Co9S8 composite material as well as preparation method and application thereof
By preparing a core-shell structured Co9S8 composite material, the problem of easy failure of existing OER catalysts under high current density was solved, and the high spin state electron transfer capability was achieved, which improved the electrocatalytic oxygen evolution performance and stability, making it suitable as an anode material for water electrolysis reaction.
Patent Information
- Application Number
- CN202511275060.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-08
- Publication Date
- 2025-11-14
AI Technical Summary
Existing OER catalysts, such as platinum-based materials and transition metal oxides, are prone to failure or performance degradation at high current densities, and the catalytic activity of Co9S8 materials still needs to be further improved.
A core-shell Co9S8 composite material, with Co9S8 as the core and sodium dodecyl sulfate as the shell, is prepared by a solvothermal method. The specific steps include mixing, solvothermal reaction, cooling, centrifugation, drying and grinding to form a high-spin Co9S8 composite material.
It achieves rapid electron transfer capability, exhibits excellent electrocatalytic oxygen evolution performance and stability, and is suitable as an anode material for water electrolysis reaction.
Smart Images
Figure CN120945407A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of oxygen evolution electrode material technology, specifically relating to a Co9S8 composite material, its preparation method and its application. Background Technology
[0002] The oxygen evolution reaction (OER) is a crucial process in water splitting, directly impacting the efficiency of electrocatalytic water splitting. Existing OER catalysts are mostly platinum-based materials, transition metal oxides, and sulfides, but these materials still have shortcomings in catalytic performance and stability. For example, platinum-based catalysts are prone to failure at high current densities, and transition metal oxides have poor conductivity and are prone to performance degradation at high potentials. To improve catalytic performance and durability, researchers have explored transition metal sulfide materials with high spin states. These materials, due to their unique electronic structure, can provide more active sites, thereby improving catalytic activity. Co9S8, as the transition metal sulfide with the highest metal content, has become a popular choice for OER catalyst research due to its excellent conductivity, stability, and high catalytic activity.
[0003] Although Co9S8 material has shown good catalytic performance in OER, its preparation process and performance optimization still face certain challenges. For example, the catalytic activity of Co9S8 material still needs to be further improved.
[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0005] The purpose of this invention is to provide a Co9S8 composite material, its preparation method and its application, which exhibits excellent electrocatalytic oxygen evolution performance and has excellent catalytic activity.
[0006] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution: a Co9S8 composite material, wherein the Co9S8 composite material has a core-shell structure, the Co9S8 composite material includes a core layer and a shell layer covering the core layer, wherein the core layer is Co9S8 and the shell layer is sodium dodecyl sulfate.
[0007] A specific embodiment of the present invention also provides a method for preparing the Co9S8 composite material as described above, comprising the following steps:
[0008] A mixed solution was obtained by thoroughly mixing a divalent cobalt source, thiourea, sodium dodecyl sulfate, and an organic solvent.
[0009] The mixed solution was subjected to a solvothermal reaction to obtain the Co9S8 composite material.
[0010] In one or more embodiments of the present invention, the temperature of the solvothermal reaction is 180~200°C, and the time of the solvothermal reaction is 10~14h.
[0011] In one or more embodiments of the present invention, the preparation method further includes: sequentially cooling, centrifuging, drying and grinding the mixed product after solvothermal reaction to obtain the Co9S8 composite material.
[0012] In one or more embodiments of the present invention, the centrifugation speed is 6000~8000 r / min and the time is 30~60 min;
[0013] The drying process is called baking, and the baking temperature is 50~70℃, and the baking time is 10~12h.
[0014] In one or more embodiments of the present invention, the divalent cobalt source is at least one of cobalt sulfate, cobalt nitrate, and cobalt acetate.
[0015] In one or more embodiments of the present invention, the mass ratio of the divalent cobalt source to thiourea is (1~2.03):1;
[0016] The mass ratio of the divalent cobalt source to sodium dodecyl sulfate is (1.975~3.95):1.
[0017] In one or more embodiments of the present invention, the organic solvent is ethylene glycol and N,N-dimethylformamide, wherein the volume ratio of ethylene glycol to N,N-dimethylformamide is 1:(3~5); or,
[0018] The organic solvent is ethylene glycol and N,N-dimethylacetamide, and the volume ratio of ethylene glycol to N,N-dimethylacetamide is 1:(3~5).
[0019] In one or more embodiments of the present invention, the step of uniformly mixing the divalent cobalt source, thiourea, sodium dodecyl sulfate, and organic solvent specifically includes:
[0020] The above mixture was then subjected to stirring and ultrasonic treatment in sequence;
[0021] The stirring speed is 500~800 r / min, and the time is 20~40 min; the ultrasonic power is 80~100W, and the time is 60~90 min.
[0022] A specific embodiment of the present invention also provides the application of the Co9S8 composite material as described above in the electrode material of the oxygen evolution reaction.
[0023] Compared with the prior art, the Co9S8 composite material, its preparation method and its application of the present invention have a faster electron transfer capability, thus exhibiting excellent electrocatalytic oxygen evolution performance. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a scanning electron microscope image of the Co9S8 material prepared in Comparative Example 1 of the present invention;
[0026] Figure 2 A scanning electron microscope image of the Co9S8 composite material prepared in Example 1 of the present invention;
[0027] Figure 3 XRD patterns of the materials prepared in Comparative Example 1, Example 1 and Example 2 of the present invention;
[0028] Figure 4 Electron spin resonance diagrams of the Co9S8 material prepared in Comparative Example 1 and the Co9S8 composite material prepared in Example 1 of the present invention;
[0029] Figure 5 Linear scan voltammetry curves of the materials prepared in Comparative Example 1, Example 1, and Example 2 of the present invention;
[0030] Figure 6 The chronopotential curve of the Co9S8 composite material prepared in Example 1 of the present invention is shown.
[0031] Figure 7 A scanning electron microscope image of the Co9S8 composite material prepared in Example 2 of the present invention;
[0032] Figure 8 The image shows a scanning electron microscope (SEM) image of the Co9S8 composite material prepared in Example 3 of this invention. Detailed Implementation
[0033] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.
[0034] In one example of the present invention, the Co9S8 composite material has a core-shell structure. The Co9S8 composite material includes a core layer and a shell layer covering the core layer. The core layer is Co9S8 (cobalt octasulfide), and the shell layer is sodium dodecyl sulfate.
[0035] It should be noted that, due to the extremely high coordination ratio of octahedral cobalt in Co9S8, its spin state tends to transition to a low-spin state. This creates a spin-forbidden effect on the subsequent charge transfer process, suppressing charge jumps. Since the Co9S8 composite material of this invention is a high-spin Co9S8 composite material, it possesses a faster electron transfer capability, which helps enhance electron jumping ability, thus exhibiting excellent electrocatalytic oxygen evolution performance.
[0036] A specific example of the present invention also provides a method for preparing the Co9S8 composite material as described above, comprising the following steps:
[0037] S1. Mix the divalent cobalt source, thiourea, sodium dodecyl sulfate and organic solvent evenly to obtain a mixed solution.
[0038] Specifically, in step S1, the divalent cobalt source is at least one of cobalt sulfate, cobalt nitrate, and cobalt acetate. The mass ratio of the divalent cobalt source to thiourea is (1~2.03):1. The mass ratio of the divalent cobalt source to sodium dodecyl sulfate is (1.975~3.95):1. The amount of organic solvent can be selected according to requirements; for example, the volume ratio of the divalent cobalt source to the solvent can be 790 mg: (70~120) ml.
[0039] The organic solvent is ethylene glycol and N,N-dimethylformamide, with a volume ratio of ethylene glycol to N,N-dimethylformamide of 1:(3~5); or, the organic solvent is ethylene glycol and N,N-dimethylacetamide, with a volume ratio of ethylene glycol to N,N-dimethylacetamide of 1:(3~5). N,N-dimethylformamide and N,N-dimethylacetamide promote nucleation of the substance during the reaction, while ethylene glycol promotes reduction of the substance during the reaction and prevents excessive growth.
[0040] Specifically, the step of uniformly mixing the divalent cobalt source, thiourea, sodium dodecyl sulfate, and organic solvent includes:
[0041] The mixture was then subjected to stirring and ultrasonic treatment sequentially; the stirring speed was 500-800 r / min for 20-40 min; the ultrasonic power was 80-100 W for 60-90 min. This process was performed to ensure that the substances in the mixture were mixed more evenly.
[0042] S2. The mixed solution is subjected to a solvothermal reaction to obtain the Co9S8 composite material.
[0043] Specifically, in step S2, the temperature of the solvothermal reaction is 180~200℃, and the reaction time is 10~14h. The heating rate can be selected according to actual needs.
[0044] Step S2 further includes: sequentially cooling, centrifuging, drying and grinding the mixed product after the solvothermal reaction to obtain the Co9S8 composite material.
[0045] Specifically, the centrifugation speed is 6000~8000 r / min, and the time is 30~60 min; the drying is done by baking, and the drying temperature is 50~70℃, and the drying time is 10~12 h.
[0046] A specific example of the present invention also provides the application of the Co9S8 composite material as described above in the electrode material of the oxygen evolution reaction. That is, the Co9S8 composite material of the present invention can be used as the anode material (i.e., the oxygen evolution electrode material) in the water electrolysis reaction.
[0047] The Co9S8 composite material of the present invention, its preparation method and its application will be described in detail below with reference to specific embodiments and comparative examples.
[0048] Example 1
[0049] 790 mg of cobalt sulfate, 640 mg of thiourea, 300 mg of sodium dodecyl sulfate, 15 mL of ethylene glycol, and 55 mL of N,N-dimethylformamide were stirred at 500 r / min for 30 min, and then sonicated at 90 W for 75 min to obtain a mixed solution.
[0050] The mixed solution was heated to 190°C at a heating rate of 10°C / min and subjected to a solvothermal reaction for 12 h. The product of the solvothermal reaction was cooled to 25°C and centrifuged at 8000 r / min for 40 min. The solid obtained by centrifugation was washed (washed 3 times with water and 2 times with anhydrous ethanol) and then dried at 60°C for 12 h to obtain the Co9S8 composite material.
[0051] Example 2
[0052] 790 mg of cobalt sulfate, 390 mg of thiourea, 400 mg of sodium dodecyl sulfate, 20 mL of ethylene glycol, and 60 mL of N,N-dimethylformamide were stirred at 500 r / min for 20 min and then sonicated at 80 W for 60 min to obtain a mixed solution.
[0053] The mixed solution was heated to 190°C at a heating rate of 10°C / min and subjected to a solvothermal reaction for 10 h. The product of the solvothermal reaction was cooled to 25°C and centrifuged at 6000 r / min for 30 min. The solid obtained by centrifugation was washed (washed 3 times with water and 2 times with anhydrous ethanol) and then dried at 50°C for 10 h to obtain the Co9S8 composite material.
[0054] Example 3
[0055] 790 mg of cobalt sulfate, 790 mg of thiourea, 200 mg of sodium dodecyl sulfate, 20 mL of ethylene glycol, and 100 mL of N,N-dimethylformamide were stirred at 800 r / min for 40 min, and then sonicated at 100 W for 90 min to obtain a mixed solution.
[0056] The mixed solution was heated to 200 °C at a heating rate of 10 °C / min and subjected to a solvothermal reaction for 14 h. The product of the solvothermal reaction was cooled to 25 °C and centrifuged at 9000 r / min for 60 min. The solid obtained by centrifugation was washed (washed 3 times with water and 2 times with anhydrous ethanol) and then dried at 70 °C for 12 h to obtain the Co9S8 composite material.
[0057] Example 4
[0058] 790 mg of cobalt nitrate, 600 mg of thiourea, 330 mg of sodium dodecyl sulfate, 15 mL of ethylene glycol, and 60 mL of N,N-dimethylformamide were stirred at 550 r / min for 30 min, and then sonicated at 90 W for 75 min to obtain a mixed solution.
[0059] The mixed solution was heated to 190°C at a heating rate of 10°C / min and subjected to a solvothermal reaction for 12 h. The product of the solvothermal reaction was cooled to 25°C and centrifuged at 8000 r / min for 45 min. The solid obtained by centrifugation was washed (washed 3 times with water and 2 times with anhydrous ethanol) and then dried at 65°C for 12 h to obtain the Co9S8 composite material.
[0060] Comparative Example 1
[0061] 790 mg of cobalt sulfate, 640 mg of thiourea, 15 mL of ethylene glycol, and 55 mL of N,N-dimethylformamide were stirred at 500 r / min for 30 min, and then sonicated at 90 W for 75 min to obtain a mixed solution.
[0062] The mixed solution was heated to 190°C at a heating rate of 10°C / min and subjected to a solvothermal reaction for 12 h. The product of the solvothermal reaction was cooled to 25°C and centrifuged at 8000 r / min for 40 min. The solid obtained by centrifugation was washed (washed 3 times with water and 2 times with anhydrous ethanol) and then dried at 60°C for 12 h to obtain Co9S8 material.
[0063] Figure 1 The image shows a scanning electron microscope (SEM) image of the Co9S8 material prepared in Comparative Example 1. Figure 1 The granular structure of Co9S8 material can be observed, and the overall morphology shows that the particle size is relatively large.
[0064] Figure 2 These are scanning electron microscope (SEM) images of the Co9S8 composite material prepared in Example 1. Figure 2 It can be seen that the Co9S8 composite material has a nanoparticle structure with small particle size and a large exposed specific surface area, which is conducive to the rapid transport of electrons.
[0065] Figure 3 The images show the XRD patterns of the materials prepared in Comparative Example 1, Example 1, and Example 2. Figure 3 It can be seen that the diffraction peaks of the prepared material are consistent with those of PDF#86-2273, and there are no impurity peaks, indicating that the Co9S8 material and Co9S8 composite material prepared by the preparation method of the present invention have high purity.
[0066] Figure 4 The electron spin resonance diagrams are those of the Co9S8 material prepared in Comparative Example 1 and the Co9S8 composite material prepared in Example 1. Figure 4 As can be seen, the Co9S8 composite material in Example 1 exhibits a higher peak intensity, demonstrating its stronger spin behavior. This will provide a high-spin polarization pathway for subsequent electron charge transport hopping, thereby enhancing the catalytic reaction efficiency.
[0067] Figure 5 This is a linear sweep voltammetry curve of the Co9S8 composite material prepared in Example 2, with the electrolyte solution being a 1 mol / L KOH solution. Figure 5 It can be seen that at 10mA cm -2The required potential is only 1.39V at the specified current density, and the overpotential is only 223mV, indicating that this Co9S8 composite material exhibits excellent electrocatalytic oxygen evolution performance. This suggests that the opening of the spin pathway makes it easier for the reaction intermediate to react with the high-spin ee state of Co. g The orbitals form multidimensional pairings, creating multiple spin-polarized electron hopping pathways, which optimizes the electron hopping capability and the adsorption energy barrier of reaction intermediates.
[0068] Among them, Figures 3 to 5 In the text, Co9S8-400 represents Example 2; Co9S8-300 represents Example 1; and Co9S8 represents Comparative Example 1.
[0069] Figure 6 This is a chronopotential curve of the Co9S8 composite material prepared in Example 1, from which... Figure 6 It can be seen from this that at 100mA cm -2 The Co9S8 composite material prepared in Example 1 exhibits an ultra-long durability of at least 3000 hours at a given current density, indicating that the Co9S8 composite material has excellent stability and good application prospects.
[0070] Figure 7 These are scanning electron microscope (SEM) images of the Co9S8 composite material prepared in Example 2. Figure 7 It can be seen that the stacked nanoparticle pore structure of the Co9S8 composite material has a relatively regular overall morphology and a large exposed specific surface area, which is more conducive to electron transport.
[0071] Figure 8 This is a scanning electron microscope image of the Co9S8 composite material prepared in Example 3. Figure 8 It can be seen that the Co9S8 composite material has a stacked nanoparticle pore structure with a relatively regular overall morphology and a large exposed specific surface area.
[0072] In summary, the Co9S8 composite material of this invention exhibits rapid electron transfer capability, thus demonstrating excellent electrocatalytic oxygen evolution performance. The preparation method of this invention is simple, safe, and low-cost, making it suitable for industrial production and providing a new technical approach for improving the oxygen evolution performance of transition metal sulfide catalysts.
[0073] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0074] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A Co9S8 composite material, characterized in that, The Co9S8 composite material has a core-shell structure, comprising a core layer and a shell layer covering the core layer. The core layer is Co9S8, and the shell layer is sodium dodecyl sulfate.
2. A method for preparing the Co9S8 composite material as described in claim 1, characterized in that, Includes the following steps: A mixed solution was obtained by thoroughly mixing a divalent cobalt source, thiourea, sodium dodecyl sulfate, and an organic solvent. The mixed solution was subjected to a solvothermal reaction to obtain the Co9S8 composite material.
3. The method for preparing the Co9S8 composite material according to claim 2, characterized in that, The temperature of the solvothermal reaction is 180~200℃, and the time of the solvothermal reaction is 10~14h.
4. The method for preparing the Co9S8 composite material according to claim 2, characterized in that, The preparation method further includes: sequentially cooling, centrifuging, drying and grinding the mixed product after the solvothermal reaction to obtain the Co9S8 composite material.
5. The method for preparing the Co9S8 composite material according to claim 4, characterized in that, The centrifugation speed is 6000~8000 r / min, and the time is 30~60 min; The drying process is called baking, and the baking temperature is 50~70℃, and the baking time is 10~12h.
6. The method for preparing the Co9S8 composite material according to claim 2, characterized in that, The divalent cobalt source is at least one of cobalt sulfate, cobalt nitrate, and cobalt acetate.
7. The method for preparing the Co9S8 composite material according to claim 2, characterized in that, The mass ratio of the divalent cobalt source to thiourea is (1~2.03):1; The mass ratio of the divalent cobalt source to sodium dodecyl sulfate is (1.975~3.95):
1.
8. The method for preparing the Co9S8 composite material according to claim 2, characterized in that, The organic solvent is ethylene glycol and N,N-dimethylformamide, wherein the volume ratio of ethylene glycol to N,N-dimethylformamide is 1:(3~5); or, The organic solvent is ethylene glycol and N,N-dimethylacetamide, and the volume ratio of ethylene glycol to N,N-dimethylacetamide is 1:(3~5).
9. The method for preparing the Co9S8 composite material according to claim 2, characterized in that, The specific steps of uniformly mixing the divalent cobalt source, thiourea, sodium dodecyl sulfate, and organic solvent include: The above mixture was then subjected to stirring and ultrasonic treatment in sequence; The stirring speed is 500~800 r / min, and the time is 20~40 min; the ultrasonic power is 80~100W, and the time is 60~90 min.
10. The application of the Co9S8 composite material as described in claim 1 in the electrode material of the oxygen evolution reaction.