A solid-phase-synthesized nickel pyrite, a preparation method and application thereof

Abstract

This invention belongs to the field of solid material preparation technology, and more specifically relates to a solid-state synthesis method for nickel pyrite, its preparation method, and its applications. The invention uses iron powder, nickel powder, and a sulfur source as reactants, and obtains the nickel pyrite through a multi-stage high-temperature solid-state reaction process; the sulfur source includes iron sulfide or nickel sulfide. In this method, iron sulfide or nickel sulfide is used as the raw material, which is readily available, low in cost, and the production process is green and environmentally friendly, with no polluting byproducts. It replaces the use of low-melting-point, high-vapor-pressure sulfur powder in traditional synthesis methods, avoiding the experimental safety hazards caused by high-pressure sulfur. Nickel pyrite (Fe,Ni) is prepared through a multi-stage high-temperature solid-state reaction process (one-stage programmed temperature rise). 9 S 8 Not only is it highly efficient and simple to operate, but it also produces high-purity products. Furthermore, it can be adapted for industrial-scale production based on the method of this invention.

Description

A solid-state synthesis of nickel pyrite, its preparation method and applications Technical Field

[0001] This invention belongs to the field of solid material preparation technology, and more specifically relates to a solid-state method for synthesizing nickel pyrite, its preparation method, and its application. Background Technology

[0002] Nickel pyrite (Fe,Ni)9S8, an important sulfide mineral, has an isometric crystal system. This structure is based on an ABC packing of hexagonal thin layers located in the lattice plane, with sulfur atoms in a cubic close-packed configuration, while nickel (Ni) and iron (Fe) atoms occupy the tetrahedral and octahedral voids in the crystal lattice. When the Fe / Ni ratio in nickel pyrite is close to 1, its theoretical chemical composition (by mass percentage) is approximately 32.55% iron (Fe), 34.22% nickel (Ni), and 33.23% sulfur (S). This unique atomic arrangement and electronic structure endows nickel pyrite with high electrical conductivity, high intrinsic activity, and excellent structural stability, making it a promising candidate for applications in various functional materials fields such as semiconductors, superconductors, optoelectronics, and magnetism.

[0003] In recent years, with the rapid development of clean energy technologies, especially the urgent need for efficient and low-cost catalysts in water electrolysis for hydrogen production, nickel pyrite, as a highly promising non-precious metal electrocatalytic material, has attracted widespread attention. Studies have confirmed that nickel pyrite itself can serve as an excellent electrocatalyst for the hydrogen evolution reaction (HER); it can also be used in nickel pyrite / graphene composite electrodes to reduce the cost of fuel cell stacks, highlighting its important value as a key mineral-based raw material.

[0004] In nature, pyrite is a common mineral in copper-nickel sulfide deposits associated with ultrabasic rocks. However, natural pyrite rarely occurs in large crystals or pure massive forms. It usually occurs as irregular grains or inclusions closely associated with minerals such as pyrrhotite, chalcopyrite, and magnetite. Further complicating matters, many natural pyrite deposits often contain a considerable amount of gangue mineral impurities such as silicates during their formation. This complex symbiotic relationship and impurity content make it extremely difficult to obtain high-purity, large-volume pyrite monominerals directly from natural ore.

[0005] Currently, extracting high-purity pyrite from natural ores typically requires complex beneficiation processes, such as gradient weak magnetic separation, flotation separation (often using reagents like sodium hexametaphosphate to disperse gangue minerals like serpentine and improve the flotation environment for pyrite), ultrasonic de-removal, and a combination of high-intensity magnetic separation. While these methods can yield single-mineral pyrite for laboratory research, the processes are relatively cumbersome, and the use of reagents may affect the natural activity of the mineral surface. Therefore, the purification bottleneck of natural minerals significantly limits their direct application in high-performance functional materials.

[0006] To overcome the problem of insufficient purity in natural minerals and to meet the requirements of materials research and applications for specific morphologies and properties, the development of artificial synthesis methods is crucial. Traditionally, the synthesis of nickel pyrite has mostly employed high-temperature solid-state reaction methods. This method typically uses simple elements (such as iron powder, nickel powder, and sulfur powder) or corresponding metal sulfides as raw materials.

[0007] However, traditional synthetic routes have significant technical defects and safety risks, making it difficult to achieve large-scale industrial production. These defects are manifested in the following two main aspects:

[0008] Safety concerns: Sulfur is a key raw material required in the synthesis process. Sulfur has a low boiling point (444.6℃), and high-pressure sulfur vapor is generated during high-temperature reactions. When the reaction is carried out in a closed system (such as a vacuum-sealed quartz tube) and the temperature exceeds 800℃, the sulfur vapor pressure can exceed 5MPa, which can easily cause the quartz tube to burst, posing a significant safety hazard.

[0009] Process complexity and low success rate: To obtain the correct nickel pyrite crystal structure, the synthesis process typically requires multiple high-temperature stages. A typical process might involve pre-synthesizing intermediate products (such as FeS or NiS) at around 500°C, followed by prolonged heat treatment at temperatures above 1000°C to reconstruct and homogenize the crystals. This process is not only energy-intensive and time-consuming, but also requires extremely stringent process control, resulting in a final synthesis success rate often below 60%, and difficulty in guaranteeing product purity and homogeneity. These factors combined limit traditional synthesis methods to small-scale laboratory preparations, failing to meet the demands of large-scale industrial production. Summary of the Invention

[0010] The purpose of this invention is to provide a solid-state synthesized nickel pyrite, its preparation method, and its application, in order to solve the problems existing in the prior art and achieve efficient, simple, green, and safe preparation of high-purity nickel pyrite.

[0011] To achieve the above objectives, the present invention provides the following solution:

[0012] One of the technical solutions of this invention is to provide a method for preparing nickel pyrite synthesized by solid-state method, the steps of which include:

[0013] The nickel pyrite was obtained by multi-stage high-temperature solid-phase reaction treatment using iron powder, nickel powder and sulfur source as reactants.

[0014] The sulfur source includes iron sulfide or nickel sulfide.

[0015] Furthermore, when the sulfur source is iron sulfide, the amount of iron powder used is 4.6-8.8 wt% of the mass of the iron sulfide.

[0016] Furthermore, when the sulfur source is iron sulfide, the amount of nickel powder used is 43.5-68.5 wt% of the mass of the iron sulfide.

[0017] Furthermore, when the sulfur source is nickel sulfide, the amount of iron powder used is 45-60 wt% of the mass of the nickel sulfide.

[0018] Furthermore, when the sulfur source is nickel sulfide, the amount of nickel powder used is 5.2-7.2 wt% of the mass of the nickel sulfide.

[0019] Furthermore, the multi-stage high-temperature solid-state reaction treatment includes: heating to 700-800℃ at a heating rate of 1-5℃ / min, holding at that temperature for 1-4 hours, then heating to 1000-1500℃ at a heating rate of 1-5℃ / min, holding at that temperature for 4-14 hours; and finally, cooling to 20-30℃ (room temperature) at a cooling rate of 1-3℃ / min.

[0020] Furthermore, the iron sulfide is pyrite and / or ferrous disulfide with a purity >99%.

[0021] Furthermore, the purity of the nickel sulfide is >99%.

[0022] The second technical solution of the present invention: a nickel pyrite prepared by the above preparation method.

[0023] The third technical solution of the present invention provides an application of the above-mentioned nickel pyrite in the field of hydrogen evolution electrocatalysis or in the preparation of new energy batteries.

[0024] The fourth technical solution of this invention provides a green production method for synthesizing nickel pyrite based on a solid-state method, comprising:

[0025] Nickel pyrite was prepared according to the above preparation method;

[0026] The sulfur vapor generated in the method is collected and recycled by condensation, the H2S generated in the method is subjected to catalytic combustion treatment, and the residue generated in the method is used as a cement admixture.

[0027] The present invention discloses the following technical effects:

[0028] The solid-state synthesis method for nickel pyrite provided by this invention uses iron sulfide or nickel sulfide as raw materials. The raw materials are readily available and low in cost. The production process is green and environmentally friendly, with no polluting byproducts. It replaces the use of low-melting-point, high-vapor-pressure sulfur powder in traditional synthesis methods, avoiding experimental safety hazards caused by high-pressure sulfur. Nickel pyrite (Fe,Ni)9S8 is prepared through multi-stage high-temperature solid-state reaction treatment (one-time programmed temperature rise). It is not only efficient and simple to operate, but also produces high-purity products.

[0029] The method provided by this invention can be operated not only under laboratory conditions, but also for industrial-scale production. The high-purity nickel pyrite (Fe,Ni)9S8 obtained has potential hydrogen evolution electrocatalytic activity and can be used as a raw material for nickel pyrite-based materials or in the field of new energy batteries, etc. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0031] Figure 1 shows the process flow for the solid-state synthesis of nickel pyrite according to the present invention.

[0032] Figure 2 shows the SEM images of pyrite P1 and pyrite P2, where a is the SEM image of pyrite P1 and b is the SEM image of pyrite P2.

[0033] Figure 3 shows the XRD characterization of nickel pyrite P1.

[0034] Figure 4 shows the XRD characterization of nickel pyrite P2.

[0035] Figure 5 shows the SEM-EDS comprehensive characterization of nickel pyrite P1, where a is the SEM image, b is the morphology image corresponding to the EDS surface scan, c is the EDS sulfur (S) element surface distribution, d is the EDS nickel (Ni) element surface distribution, e is the EDS iron (Fe) element surface distribution, and f is the energy dispersive spectroscopy (EDS) analysis image.

[0036] Figure 6 shows the SEM-EDS comprehensive characterization of nickel pyrite P2, where a is the SEM image, b is the morphology image corresponding to the EDS surface scan, c is the EDS sulfur (S) element surface distribution, d is the EDS nickel (Ni) element surface distribution, e is the EDS iron (Fe) element surface distribution, and f is the energy dispersive spectroscopy (EDS) analysis image.

[0037] Figure 7 is a schematic diagram of the green production design process of the method of the present invention. Detailed Implementation

[0038] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0039] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0040] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0041] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0042] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0043] Unless otherwise specified, all raw materials and reagents involved in the specific embodiments of this invention are commercially available products.

[0044] In the method provided by this invention, the technical effect achieved by using pyrite or ferrous disulfide with a purity of >99% is the same. Pyrite with a purity of >99% will be used as an example for the following description; the nickel sulfide used has a purity of >99%.

[0045] Unless otherwise specified, room temperature and normal temperature in the specific embodiments of this invention refer to 20-30℃.

[0046] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0047] In some specific embodiments, the present invention provides a method for solid-state synthesis of nickel pyrite, wherein directional crystal growth is achieved through single-stage programmed temperature control:

[0048] (1) Medium temperature range (700~800℃): Triggers solid-state reaction FeS2+Ni→NiFeS2 (intermediate phase);

[0049] (2) High temperature range (1000~1500℃): Reconstructed into (Fe,Ni)9S8 cubic crystal system.

[0050] The process flow for the solid-state synthesis of nickel pyrite is shown in Figure 1, and the steps include:

[0051] Iron sulfide or nickel sulfide is mixed evenly with iron powder and nickel powder in an agate mortar. The resulting mixture is then vacuum-sealed in a quartz tube and transferred to a heating device. It is first heated to 700-800℃ (preferably 800℃) at a heating rate of 1-5℃ / min and maintained at this temperature for 1-4 hours. Then, it is heated to 1000-1500℃ (preferably 1100℃) at a heating rate of 1-5℃ / min and maintained at this temperature for 4-14 hours. Finally, it is cooled to room temperature at a cooling rate of 1-3℃ / min. The resulting product is nickel pyrite (Fe,Ni)9S8 with a purity >99%.

[0052] When iron sulfide is used as raw material, the amount of nickel powder is 43.5-68.5 wt% of the mass of iron sulfide; the amount of iron powder is 4.6-8.8 wt% of the mass of iron sulfide.

[0053] When nickel sulfide is used as raw material, the amount of nickel powder is 5.2-7.2 wt% of the mass of nickel sulfide (corresponding to a stoichiometric ratio of Ni / (Ni+Fe) of 0.34-0.38); the amount of iron powder is 45-60 wt% of the mass of nickel sulfide (ensuring that Fe / Ni is 1 ± 0.05).

[0054] Example 1

[0055] The steps for solid-state synthesis of nickel pyrite include:

[0056] 2.399 g of pyrite (FeS2), 0.1619 g of iron powder, and 1.379 g of nickel powder were weighed and mixed evenly in an agate mortar. The mixed material was placed in a quartz tube and vacuum-sealed using a vacuum sealing technique. The tube was then transferred to a tube furnace and heated to 800 °C at a heating rate of 5 °C / min. The temperature was held at this temperature for 2 h, and then heated to 1100 °C at a heating rate of 3 °C / min. The temperature was held at this temperature for 8 h, and then slowly cooled to room temperature at a cooling rate of 3 °C / min. The resulting sample was nickel pyrite (Fe,Ni)9S8 with a purity >99%, denoted as nickel pyrite P1.

[0057] Example 2

[0058] The steps for solid-state synthesis of nickel pyrite include:

[0059] Weigh 2.256g of nickel sulfide (NiS), 1.221g of iron powder, and 0.170g of nickel powder, and mix them evenly in an agate mortar. Place the mixed material in a quartz tube, vacuum seal the quartz tube using vacuum sealing technology, and then transfer it to a tube furnace. Heat the material to 800℃ at a heating rate of 5℃ / min and hold it at this temperature for 2 h. Then heat it to 1100℃ at a heating rate of 3℃ / min and hold it for 8 h. Finally, slowly cool it to room temperature at a cooling rate of 3℃ / min. The resulting sample is nickel pyrite (Fe,Ni)9S8 with a purity >99%, denoted as nickel pyrite P2.

[0060] Test case

[0061] To characterize the microstructure and morphology of the samples, scanning electron microscopy was performed on nickel pyrite P1 and nickel pyrite P2 samples, and the results are shown in Figure 2.

[0062] Figure 2 shows the SEM images of pyrite P1 and pyrite P2, where a is the SEM image of pyrite P1 and b is the SEM image of pyrite P2. As can be seen from the figure, the pyrite (Fe,Ni)9S8 prepared from pyrite (iron sulfide) or nickel sulfide as raw materials exhibits a relatively uniform particle size distribution under scanning electron microscopy.

[0063] To characterize the composition and atomic or molecular structure or morphology of pyrite P1 and pyrite P2 samples, and to determine their crystal structure, X-ray diffraction (XRD) analysis was performed on the pyrite P1 and pyrite P2 samples after grinding. The results are shown in Figures 3 and 4.

[0064] Figure 3 shows the XRD characterization of nickel pyrite P1. As shown in the figure, the nickel pyrite P1 sample exhibits XRD patterns at 15.19°, 17.56°, 24.93°, 29.32°, 30.66°, 35.55°, 38.86°, 39.91°, 43.91°, 46.72°, 51.15°, 53.68°, 54.50°, 57.72°, 60.06°, 60.82°, and 63.8°. The diffraction peaks at 4°, 66.05°, 66.78°, 69.65°, 71.77°, 75.26°, 77.32°, 78.00°, 80.72°, 82.74°, 83.41°, 86.09°, 88.10°, and 88.77° correspond to (1) in the PDF#01-078-0167 standard card for nickel pyrite. The crystal planes (1 1), (2 0 0), (2 2 0), (3 1 1), (2 2 2), (4 0 0), (3 3 1), (4 2 0), (4 2 2), (5 1 1), (4 4 0), (4 4 2), (5 3 3), (6 2 2), (4 4 4), (7 1 1), (6 40), (6 4 2), (5 5 3), (8 0 0), (7 3 3), (6 4 4), (6 6 0), (7 5 1), (6 6 2), (8 4 0), (75 3), (6 6 4) are shown in the figure. The spectrum indicates that the method successfully prepared nickel pyrite (Fe,Ni)9S8, and no other diffraction peaks can be observed in the figure, indicating that the prepared nickel pyrite has high purity.

[0065] Figure 4 shows the XRD characterization of pyrite P2. The pyrite P2 sample exhibits XRD patterns at 15.19°, 17.56°, 24.93°, 29.32°, 30.66°, 35.55°, 38.86°, 39.91°, 43.91°, 46.72°, 51.15°, 53.68°, 54.50°, 57.72°, 60.06°, 60.82°, and 63.84°. The diffraction peaks at 66.05°, 66.78°, 69.65°, 71.77°, 75.26°, 77.32°, 78.00°, 80.72°, 82.74°, 83.41°, 86.09°, 88.10°, and 88.77° correspond to (1) in the PDF#01-078-0167 standard card for nickel pyrite. The crystal planes (1 1), (2 0 0), (2 2 0), (3 1 1), (2 2 2), (4 0 0), (3 3 1), (4 2 0), (4 2 2), (5 1 1), (4 4 0), (4 4 2), (5 3 3), (6 2 2), (4 4 4), (7 1 1), (6 4 0), (6 4 2), (5 5 3), (8 0 0), (7 3 3), (6 4 4), (6 6 0), (7 5 1), (6 6 2), (8 4 0), (7 5 3), (66 4) are shown in the figure. The spectrum indicates that the method successfully prepared nickel pyrite (Fe,Ni)9S8. The absence of other diffraction peaks in the figure indicates that the prepared nickel pyrite has high purity.

[0066] To characterize the distribution of elements in the sample, energy dispersive spectroscopy was performed on the sample, and the results are shown in Figures 5-6 and Tables 1-2.

[0067] Figure 5 shows the SEM-EDS comprehensive characterization of nickel pyrite P1, where a is the SEM image, b is the morphology image corresponding to the EDS surface scan, c is the EDS sulfur (S) element surface distribution, d is the EDS nickel (Ni) element surface distribution, e is the EDS iron (Fe) element surface distribution, and f is the energy dispersive spectroscopy (EDS) analysis image.

[0068] Table 1. EDS quantitative analysis results of nickel pyrite P1

[0069]

[0070] As shown in Figure 5 and Table 1, the sample contains three elements: S, Fe, and Ni. The relative contents of S, Fe, and Ni are evenly distributed, at 29.72%, 34.27%, and 36.01%, respectively. The Fe / Ni atomic ratio is approximately 1.03, which is close to the theoretical value. This indicates that the prepared pyrite (Fe,Ni)9S8 sample has good dispersibility and high purity.

[0071] Figure 6 shows the SEM-EDS comprehensive characterization of nickel pyrite P2, where a is the SEM image, b is the morphology image corresponding to the EDS surface scan, c is the EDS sulfur (S) element surface distribution, d is the EDS nickel (Ni) element surface distribution, e is the EDS iron (Fe) element surface distribution, and f is the energy dispersive spectroscopy (EDS) analysis image.

[0072] Table 2. EDS quantitative analysis results of nickel pyrite P2

[0073]

[0074] As can be seen from Figure 6 and Table 2, the sample contains three elements: S, Fe, and Ni. The relative contents of S, Fe, and Ni are evenly distributed, at 30.01%, 35.12%, and 34.87%, respectively, which are close to the theoretical values. This indicates that the prepared nickel pyrite (Fe,Ni)9S8 sample has good dispersibility and high purity.

[0075] The technical solution of this invention can be further adapted to industrial mass production. The core bottlenecks and solutions for mass production are shown in Table 3, the key process parameters for industrial scale-up are shown in Table 4, and the product performance is benchmarked against industry requirements in Table 5.

[0076] Table 3 Core Bottlenecks and Solutions for Mass Production

[0077]

[0078] Table 4 Key process parameters for industrial scale-up

[0079]

[0080] In Table 4, the quenching medium is high-purity nitrogen (dew point ≤ -70℃) to avoid oxidation.

[0081] Table 5 Product Performance Benchmarking Against Industry Demand

[0082]

[0083] Table 6 shows a cost comparison between nickel pyrite prepared by the solid-phase synthesis method according to the present invention and nickel pyrite prepared by the conventional sulfur powder method, based on the contents shown in Tables 3-5.

[0084] The preparation steps of the traditional sulfur powder method are as follows:

[0085] Nano-iron powder, nano-nickel powder, and sulfur powder were weighed according to a mass ratio of 100:105:115. After adding anhydrous ethanol, they were ground. The mixture was evenly placed in a mortar and transferred to a tube furnace. Nitrogen gas was introduced through a sealed pipe. The quartz tube was cleaned for 20 minutes. The temperature was increased to 700℃ at a heating rate of 5℃ / min and held for 3 hours. Then, the temperature was increased to 1100℃ at the same heating rate and held for 10 hours. The sample was then annealed to room temperature and removed to obtain the final sample.

[0086] Table 6 Cost Comparison (per ton of product)

[0087]

[0088] Figure 7 is a schematic diagram of the green and safe production design process of the method of this invention. It can be seen that, based on the innovation of the nickel-iron ore synthesis method, the explosion-proof treatment and recovery of high-temperature sulfur vapor in industrial production will no longer be a priority. A certain proportion of nickel powder, iron powder, and sulfur source (nickel sulfide or iron sulfide) are ground uniformly in a high-energy ball mill → the raw materials are vacuum-treated in a vacuum induction furnace and sealed in a tube → the product is obtained through programmed heating and cooling. This includes a gas quenching system, which effectively improves the purity of the synthesized nickel-pyrite.

[0089] The nickel pyrite synthesized by the solid-state method of this invention can be used in the field of new energy batteries to prepare nickel pyrite / graphene composite electrodes with a specific capacity of 420 mAh / g (0.2C), replacing 20% ​​of commercial Pt / C catalysts and reducing the cost of the battery stack by 35%. The steps are as follows:

[0090] The nickel pyrite synthesized by the solid-state method of this invention has high purity and can be used as a synthetic mineral to replace natural ore in mineral standardization applications (ASTM B39-06), with purity increasing from 92% to 99.5%; MgO impurities are <100ppm (natural ore >2000ppm). Through industrial adaptation as shown in Tables 3-5, this invention reduces the synthesis cost of nickel pyrite to $28.5 / kg (compared to international similar materials >$120 / kg), completely opening up a closed loop from laboratory innovation to industrial application.

[0091] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0092] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing nickel pyrite synthesized by solid-state method, characterized in that the steps include... include: The nickel pyrite was obtained by multi-stage high-temperature solid-phase reaction treatment using iron powder, nickel powder and sulfur source as reactants. The sulfur source includes iron sulfide or nickel sulfide; The multi-stage high-temperature solid-state reaction treatment includes: heating to 700-800℃ at a heating rate of 1-5℃ / min, holding at that temperature for 1-4 hours, then heating to 1000-1500℃ at a heating rate of 1-5℃ / min, holding at that temperature for 4-14 hours; and finally, cooling to 20-30℃ at a cooling rate of 1-3℃ / min.

2. The preparation method according to claim 1, characterized in that, When the sulfur source is iron sulfide, the amount of iron powder used is 4.6-8.8 wt% of the mass of the iron sulfide.

3. The preparation method according to claim 1, characterized in that, When the sulfur source is iron sulfide, the amount of nickel powder used is 43.5-68.5 wt% of the mass of the iron sulfide.

4. The preparation method according to claim 1, characterized in that, When the sulfur source is nickel sulfide, the amount of iron powder used is 45-60 wt% of the mass of nickel sulfide.

5. The preparation method according to claim 1, characterized in that, When the sulfur source is nickel sulfide, the amount of nickel powder used is 5.2-7.2 wt% of the mass of the nickel sulfide.

6. The preparation method according to claim 1, characterized in that, The iron sulfide is pyrite and / or ferrous disulfide with a purity >99%; the nickel sulfide has a purity >99%.

7. A nickel pyrite prepared by any one of claims 1-6.

8. The application of the nickel pyrite according to claim 7 in the field of hydrogen evolution electrocatalysis or in the preparation of new energy batteries.

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