A ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterogeneous interfaces, a preparation method thereof, and an application thereof in catalytic electrolytic water hydrogen production

Abstract

The present invention belongs to the technical field of catalytic electrolytic water, relates to a catalyst for electrolytic water, and relates to a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces, a preparation method thereof, and its application in catalytic electrolytic water for hydrogen production. The composite material is nanoparticles, including metal sulfides and a carbon matrix supporting the metal sulfides; the metal sulfides form a heterostructure composed of RuS₂ and (FeNi)S₁.₀₃, the heterostructure is a crystal structure and the grain size is 5-50 nm, and the interface between the two grains is a heterointerface. In the present invention, through the liquid-phase chelation coprecipitation method, cations are first dispersed to obtain a uniform precursor precipitate, and then synchronous high-temperature calcination is carried out to better construct a rich heterostructure. The composite material provided by the present invention can efficiently catalyze both hydrogen evolution and oxygen evolution reactions, and shows good industrial application prospects in the applications of laboratory electrolytic cells and commercial AEM electrolyzers.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalytic electrolytic water, relates to a catalyst for electrolytic water, and relates to a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces, a preparation method thereof, and an application thereof in catalytic electrolytic water for hydrogen production. Background Art

[0002] Disclosing the information of this background art section is only intended to increase the understanding of the overall background of the present invention, and is not necessarily regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in electrolytic water usually require the use of noble metal-based electrocatalysts such as platinum (Pt) and iridium (Ir). However, the scarcity and high cost of Pt and Ir seriously hinder their practical applications.

[0004] Ruthenium-based chalcogenides are considered to be an ideal electrocatalytic material due to their relatively low price and Pt-like catalytic activity. Currently, the reported preparation methods of ruthenium disulfide are mostly derived from the sulfidation of RuO2, with high costs and complex processes. Although ruthenium-based chalcogenides currently show excellent HER activity, they are not suitable for the OER reaction and have poor OER activity. Currently, most of the reported ruthenium disulfide-based catalysts are about HER, and there is no report on ruthenium disulfide acting as a bifunctional catalyst for both HER and OER at the same time, which limits its application in overall water splitting. Therefore, how to obtain a bifunctional catalytic activity for HER and OER through a simple preparation method, control the cost, and apply it to overall water splitting is the research focus and difficulty of ruthenium disulfide as an electrocatalyst. Summary of the Invention

[0005] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces, a preparation method thereof, and an application thereof in catalytic electrolytic water. The composite material provided by the present invention can simultaneously catalyze the hydrogen evolution and oxygen evolution reactions efficiently, and shows good industrial application prospects in the applications of laboratory electrolytic cells and commercial AEM electrolyzers.

[0006] In order to achieve the above purpose, the technical solution of the present invention is as follows:

[0007] In a first aspect, a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces, the composite material is nanoparticles, including metal sulfides and a carbon matrix supporting the metal sulfides; the metal sulfides are composed of RuS2 and (FeNi)S 1.03 to form a heterostructure, the heterostructure is a crystal structure and the grain size is 5-50 nm, and the interface between the two grains is a heterointerface.

[0008] The present invention provides (FeNi)S with good OER performance 1.03 nanomaterials, and introduces (FeNi)S into the nano-RuS2 material 1.03 At the same time, through the heterointerface between RuS2 and (FeNi)S 1.03 grains, a hetero-structured interface is constructed, which can adjust the charge redistribution of active sites, thereby creating a local electronic structure with optimized adsorption strength of key reaction intermediates. Through the synergistic effect of multiple active sites, the electrocatalytic activity of the composite material is improved.

[0009] In a second aspect, a method for preparing a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces as described above is provided. Sodium dimethyldithiocarbamate (C3H6NNaS2) is used to simultaneously carry out a chelation precipitation reaction on ruthenium salt, ferric salt and nickelous salt in a solution to obtain a precursor precipitate; then, under an inert atmosphere condition, the precursor precipitate is heated to 500-600 °C for synchronous annealing treatment to obtain the product.

[0010] The preparation method provided by the present invention can construct a composite material with the above rich heterointerfaces, and the preparation method is simple and the cost is low.

[0011] In a third aspect, an application of a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces as described above in catalytic electrolytic water for hydrogen production.

[0012] The beneficial effects of the present invention are as follows:

[0013] 1. The ruthenium disulfide / iron nickel sulfide / carbon (named RuS2 / (FeNi)S 1.03 / C) composite material with rich heterointerfaces provided by the present invention has rich hetero-structures and multiple active sites, and exhibits high-efficiency HER and OER bifunctional catalysts as an electrocatalyst, with excellent electrolytic water performance: (1) For HER catalytic activity, the overpotential of its hydrogen evolution reaction polarization curve is lower under the same current density condition. At the same time, the overpotential only decays less after continuous catalysis for 5000 cycles, which is better than the overpotential decay (18 mV) of commercial Pt / C; (2) For OER catalytic activity, the overpotential of its oxygen evolution reaction polarization curve is lower under the same current density condition, especially lower than that of commercial RuO2, and the overpotential decay is less after continuous catalysis for 5000 cycles, which is better than the overpotential decay (64 mV) of RuO2; (3) For overall water splitting performance, it can be used as the positive and negative electrode materials to effectively drive the electrolytic water device. Whether it is the potential (~1.68V) under a small current density (for example, 10 mA cm -2 ) condition or a large current density (for example, 40 mAcm -2The potential (~1.78 V) under the conditions is better than 1.92 V of commercial Pt / C ‖ RuO2; (4) For industrial AEM water electrolysis applications, it is used as a cathode catalyst (RuS2 / (FeNi)S 1.03 / C-3‖ NiFe LDH) in an actual AEM water electrolysis device. It can stably operate for more than 255 hours at a large current density of 1000 mA·cm -2 , and its performance is comparable to that of a commercial electrolytic cell (Pt / C ‖NiFe LDH), showing good industrial application prospects.

[0014] 2. The RuS2 / (FeNi)S 1.03 / C composite material provided by the present invention can obtain a RuS2-based HER and OER bifunctional overall water splitting catalytic material with rich heterointerfaces and low cost only through simple liquid-phase homogeneous chelation coprecipitation and synchronous high-temperature calcination. The steps are simple and the cost is low, which is conducive to large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0016] Figure 1 SEM image of RuS2 / (FeNi)S 1.03 / C-3 prepared in Example 3 of the present invention. (a) is at low magnification, and (b) is at high magnification;

[0017] Figure 2 HRTEM image of RuS2 / (FeNi)S 1.03 / C-3 prepared in Example 3 of the present invention. (a) is the crystal structure, (b) is the high-resolution transmission image and its corresponding fast Fourier transform diagram, (c) is the high-resolution transmission image and its corresponding fast Fourier transform diagram, (d) is the selected area electron diffraction, and (e) is the high-angle annular dark field element mapping;

[0018] Figure 3 XRD patterns of the composite materials prepared in Examples 1, 3, 5 and Comparative Examples 1, 2 of the present invention. (a) is from 5 to 80 degrees, and (b) is from 20 to 60 degrees;

[0019] Figure 4 HER performance test result diagrams of the composite materials prepared in Examples 1-5 and Comparative Examples 1, 2 of the present invention. (a) is the linear sweep voltammetry (LSV) polarization curve, and (b) is at 10 mA·cm -2 and 20 mA·cm -2Potential comparison diagram;

[0020] Figure 5 RuS2 / (FeNi)S prepared in Example 3 of the present invention 1.03 / C-3 and commercial Pt / C HER cyclic stability result diagram;

[0021] Figure 6 OER performance test result diagram of the composite materials prepared in Examples 1-5 and Comparative Examples 1 and 2 of the present invention. (a) is the linear sweep voltammetry (LSV) polarization curve, and (b) is the comparison diagram at 20 mA·cm -2 and 50 mA·cm -2 Potential comparison diagram;

[0022] Figure 7 RuS2 / (FeNi)S prepared in Example 3 of the present invention 1.03 / C-3 and commercial RuO2 OER cyclic stability result diagram;

[0023] Figure 8 RuS2 / (FeNi)S prepared in Example 3 of the present invention 1.03 / C-3 and commercial Pt / C ‖ RuO2 overall water splitting performance comparison diagram;

[0024] Figure 9 RuS2 / (FeNi)S of the present invention 1.03 / C-3 ‖ NiFe LDH electrolytic cell stability test result diagram at 1000 mA·cm -2 at 25 °C. Detailed implementation manners

[0025] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0026] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] In view of the poor OER activity of existing ruthenium disulfide, which is difficult to act on HER and OER simultaneously, limiting its application in overall water splitting, the present invention proposes a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces, a preparation method thereof, and its application in catalytic electrolysis of water.

[0028] A typical embodiment of the present invention provides a ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces. The composite material is nanoparticles, including metal sulfide and a carbon matrix supporting the metal sulfide; the metal sulfide is composed of RuS2 and (FeNi)S 1.03 to form a heterostructure. The heterostructure is a crystal structure with a grain size of 5-50 nm, and the interface between the two grains is a heterointerface.

[0029] In some embodiments, the particle size of the nanoparticles is 10-500 nm.

[0030] Another embodiment of the present invention provides a preparation method of the above ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces. Sodium dimethyldithiocarbamate (C3H6NNaS2) is used to simultaneously carry out a chelation precipitation reaction on ruthenium salt, ferric salt, and nickelous salt in a solution to obtain a precursor precipitate; then, under an inert atmosphere condition, the precursor precipitate is heated to 500-600 °C for synchronous annealing treatment to obtain the product.

[0031] The ruthenium salt is a compound with ruthenium ion as the cation, such as ruthenium trichloride, ruthenium nitrate, ruthenium sulfate, etc.

[0032] The ferric salt is a compound with ferric ion as the cation, such as ferric chloride, ferric nitrate, ferric sulfate, etc.

[0033] The nickelous salt is a compound with nickelous ion as the cation, such as nickel chloride, nickel nitrate, nickel sulfate, etc.

[0034] In some embodiments, the ruthenium salt, ferric salt, and nickelous salt are dissolved in water to obtain a mixed salt solution, and then mixed and reacted with an aqueous solution of sodium dimethyldithiocarbamate to obtain a precursor precipitate. Using water to disperse the ruthenium salt, ferric salt, and nickelous salt evenly and then carrying out the precipitation reaction can obtain a precursor precipitate with a more uniform element distribution, so that the subsequent annealing (or calcination) can better construct the heterostructure.

[0035] Specifically, the concentration of nickelous in the mixed salt solution is 0.11-0.13 mol / L.

[0036] Specifically, the concentration of the aqueous solution of sodium dimethyldithiocarbamate is 0.09-0.11 mol / L.

[0037] Specifically, under stirring conditions, the mixed salt solution was slowly added to an aqueous solution of sodium dimethyldithiocarbamate.

[0038] Specifically, after the chelation precipitation reaction, solid-liquid separation was performed, and then the precursor precipitate was washed and dried. The drying temperature was 50-70 °C, and the drying time was overnight.

[0039] In some embodiments, the molar ratio of ruthenium element, iron element, and nickel element is 0.15:0.5:1 to 0.18:0.5:1. Research shows that the yield of the target material is higher under this condition. When the ruthenium element is too high, too many impurity phases will be produced.

[0040] In some embodiments, the molar ratio of sodium dimethyldithiocarbamate to nickel element is 1.8-2.2:1.

[0041] In some embodiments, during the annealing treatment, it was heated to 500-600 °C and held for 1.5-2.5 hours.

[0042] In some embodiments, during the annealing treatment, the heating rate was 4-6 °C·min -1 。

[0043] The third implementation manner of the present invention provides an application of the above-mentioned ruthenium disulfide / iron-nickel sulfide / carbon composite material with rich heterogeneous interfaces in catalytic electrolytic water for hydrogen production.

[0044] In some embodiments, the ruthenium disulfide / iron-nickel sulfide / carbon composite material with rich heterogeneous interfaces serves as an anode catalyst and a cathode catalyst for catalytic electrolytic water for hydrogen production.

[0045] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in combination with specific examples and comparative examples.

[0046] Example 1

[0047] RuS2 / (FeNi)S 1.03 / C-1 preparation method, including the following steps:

[0048] First, 1.2 mmol of FeCl3∙6H2O, 2.4 mmol of NiCl2∙6H2O, and 0.19 mmol of RuCl3 were dissolved in 20 mL of deionized water and dispersed evenly to obtain a mixed salt solution. At the same time, 5 mmol of C3H6NNaS2·2H2O was evenly dispersed in 50 mL of deionized water to form a clear and transparent solution, namely the ligand solution. Then, under continuous magnetic stirring, the mixed salt solution was slowly added to the ligand solution and reacted for 30 minutes to obtain a black precipitate. After the reaction, the precipitate was washed thoroughly with deionized water and dried overnight at 60 °C. Subsequently, the obtained black powder was transferred to a tubular furnace and heated to 550 °C at a heating rate of 5 °C min -1 and held at this temperature for 1.5 hours to complete the thermal annealing treatment, obtaining a black sample RuS2 / (FeNi)S 1.03 / C-1.

[0049] Example 2

[0050] The preparation method of RuS2 / (FeNi)S 1.03 / C-2 includes the following steps:

[0051] First, 1.2 mmol of FeCl3∙6H2O, 2.4 mmol of NiCl2∙6H2O, and 0.238 mmol of RuCl3 were dissolved in 20 mL of deionized water and dispersed evenly to obtain a mixed salt solution. At the same time, 5 mmol of C3H6NNaS2·2H2O was evenly dispersed in 50 mL of deionized water to form a clear and transparent solution, namely the ligand solution. Then, under continuous magnetic stirring, the mixed salt solution was slowly added to the ligand solution and reacted for 30 minutes to obtain a black precipitate. After the reaction, the precipitate was washed thoroughly with deionized water and dried overnight at 60 °C. Subsequently, the obtained black powder was transferred to a tubular furnace and heated to 550 °C at a heating rate of 5 °C min -1 and held at this temperature for 1.5 hours to complete the thermal annealing treatment, obtaining a black sample RuS2 / (FeNi)S 1.03 / C-2.

[0052] Example 3

[0053] The preparation method of RuS2 / (FeNi)S 1.03 / C-3 includes the following steps:

[0054] First, 1.2 mmol of FeCl3∙6H2O, 2.4 mmol of NiCl2∙6H2O, and 0.285 mmol of RuCl3 were dissolved in 20 mL of deionized water and dispersed evenly to obtain a mixed salt solution. At the same time, 5 mmol of C3H6NNaS2·2H2O was evenly dispersed in 50 mL of deionized water to form a clear and transparent solution, which is the ligand solution. Then, under continuous magnetic stirring, the mixed salt solution was slowly added to the ligand solution and reacted for 30 minutes to obtain a black precipitate. After the reaction, the precipitate was washed thoroughly with deionized water and dried overnight at 60 °C. Subsequently, the obtained black powder was transferred to a tubular furnace and heated to 550 °C at a heating rate of 5 °C / min in a nitrogen atmosphere and held for 1.5 hours to complete the thermal annealing treatment, obtaining a black sample RuS2 / (FeNi)S -1 The heating rate of 5 °C / min was used to heat to 550 °C and hold for 1.5 hours to complete the thermal annealing treatment, obtaining a black sample RuS2 / (FeNi)S 1.03 / C-3.

[0055] Example 4

[0056] RuS2 / (FeNi)S 1.03 The preparation method of / C-4 includes the following steps:

[0057] First, 1.2 mmol of FeCl3∙6H2O, 2.4 mmol of NiCl2∙6H2O, and 0.333 mmol of RuCl3 were dissolved in 20 mL of deionized water and dispersed evenly to obtain a mixed salt solution. At the same time, 5 mmol of C3H6NNaS2·2H2O was evenly dispersed in 50 mL of deionized water to form a clear and transparent solution, which is the ligand solution. Then, under continuous magnetic stirring, the mixed salt solution was slowly added to the ligand solution and reacted for 30 minutes to obtain a black precipitate. After the reaction, the precipitate was washed thoroughly with deionized water and dried overnight at 60 °C. Subsequently, the obtained black powder was transferred to a tubular furnace and heated to 550 °C at a heating rate of 5 °C / min in a nitrogen atmosphere and held for 1.5 hours to complete the thermal annealing treatment, obtaining a black sample RuS2 / (FeNi)S -1 The heating rate of 5 °C / min was used to heat to 550 °C and hold for 1.5 hours to complete the thermal annealing treatment, obtaining a black sample RuS2 / (FeNi)S 1.03 / C-4.

[0058] Example 5

[0059] RuS2 / (FeNi)S 1.03 The preparation method of / C-5 includes the following steps:

[0060] First, 1.2 mmol of FeCl3∙6H2O, 2.4 mmol of NiCl2∙6H2O, and 0.38 mmol of RuCl3 were dissolved in 20 mL of deionized water and dispersed evenly to obtain a mixed salt solution. At the same time, 5 mmol of C3H6NNaS2·2H2O was evenly dispersed in 50 mL of deionized water to form a clear and transparent solution, namely the ligand solution. Then, under continuous magnetic stirring, the mixed salt solution was slowly added to the ligand solution and reacted for 30 minutes to obtain a black precipitate. After the reaction, the precipitate was washed thoroughly with deionized water and dried overnight at 60 °C. Subsequently, the obtained black powder was transferred to a tubular furnace and heated to 550 °C at a heating rate of 5 °C min -1 and held for 1.5 hours to complete the thermal annealing treatment, obtaining a black sample RuS2 / (FeNi)S 1.03 / C-5.

[0061] Comparative Example 1

[0062] First, 0.19 mmol of RuCl3 was dissolved in 20 mL of deionized water and dispersed evenly to obtain a ruthenium salt solution. At the same time, 5 mmol of C3H6NNaS2·2H2O was evenly dispersed in 50 mL of deionized water to form a clear and transparent solution, namely the ligand solution. Then, under continuous magnetic stirring, the ruthenium salt solution was slowly added to the ligand solution and reacted for 30 minutes to obtain a precipitate. After the reaction, the precipitate was washed thoroughly with deionized water and dried overnight at 60 °C. Subsequently, the obtained powder was transferred to a tubular furnace and heated to 550 °C at a heating rate of 5 °C min -1 and held for 1.5 hours to complete the thermal annealing treatment, obtaining a sample without a heterostructure, namely RuS2 / C.

[0063] Comparative Example 2

[0064] First, 1.2 mmol of FeCl3∙6H2O and 2.4 mmol of NiCl2∙6H2O were dissolved in 20 mL of deionized water and dispersed evenly to obtain a mixed salt solution. At the same time, 5 mmol of C3H6NNaS2·2H2O was evenly dispersed in 50 mL of deionized water to form a clear and transparent solution, namely the ligand solution. Then, under continuous magnetic stirring, the mixed salt solution was slowly added to the ligand solution and reacted for 30 minutes to obtain a precipitate. After the reaction, the precipitate was washed thoroughly with deionized water and dried overnight at 60 °C. Subsequently, the obtained powder was transferred to a tubular furnace and heated to 550 °C at a heating rate of 5 °C min -1 and held for 1.5 hours to complete the thermal annealing treatment, obtaining a sample without a heterostructure, namely (FeNi)S 1.03 / C.

[0065] RuS2 / (FeNi)S prepared in Example 3 1.03 The SEM image of / C-3 is as Figure 1 shown. After high-temperature carbonization, an irregular nanoparticle structure is formed, with a particle size diameter of 10 - 500 nm.

[0066] Figure 2 In (a) of [reference], it clearly shows the crystal structure in the RuS2 / (FeNi)S 1.03 / C-3 sample, and the grain size is 5 - 50 nm. Different crystal structures constitute rich heterostructures and interfaces. The crystal structures of RuS2 and NiS 1.03 correspond to the (100) plane of the NiS 1.03 phase and the (210) plane of the RuS2 phase respectively. From Figure 2 the high-magnification transmission (TEM) in (a) of [reference] and Figure 2 the fast Fourier transform (FFT) diffraction patterns in (b) and (c) of [reference], it can be seen that their lattice fringe spacings are 0.298 nm and 0.250 nm respectively. As shown in Figure 2 (d) of [reference], the existence of various crystal planes of RuS2 and NiS is also verified through the selected area electron diffraction pattern. From 1.03 it can be seen that Figure 2 in (e) of [reference], RuS2 / (FeNi)S 1.03 / C-3 contains uniformly distributed elements of Fe, Ni, Ru, S, and C, and it can be seen that the distribution trends of Fe and Ni are completely consistent, only a matter of signal strength, while it is not completely consistent with Ru, which is attributed to the inevitable coverage and overlap of various fine grains in the bulk.

[0067] Figure 3 (a) of [reference] is the XRD pattern of the prepared RuS2 / (FeNi)S 1.03 / C-1, RuS2 / (FeNi)S 1.03 / C-3, RuS2 / (FeNi)S 1.03 / C-5, RuS2 / C, and (FeNi)S 1.03 / C. In the XRD spectra of Examples 1, 3, and 5, several sharp peaks are shown, corresponding to the standard PDF cards of RuS2 (PDF#19 - 1107) and NiS 1.03 (PDF#02 - 1273) respectively, proving the coexistence of RuS2 and NiS in the material. And 1.03 while Figure 3The enlarged XRD pattern in (b) shows that the angles of several main peaks (gray areas) of RuS2 / C do not show obvious deviation relative to the standard PDF card, indicating that no heteroatoms enter RuS2 / C. However, (FeNi)S 1.03 / C, RuS2 / (FeNi)S 1.03 / C-1, RuS2 / (FeNi)S 1.03 / C-3, RuS2 / (FeNi)S 1.03 / C-5 show obvious deviation in the angles of several main diffraction peaks (pink areas), which is attributed to the entry of a small amount of larger Fe atoms into NiS 1.03 to replace the sites of smaller Ni, resulting in lattice expansion and thus increasing the interplanar spacing. In addition, the different degrees of deviation angles are mainly due to the formation of heterojunctions and different Ru contents. In short, the XRD results are in complete agreement with the SEM results. In addition to RuS2 and NiS 1.03 when the content of Ru is too high, there are also several sharp miscellaneous peaks in Example 5, and these miscellaneous peaks correspond to the standard peaks of (FeNi)9S8, indicating that the increase of Ru will interfere with the crystal structure of Fe-doped NiS 1.03 and derive other miscellaneous peaks, which also indirectly confirms that Fe is doped into the crystal structure of NiS 1.03 In addition, the peaks of Comparative Example 1 without adding Fe and Ni correspond well to NiS 1.03 and the sharp peaks of Comparative Example 2 just correspond to the standard PDF card of RuS2, indicating that both comparative examples form their respective pure phases without the existence of heterointerfaces.

[0068] In 1 M KOH electrolyte, the HER performance of the composite materials prepared in each example was evaluated. The preparation processes of the slurry and the electrode head are as follows. 2 mg of the catalyst is mixed with 2 mg of acetylene black and ultrasonically dispersed in a mixture of 20 μL of Nafion, 380 μL of ethanol and 100 μL of deionized water for 30 minutes to obtain an ink with a loading of 0.32 mg·cm -2 . It is dropped on the glassy carbon working electrode, while the graphite rod and Hg / HgO are used as the counter electrode and the reference electrode respectively. RuS2 / (FeNi)S 1.03 / C-3 heterostructure has an overpotential of only 188 mV at 10 mA cm -2 , while the two pure-phase comparative examples RuS2 / C and (FeNi)S 1.03 / C require 190 and 365 mV respectively to reach the same current density, as shown in Figure 4 in (a). Compared with the pure-phase materials without heterointerfaces, RuS2 / (FeNi)S 1.03Heterostructures can effectively enhance the HER catalytic activity. The existence of the heterointerfaces accelerates electron transfer and improves the electrochemical performance. Figure 4 The (b) in 1.03 lists RuS2 / (FeNi)S 1.03 / C-1, RuS2 / (FeNi)S 1.03 / C-2, RuS2 / (FeNi)S 1.03 / C-3, RuS2 / (FeNi)S 1.03 / C-4, RuS2 / (FeNi)S 1.03 / C-5, (FeNi)S -2 / C, RuS2 / C and Pt / C at 10 mA·cm -2 and 20 mA·cm

[0069] As Figure 5 shown, after 5000 consecutive cycles, the polarization curve of RuS2 / (FeNi)S 1.03 / C-3 HER only decays by 7 mV, while the commercial Pt / C material decays by 18 mV under the same voltage conditions, demonstrating the advantage of RuS2 / (FeNi)S 1.03 / C-3 material in terms of HER stability. This advantage is attributed to the optimization of electron transfer at the heterointerfaces, promoting the electrocatalytic reaction. This enables RuS2 / (FeNi)S 1.03 / C-3 catalyst to maintain high catalytic performance during long-term operation, showing excellent electrochemical stability.

[0070] To study the effect of Ru in the RuS2 / (FeNi)S 1.03 / C heterostructure on the OER performance in alkaline media (the preparation processes of the slurry and the electrode tip are the same as those for HER), the OER performances of RuS2 / (FeNi)S 1.03 / C-1, RuS2 / (FeNi)S 1.03 / C-2, RuS2 / (FeNi)S 1.03 / C-3, RuS2 / (FeNi)S 1.03 / C-4, RuS2 / (FeNi)S 1.03 / C-5, (FeNi)S 1.03 / C, RuS2 / C and RuO2 were evaluated, as Figure 6 shown. As can be seen from Figure 6 the (a) in 1.03 the overpotential of the RuS2 / (FeNi)S -2is 277 mV at a current density of 277 mV@η 20 ), significantly lower than that of pure-phase RuS2 / C (423 mV@ η 20 ), indicating that the addition of Fe and Ni forms RuS2 / (FeNi)S 1.03 heterointerface, which optimizes the local coordination environment of RuS2 and thus improves the electrocatalytic performance. RuS2 / (FeNi)S 1.03 / C-3 exhibits the lowest overpotential, indicating that excessive Ru may cause aggregation and lead to a decrease in activity, while it is difficult to play a role when the content of Ru is low. Figure 6 Listed in (b) of 1.03 RuS2 / (FeNi)S 1.03 / C-1, RuS2 / (FeNi)S 1.03 / C-2, RuS2 / (FeNi)S 1.03 / C-3, RuS2 / (FeNi)S 1.03 / C-4, RuS2 / (FeNi)S 1.03 / C-5, (FeNi)S -2 / C, RuS2 / C and RuO2 at 20 mA·cm -2 and 50 mA·cm

[0071] As Figure 7 shown, after 5000 consecutive cycles, the OER polarization curve of RuS2 / (FeNi)S 1.03 / C-3 only decays by 19 mV, while the commercial RuO2 material decays by 64 mV under the same voltage conditions, demonstrating the advantage of RuS2 / (FeNi)S 1.03 / C-3 material in terms of OER stability.

[0072] As Figure 8 shown, using two glassy carbon working electrodes with the catalyst dropped on them as the imprint and anode respectively (the preparation process is the same as that of HER and OER), RuS2 / (FeNi)S 1.03 / C-3 is used as both the cathode and anode catalyst to form an electrolyzed water device. At a current density of 10 mA cm -2 , the voltage reaches 1.68 V, slightly higher than that of commercial Pt / C ‖ RuO2 (1.64 V). However, as the current density increases, at a current density of 40 mA cm -2 , it is 1.78 V, significantly better than 1.92 V of commercial Pt / C ‖ RuO2, preliminarily demonstrating the practical application of this RuS2 / (FeNi)S 1.03 / C composite material with a rich heterointerface.

[0073] To further evaluate the feasibility of the catalyst in actual commercial applications, 0.25 g of RuS2 / (FeNi)S 1.03 / C-3 (cathode catalyst) or 0.4 g of NiFe LDH (anode catalyst) and 0.8 mL of FAA-3-SOLUTE-10 anionic polymerization solution were ultrasonically treated (ice-water bath, 40 kHz) for 60 min in a 1:1 (v / v) ethanol-isopropanol solvent mixture to prepare the ink. First, the catalyst slurry was sprayed onto a Teflon plate, and then the cathode and anode catalysts were respectively pressed onto both sides of the anion exchange membrane by hot pressing transfer printing to assemble an anion exchange membrane (AEM) electrolytic cell. As Figure 9 shown, its long-term durability was evaluated under the condition of 1 M KOH and a current density of 1000 mA·cm -2 . The electrolytic cell with an assembled application area of 45 cm 2 exhibited excellent stability and operated at 25°C and 1000 mA·cm -2 for more than 255 hours, comparable to the performance of the electrolytic cell assembled with the commercial catalyst Pt / C‖NiFe LDH, demonstrating the good industrial application prospects of this catalyst.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterogeneous interfaces, characterized in that, The composite material is nanoparticles, including metal sulfide and a carbon matrix supporting the metal sulfide; the metal sulfide consists of RuS2 and (FeNi)S 1.03 to form a heterostructure, the heterostructure being a crystal structure with a grain size of 5 - 50 nm, and the interface between the two grains being a heterojunction interface; Fe doping in NiS 1.03 in the crystal structure.

2. The ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterogeneous interfaces as described in claim 1, characterized in that, The particle size of the nanoparticles is 10 to 500 nm.

3. A preparation method of the ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterogeneous interfaces as described in claim 1, characterized in that, Sodium dimethyldithiocarbamate is used to simultaneously carry out chelation precipitation reactions on ruthenium salt, ferric salt and nickelous salt in a solution to obtain a precursor precipitate; then, under an inert atmosphere condition, the precursor precipitate is heated to 500 to 600 °C for synchronous annealing treatment to obtain the product.

4. The preparation method according to claim 3, characterized in that, The ruthenium salt, ferric salt and nickelous salt are dissolved in water to obtain a mixed salt solution, and then the mixed salt solution is mixed and reacted with an aqueous solution of sodium dimethyldithiocarbamate to obtain a precursor precipitate.

5. The preparation method according to claim 4, characterized in that, Under stirring conditions, the mixed salt solution is added to the aqueous solution of sodium dimethyldithiocarbamate.

6. The preparation method according to claim 3, characterized in that, The molar ratio of sodium dimethyldithiocarbamate to nickel element is 1.8 to 2.2:

1.

7. The preparation method according to claim 3, characterized in that, During the annealing treatment process, it is heated to 500 to 600 °C and kept warm for 1.5 to 2.5 hours; Or, during the annealing process, the heating rate is 4 - 6 °C·min -1 .

8. Application of the ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces described in claim 1 or 2 in catalytic electrolytic water for hydrogen production.

9. The application according to claim 8, characterized in that, The ruthenium disulfide / iron nickel sulfide / carbon composite material with rich heterointerfaces is used as an anode catalyst and a cathode catalyst for catalytic electrolytic water for hydrogen production.

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