuO₂||Pt/C(?) couple, demonstrating great potential for applications in cost-efficient water splitting devices.     

The influence of increased content of Ni(III) in NiFe LDH via Zn doping on electrochemical catalytic oxygen evolution reaction

Developing efficient oxygen evolution electrocatalysts always shows great importance in the field of electrolysis of water. In this work, Zn-doped NiFe LDH is synthesized via a facile hydrothermal reaction. A series of structural characterizations revealed that the doping of Zn into NiFe LDH lattice can cause lattice distortion, which facilitates the formation of active NiOOH layers. The Zn–NiFe LDH electrocatalyst shows excellent performance in electrocatalytic oxygen evolution reaction, even overbeat the state-of-art RuO₂. In addition, the doping of Zn into NiFe LDH significantly enhances the electrocatalytic stability of NiFe LDH, with only a 32.7 mV increase in potential after 100 h continuous OER electrolysis in 1.0 M KOH. The Zn–NiFe LDH provides an ideal strategy for designing highly efficient OER electrocatalysts for real applications.     

Thin porous nanosheets of NiFe layered-double hydroxides toward a highly efficient electrocatalyst for water oxidation

NiFe layered double hydroxides (NiFe-LDH) are low cost and earth abundant electrocatalysts for oxygen evolution reaction (OER). Herein, the NiFe-LDH nanosheets induced by ZIF-67 (NiFe-LDH/ZIF-67) were prepared via a coupling method of a self-sacrificing template method and a co-precipitation method. Atomic force microscope and field emission transmission electron microscopy analysis indicate that NiFe-LDH/ZIF-67 consist of thin porous nanosheets. X-ray photoelectron spectra analysis show that NiFe-LDH/ZIF-67 contains more oxygen vacancies than pristine NiFe-LDH. The overpotential of NiFe-LDH/ZIF-67 is 222 mV at 10 mA cm⁻² for OER, lower than that of ZIF-67, pristine NiFe-LDH, and the commercial RuO₂, indicating that its high electrocatalytic activity for OER. The high electrocatalytic activity of NiFe-LDH/ZIF-67 may be attributed to its thin porous nanosheet structure, which is derived from the structural influence of ZIF-67 and the coupling effect of a self-sacrificing template method and a co-precipitation method.     

Accelerated oxygen evolution kinetics on NiFeAl-layered double hydroxide electrocatalysts with defect sites prepared by electrodeposition

NiFe layered double hydroxides (LDHs) is considered to be one of the LDHs electrocatalyst materials with the best electrocatalytic oxygen evolution properties. However, its poor conductivity and inherently poor electrocatalytic activity are considered to be the limiting factors inhibiting the electrocatalytic properties for oxygen evolution reaction (OER). The amorphous NiFeAl-LDHs electrocatalysts were prepared by electrodeposition with nickel foam as the support, and the D-NiFeAl-LDHs electrocatalyst with defect sites was then obtained by alkali etching. The mechanism of catalysts with defect sites in OER was analyzed. The ingenious defects can selectively accelerate the adsorption of OH⁻, thus enhancing the electrochemical activity. The D-NiFeAl-LDHs electrocatalyst had higher OER electrocatalytic activity than NiFe-LDHs electrocatalyst: its accelerated OER kinetics were mainly due to the introduction of iron and nickel defects in NiFeAl-LDHs nanosheets, which effectively adjusted the surface electronic structure and improved OER electrocatalytic performance. There was only a low overpotential of 262 mV with the current density of 10 mA cm⁻², and the Tafel slope was as low as 41.67 mV dec⁻¹. The OER electrocatalytic performance of D-NiFeAl-LDHs was even better than those of most of the reported NiFe-LDHs electrocatalysts.     

Electrodeposition of NiFe layered double hydroxide on Ni3S2 nanosheets for efficient electrocatalytic water oxidation

The oxygen evolution reaction (OER) plays a vital role in various energy conversion applications. Up to now, the highly efficient OER catalysts are mostly based on noble metals, such as Ir- and Ru-based catalysts. Thus, it is extremely urgent to explore the non-precious electrocatalysts with great OER performance. Herein, a simple electrodeposition combined with hydrothermal method is applied to synthesize a non-precious OER catalyst with a three-dimensional (3D) core-shell like structure and excellent OER performance. In our work, NiFe layered double hydroxide (LDH) was electrodeposited on Ni₃S₂ nanosheets on nickel foam (NF), which exhibits a better performance compared with RuO₂, and a low overpotential of 200 mV is needed to reach the current density of 10 mA/cm² in 1 M KOH. Notably, the Ni₃S₂/NiFe LDH only need an overpotential of 273 mV to reach the current density of 200 mA/cm².     

NiFe layered double hydroxide as an efficient bifunctional catalyst for electrosynthesis of hydrogen peroxide and oxygen

Two electron oxygen reduction reaction to produce hydrogen peroxide (H₂O₂) is a promising alternative technique to the multistep and high energy consumption anthraquinone process. Herein, Ni–Fe layered double hydroxide (NiFe-LDH) has been firstly demonstrated as an efficient bifunctional catalyst to prepare H₂O₂ by electrochemical oxygen reduction (2e^? ORR) and oxygen evolution reaction (OER). Significantly, the NiFe-LDH catalyst possesses a high faraday efficiency of 88.75% for H₂O₂ preparation in alkaline media. Moreover, the NiFe-LDH catalyst exhibits excellent OER electrocatalytic property with small overpotential of 210 mV at 10 mA cm^?2 and high stability in 1 M KOH solution. On this basis, a new reactor has been designed to electrolyze oxygen and generate hydrogen peroxide. Under the ultra-low cell voltage of 1 V, the H₂O₂ yield reaches to 47.62 mmol g_cat^?1 h^?1. In order to evaluate the application potential of the bifunctional NiFe-LDH catalyst for H₂O₂ preparation, a 1.5 V dry battery has been used as the power supply, and the output of H₂O₂ reaches to 83.90 mmol g_cat^?1 h^?1. The excellent electrocatalytic properties of 2e^? ORR and OER make NiFe-LDH a promising bifunctional electrocatalyst for future commercialization. Moreover, the well-designed 2e^? ORR-OER reactor provides a new strategy for portable production of H₂O₂.     

Superhydrophilic 3D peony flower-like Mo-doped Ni2S3@NiFe LDH heterostructure electrocatalyst for accelerating water splitting

Constructing highly efficient nonprecious electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is essential to improve the efficiency of overall water splitting, but still remains lots of obstacles. Herein, a novel 3D peony flower-like electrocatalyst was synthesized by employing Mo–Ni₂S₃/NF nanorod arrays as scaffolds to in situ growth ultrathin NiFe LDH nanosheets (Mo-Ni₂S₃@NiFe LDH). As expected, the novel peony flower-like Mo–Ni₂S₃@NiFe LDH displays superior electrocatalytic activity and stability for both OER and HER in alkaline media. Low overpotentials of only 228 mV and 109 mV are required to achieve the current densities of 50 mA cm^?2 and 10 mA cm^?2 for OER and HER, respectively. Additionally, the material remarkably accelerates water splitting with a low voltage of 1.54 V at 10 mA cm^?2, which outperforms most transition metal electrodes. The outstanding electrocatalytic activity benefits from the following these features: 3D peony flower-like structure with rough surface provides more accessible active sites; superhydrophilic surfaces lead to the tight affinity between electrode with electrolyte; metallic Ni substrate and highly conductive Mo–Ni₂S₃ nanorods scaffold together with offer fast electron transfer; the nanorod arrays and porous Ni foam accelerate gas bubble release and ions transmission; the strong interfacial effect between Mo-doped Ni₃S₂ and NiFe LDH shortens transport pathway, which are benefit for electrocatalytic performance enhancement. This work paves a new avenue for construction and fabrication the 3D porous structure to boost the intrinsic catalytic activities for energy conversion and storage applications.     

Oxygen vacancy-based ultrathin Co3O4 nanosheets as a high-efficiency electrocatalyst for oxygen evolution reaction

Enhancing the catalytic activity of Co₃O₄ electrocatalysts featuring abundant oxygen vacancies is required to enable their application in oxygen evolution reaction (OER). However, developing a harmless defect engineering strategy based on mild conditions to realize such an enhancement remains a challenge. Here, ultrathin Co₃O₄ nanosheets with abundant oxygen vacancies were prepared through a simple two-step method comprising a hydrothermal process and pre-oxidation to study the catalytic activity of the nanosheets toward OER. The ultrathin sheet structure and the Co₃O₄ nanosheets surface provide abundant active sites. The oxygen vacancy not only improves the catalyst activity, but also improves the electron transfer efficiency. These advantages make ultrathin Co₃O₄ nanosheets with abundant oxygen vacancies an excellent electrocatalyst for oxygen evolution. In an alkaline medium, ultrathin Co₃O₄ nanosheets exhibited excellent OER catalytic activity, with a small overpotential (367 mV for 10 mA/cm²) and faster reaction kinetics (65 mV/dec).Moreover, the electrocatalyst still maintained 68% of its original catalytic activity after 24 h operation. This work provides an extensive and reliable method for the preparation of low-cost and highly efficient OER electrocatalysts.     

Co–NiFe layered double hydroxide nanosheets as an efficient electrocatalyst for the electrochemical evolution of oxygen

The development of non-precious metal catalysts for the electrochemical oxygen evolution reaction (OER) is especially important for the water electrolysis process. Herein, a two-dimensional (2D) ultrathin hybrid Co–NiFe layered double hydroxide (LDH) is synthesized via a facile hydrothermal method. In 1.0 M KOH electrolyte, Co–NiFe LDH exhibits remarkable activities for OER. At the current density of 10 mA cm⁻², it only needs an overpotential of 278 mV, which is ca. 50 mV and 20 mV lower than those for NiFe LDH (328 mV) and RuO₂ catalysts (298 mV), respectively. In addition, Co–NiFe LDH also shows impressive long-term stability for OER. Besides the stable morphology and crystal structure, the potential is always kept at 1.50 V and shows almost no attenuation during the 20 h of durability test. Changes in the electronic structure of LDH due to introduction of Co ions, as well as the large specific surface area facilitate the mass/electron transfer and the oxygen bubbles release, and thus lead to the enhanced catalytic properties for OER. This work can be informative not only for understanding the role of physical and electronic structures on OER but also for designing high-performance non-precious metal OER electrocatalysts.     

Facile deposition of NiFe-LDH ultrathin film on pyrolytic graphite sheet for oxygen evolution reaction in alkaline electrolyte

NiFe-layered doubly hydroxide (LDH) is one of the most active materials for hydroxyl oxidation in an alkaline electrolyte. In this study, we explored a facile method of depositing NiFe-LDH catalyst on pyrolytic graphite sheets (PGSs) to explore the synergistic effects at the substrate–electrocatalyst interface. The catalyst was electrodeposited on PGSs using chronoamperometry. The homogeneous distribution of the catalyst with nanosheet morphology on the PGS's surface produced an ultrathin film. The NiFe25/PGS sample showed a low overpotential (332 mV) and Tafel slope (33 mV dec^?1). The fitting of the Nyquist plots was performed using an equivalent circuit, and the NiFe25/PGS (1.69 Ω) sample showed the lowest charge transfer resistance among the studied catalysts. In addition, PGS proved a better substrate for the alkaline oxygen evolution reaction compared to glassy carbon and fluorine-doped tin oxide.     

Spontaneous synthesis of Ag nanoparticles on ultrathin Co(OH)2 nanosheets@nitrogen-doped carbon nanoflake arrays for high-efficient water oxidation

The slow four-electron transfer of the oxygen evolution reaction (OER) greatly limits the water splitting efficiency, so the development of high-efficiency and stable OER electrocatalysts is of great significance for large-scale alkaline water splitting. Herein, we reported an efficient self-supported OER electrocatalyst of Ag NPs decorated ultrathin Co(OH)₂ nanosheets supported on nitrogen-doped carbon (NC) nanoflake arrays on carbon cloth (Ag/Co(OH)₂@NC/CC). Our designed 3D unique electrode structure with heterointerfaces and hierarchical nanosheets endow Ag/Co(OH)₂@NC/CC with outstanding OER electrocatalytic activity (300 and 350 mV at 50 and 100 mA/cm², 79.8 mV/dec of Tafel slope) and good long-term durability in 1 M KOH. Furthermore, the related results of electrochemical tests show that the improved conductivity, increased electrochemical active sites and enhanced intrinsic active sites explain the superior OER performance. Our study will offer some new ideas in constructing new highly-active materials for various other energy conversion fields.     

Hydrochloric acid etching induced flower-like NiFe-layered double hydroxide as efficient electrocatalyst for oxygen evolution reaction

To meet the increasing demand for clean energy storage in modern society, the development of efficient and low-cost electrocatalysts that can overcome and accelerate the sluggish kinetics of electrochemical reactions is required. NiFe-Layered Double Hydroxide (NiFe-LDH) is regarded as an effective oxygen evolution reaction (OER) electrocatalyst, but most of the current synthesis methods, such as electrochemical deposition and calcination, are complex and difficult to operate on a large scale. Herein, we report the preparation of NiFe-LDH directly on a NiFe foam substrate using a simple two-step method in which the surface oxide layer is first removed from NiFe foam using a room-temperature hydrochloric acid bath for 10 min, followed by soaking in hydrochloric acid solution at 80 $°C$ for 20 h. The prepared NiFe foam etched by hydrochloric acid for 20 h (NiFe-20-H) exhibited a unique hydrangea flower-like structure with a large surface area and abundant active sites, which is favorable for OER. Combining the structural advantages of large number of exposed active sites, synergistic effects of nickel and iron, and the convenient charge transfer path provided by the NiFe foam, the resulting NiFe-20-H sample achieved a current density of 10 mA cm⁻² at an extremely low overpotential (241 mV) and a small Tafel slope of 44.2 mV dec⁻¹, providing excellent long-term stability in alkaline electrolyte, surpassing pristine NiFe foam reported in our work, as well as many state-of-the-art electrocatalysts and IrO₂. This efficient synthesis of NiFe-LDH provides a new approach for the development of non-noble OER electrocatalysts and has wide application prospects in the field of electrocatalysts.     

Interface engineering and heterometal doping Co–Mo/FeS for oxygen evolution reaction

The sluggish kinetics of the oxygen evolution reaction (OER) limits the development of water electrolysis technology and the long-term efficiency of hydrogen energy production. In addition, it is important to evaluate the reconstruction performance of OER catalysts for actual water electrolysis. We created a self-supported electrode with FeS film coated Fe foam as a substrate, ordered resoluble molybdate (MoO₄²⁻) anions in interlayers, and Co-doped as a catalytically active phase for the OER. The catalyst is capable of electrochemical self-reconstruction (ECSR). With the dissolution of molybdate and sulfur ions, the catalyst surface cobalt iron oxide (CoFe₂O₄) forms an active amorphous FeCoOOH, which is favorable for alkaline OER. We realized the introduction of new active sites in the catalyst reconstruction process. Finally, the composite CoFeO_x catalyst increased the specific surface area, promoted bubble transport, and enhanced electron mass transfer. The synergistic coupling effect of the catalyst makes it have excellent OER activity and stability. Remarkably, Co–Mo/FeS nanosheets afforded an electrocatalytic OER with a current density of 100 mA cm⁻² at a low overpotential of 321 mV. These discoveries open up new opportunities for the application of doping and template-directed surface reconfiguration, which holds promise as an effective electrocatalyst for the OER.     

Bimetallic-MOF derived nickel-iron phosphide nanosheets on carbon cloth for efficacious oxygen evolution reaction

It is of momentously realistic significance to exploit highly efficacious and cost-effective non-noble metal electrocatalysts for oxygen evolution reaction (OER), considering its promising renewable energy application. Herein, a self-supporting electrocatalyst composed of nickel-iron phosphide nanosheets on carbon cloth (NiFeP@CC) is proposed for OER, which are derived from the phosphating treatment of two-dimensional NiFe-MOF nanosheets. The NiFeP@CC composite possesses the synergistic effect of bimetallic NiFe phosphides in promoting the OER, the fully exposed active sites of the nano-sheet structure and the fast charge/mass transfer from the hierarchical porous structure. Owing to the above structural features, the optimized NiFeP@CC presents an impressive OER performance in alkaline solution. The overpotential and Tafel slope are as low as 229 mV and 36.4 mV dec^?1 under a current density of 10 mA cm^?2, respectively, much superior to those for the commercial IrO₂ catalyst. More excitingly, this self-supporting electrocatalyst also possesses an exceptionally high durability, showing no activity degradation for 25 h. This work offers a simple and feasible strategy for developing practically available OER catalysts with a high activity and stability.     

Hydrothermally synthesized nickel molybdenum selenide composites as cost-effective and efficient trifunctional electrocatalysts for water splitting reactions

The development of efficient, cost-effective routes to prepare non-platinum-based electrocatalysts is a significant scientific challenge in water-splitting systems. A multifunctional electrocatalyst for the hydrogen evolution, oxygen evolution, and oxygen reduction reactions (HER/OER/ORR) involved in the water-splitting process was fabricated using a simple and eco-friendly strategy. The present study involves the simple synthesis of nanostructured nickel selenide (NiSe) via a hydrothermal method. The different phases of nickel selenide and their dependency on the precursor concentration were analyzed using X-ray diffraction (XRD). The morphologies of coral-like structured pure and Mo-doped NiSe (Ni_1-xMo_xSe) samples were investigated systematically using scanning electron microscopy (SEM). The as-prepared Ni_0.5Mo_0.5Se material showed an enhanced electrochemical activity of 1.57 V @ 10 mA/cm² for OER and 0.19 V @ 10 mA/cm² to HER, and follows the Volmer-Heyrovsky for HER mechanism. In addition, the electrocatalyst exhibits a large electrochemical surface area and high stability. Therefore, the hydrothermally synthesized Ni_1–xMo_xSe has been proven to be a perfect platinum-free trifunctional electrocatalyst for water splitting process.     

Constructing microstructures in nickel-iron layered double hydroxide electrocatalysts by cobalt doping for efficient overall water splitting

The development of Ni–Fe layered double hydroxide (NiFe LDH) catalysts for overall water splitting (OWS) is urgently required. NiFe LDHs are promising catalysts for the oxygen evolution reaction (OER). However, their hydrogen evolution reaction (HER) performance is restricted by slow kinetics. The construction of multiple types of active sites to simultaneously optimise the OER and HER performance is significant for OWS using NiFe LDHs. Hence, a Co-doped NiFe LDH electrocatalyst with dislocations and stacking faults was designed to modulate the electronic structure and generate multiple types of activity sites. The Co_0.03-NiFe_0.97 LDH catalyst only required overpotentials of 280 (50 mA cm⁻², OER) and 170 mV (10 mA cm⁻², HER). However, it reached a current density of 50 mA cm⁻² at 1.53 V during OWS. Co_0.03-NiFe_0.97 LDHs could be stabilised for 140 h at 1.52 V. Furthermore, Co_0.03-NiFe_0.97 LDHs exhibited a higher electrocatalytic activity than commercial Raney nickel and Pt/C||IrO₂ under industrial conditions. The significant specific surface area, high conductivity, and unique microstructures are the major factors contributing to the excellent OWS performance. This study suggests an efficient strategy for introducing microstructures to fabricate catalysts with high activity for application in OWS.     

Tracking the role of Fe in NiFe-layered double hydroxide for solar water oxidation and prototype demonstration towards PV assisted solar water-splitting

NiFe based layered hydroxides (LDH) is an efficient oxygen evolution catalysts used in energy conversion and storage devices. Herein, we used in-situ electrochemical impedance spectroscopy (EIS) to study the role of Fe in improving the oxygen evolution reaction (OER) of NiFe-LDH, as an alternative to expensive techniques. Optimized Ni_0·46Fe_0.54-LDH showed Tafel slope of 49 mV dec^?1 and over potential of~340 mV at 10 mA cm^?2. Increase in Fe content in NiFe-LDH, lowered the average oxidation of the Ni, revealing the stabilization of lower oxidation state of Ni. Potential dependent EIS supported this effect showing that multi-metal LDH favors the surface intermediate stabilization thereby reducing the overall charge transfer resistance at interface compared to mono metal catalysis. Surface intermediate relaxation process is dependent on Fe content and is playing a role in deciding the rate limiting step. The Fe–O–Ni linkages in FeO_x-NiFe-LDH systems exert partial charge transfer activation for OER process. A prototype demonstration of overall water splitting using a photovoltaic-electrolyser assembly is conducted with Ni_0·46Fe_0.54-LDH as bifunctional catalysts which yields a constant current density of ~10 mA cm^?2 at a V_oc = 1.65 V. Present study provide experimental evidence of improved activity of FeO_x-NiFe-LDH with the help of potential dependent EIS studies and makes practically attractive for renewable energy conversion and storage applications.     

Zn-substituted MnCo2O4 nanostructure anchored over rGO for boosting the electrocatalytic performance towards methanol oxidation and oxygen evolution reaction (OER)

Mixed valence spinel oxides have emerged as an attractive and inexpensive anode electrocatalyst for water oxidation to replace noble metals based electrocatalysts. The present work demonstrates the facile synthesis of Zn substituted MnCo₂O₄ supported on 3D graphene prepared by simple hydrothermal technique and its application as an electrocatalyst for water oxidation and methanol oxidation. The physico-chemical properties of the nanocatalyst were studied using various microscopic, spectroscopic and diffraction analyses confirming the formation of the composite. The electrocatalytic performance of the prepared electrocatalyst was evaluated using potentiodynamic, potentiostatic and impedance techniques. The synthesized Zn_1-xMn_xCo₂O₄/rGO electrocatalyst with x = 0.2 and 0.4 offered the same onset potential and overpotential at 10 mA/cm². However, catalyst x = 0.4 delivered a higher current density indicating the superiority of the same over other compositions which is attributed to better kinetics that it possessed for OER as revealed by the smallest Tafel slope (80.6 mV dec⁻¹). The prepared electrocatalysts were tested for methanol oxidation in which electrocatalyst Zn_1-xMn_xCo₂O₄/rGO with x = 0.4 shows a better electrochemical performance in oxidizing methanol with the higher current density of 142.3 mA/cm². The above catalyst also revealed excellent stability and durability during both MOR and OER, suggesting that it can be utilized in practical applications.     

Understanding the photothermal contribution to electrocatalysis: A case study of carbon supported NiFe layered double hydroxide

External field assisted water splitting, as a sustainable and highly-efficient route to achieving hydrogen production, has recently attracted a considerable attention in the renewable energy research field. In particular, electrocatalysts with superior light absorption ability is likely to show an excellent electrocatalytic performance under light irradiation. Herein, a composite consisting of NiFe layered double hydroxide (LDH) and carbon is prepared as an electrocatalyst for oxygen evolution reaction (OER). Compared to the pristine NiFe LDH,carbon supported NiFe layered double hydroxide (NiFe LDH@C) composite exhibits an enhanced light harvesting under light irradiation, not only increasing the local temperature of electrocatalyst but also lowering the charge transfer resistance during the OER reaction process. Consequently, the photothermal effect enables NiFe LDH@C composite to facilitate the charge transport and accelerate the reaction kinetics, thereby showing an improved OER performance in comparison to neat NiFe LDH. This work offers a new vision toward the rational design of advanced electrocatalyst for solar-assisted water electrolysis application.     

A hierarchical nickel-iron hydroxide nanosheet from the high voltage cathodic polarization for alkaline water splitting

Developing efficient and stable oxygen evolution reaction (OER) electrocatalysts is a promising method to relieve the pressure of noble metals for catalyzing water splitting. Among the prominent candidates, nickel-iron layered double hydroxides (NiFe-LDH) have been found excellent catalytic activity, but their poor conductivity and stability seriously impede their performance. Herein, we report hierarchical NiFe-LDH nanosheets prepared from NiFe-Alloy on nickel mesh (NM) by high voltage cathodic polarization. The resultant NiFe-LDH/NM exhibits a remarkable OER activity and stability, which has a low overpotential of 340 mV at a current density of 10 mA cm^?2, and maintains a current density of 15 mA cm^?2 at a constant voltage of 1.56 V for 50 h if the NiFe-Alloy/NM is used as the cathode. The successful conversion of NiFe-LDH nanosheets originating from NiFe-Alloy nanoparticles would open a new avenue for synthesizing transition metal-based LDH compounds.