Mixed Nitride Research Articles

Supported highly dispersed molybdenum nitride derived from molybdate-intercalated Mg‒Al hydrotalcite-like compounds as a catalyst for ammonia decomposition

Molybdate-intercalated magnesium–aluminum hydrotalcite-like compounds (HTlc) were synthesized by anion-exchange and used as precursor to prepare supported molybdenum nitride catalyst for ammonia decomposition. The as-synthesized precursors and the derived mixed metal oxides and nitride catalysts were characterized by ICP, XRD, Raman spectroscopy, XPS, H2-TPR, and HAADF-STEM-EDX. The characterizations indicated that molybdate was well intercalated into the HTlc interlayer as MoO42– and the Mo content was tunable by altering the intercalation degree of molybdate. Upon calcination, molybdena was dominantly presented as isolated tetrahedrally coordinated MoOx species. Upon nitridation with ammonia at 700 ºC, highly dispersed and composition-uniform molybdenum nitride (Mo2±xN) was formed. The Mo0.5Mg3Al nitride catalyst showed good activity for ammonia decomposition, providing nearly full conversion of ammonia at 625 ºC under a space velocity of 5,000 mL gcat–1 h–1. The optimal catalyst also exhibited high catalytic stability during 100 h operation at 625 ºC, and no obvious aggregation took place, attributable to the strong metal–support interaction between molybdenum nitride and Mg–Al mixed oxide. It is suggested that the hydrotalcite-derived Mg–Al mixed oxide supported highly dispersed Mo2±xN species was active and stable for ammonia decomposition.

Corrosion resistance of chromium coating on the inner surface of EP823-Sh steel cladding

The processes of corrosion damage of the inner surface of the cladding are determined by corrosive reagents aggressive with respect to the cladding and the type of fuel used. Reactor irradiation of cladding made of EP823-Sh steel with mixed nitride fuel planned for use in the BREST-OD-300 reactor revealed non-uniform corrosion of the inner surface of the cladding. In this paper, the use of the chromium coating is proposed to prevent the corrosion of the inner surface of the steel fuel cladding. The results of corrosion tests of chromium coating applied to the inner surface of cladding made of EP823-Sh steel by electrolytic deposition are presented. Electron-microscopic studies of the chromium coating on EP823-Sh steel showed no significant signs of corrosion damage when tested in the environment of simulant fission products (CsI+Te) and in liquid lead at 650 °C.

Ordered phases in ternary wurtzite group-III nitrides: A first-principles study

A first-principles-based lattice model is applied to investigate the ordered phases of mixed group-III nitride ternary alloys. The model surveys the atomistic configurations with the lowest formation enthalpy for a wide range of compositions. We found novel ordered phases in wurtzite structures having specific compositions of three- and four-sevenths molar fractions of group-III cations. The configurations of group–III atoms on cation sites in those phases consist of a characteristic fragment of the ordered phases of one-third and one-half ordered phases that were previously reported. The simulation results indicate that group-III cations in ternary nitrides follow spatial positioning “atomistic distancing rules” that can be described by the pairwise interaction energy of group-III cations to realize the stabilities of the ordered structures. To minimize the formation enthalpy of a mixed crystal, the minor B, Al, Ga, and In atoms on cation sites remain neither too close to nor too distant from each other, allowing those ordered phases to be realized.

Synthesis of Nano-aluminum Nitride powder at low temperature by Sol-gel method

In this paper, molecular-level mixed aluminum nitride has been prepared from aluminum sec-butyl alcohol, glucose, and urea by sol-gel processing. Then, the nano-aluminum nitride powder with uniform particle size distribution was obtained by carbothermal reduction nitridation reaction. The effects of different feed ratios, reaction temperatures, and holding times on the phase of AlN powder were systematically studied. The prepared nano-aluminum nitride powder has a uniform particle size and a near-spherical shape, and its grain size is approximately 20~30 nm. The preparation temperature in this method was significantly reduced from the same preparation method of aluminum nitride powder.

Layered oxide precursor strategy for the synthesizing of titanium oxynitrides

Oxynitride is a mixture of mixed oxide and nitride anions. The creation of simple synthesis methods remains a challenge. Herein, we propose a synthetic method that uses the layered oxide Cs0.68Ti1.83O4 precursor to directly create oxynitride Ti2.85O4N without the need for ammonia. Using a topochemical reaction at 500 °C, a combination of solid Cs2CO3 and TiO2 was converted into the layered oxynitride Cs0.68+xTi1.83O4-xNx.‬‬‬‬‬‬ The crystal structure of Ti2.85O4N has been analyzed by Rietveld refinement with synchrotron radiation data. The UV–Vis spectra revealed that Ti2.85O4N has an absorption edge around 650 nm. Ti2.85O4N exhibits photocatalytic activity for hydrogen evolution utilizing methanol as a reversible electron donor in the visible range (λ > 420 nm) when promoted by platinum. In contrast, the intermediate oxynitride Cs0.68+xTi1.83O4−xNx with surface NHx species does not exhibit photocatalytic activity. These findings open new opportunities for novel titanium oxynitrides photocatalysts.‬‬‬‬‬‬‬

POSSIBILITIES OF NEUTRON ACTIVATION ANALYSIS FOR STUDYING THE CORROSION BEHAVIOR OF METALLIC MATERIALS IN MOLTEN SALTS

For the BREST-OD-300 reactor facility [1, 2], the technology for evaluating mixed nitride uranium-plutonium spent economical fuel is being determined [3–9]. To separate MNUP SNF from fuel claddings made of materials with high radiation resistance – ferritic-martensitic steel EP-823 [10–16], it is planned to use pyrometallurgical grades of “soft chlorination” [17]. When alloying and impurity elements of steel EP-823 are dissolved in molten salts of eutectic composition based on lithium and potassium chlorides, the melt will be contaminated. For the same reason, the formation of volatile compounds will occur, with their further mass transfer from hot to cold sections of process equipment. When studying the corrosion behavior of metals and alloys in liquid media, the problem often arises of determining small amounts of dissolution products in solution. This problem arises, for example, the rate of dissolution of microimpurities. The sensitivity of the usual, traditional methods used in corrosion testing such as mass loss or colorimetric determination of corrosion products in solution is often insufficient to make appropriate measurements. In these cases, the most effective is the use of the radiochemical method of neutron activation analysis based on. qualitative and quantitative determination of chemical elements, based on the measurement of the radiation characteristics of radionuclides formed during the irradiation of materials with neutrons. This paper presents the results of a study of the corrosion behavior and mass transfer of corrosion products of EP-823 steel pre-irradiated in the IVV-2M research nuclear reactor in molten salts 2KCl–3LiCl and 2KCl–3LiCl–PbCl2 at temperatures of 500 and 650°C for 24 h. It is shown that the method of neutron activation analysis can be used to study the corrosion behavior of EP-823 steel in molten salts of various compositions.

POSSIBILIITY OF URANIUM EXTRACTION FROM SPENT NUCLEAR FUEL IN FUSED ELECTROLITES CONTAINING RARE ELEMENTS

Link for citation: Nikitin D.I., Polovov I.B., Rebrin O.I. Possibility of uranium extraction from spent nuclear fuel in fused electrolytes containing rare elements . Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 210-218. In Rus. The relevance of the research is caused by the plans of using electrolytic separation of metalized spent nuclear fuel as a stage in pyrochemical reprocessing of mixed nitride uranium-plutonium fuel. The main aim is to determine the parameters of uranium electrolytic separation from an alloy with simulators of fission products (precious metals and rare earth elements) simulating spent nuclear fuel in salt mixtures based on 3LiCl–2KCl with additives of rare earth element chlorides. Objects: model spent nuclear fuel – uranium alloy with simulators of fission product (precious metals and rare earth elements) with a mass compound of Pd:Ru:Ag:Rh=25:1:3:3, Nd:Ce:La:Pr:Sm:Y=15:10:5:5:5:1). Methods: electrorefining, X-ray fluorescence and X-ray diffraction method of analysis, inductively coupled plasma mass spectrometry, assessment of distribution of components in the system. Results. The data obtained showed that uranium deposits have dendrite formations of alpha-uranium at 550 °C in orthorhombic crystal system toward needle cathode current density. The resulting cathode deposits are free from impurities of ruthenium, rhodium, molybdenum, praseodymium and yttrium. The purification coefficient for palladium reaches 3000, and for silver 1700. Noble metals accumulate in the anode sludge, and even with the complete depletion of the anode material. The concentration of noble metals in the cathode deposit does not exceed 0,0015 wt %. Despite the high concentration of rare-earth chlorides in the electrolyte, which simulates the accumulation of rare-earth ions during repeated reprocessing of spent nuclear fuel, the concentration of rare-earth metals in the cathode product did not exceed 0,007 wt %. During uranium electrowinning from a model spent nuclear fuel in the 3LiCl–2KCl–UCl3 electrolyte (10,1 wt %) with REE chlorides, which imitate their accumulation in the electrolyte during repeated processing, at 550 °C, as well as the initial cathode current density of 0,2 A/cm2, the specific amount of electricity is 1,0 A∙h/cm2. A cathode uranium deposit is released with a current efficiency exceeding 90 % with all anode mass depletion, and purification coefficient 1800 for the sum of precious metals and for the sum of rare earth metals.

Highly efficient Cd(II) removal from groundwater utilizing layered mixed metal oxides-graphitic carbon nitride composite with improved cycling stability

Graphitic carbon nitride (GCN) and its mixed metal oxide (MMO) composites are synthesized via co-precipitation followed by the pyrolysis method using various ratios of calcium aluminium (Ca:Al) with GCN, to enhance the adsorption ability towards Cd(ii) present in wastewater. Synthesized composite materials were characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analysis, Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. Due to its higher specific surface area (218.65 m2/g), the produced GCN and CaAl mixed metal oxide composite (GCN-MMO) exhibits improved adsorption ability towards Cd(II) ions. Approximately >99 % were adsorbed with Langmuir qmax of 131.57 mg/g. An overall pseudo-second-order (PSO) model fitted the kinetics data well. The possible mechanisms were surface complexation and precipitation, outer-sphere complexation, and acid-base mechanism. Further, the groundwater application was studied, and it achieved adsorption below the maximum permissible limit of USEPA with excellent cycling stability. The findings of this study showed that GCN-MMO composite material may be useful for the adsorption of Cd(II) heavy metal from an aqueous solution.

Effects of LiPON Incorporation on the Structures and Properties of Mixed Oxy-Sulfide-Nitride Glassy Solid Electrolytes.

Glassy solid electrolytes (GSEs) are promising solid electrolytes in the development of all solid-state batteries. Mixed oxy-sulfide nitride (MOSN) GSEs combine the high ionic conductivity of sulfide glasses, the excellent chemical stability of oxide glasses, and the electrochemical stability of nitride glasses. However, the reports on the synthesis and characterization of these novel nitrogen containing electrolytes are quite limited. Therefore, the systematic incorporation of LiPON during glass synthesis was used to explore the effects of nitrogen and oxygen additions on the atomic-level structures in the glass transition (Tg) and crystallization temperature (Tc) of MOSN GSEs. The MOSN GSE series 58.3Li2S + 31.7SiS2 + 10[(1 - x)Li0.67PO2.83 + x LiPO2.53N0.314], x = 0.0, 0.06, 0.12, 0.2, 0.27, 0.36, was prepared by melt-quench synthesis. Differential scanning calorimetry was used to determine the Tg and Tc values of these glasses. Fourier transformation-infrared, Raman, and magic angle spinning nuclear magnetic resonance spectroscopies were used to examine the short-range order structures of these materials. X-ray photoelectron spectroscopy was conducted on the glasses to further understand the bonding environments of the doped nitrogen. Finally, N and S elemental analyses were used to confirm the composition of these GSEs. These results are used to elucidate the structure of these glasses and to understand the thermal property impact oxygen and nitrogen doping in these GSEs.

ELECTROREFINING OF URANIUM ALLOYS CONTAINING PALLADIUM AND NEODYMIUM IN 3LiCl–2KCl–UCl<sub>3</sub> MELTS

The technology of pyrochemical processing of mixed nitride uranium-plutonium spent fuel, realizable at the experimental and demonstration energy complex of the site of the Siberian Chemical Plant, includes several operations with the ultimate goal of isolating the target fission products. It’s planned to use the electrofining of the products of the previous stage, metallized spent nuclear fuel, аs the penultimate stage of processing. It’s necessary to determine the processes and technological modes of electrolytic refining of alloys modeling the product of this stage of the processing module to implement electrolytic refining. This paper presents the results of electrofining of model alloys (simulating the raw materials of the stage of electrofining processing) on an enlarged laboratory electrolyzer. The initial parameters of uranium refining processes in melts based on 3LiCl–2KCl–UCl3 were determined earlier. The basic parameters of refining were the use of electrolyte 3LiCl–2KCl–UCl3 (10.1 wt % UCl3) and conducting experiments at 550°C. Uranium alloys containing palladium and neodymium were prepared by direct fusion of uranium metal, PdAP-1 grade palladium metal powders and neodymium metal (99.99%) in a medium of high-purity argon (99.998%). The data obtained showed that at a temperature of 550°C, cathode precipitates are typical dendritic forms of alpha-uranium in rhombic syngony with a tendency to needle formation with an increase in cathode current density. An increase in the company time and cathode current density leads to a decrease in the current output due to short-circuiting of the electrodes with cathode sediment needles or metal shedding from the cathode. The modes of the cathode process have been experimentally refined as a result of electrofining. When electrofining alloys U–Pd(1.59 wt %), U–Pd(1.62 wt %), U–Pd(1.54 wt %), U–Pd(1.58 wt %)–Nd(5.64 wt %), U–Pd(1.84 wt %)–Nd(6.49 wt %), U–Pd(1.79 wt %)–Nd(6.54 wt %), uranium cathode precipitates were obtained, which were subjected to chemical analysis, which showed the high purity of the resulting metallic uranium, as well as the absence of metallic palladium and molybdenum in it. The palladium purification coefficient exceeds 5000, the neodymium purification coefficient exceeds 1000, which meets the requirements for purification from fission products at this stage of pyrochemical processing of spent fuel. Palladium accumulates in anode slime, while the bulk of neodymium passes into the molten electrolyte.

Determining the swelling of mixed nitride uranium-plutonium fuel based on the post-reactor studies of experimental BN-600 and BOR-60 fuel rods

Determining the swelling of mixed nitride uranium-plutonium fuel based on the post-reactor studies of experimental BN-600 and BOR-60 fuel rods

Voloxidation of Mixed Nitride Uranium–Plutonium Spent Nuclear Fuel

The efficiency of voloxidation of mixed nitride uranium–plutonium spent nuclear fuel (MNUP SNF) for the separation of the fuel composition from the fuel rod cladding and removal of 3H and 14C was estimated. It was shown that the completeness of SNF separation from fuel rod cladding under optimal conditions is at the level of 98–99%. The residual content of tritium in the voloxidized fuel does not exceed 0.2% of its content in the original SNF sample; radiocarbon is removed by 98%.

ANODIC PROCESSES OF URANIUM ALLOYS CONTAINING PALLADIUM AND NEODYMIUM IN 3LiCl–2KCl-UCl<sub>3</sub> MELTS

At the reprocessing module of the pilot demonstration power complex site of the Siberian Chemical Combine, a combined technological scheme for the reprocessing of mixed nitride uranium-plutonium spent fuel consisting of pyrochemical operations, hydrometallurgical refining of uranium, plutonium and neptunium is implemented step by step. According to this scheme, the target pyrochemical reprocessing products, purified from the main mass of fission products with actinoid content not less than 99.9%, are sent for hydrometallurgical reprocessing. For pyrochemical reprocessing it is necessary to develop a technology of electrorefining of metallised spent nuclear fuel. To carry out electrolytic refining it is necessary to define processes and regimes of anodic dissolution of alloys simulating product of this head operation “metallization”. In the present work the results of investigations of processes of anodic dissolution of U–Pd and U–Pd–Nd model alloys with different concentrations of palladium and neodymium in melts based on 3LiCl–2KCl–UCl3 (10.1 wt % UCl3) at 550°C using different methods are presented. Uranium alloys containing palladium and neodymium were prepared by direct alloying of uranium metal and palladium metal powders of PdAP-1 grade, and neodymium metal (99.99%) in high-purity argon medium (99.998%). Electrochemical measurements were performed using an Autolab 302N potentiostat/halvanostat equipped with a Booster 20A high-current module. The anodic polarisation curves consist of only one oxidation wave which was attributed to the dissolution of uranium metal. Increasing the palladium content in the alloy from 1.5 to 10.0 wt %, does not affect the shape of the polarisation curves. The increase of neodymium content in the alloy from 1.0 to 10.0 wt % also does not affect the shape of polarization curves. Electrorefining parameters of uranium alloys containing palladium and neodymium were determined. The limiting current density of uranium evolution from uranium alloys containing palladium and neodymium in the electrolyte 3LiCl–2KCl–UCl3 (10.1 wt % UCl3) at 550°C was 0.4 A/cm2. It was shown that palladium does not diffuse into the melt as a result of anodic dissolution and neodymium accumulates in the electrolyte only when the alloy is refined with 10.0 wt % neodymium, which is much higher than the future real concentrations of electrotreated uranium alloy components in the technological chain of spent nuclear fuel processing.

Incorporation and migration of xenon in uranium-plutonium mixed nitride; A density functional theory study

Actinide nitride materials are promising candidates for advanced nuclear fuels. In this work, we investigate the bulk properties of the mixed nitrides U0.75Pu0.25N and U0.5Pu0.5N, and study the incorporation and migration behaviour of the fission gas Xe. The disordered U0.75Pu0.25N and U0.5Pu0.5N structures are constructed using the special quasi-random structure method. Their lattice parameters are closer to the experimentally determined values than the corresponding ordered structures. The density of states show that Pu f states are located at lower energy than U f, consistent with the trend of increasing f orbital stability across the actinide series. The actinide vacancy formation energy (Ef) in disordered and ordered U0.5Pu0.5N is highly dependent on the chemical environment around the vacancy: it increases as the number of U atoms in the first nearest-neighbour shell (NU(1NN)) increases, but decreases as the number of U atoms in the second nearest-neighbour shell (NU(2NN)) increases. The Xe incorporation energy (Ei) is found to be independent of vacancy species, depending only on the chemical environment of the vacancy. As does Ef, Ei increases with increasing NU(1NN), while decreases with increasing NU(2NN), because the smaller the NU(1NN) and the larger the NU(2NN), the larger the vacancy steric space. The Ei of Xe and Kr are calculated to be within the ranges 4.47–6.01 eV and 3.30–4.64 eV, respectively. The Xe migration energy barrier in ordered U0.5Pu0.5N allows us to set the energy range for Xe diffusion in disordered U0.5Pu0.5N as 0.50–1.75 eV. A lower range of 0.30–1.25 eV is found for Kr diffusion.

Phase pure synthesis of iron-nickel nitride nanoparticles: A low cost electrocatalyst for oxygen evolution reaction

Synthesis of mixed transition metal nitrides often leads to the formation of more than one phases in the final product. A control over molar ratio of metals (Fe:Ni) along with synthetic strategy is used to form phase pure product (Fe3Ni7N@C). The synthesized material is used as an efficient and cost-effective electrocatalyst for oxygen evolution reaction (OER). Fe3Ni7N@C requires a low overpotential of 290 mV to achieve a catalytic current density of 10 mA cm−2 which holds Tafel slope of 40 mV dec−1 superior to the noble metal benchmark catalysts. The physicochemical integrity of Fe3Ni7N@C is maintained up to 12 h activity as evident from post catalytic characterization.

Criticality analysis of pyrochemical reprocessing apparatuses for mixed uranium-plutonium nitride spent nuclear fuel using the MCU-FR and MCNP program codes

A preliminary criticality analysis for novel pyrochemical apparatuses for the reprocessing of mixed uranium-plutonium nitride spent nuclear fuel from the BREST-OD-300 reactor was performed. High-temperature processing apparatuses, “metallization” electrolyzer, refinery remelting apparatus, refining electrolyzer, and “soft” chlorination apparatus are considered in this work. Computational models of apparatuses for two neutron radiation transport codes (MCU-FR and MCNP) were developed and calculations for criticality were completed using the Monte Carlo method.The criticality analysis was performed for different loads of fissile material into the apparatuses including overloading conditions. Various emergency situations were considered, in particular, those associated with water ingress into the chamber of the refinery remelting apparatus. It was revealed that for all the considered computational models nuclear safety rules are satisfied.

Preparation of Li-Si-P-S-O-N Glasses: The Impact of Lipon Incorporation on Ionic Conductivity

Lithium glassy solid electrolytes (GSEs) are an alternative to liquid electrolytes in the development of solid-state batteries. Mixed oxy-sulfide nitride GSEs incorporate the useful properties of sulfide glasses, which show high ionic conductivity, of oxide glasses which display excellent chemical stability, and of nitride glasses which exhibit good electrochemical stability. In our investigation of these new GSEs, the following compositional series was explored Li2S + SiS2 + [(1-x)Li0.67PO2.83 + xLiPON]. Differential scanning calorimetry (DSC) was employed to determine the crystallization and glass temperatures of these GSEs. In addition, electrochemical impedance spectroscopy (EIS) was used to determine the temperature-dependent ionic conductivity of theses GSEs. X-ray Photoelectron Spectroscopy (XPS) was conducted on the glasses to further understand the chemical bonding environment of nitrogen. It was found that x = 0.2 displayed the highest ionic conductivity suggesting that nitrogen incorporation can be used to optimize mixed oxy-sulfide glasses.Support of this research by NSF Grant NSF-DMR-1936913 is acknowledged.

Synthesis of Mixed Actinide Oxides Using Microwave Radiation

A method has been developed for producing mixed actinide oxides suitable for fabricating mixed nitride uranium plutonium fuel for fast neutron reactors. The method is based on the use of microwave radiation for the direct denitration of actinide nitrate solutions. The possibility of producing uranium, plutonium, and neptunium-mixed oxides was shown. A pilot installation for preparing actinide oxides by microwave denitration was designed and tested. Mixed oxides of uranium and cerium (for plutonium imitation) were successfully used to synthesize uranium cerium nitrides and produce fuel pellets. Compared with the precipitation (ammonia) method of producing mixed oxides, microwave denitration reduces the generation of secondary liquid radioactive waste by more than six times.

Behavior of Glass-like and Mineral-like Phosphate Compounds with an Immobilized Chloride Mixture in Hydrogen Peroxide Solutions

A new type of high-level waste (HLW) is generated during pyrochemical reprocessing of mixed nitride spent uranium–plutonium nuclear fuel. Such waste is a spent electrolyte, which is a mixture of chloride salts containing approximately 25.7 wt.% LiCl + 31.6 wt.% KCl + 4.1 wt.% CsCl + 5.1 wt.% BaCl2 + 3.8 wt.% SrCl2 + 29.7 wt.% LaCl3, and its immobilization in reliable matrices is an actual radiochemical problem. The structure and hydrolytic stability of sodium aluminoironphosphate (NAFP) glass and a low-temperature mineral-like magnesium potassium phosphate (MPP) matrix, which are promising for spent electrolyte immobilization in the presence of hydrogen peroxide solutions simulating natural water radiolysis products, were studied in this work. The structure of the samples was studied using the SEM-EDS method. It was shown that the initial samples of NAFP glass after leaching in hydrogen peroxide solutions are prone to precipitation of crystalline phases on the surface, which are mainly represented by a mixture of sodium–iron–aluminum pyrophosphates. It was established that the leaching rate of structure-forming components of NAFP and MPP matrices generally increase, but remain at a low level, meeting modern requirements for HLW immobilization. This confirms the effectiveness of the studied matrices for the industrial use of the spent electrolyte.

Coupling of ruthenium with hybrid metal nitrides heterostructure as bifunctional electrocatalyst for water electrolysis

Noble metal-based materials are the benchmark catalysts for electrocatalysis, but their wide applications are hindered due to their scarcity and high cost. Developing a feasible strategy to achieve higher catalytic activity with low usage of noble metals is vital and urgent. Herein, a simple nitridation route is proposed to design a hybrid material with both ruthenium (Ru) species and mixed metal nitride matrixes (Ru-NiWNx). Benefitting from the intrinsic high conductivity of metal nitrides, abundant catalytic active sites, and strong electron interactions, the Ru-NiWNx catalyst shows excellent bifunctional activity in alkaline electrolytes. The overpotentials are 70 mV and 270 mV at the geometric current density of 100 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. After further assembly into an electrolyzer, the Ru-NiWNx also shows superior performance. The voltage of the electrolyzer only needs 1.49 V to reach 100 mA cm−2 at the test temperature of 80 °C, indicating the promising application for hydrogen production. Our work paves a new strategy to design high-active hybrid materials for overall water splitting.