Flower-like HEA/MoS2/MoP heterostructure based on interface engineering for efficient overall water splitting

The development of cheap, efficient, and active non-noble metal electrocatalysts for total hydrolysis of water (oxygen evolution reaction (OER) and hydrogen evolution reaction (HER)) is of great significance to promote the application of water splitting. Herein, a heterogeneous structured electrode based on FeAlCrMoV high-entropy alloy (HEA) was synthesized as a cost-effective electrocatalyst for hydrogen and oxygen evolution reactions in alkaline media. In combination of the interfacial synergistic effect and the high-entropy coordination environment, flower-like HEA/MoS₂/MoP exhibited the excellent HER and OER electrocatalytic performance. It showed a low overpotential of 230 mV at the current density of 10 mA cm⁻² for OER and 148 mV for HER in alkaline electrolyte, respectively. Furthermore, HEA/MoS₂/MoP as both anode and cathode also exhibited an overpotential of 1.60 V for overall water splitting. This work provides a new strategy for heterogeneous structure construction and overall water splitting based on high-entropy alloys.     

Bimetallic metal-organic framework derived electrocatalyst for efficient overall water splitting

The development of bifunctional catalysts that can be applied to both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is widely regarded as a key factor in the production of sustainable hydrogen fuel by electrochemical water splitting. In this work, we present a high-performance electrocatalyst based on nickel-cobalt metal-organic frameworks for overall water splitting. The as-obtained catalyst shows low overpotential to reaches the current density of 10 mA cm⁻² with 249 mV for OER and 143 mV for HER in alkaline media, respectively. More importantly, when the electrolyzer was assembled with the as-prepared catalyst as anode and cathode simultaneously, it demonstrates excellent activity just applies a potential of 1.68 V to achieve 10 mA cm⁻² current density for overall water splitting.     

Self-supported hierarchical porous FeNiCo-based amorphous alloys as high-efficiency bifunctional electrocatalysts toward overall water splitting

Rationally designing an efficient and cost-effective bifunctional electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is a primary matter in applying electrocatalytic water splitting. Herein, a self-supported FeNiCo-based amorphous catalyst with a hierarchical micro/nanoporous structure is fabricated by dealloying an amorphous/nanocrystalline precursor. The amorphous nanoporous framework enables the prepared electrocatalyst to afford fast reaction kinetics, abundant active sites, and enhanced electrochemical active surface areas (ECSAs). Such structural advantages and the synergistic effects of the ternary transition metals contribute to a dramatic catalytic activity of this electrocatalyst under alkaline conditions, which delivers the current density of 10 mA cm⁻² at a low overpotential of 134 mV for HER and 206 mV for OER, respectively. Furthermore, a full electrolysis apparatus constructed by the self-supported hierarchical micro/nanoporous FeNiCo-based amorphous electrocatalyst as both cathode and anode acquires a dramatically low voltage of 1.58 V operating at 10 mA cm⁻² along with stability for more than 24 h for overall water splitting.     

Binder-free bifunctional SnFe sulfide/oxyhydroxide heterostructure electrocatalysts for overall water splitting

Developing robust non-noble catalysts towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is vital for large-scale hydrogen production from electrochemical water splitting. Here, we synthesize Sn- and Fe-containing sulfides and oxyhydroxides anchored on nickel foam (SnFeS_xO_y/NF) using a solvothermal method, in which a heterostructure is generated between the sulfides and oxyhydroxides. The SnFeS_xO_y/NF exhibits low overpotentials of 85, 167, 249, and 324 mV at 10, 100, 500 and 1000 mA cm^?2 for the HER, respectively, and a low overpotential of only 281 mV at 100 mA cm^?2 for the OER. When it serves as both anode and cathode to assemble an electrolyzer, the cell voltage is only 1.69 V at 50 mA cm^?2. The sulfides should be the efficient active species for the HER, while the oxyhydroxides are highly active for the OER. The unique sulfide/oxyhydroxide heterostructure facilitates charge transfer and lowers reaction barrier, thus promoting electrocatalytic processes.     

Black phosphorous dots phosphatized bio-based carbon nanofibers/bimetallic organic framework as catalysts for oxygen evolution reaction

As a multi-step and more complex half-cell reaction than the hydrogen reverse evolution reaction (HER), the oxygen evolution reaction (OER) always requires a higher overpotential than HER. In order to minimize the associated energy loss as an overpotential, these electrochemical half-reactions of water splitting should be catalyzed by suitable materials. Due to the abundant exposed surface area and extensive active edge sites, black phosphorous quantum dots (BP QDs) have shown great potential in OER. Here, BP QDs was introduced to incorporate with bio-based carbon nanofibers (CNF) and Co–Ni bimetallic organic framework (CoNiMOF), preparing a novel catalyst for oxygen evolution reaction (OER) by a facile one-pot reaction (Scheme 1). The unique structures and greater BET surface areas of CoNiMOF-BP QDs/CNF could possibly supply a larger electrocatalytic surface, expose further active sites. The obtained CoNiMOF-BP QDs/CNF possesses excellent electrocatalytic activity in alkaline electrolyte (1 M KOH) with a low overpotential of 281 mV at 10 mA cm^?2 and a low Tafel slope of 111.9 mV dec^?1. The CoNiMOF-BP QDs/CNF can remain stable for 25,000 s under alkaline electrolyte, showing excellent stability. The increase of electrocatalyst activity is mainly attributed to the synergistic effect of excellent conductivity and enriched active sites arising from BP QDs. This work not only provides an effective strategy for the development of bimetallic MOFs derived electrocatalysts, but also puts forward a new insight for the application of BP QDs in water splitting.     

Bifunctional nanoporous ruthenium-nickel alloy nanowire electrocatalysts towards oxygen/hydrogen evolution reaction

A class of ruthenium-nickel alloy catalysts featured with nanoporous nanowires (NPNWs) were synthesized by a strategy combining rapid solidification with two-step dealloying. RuNi NPNWs exhibit excellent electrocatalytic activity and stability for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in which the RuNi-2500 NPNWs catalyst shows an OER overpotential of 327 mV to deliver a current density of 10 mA cm^?2 and the RuNi-0 NPNWs catalyst requires the overpotential of 69 mV at 10 mA cm^?2 showing the best HER activity in alkaline media. Moreover, the RuNi-1500 NPNWs catalyst was used as the bifunctional electrocatalyst in a two-electrode alkaline electrolyzer for water splitting, which exhibits a low cell voltage of 1.553 V and a long-term stability of 24 h at 10 mA cm^?2, demonstrating that the RuNi NPNWs catalysts can be considered as promising bifunctional alkaline electrocatalysts.     

Mesoporous nickel-sulfide/nickel/N-doped carbon as HER and OER bifunctional electrocatalyst for water electrolysis

The development of non-precious metal-based highly active bi-functional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is critical factor for making water electrolysis a viable process for large-scale industrial applications. In this study, bi-functional water splitting electrocatalysts in the form of nickel-sulfide/nickel nanoparticles integrated into a three-dimensional N-doped porous carbon matrix, are prepared using NaCl as a porous structure-forming template. Microstructures of the catalytic materials are characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and N₂ adsorption-desorption analysis. The most active catalyst synthesized in this study exhibits a low HER overpotential of 70 mV at 10 mA cm⁻² and a low Tafel slope of 45 mV dec⁻¹. In OER, the optimized sample performs better than a state-of-the-art RuO₂ catalyst and produces an overpotential of 337 mV at 10 mA cm⁻², lower than that of RuO₂. The newly obtained materials are also used as HER/OER electrocatalysts in a specially assembled two-electrode water splitting cell. The cell demonstrates high activity and good stability in overall water splitting.     

Electrodeposition of Ni–Fe–Mn ternary nanosheets as affordable and efficient electrocatalyst for both hydrogen and oxygen evolution reactions

The synthesis of high performance and economical electrocatalysts in the process of overall water splitting is very important for the production of hydrogen energy and has become one of the most important challenges. Here, various Ni, Ni–Fe, Ni–Mn nanosheets and Ni–Fe–Mn ternary nanosheets were created using cost-effective, versatile and binder-free electrochemical deposition methods, and the electrocatalytic activity of various electrodes for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were investigated in an alkaline environment. Due to the high electrochemical active surface area due to the fabrication of nanosheets, the synergistic effect between different elements on the electronic structure, the high wettability due to the formation of nanosheets and the quick detachment of formed gasses from the electrode, the Ni–Fe–Mn nanosheets electrode showed excellent electrocatalytic activity. In order to deliver the 10 mA cm⁻² current density in HER and OER processes, this electrode required values of 64 mV and 230 mV overpotential, respectively. Also, the stability test showed that after 10 h of electrolysis at a current density of 100 mA cm⁻², the overpotential changes was very small (less than 4%), indicating that the electrode was excellent electrostatic stability. Also, when using as a bi-functional electrode in the full water splitting system, it only needed a cell voltage of 1528 V to deliver a current of 10 mA cm⁻². The results of this study indicate a new strategy for the synthesis of active and stable electrocatalysts.     

Nickel foam-supported Fe,Ni-Polyporphyrin microparticles: Efficient bifunctional catalysts for overall water splitting in alkaline media

Developing highly active, stable and sustainable electrocatalysts for overall water splitting is of great importance to generate renewable H₂ for fuel cells. Herein, we report the synthesis of electrocatalytically active, nickel foam-supported, spherical core-shell Fe-poly(tetraphenylporphyrin)/Ni-poly(tetraphenylporphyrin) microparticles (FeTPP@NiTPP/NF). We also show that FeTPP@NiTPP/NF exhibits efficient bifunctional electrocatalytic properties toward both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). Electrochemical tests in KOH solution (1 M) reveal that FeTPP@NiTPP/NF electrocatalyzes the OER with 100 mA cm⁻² at an overpotential of 302 mV and the HER with 10 mA cm⁻² at an overpotential of 170 mV. Notably also, its catalytic performance for OER is better than that of RuO₂, the benchmark OER catalyst. Although its catalytic activity for HER is slightly lower than that of Pt/C (the benchmark HER electrocatalyst), it shows greater stability than the latter during the reaction. The material also exhibits electrocatalytic activity for overall water splitting reaction at a current density of 10 mA cm⁻² with a cell voltage of 1.58 V, along with a good recovery property. Additionally, the work demonstrates a new synthetic strategy to an efficient, noble metal-free-coordinated covalent organic framework (COF)-based, bifunctional electrocatalyst for water splitting.     

Carbon nanorod supported metal alloy nanocubes using polydopamine as location reagent for water splitting

Transition metal catalysts were supposed to be the most likely substitute for commercial noble metal catalysts, and the development of highly active and long-term catalyst for water splitting are the future trend. Herein, Ni rectangular nitrogen doped carbon nanorods@Fe–Co nanocubes (Ni-CNRs@Fe–Co cubes) were fabricated via a facile template-free method. This simple strategy not only realizes the structure tailoring, but also achieves high-quality nitrogen-doping. Specifically, nickel dimethylglyoxime [Ni(dmg)₂] with rectangular rodlike structure was firstly synthesized by solution method, then metal-organic frameworks Fe–Co nanocube with different contents were loaded on rectangular carbon nanorods with polydopamine as the locating and the connecting agent, and finally Ni-CNRs@xFe-Co cubes were obtained by a one-step calcination. A series of electrochemical tests were researched on materials with different metal contents in the 1 M KOH solution. The Ni-CNRs@Fe–Co cubes show excellent electrocatalytic activity in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). For HER and OER, the Tafel slopes were 83.3 mV dec⁻¹ and 71 mV dec⁻¹, the onset potential were −167 mV and 1.62 V, and reached the current densities of 10 mA cm⁻², the overpotential just needed 196 mV and 433 mV, respectively. This novel synthetic strategy will provide a template-free way for cheap electrocatalysts of non-precious metal for OER and HER.     

Electrochemical fabrication of Ni–Mo nanostars with Pt-like catalytic activity for both electrochemical hydrogen and oxygen evolution reactions

Synthesis of electrocatalysts with excellent performance for hydrogen and oxygen evolution are the main challenges for production of hydrogen by electrochemical water splitting method. Here, Ni–Mo nanostars were created by electrochemical deposition process at different morphologies and their electrocatalytic behavior was studied for hydrogen and oxygen evolution reactions in 1.0 M KOH solution. Increased electrochemically active surface area due to the nanostars formation, improved intrinsic electrocatalytic activity, increased surface wettability, as well as being binder-free during electrode production, resulted in excellent electrocatalytic behavior. For optimized condition, 60 mV and 225 mV overpotential are needed for generating the current density of 10 mA.cm-² in HER and OER process respectively in the alkaline medium. The lower slope of the electrode compared to the other electrodes also indicated that the kinetics of HER on the surface of the electrode was better. Also, there was very little change in the potential during the stability test, indicating the excellent electrocatalytic stability of the synthesized electrode. The present study introduces a rational, cost-effective and binder-free method for the synthesis of high performance electrocatalysts.     

Preparation of NiCo-LDH@NiCoV-LDH interconnected nanosheets as high-performance electrocatalysts for overall water splitting

Alkaline water electrolysis is a promising strategy for the production of hydrogen and oxygen. However, developing high-efficiency non-precious electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is still a big challenge. Here, we report a nickel foam-based electrode coated with NiCoV-LDH and NiCo-LDH nanosheets (denoted as NiCo-LDH@NiCoV-LDH/NF) by a two-step method for efficient water splitting performance. The NiCo-LDH@NiCoV-LDH/NF with unique nanosheet-on-nanosheet construction can enlarge the electrochemical active specific surface area greatly, and thus accelerate the charge transfer of electrocatalytic reactions. Besides, the doping of vanadium could also improve the OER performance. The electrode only requires a low overpotential for OER (260 mV at 100 mA cm^?2), and HER (80 mV at 10 mA cm^?2) reactions in 1.0 mol/L KOH solution at room temperature. Furthermore, in the two-electrode water splitting test, a current density of 10 mA cm^?2 was achieved at 1.55 V using 1.0 mol/L KOH solution, with excellent durability of 40 h. This work provided a facile method for developing new bifunctional catalysts.     

High throughput preparation of Ni–Mo alloy thin films as efficient bifunctional electrocatalysts for water splitting

The synthesis of cost-effective and high-performance electrocatalysts for water splitting is the main challenge in electrochemical hydrogen production. In this study, we adopted a high throughput method to prepare bi-metallic catalysts for oxygen/hydrogen evolution reactions (OER/HER). A series of Ni–Mo alloy electrocatalysts with tunable compositions were prepared by a simple co-sputtering method. Due to the synergistic effect between Ni and Mo, the intrinsic electrocatalytic activity of the Ni–Mo alloy electrocatalysts is improved, resulting in excellent HER and OER performances. The Ni₉₀Mo₁₀ electrocatalyst shows the best HER performance, with an extremely low overpotential of 58 mV at 10 mA cm^?2, while the Ni₄₀Mo₆₀ electrocatalyst shows an overpotential of 258 mV at 10 mA cm^?2 in OER. More significantly, the assembled Ni₄₀Mo₆₀//Ni₉₀Mo₁₀ electrolyzer only needs a cell voltage of 1.57 V to reach 10 mA cm^?2 for overall water splitting.     

Novel 3-D urchin-like Ni– Co–W porous nanostructure as efficient bifunctional superhydrophilic electrocatalyst for both hydrogen and oxygen evolution reactions

Fabrication of an electrocatalyst with remarkable electrocatalytic activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is important for the production of hydrogen energy. In this study, Ni–Co–W alloy urchin-like nanostructures were fabricated by binder-free and cost-effective electrochemical deposition method at different applied current densities and HER and OER electrocatalytic activity was studied. The results of this study showed that the microstructure and morphology are strongly influenced by the electrochemical deposition parameters and the best electrocatalytic properties are obtained at the electrode created at the 20 mA.cm⁻²applied current density. The optimum electrode requires −66 mV and 264 mV, respectively, for OER and HER reactions for delivering the 10 mA cm⁻² current density. The optimum electrode also showed negligible potential change after 10 h electrolysis at 100 mA cm⁻², which means remarkable electrocatalytic stability. In addition, when this electrode used as a for full water splitting, it required only 1.58 V to create a current density of 10 mA cm⁻². Such excellent electrocatalytic activity and stability can be related to the high electrochemical active surface area, being binder-free, high intrinsic electrocatalytic activity and hydrophilicity. This study introduces a simple and cost-effective method for fabricating of effective electrodes with high electrocatalytic activity.     

Iron-substituted Co-Ni phosphides immobilized on Ni foam as efficient self-supported 3D hierarchical electrocatalysts for oxygen evolution reaction

Electrocatalytic water splitting for hydrogen evolution is significantly impeded by the kinetically sluggish oxygen evolution reaction (OER). Thus, the development of highly efficient and durably stable non-noble-metal OER electrocatalyst is necessary and challenging for the large-scale electrocatalytic water splitting. Herein, a series of iron-substituted cobalt-nickel phosphides grown on Ni foam (FeCoNi-P/NFs) were easily prepared though successive hydrothermal and phosphorization treatments. The chemical compositions, crystalline and electronic structures as well as surface morphologies of these resulting electrocatalysts are strongly related with the iron substitution ratio. More interestingly, the FeCoNi-P/NF-2 nanosheet arrays prepared from equivalent molar ratio of iron and cobalt precursors exhibit the best OER performance with a low overpotential of 266 mV to produce a current density of 50 mA cm⁻² and a low Tafel slope of 61.2 mV dec⁻¹ in 1.0 M KOH condition, which is comparable to the reported state-of-the-art OER electrocatalysts. Additionally, the FeCoNi-P/NF-2 nanosheet arrays also show satisfactory long-term durability over 60 h. The superior OER activity of the electrocatalyst is essentially attributed to the heteroatomic substitution and the unique three-dimensional hierarchical morphology, which greatly increase the electrical conductivity, afford more active sites and facilitate the efficient charge transfer ability.     

Bifunctional electrocatalysts for water splitting from a bimetallic (V doped-NixFey) Metal–Organic framework MOF@Graphene oxide composite

An ongoing challenge still lies in the exploration of proficient electrocatalysts from earth-abundant non-precious metals instead of noble metal-based catalysts for clean hydrogen energy through large-Scale electrochemical water splitting. However, developing a non-precious transition metals based, stable electrocatalyst for cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) is important challenge for modern energy conversion technology. In this report Vanadium doped bimetallic nickel-iron nanoarray, fabricated by carbon supported architecture through carbonization process for electrochemical water splitting. Three types of catalysts were prepared in different molar ratio of Ni/Fe. The electrocatalytic performance demonstrated that the catalyst with equal mole ratio (0.06:0.06) of Ni/Fe possess high catalytic activity for both OER and HER in alkaline and acidic medium. Besides, our findings revealed that the doping of vanadium could play a strong synergetic effect with Ni/Fe, which provide a small overpotential of 90 mV and 210 mV at 10 mA cm^?2 for HER and OER respectively compared to the other two catalyst counterparts. Also, the catalyst with 1:1 (Ni/Fe) molar ratio showed a high current density of 208 mA cm^?2 for HER at 0.5 M H₂SO₄ and 579 mA cm^?2 for OER at 1 M KOH solution, the both current densities are much higher than the other two catalysts (different Ni/Fe ratio). In addition, the presented catalysts showed extremely good durability, reflecting in more than 20 h of consistent Chronoamprometry study at fixed overpotential η = 250 mV without any visible voltage elevation. Similarly, the (Ni/Fe) equal ratio catalyst showed better corrosion potential 0.209 V vs Ag/AgCl and lower current density 0.594 × 10^?12 A cm^?2 in high alkaline medium. The V-doping, MOF/GO surface defects are significantly increased the corrosion potential of the V-Ni_xFe_y-MOF/GO electrocatalyst. Besides, the water electrolyzed products were analysed by gas chromatography to get clear insights on the formed H₂ and O₂ products.     

Rapid synthesis of porous Ni/Co/Fe-LDHs nanosheets for effective electrochemical oxygen evolution reaction and zinc-air batteries

Transition metal compounds, especially layered double hydroxide materials (LDHs), show excellent catalytic activity in oxygen evolution reaction (OER). The ethanol oxidation reaction (EOR) is an innovative alternative anodic reaction to OER for improving the efficiency of water splitting to produce hydrogen. In order to improve the reactivity and explore the similarities and differences of active sites in the two reactions, three kinds of porous LDHs (NiFe, NiCo, CoFe LDHs) were synthesized and a series of tests were carried out. Among them, the best performing OER catalyst is NiFe-LDHs with a low overpotential of 1.44 V vs. RHE at 10 mA cm^?2 and a Tafel slope of 23.85 mV dec^?1. As for the EOR reaction, NiCo-LDHs is the best, with an overpotential of only 1.38 V vs. RHE at 10 mA cm^?2 and a Tafel slope of 71.58 mV dec-1. In addition, compared with OER, the LHDs material exhibited better stability in the EOR. This work provides a new direction for studying the electrocatalytic activity of LDHs materials in OER and EOR.     

Effect of iron on Ni–Mo–Fe composite as a low-cost bifunctional electrocatalyst for overall water splitting

By increasing demand for hydrogen and oxygen gas for energy and industrial applications, designing a cheap, high-efficiency, and bifunctional electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) seems necessary. For this purpose Ni–Mo–Fe as a bifunctional electrocatalyst was synthesized by one-step electrodeposition. From this electrocatalyst with optimal composition and current density, a small overpotential of 65, 161 mV for delivering 10, 100 mA/cm² on HER in alkaline media was achieved. As-fabricated electrode exhibited 344,408 mV for delivering 10, 100 mA/cm² in OER. Furthermore, this electrocatalyst shows high stability and negligible degradation in overpotential for HER and OER under long term stability tests in alkaline media. The notable function of As-fabricated Ni–Mo–Fe is due to the synergism effect between Ni, Mo, and Fe element and binder-free structure. Owing to the high-performance and high-stability of Ni–Mo–Fe electrocatalyst under Hydrogen and Oxygen evolution reactions is a candidate for industrial uses in the alkaline electrolyzer.     

Facile synthesis of highly active monolithic water-separated W-doped Ni–Fe–P catalysts

A new type of highly active and cost-effective nanoporous W-doped Ni–Fe–P catalyst on nickel foam (NF) was synthesized by a facile electroless plating method. The W-doped Ni–Fe–P/NF catalysts exhibit extraordinary catalytic activity for hydrogen evolution reaction (HER) in alkaline media, capable of yielding a current density of −10 mA cm⁻² at an overpotential of only 68 mV. Furthermore, the catalysts also show efficient activity towards oxygen evolution reaction (OER) with an overpotential of 210 mV at j = 10 mA cm⁻² as well. The W-doped Ni–Fe–P/NF electrocatalyst exhibits a long-term durability over 13 h test.     

MoS2/NiFeS2 heterostructure as a highly efficient electrocatalyst for overall water splitting at high current densities

Searching for efficient, stable and low-cost nonprecious catalysts for oxygen and hydrogen evolution reactions (OER and HER) is highly desired in overall water splitting (OWS). Herein, presented is a nickel foam (NF)-supported MoS₂/NiFeS₂ heterostructure, as an efficient electrocatalyst for OER, HER and OWS. The MoS₂/NiFeS₂/NF catalyst achieves a 500 mA cm⁻² current density at a small overpotential of 303 mV for OER, and 228 mV for HER. Assembled as an electrolyzer for OWS, such a MoS₂/NiFeS₂/NF heterostructure catalyst shows a quite low cell voltage (≈1.79 V) at 500 mA cm⁻², which is among the best values of current non-noble metal electrocatalysts. Even at the extremely large current density of 1000 mA cm⁻², the MoS₂/NiFeS₂/NF catalyst presents low overpotentials of 314 and 253 mV for OER and HER, respectively. Furthermore, MoS₂/NiFeS₂/NF shows a ceaseless durability over 25 h with almost no change in the cell voltage. The superior catalytic activity and stability at large current densities (>500 mA cm⁻²) far exceed the benchmark RuO₂ and Pt/C catalysts. This work sheds a new light on the development of highly active and stable nonprecious electrocatalysts for industrial water electrolysis.