Process for the preparation of a cobalt (phosphorus) sulphide compound of the pyrite type

Abstract

The present application belongs to the technical field of transition metal compound material, chemical vapor deposition preparation technology and multi-anion regulated functional material, and specifically discloses a preparation method of pyrite type cobalt (phosphorus) sulfide compound. The preparation method uses a tube furnace as a reaction device, and makes the source and the cobalt source arranged in the same heating environment respectively, so that the deposition substrate reacts to generate cobalt (phosphorus) sulfide compounds with different phosphorus-sulfur ratios under the controlled gas phase chemical potential. The present application uses the above-mentioned preparation method of pyrite type cobalt (phosphorus) sulfide compound, takes pyrite type CoS2 as a parent phase, and realizes the controllable preparation method of CoS2, Co2PS3, CoPS and other cobalt (phosphorus) sulfide compounds with different compositions by regulating the gas phase phosphorus and sulfur chemical potential in the same chemical vapor deposition process system. The obtained material has high purity and structural integrity, thereby solving the problems of unregulated composition, insufficient phase stability and poor preparation consistency in the prior art.

Description

Technical Field

[0001] This invention belongs to the technical fields of transition metal compound materials, chemical vapor deposition preparation technology and multi-anion-controlled functional materials, specifically relating to a method for preparing pyrite-type cobalt (phosphorus) sulfur compounds. Background Technology

[0002] Transition-metal phosphorosulfides (TMPs) have attracted widespread attention in electrocatalysis, water splitting, energy storage and conversion, and electronic materials due to their combination of anionic chemical properties of phosphides and sulfides. Existing technologies indicate that materials formed by transition metals (such as Co, Fe, and Ni) with sulfur and phosphorus can improve catalytic activity and material stability by altering bond covalentity, electronic band structure, and local coordination environment. However, current research on TMPs largely focuses on single-component or local anion modulation. Furthermore, most preparation methods employ solid-phase or solution-phase pathways, which, due to limitations in reaction uniformity, kinetics, and diffusion behavior, make it difficult to achieve structurally intact and highly pure Co-PS compounds.

[0003] Among existing transition metal chalcogenides, pyrite-type CoS2 possesses a stable three-dimensional framework and S2... 2- Dimeric anions, whose structural topology can be considered as being formed by the interlocking of specific pentagonal units. According to literature reports, monolayer CoS2 and its derivative CoAsS have a Cairo tessellation pentagonal interlocking atomic arrangement, and the integrity of the overall topological structure can be maintained through heterogeneous anion substitution. Phonon spectrum analysis in the literature also shows that such pentagonal substrate structures have good kinetic stability and can tolerate local bond length changes caused by anion substitution without destroying the overall lattice continuity. The above characteristics indicate that the pentagonal interlocking pyrite-type framework has high anion tolerance and can be used as an effective template for P-step substitution of S. However, existing research on Co-PS compounds mainly focuses on: (1) single composition prepared by solid-phase or solution-phase methods; (2) subsequent phosphating / sulfidation reactions using CoS2 or CoP as starting materials; (3) forming heterogeneous materials with core-shell or composite forms.

[0004] Existing methods for preparing transition metal phosphorus and sulfur compounds generally rely on solid-phase phosphating, sulfidation, or solution processing. The resulting materials typically suffer from problems such as uncontrollable composition, low phase purity, non-uniform crystal structure, and difficulty in maintaining the stability of the pyrite framework. Therefore, the above-mentioned preparation methods generally have the following limitations: (1) They cannot achieve the synthesis of compounds with different composition ratios; (2) Phase purity is difficult to guarantee: post-treatment phosphating / sulfidation usually leads to surface modification rather than a uniform transformation of the overall crystal structure, which easily results in multiphase coexistence; (3) The material structure is limited to nano-aggregates, making it difficult to conduct systematic physical property studies.

[0005] In particular, for pyrite-type systems using CoS2 as a structural template, current technologies cannot controllably obtain a series of compounds with different phosphorus-sulfur ratios while maintaining the integrity of their topological framework. This makes it difficult to conduct systematic structure-property correlation studies on the materials and also hinders their application optimization in catalysis and electronic devices.

[0006] Furthermore, although pentagonal structures have been predicted to possess good anion tunability and structural stability, existing literature lacks a method for constructing Co-PS compounds using a pentagonal / pyrite framework under chemical vapor deposition conditions. Therefore, a technical solution is currently lacking that can precisely control the phosphorus and sulfur chemical potentials in a single step and, using the CoS2 pentagonal topology as a template, achieve highly crystallinity and variable composition pyrite-type Co-PS compounds.

[0007] Given the shortcomings of the existing technologies, there is an urgent need in this field for a new preparation method that can synthesize stable transition metal (phosphorus) sulfur compounds with different P / S ratios by controlling the anionic composition through chemical vapor deposition while maintaining the integrity of the pyrite / pentagonal topological framework, so as to provide for subsequent systematic research and application of structure, electronic and catalytic properties. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing pyrite-type cobalt (phosphorus) sulfur compounds. Using pyrite-type CoS2 as the parent phase, under the same chemical vapor deposition (CVD) process system, by controlling the chemical potential of phosphorus and sulfur in the gas phase, a controllable preparation method for cobalt (phosphorus) sulfur compounds with different compositions such as CoS2, Co2PS3, and CoPS can be achieved. This results in materials with high purity and structural integrity, thereby solving the problems of uncontrollable composition, insufficient phase stability, and poor preparation consistency in the prior art.

[0009] To achieve the above objectives, the present invention provides a method for preparing pyrite-type cobalt (phosphorus) sulfur compounds. The method uses a tube furnace as a reaction device and arranges the source and cobalt source separately in the same heating environment to generate cobalt (phosphorus) sulfur compounds with different phosphorus-sulfur ratios by reacting the deposited substrate under controlled gas phase chemical potential. Among them, cobalt (phosphorus) sulfur compounds include cobalt disulfide, cobalt diphosphorus sulfur tri, and cobalt phosphorus sulfur.

[0010] Preferably, it includes the following steps: Step S1: Select cobalt source, supply source, and deposit substrate; Step S2: Arrange the cobalt source, supply the source, and deposit the substrate; Step S3: Adjust the relative distance between the cobalt source and the supply source to carry out the deposition reaction and generate the target product; achieve controllable adjustment of the partial pressure ratio of phosphorus vapor and sulfur vapor, thereby selectively obtaining pyrite-type cobalt (phosphorus) sulfur compounds with different stoichiometric ratios under the same process system; Step S4: After the deposition reaction is completed, the target product is cooled using a controlled cooling procedure to fix the material structure and suppress compositional deviation, so that the obtained thin film or solid sample maintains the target stoichiometry and structural stability, that is, selectively obtain pyrite-type cobalt (phosphorus) sulfur compounds with different stoichiometry. The obtained product preferably has a pyrite-type crystal framework or maintains a topological structure similar to that of pyrite.

[0011] Preferably, in step S1, a SiO2 / Si substrate is selected as the deposition substrate, and its thickness is 200 nm. When preparing cobalt disulfide, the cobalt source is 10-20 mg of cobalt dichloride (CoCl2), which can be adjusted according to the pipe diameter, airflow, and target thickness; the supply source is 150-200 mg of sulfur powder, which can be adjusted according to the pipe diameter, airflow, and target thickness. When preparing cobalt phosphorus sulfur or cobalt diphosphorus sulfur, the cobalt source is 10-20 mg of cobalt dichloride (CoCl2); the source is a phosphorus / sulfur composite source of 50-100 mg of red phosphorus and 150-300 mg of phosphorus pentasulfide (P2S5) in uniform mixture.

[0012] Preferably, in step S2, an upstream supply zone and a downstream reaction deposition zone are set in the tubular furnace. The temperature of the upstream supply zone is lower than that of the downstream reaction deposition zone, which allows the supply to sublimate / decompose at a controlled rate, forming a stable P / S (or S only) gas phase flux.

[0013] Preferably, step S2 specifically involves: placing the polished surface of the deposition substrate downwards above the graphite boat carrying the cobalt source, and arranging it in the downstream reaction deposition zone to facilitate thin-layer deposition; and arranging the quartz boat carrying the source in the upstream source supply zone.

[0014] Preferably, in step S3, When preparing cobalt disulfide, the relative (axial) distance between the cobalt source and the source donor is 13-14 cm; When preparing cobalt diphosphorus sulfur tri, the relative (axial) distance between the cobalt source and the source donor is 9-10 cm; When preparing cobalt-phosphorus-sulfur, the relative (axial) distance between the cobalt source and the supply source is 7-8 cm.

[0015] Preferably, in step S3, the deposition reaction specifically includes: A. Introduce 100-200 sccm of inert carrier gas into the reaction apparatus and maintain it for 10-15 minutes to remove air and water vapor from the tubes of the reaction apparatus. The inert carrier gas includes argon (Ar) to form a stable reaction atmosphere; B. Under the condition of continuous inert carrier gas supply, the temperature is increased to the target reaction temperature of 650-750℃ at a rate of 40-50℃ / min; C. Maintain a constant temperature at the target temperature for 8-12 minutes to allow the gaseous components generated by the source to react with the cobalt source in a gas / solid phase and deposit the target product on the surface of the deposition substrate.

[0016] Preferably, step S4 specifically involves: after the deposition reaction is completed, turning off the heating power supply and allowing it to cool naturally to 22-26°C under the protection of an inert carrier gas, thereby obtaining a pyrite-type cobalt (phosphorus) sulfur compound.

[0017] The present invention employs the above-mentioned method for preparing a pyrite-type cobalt (phosphorus) sulfide compound, and has the following beneficial effects: (1) Achieving tunable composition of cobalt (phosphorus) sulfides: By employing a controlled gas-phase chemical potential adjustment method, this invention can obtain a series of stable compounds from S-rich to P-rich within the same pyrite topology, allowing for variations in material composition rather than the single composition found in existing technologies. This method solves the problem of precisely controlling the phosphorus-sulfur ratio in existing solid-phase / solution methods, providing a reproducible sample basis for systematic structure-property studies of materials.

[0018] (2) The obtained material has high phase purity and good crystal integrity: The preparation method in this invention has both the adjustability of material stoichiometry and the ability to maintain the target crystal structure (such as pyrite-type structure). The obtained compound exhibits clear and stable crystal structure characteristics in Raman, EDS and STEM characterization, which shows that the process of this invention can effectively suppress the generation of non-target phases and improve the structural uniformity and reproducibility of the material.

[0019] (3) Enhancing the electronic structure tunability and application adaptability of materials: Due to the adjustment of the P / S ratio, the compounds obtained in this invention can exhibit predictable differences in electronic structure with changes in composition. This effect provides a direct basis for subsequent performance optimization in fields such as electrocatalysis, energy storage, and electrochemical devices.

[0020] (4) The process has high repeatability and scalability: This invention controls the material composition through quantifiable reaction parameters (such as precursor flow rate, temperature distribution, and chemical potential gradient), giving the preparation process advantages such as high operability and scalability. Compared with the traditional solid-phase phosphating / sulfurization method, this invention has significant improvements in terms of time, material utilization rate, and controllability of the generated phase, which can reduce production costs and enhance industrialization potential.

[0021] (5) It provides a new material platform with significant scientific research and application value: By establishing a complete series of cobalt (phosphorus) sulfur compounds, this invention provides a new research system for exploring the role of multi-anion regulation strategies in energy catalysis, energy storage materials and electronic devices, which can promote subsequent mechanism research and application development, and has positive technical and social benefits.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a tubular furnace in an embodiment of a method for preparing pyrite-type cobalt (phosphorus) sulfide compounds according to the present invention; Figure 2 The image shows optical microscope (OM) images of CoS2, Co2PS3, and CoPS in an experimental example of a method for preparing pyrite-type cobalt (phosphorus) sulfur compounds according to the present invention; where a is CoS2, b is Co2PS3, and c is CoPS. Figure 3 The images show the Raman spectra of CoS2, Co2PS3, and CoPS in an experimental example of a method for preparing pyrite-type cobalt (phosphorus) sulfur compounds according to the present invention; where a is CoS2, b is Co2PS3, and c is CoPS. Figure 4 The image shows the EDS diagrams of CoS2, Co2PS3, and CoPS in an experimental example of a method for preparing pyrite-type cobalt (phosphorus) sulfur compounds according to the present invention; where a is CoS2, b is Co2PS3, and c is CoPS. Figure 5 The atomic structure diagram of CoS2 in the experimental example of the preparation method of pyrite-type cobalt (phosphorus) sulfur compound of the present invention is shown below; where a is the atomic-scale STEM image of CoS2 along the

[001] direction, with an atomic model superimposed, b is the experimental (Exp.) and simulated (Sim.) diffraction pattern obtained from a, c is a comparison of experimental and simulated ADF-STEM images, d is the atomic-scale STEM image of CoS2 along the

[101] direction, and e is the atomic-scale STEM image of CoS2 along the

[112] direction. Figure 6The atomic structure diagrams of Co2PS3 and CoPS in the experimental example of the preparation method of pyrite-type cobalt (phosphorus) sulfur compound of the present invention are shown below; where a is the STEM image of Co2PS3 along the

[101] and

[112] directions, b is the STEM image of CoPS along the

[101] and

[112] directions, c is the elemental mapping result of Co2PS3, and d is the elemental mapping result of CoPS. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0026] like Figure 1 As shown, the reaction apparatus in this embodiment of the invention comprises: a single-temperature zone tube furnace; a quartz reaction tube with an inner diameter of approximately 25 mm; a quartz boat as the source support vessel in the upstream source supply zone; a graphite boat as the cobalt source support vessel in the downstream reaction deposition zone; the temperature in the upstream source supply zone is lower than that in the downstream reaction deposition zone; and a gas delivery system (mass flow controller, carrier gas pipeline, and exhaust gas treatment).

[0027] Example 1 A method for preparing pyrite-type CoS2 includes the following steps: Step S1: Select a SiO2 / Si substrate as the deposition substrate, with a thickness of 200 nm. Before use, the SiO2 / Si substrate can be cleaned with acetone / isopropanol / deionized water and dried. Add 15 mg of cobalt dichloride to the graphite boat as a cobalt source. Add 170 mg of sulfur powder to the quartz boat as a sulfur source.

[0028] Step S2: Place the polished surface of the deposition substrate downwards on top of the graphite boat carrying the cobalt source, and position it in the downstream reaction deposition zone. Position the quartz boat carrying the source in the upstream source supply zone.

[0029] Step S3: Adjust the relative distance between the cobalt source and the cobalt supply to 14 cm, and carry out the deposition reaction: A. Introduce 150 sccm of argon gas into the reaction apparatus and maintain it for 10 minutes to remove air and water vapor from the tubes of the reaction apparatus.

[0030] B. Under the condition of continuous argon gas supply, the temperature is increased to 700℃ at a rate of 45℃ / min.

[0031] C. Maintain a constant temperature of 700℃ for 10 minutes to allow the gaseous components generated by the source to undergo a gas-phase / solid-phase reaction with the cobalt source and deposit the target product on the surface of the deposition substrate.

[0032] Step S4: After the deposition reaction is completed, turn off the heating power supply and allow the target product to cool naturally to 25°C under argon protection. A thin layer of CoS2 is obtained on the surface of the deposition substrate, which is pyrite-type CoS2.

[0033] The relative distance in this embodiment can be appropriately adjusted according to the furnace temperature distribution, pipe diameter, carrier gas flow rate and target deposition thickness. For example, it can be finely adjusted within the range of ±1cm, and the corresponding target phase or similar composition product can still be obtained.

[0034] Example 2 A method for preparing pyrite-type Co2PS3 includes the following steps: Step S1: Select a SiO2 / Si substrate as the deposition substrate, with a thickness of 200 nm. Before use, the SiO2 / Si substrate can be cleaned with acetone / isopropanol / deionized water and dried. Add 15 mg of cobalt dichloride to the graphite boat as a cobalt source. Add 70 mg of red phosphorus and 225 mg of P2S5 to the quartz boat and mix thoroughly and evenly as a phosphorus / sulfur source.

[0035] Step S2: Place the polished surface of the deposition substrate downwards above the graphite boat carrying the cobalt source, and position it in the downstream reaction deposition zone. Position the quartz boat carrying the phosphorus / sulfur source in the upstream source supply zone.

[0036] Step S3: Adjust the relative distance between the cobalt source and the cobalt supply to 10 cm, and carry out the deposition reaction: A. Introduce 150 sccm of argon gas into the reaction apparatus and maintain it for 10 minutes to remove air and water vapor from the tubes of the reaction apparatus.

[0037] B. Under the condition of continuous argon gas supply, the temperature is increased to 700℃ at a rate of 45℃ / min.

[0038] C. Maintain a constant temperature of 700℃ for 10 minutes to allow the gaseous components generated by the source to undergo a gas-phase / solid-phase reaction with the cobalt source and deposit the target product on the surface of the deposition substrate.

[0039] Step S4: After the deposition reaction is completed, turn off the heating power supply and allow the target product to cool naturally to 25°C under argon protection. Co2PS3 deposits are obtained on the surface of the deposition substrate, which is pyrite-type Co2PS3.

[0040] In this embodiment, the relative distance can be appropriately adjusted according to the furnace temperature distribution, pipe diameter, carrier gas flow rate, and target deposition thickness. For example, fine-tuning within ±1 cm can still obtain the corresponding target phase or a product with a similar composition. Furthermore, because the source is closer to the reaction deposition zone in this embodiment, the source temperature is higher, and the volatilization / decomposition flux is greater, a different gas phase partial pressure ratio and final stoichiometry can be achieved compared to the Co2PS3 prepared in Example 2.

[0041] Example 3 A method for preparing pyrite-type CoPS includes the following steps: Step S1: Select a SiO2 / Si substrate as the deposition substrate, with a thickness of 200 nm. Before use, the SiO2 / Si substrate can be cleaned with acetone / isopropanol / deionized water and dried. Add 15 mg of cobalt dichloride to the graphite boat as a cobalt source. Add 70 mg of red phosphorus and 225 mg of P2S5 to the quartz boat and mix thoroughly and evenly as a phosphorus / sulfur source.

[0042] Step S2: Place the polished surface of the deposition substrate downwards above the graphite boat carrying the cobalt source, and position it in the downstream reaction deposition zone. Position the quartz boat carrying the phosphorus / sulfur source in the upstream source supply zone.

[0043] Step S3: Adjust the relative distance between the cobalt source and the cobalt supply to 8 cm, and carry out the deposition reaction: A. Introduce 150 sccm of argon gas into the reaction apparatus and maintain it for 10 minutes to remove air and water vapor from the tubes of the reaction apparatus.

[0044] B. Under the condition of continuous argon gas supply, the temperature is increased to 700℃ at a rate of 45℃ / min.

[0045] C. Maintain a constant temperature of 700℃ for 10 minutes to allow the gaseous components generated by the source to undergo a gas-phase / solid-phase reaction with the cobalt source and deposit the target product on the surface of the deposition substrate.

[0046] Step S4: After the deposition reaction is completed, turn off the heating power supply and allow the target product to cool naturally to 25°C under argon protection. CoPS deposits are obtained on the surface of the deposition substrate, which is pyrite-type CoPS.

[0047] The relative distance in this embodiment can be appropriately adjusted according to the furnace temperature distribution, pipe diameter, carrier gas flow rate and target deposition thickness. For example, it can be finely adjusted within the range of ±1cm, and the corresponding target phase or similar composition product can still be obtained.

[0048] Experimental Example The CoS2, Co2PS3, and CoPS prepared in Examples 1-3 were characterized in terms of structure and composition.

[0049] like Figure 2 As shown, all compounds exhibit individual triangular morphologies, which is due to the dominant growth surface of cobalt (phosphorus) sulfur compounds being the

[111] band axis.

[0050] like Figure 3 As shown, in the Raman spectrum of CoS2, it can be observed at approximately 288 cm⁻¹. -1 315cm -1 and 390cm-1 Three distinct peaks were observed at the position. For the Co2PS3 sample, the Raman spectrum showed a peak at approximately 194 cm⁻¹. -1 214cm -1 298cm -1 327cm -1 371cm -1 400cm -1 and 430cm -1 Multiple characteristic peaks appeared at approximately 321 cm⁻¹. For the CoPS sample, the peaks were at approximately 321 cm⁻¹. -1 and 427cm -1 Two main peaks appeared at that location.

[0051] The aforementioned Raman characteristic peaks can be used to confirm the lattice vibration information of different compounds and reflect their mode characteristics related to pyrite-type structures.

[0052] like Figure 4 As shown, energy-dispersive X-ray spectroscopy (EDS) was used to determine the elemental composition of different products. The results showed that the atomic ratio of cobalt to sulfur in the obtained CoS2 sample was approximately 1:2. The atomic ratio of cobalt, phosphorus, and sulfur in the obtained Co2PS3 sample was approximately 2:1:3. The atomic ratio of cobalt, phosphorus, and sulfur in the obtained CoPS sample was approximately 1:1:1.

[0053] The results show that the elemental composition of each compound is basically consistent with its target stoichiometry, and can be used to confirm the compositional formation of different cobalt (phosphorus) sulfur compounds.

[0054] like Figure 5 As shown, aberration-corrected scanning transmission electron microscopy (STEM) was used to characterize the atomic structure of CoS2. Z-contrast images obtained using high-angle annular dark-field (HAADF) mode can distinguish the positions of different atomic pillars, with cobalt atoms appearing brighter in the image due to their higher atomic number.

[0055] like Figure 5 As shown in a, when viewed from the

[001] crystal orientation, an atomic arrangement consisting of S-Co-S can be seen, and its position corresponds to the superimposed atomic model. For example... Figure 5 As shown in b, the Fast Fourier Transform (FFT) plot of the corresponding image shows clear diffraction spots, and their distribution is consistent with the simulated diffraction. Figure 1 The alignment indicates that the sample has good crystal orientation characteristics. Furthermore, as... Figure 5 As shown in c, the intensity contrast of different atomic pillars in the HAADF image is consistent with the theoretical Z-contrast difference between Co and S in CoS2. Figure 5 d- Figure 5As shown in e, the other crystal structure features observed along the axis are consistent with the expected crystal structure of CoS2.

[0056] like Figure 6 As shown, atomic-resolution STEM images of Co2PS3 and CoPS samples, along with their corresponding elemental mapping results, are presented. Figure 6 a- Figure 6 As shown in b, the atomic arrangements of Co2PS3 and CoPS obtained from the high angle annular dark field (HAADF) mode show that both exhibit a periodic atomic framework structure similar to that of pyrite-type CoS2. Their lattices show regularly distributed bright atomic pillars in the

[101] and

[112] crystal directions, indicating that the three share a similar parent crystal framework.

[0057] To further distinguish the elemental distribution characteristics of different compounds, such as Figure 6 c- Figure 6 As shown in d, atomic-level elemental mapping analysis was performed on Co₂PS₃ and CoPS. In Co₂PS₃, the distribution of P and S exhibits a different site occupancy pattern than in CoPS.

[0058] The above atomic-level structure and elemental mapping results show that although Co2PS3 and CoPS retain a pyrite-type lattice framework similar to CoS2, the configuration of their anionic (P / S) components has changed, thus forming different atomic-level structural features that can be distinguished by STEM–EDS technology.

[0059] In summary, the comparison confirms that the crystal frameworks of CoS2, Co2PS3 and CoPS can maintain structural characteristics similar to those of pyrite. At the same time, EDS shows that there are significant differences in P / S content and distribution, thus confirming that their stoichiometry is different.

[0060] Therefore, the present invention employs the above-mentioned method for preparing pyrite-type cobalt (phosphorus) sulfur compounds, using pyrite-type CoS2 as the parent phase, and under the same chemical vapor deposition (CVD) process system, by controlling the chemical potential of phosphorus and sulfur in the gas phase, a controllable preparation method for cobalt (phosphorus) sulfur compounds with different compositions such as CoS2, Co2PS3, and CoPS is achieved, so that the obtained materials have high purity and structural integrity, thereby solving the problems of uncontrollable composition, insufficient phase stability, and poor preparation consistency in the prior art.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a pyrite-type cobalt (phosphorus) sulfide compound, characterized in that: The preparation method uses a tube furnace as a reaction device. By arranging the power source and cobalt source separately in the same heating environment, the deposition substrate reacts under controlled gas phase chemical potential to generate cobalt (phosphorus) sulfur compounds with different phosphorus-sulfur ratios. Among them, cobalt (phosphorus) sulfur compounds include cobalt disulfide, cobalt diphosphorus sulfur tri, and cobalt phosphorus sulfur.

2. The method for preparing a pyrite-type cobalt (phosphorus) sulfide compound according to claim 1, characterized in that, Includes the following steps: Step S1: Select cobalt source, supply source, and deposit substrate; Step S2: Arrange the cobalt source, supply the source, and deposit the substrate; Step S3: Adjust the relative distance between the cobalt source and the cobalt supply to carry out the deposition reaction and generate the target product; Step S4: After the deposition reaction is completed, the target product is cooled to selectively obtain pyrite-type cobalt (phosphorus) sulfur compounds with different stoichiometric ratios.

3. The method for preparing a pyrite-type cobalt (phosphorus) sulfide compound according to claim 2, characterized in that: In step S1, a SiO2 / Si substrate is selected as the deposition substrate, with a thickness of 200 nm; When preparing cobalt disulfide, the cobalt source is 10-20 mg of cobalt dichloride; the feed source is 150-200 mg of sulfur powder. When preparing cobalt phosphorus sulfur or cobalt diphosphorus sulfur, the cobalt source is 10-20 mg of cobalt dichloride; the source is a phosphorus / sulfur composite source consisting of 50-100 mg of red phosphorus and 150-300 mg of phosphorus pentasulfide.

4. The method for preparing a pyrite-type cobalt (phosphorus) sulfide compound according to claim 2, characterized in that: In step S2, an upstream supply zone and a downstream reaction deposition zone are set up inside the tubular furnace, with the temperature of the upstream supply zone being lower than that of the downstream reaction deposition zone.

5. The method for preparing a pyrite-type cobalt (phosphorus) sulfide compound according to claim 4, characterized in that, Step S2 specifically involves placing the polished surface of the deposition substrate downwards above the graphite boat carrying the cobalt source and arranging it in the downstream reaction deposition zone; and arranging the quartz boat carrying the source in the upstream source supply zone.

6. The method for preparing a pyrite-type cobalt (phosphorus) sulfide compound according to claim 2, characterized in that: In step S3, When preparing cobalt disulfide, the relative distance between the cobalt source and the cobalt supply is 13-14 cm; When preparing cobalt diphosphorus sulfur trioxide, the relative distance between the cobalt source and the supply source is 9-10 cm; When preparing cobalt-phosphorus-sulfur, the relative distance between the cobalt source and the supply source is 7-8 cm.

7. The method for preparing a pyrite-type cobalt (phosphorus) sulfide compound according to claim 6, characterized in that, In step S3, the deposition reaction specifically involves: A. Introduce 100-200 sccm of inert carrier gas into the reaction apparatus and maintain it for 10-15 minutes to remove air and water vapor from the tubes of the reaction apparatus. Among them, the inert carrier gas includes argon; B. Under the condition of continuous inert carrier gas supply, the temperature is increased to the target reaction temperature of 650-750℃ at a rate of 40-50℃ / min; C. Maintain a constant temperature at the target temperature for 8-12 minutes to allow the gaseous components generated by the source to react with the cobalt source in a gas / solid phase and deposit the target product on the surface of the deposition substrate.

8. The method for preparing a pyrite-type cobalt (phosphorus) sulfide compound according to claim 2, characterized in that, Step S4 specifically involves turning off the heating power supply after the deposition reaction is completed, and allowing the mixture to cool naturally to 22-26°C under the protection of an inert carrier gas, thereby obtaining pyrite-type cobalt (phosphorus) sulfur compounds.

Images