Preparation method and application of CuCo2O4-coated Cu2O composite catalyst
By synthesizing the CuCo2O4@Cu2O composite catalyst in one pot, the problem of low efficiency of the anodic oxygen evolution reaction of the CuCo2O4 catalyst in the electrocatalytic water splitting process was solved, and efficient electrocatalytic water splitting and low-cost production were achieved.
Patent Information
- Application Number
- CN202510972189.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-15
- Publication Date
- 2025-10-14
AI Technical Summary
Existing CuCo2O4 catalysts have problems such as high kinetic barrier of anodic oxygen evolution reaction, poor conductivity and limited active sites in the process of electrocatalytic water splitting, resulting in low water splitting efficiency.
The CuCo2O4@Cu2O composite catalyst was synthesized by a one-pot method. By controlling the ratio of Co source and Cu source, a composite material with CuCo2O4 particles distributed on the surface of cubic Cu2O was prepared. This composite material was used as an anode catalyst, which simplified the preparation process and improved the catalytic performance.
It significantly improves the efficiency of the electrocatalytic water-oxygen separation reaction, reduces the overpotential, promotes the development of renewable hydrogen energy, reduces production costs and improves the purity and dispersibility of the product.
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Figure CN120776367A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of inorganic materials, and particularly relates to a preparation method of a CuCo2O4@Cu2O composite catalyst. BACKGROUND
[0002] In recent years, renewable hydrogen energy as a clean energy has attracted more and more attention. Renewable hydrogen energy can be produced in various ways, and as a renewable energy source, it helps to alleviate the problem of energy shortage. Hydrogen is an ideal fossil energy alternative, which can be prepared by electrochemical decomposition of water. This technology is an advanced technology for developing green fuel storage, and therefore, there is an urgent need for an electrocatalyst that can be used to develop hydrogen energy production with high efficiency, energy saving, multifunction and durability. Domestic and foreign researches show that the reasons for affecting the improvement of the efficiency of electrocatalytic water decomposition are as follows: on the one hand, the high kinetic potential barrier of the anode oxygen evolution reaction and the slow kinetic rate of the anode oxygen evolution reaction reduce the overall efficiency of water decomposition, resulting in a low rate of hydrogen evolution half-reaction at the cathode, which becomes one of the bottlenecks of water decomposition reaction; on the other hand, the single-component catalyst material of the anode has poor conductivity and limited active sites.
[0003] A large number of studies have confirmed that transition metal oxides, hydroxides and phosphides exhibit excellent OER electrocatalytic performance. Among them, CuCo2O4 is a good OER electrocatalyst with a spinel nanoparticle structure, which has been widely used in the field of energy storage and conversion due to its better conductivity than (hydro) oxide. However, the low structural stability of CuCo2O4 poses a severe challenge to its electrocatalytic durability, and therefore, it is inevitable to construct a CuCo2O4-based composite catalyst. In addition, the binary material CuCo2O4@Cu2O synthesized by one-pot method has a good synergistic effect between CuCo2O4 and Cu2O, which can greatly improve the performance of alkaline electrocatalyst. Therefore, the composite catalyst material formed by growing CuCo2O4 on the surface of cubic Cu2O exhibits high efficient OER performance. The OER overpotential is as low as 360 mV and 460 mV at a current density of 10 mA cm -2 and 50 mA cm -2 . The high efficient OER catalytic performance is attributed to the perfect composite of the OER double-catalytic active center CuCo2O4 particles in the same structure. SUMMARY
[0004] The purpose of the present application is to design and synthesize CuCo2O4@Cu2O composite catalysts with different ratios of Co source and Cu source in view of the defects and deficiencies of OER catalysts. The liquid-phase synthesis is directly synthesized in a one-pot method in a reaction kettle without special equipment and harsh conditions, and the steps are simple and the cost is low. The CuCo2O4@Cu2O composite catalyst can be used as an anode catalyst in the electrocatalytic water splitting reaction, which can effectively improve the oxygen evolution efficiency of water splitting.
[0005] A preparation method of a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: respectively ultrasonic dissolve a mmol Co(NO3)2, b mmol Cu(NO3)2 and 0.3 g PVP in 30 mL deionized water to obtain solution A, and solution A is stirred at room temperature for 30 min.
[0006] S2: ultrasonic dissolve 3.76 mmol NaOH and 1.875 mmol trisodium citrate in 30 mL deionized water to obtain solution B.
[0007] S3: transfer solution A into solution B, mix and stir at room temperature for 30 min, and then transfer into a 100 mL high-pressure reaction kettle, react at 160℃ for 4 h, and the obtained solution PH value is 10.
[0008] S4: after reaction, the sample is washed with deionized water and ethanol for several times, dried in an oven at 40℃ for 6 h, and the powder product is recovered, and the obtained solution PH value is 8-9.
[0009] Further, the total amount of substance of the Co source (Co(NO3)2) and the Cu source (Cu(NO3)2) is 1.88 mmol.
[0010] A preparation method of a glassy carbon electrode sample, weigh 4 mg of CuCo2O4@Cu2O composite catalyst, dissolve in 950 μL of ethanol solution, then add 50 μL of naphthol solution dropwise, and ultrasonic for 10 min. Then take 400 μL of the above solution and drop it on the glassy carbon electrode, and dry to obtain the glassy carbon electrode sample. The loading amount is 0.014 mg cm -2 .
[0011] An application of a glassy carbon electrode sample, the above glassy carbon electrode sample is used for performance test of electrocatalytic water splitting OER.
[0012] In the OER test, the CuCo2O4@Cu2O composite catalyst can effectively improve the OER performance of electrocatalytic water splitting as an anode oxygen evolution reaction catalytic material.
[0013] Compared with the prior art, the present application has the following beneficial effects: 1. Compared with the complex process in the prior art that part of the preparation of OER electrocatalyst requires special equipment and harsh conditions, the CuCo2O4@Cu2O composite catalyst is directly synthesized in a one-pot method in a reaction kettle by using a hydrothermal method, without special equipment and simple steps. The method greatly reduces the preparation threshold, reduces the operation difficulty and time cost, and is easy to repeat operation, which is beneficial to large-scale industrial production.
[0014] 2. The CuCo2O4@Cu2O composite catalyst prepared by the application can overcome the problems of high cost of composite catalyst material, low product purity and poor dispersibility. The catalyst preparation raw material cost is low, and the product has high purity, good dispersibility, strong controllability and good reproducibility. This can reduce production cost while ensuring catalyst quality, and improve production efficiency.
[0015] 3. For the technical problems of high anode oxygen evolution reaction kinetic barrier, poor conductivity of single-component catalyst and limited active sites, the CuCo2O4@Cu2O powder sample composite catalyst of the application performs well. As an anode oxygen evolution reaction catalytic material in the electrocatalytic water splitting reaction, it can significantly improve the water splitting oxygen evolution reaction efficiency, and the required overpotential is only 0.36 V and 0.46 V under the current density of 10 mAcm -2 and 50 mA cm -2 , which is lower than some existing catalysts, effectively breaks through the bottleneck of water splitting reaction, and promotes the development of renewable hydrogen energy field. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 is a preparation flowchart of the CuCo2O4@Cu2O composite catalyst.
[0017] Figure 2 is a scanning electron microscope (SEM) image of the Co:Cu 4:1 cubic urchin-like CuCo2O4@Cu2O catalytic material prepared by the application.
[0018] Figure 3 is a scanning electron microscope (SEM) image of the Co:Cu 3:1 cubic urchin-like CuCo2O4@Cu2O catalytic material prepared by the application.
[0019] Figure 4 is a scanning electron microscope (SEM) image of the Co:Cu 2:1 cubic urchin-like CuCo2O4@Cu2O catalytic material prepared by the application.
[0020] Figure 5 is a scanning electron microscope (SEM) image of the Co:Cu 1:1 cubic urchin-like CuCo2O4@Cu2O catalytic material prepared by the application.
[0021] Figure 6 Scanning electron microscope (SEM) image of the cubic urchin-like CuCo204@Cu20 catalytic material prepared for the present invention with Co:Cu of 1:2.
[0022] Figure 7 Scanning electron microscope (SEM) image of the cubic urchin-like CuCo204@Cu20 catalytic material prepared for the present invention with Co:Cu of 1:3.
[0023] Figure 8 Scanning electron microscope (SEM) image of the cubic urchin-like CuCo204@Cu20 catalytic material prepared for the present invention with Co:Cu of 1:4.
[0024] Figure 9 X-ray diffraction (XRD) image of the cubic urchin-like CuCo204@Cu20 prepared for Examples 1-7.
[0025] Figure 10 X-ray diffraction (XRD) image of the pure sample prepared for the present invention after adding only Co(N03)2, Cu(N03)2.
[0026] Figure 11 Linear sweep voltammetry (LSV) plot of the OER performance of the cubic urchin-like CuCo204@Cu20 catalytic material prepared for Examples 1-7.
[0027] Figure 12 Linear sweep voltammetry (LSV) plot of the water electrolysis oxidation of the CuCo204@Cu20 catalytic material prepared for Examples 1-7 at 10 mA cm-2and 50 mA cm-2. –2 and 50 mA cm –2 Corresponding bar chart of the potential values.
[0028] Figure 13 Tafel slope plot of the CuCo204@Cu20 catalytic material prepared for Examples 1-7.
[0029] Figure 14 Impedance spectroscopy (EIS) plot of the CuCo204@Cu20 catalytic material prepared for Examples 1-7. DETAILED DESCRIPTION
[0030] The present invention will be described in detail below with reference to the attached drawings. The reagents, methods and equipment used in the experiments are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.
[0031] Example 1 A preparation method of a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: a mmol of Co(NO3)2 and b mmol of Cu(NO3)2 (a:b = 4:1) and 0.3 g of PVP are respectively ultrasonically dissolved in 30 mL of deionized water to obtain solution A, and solution A is stirred at room temperature for 30 min.
[0032] S2: 3.76 mmol of NaOH and 1.875 mmol of trisodium citrate are ultrasonically dissolved in 30 mL of deionized water to obtain solution B.
[0033] S3: Solution A is transferred into solution B, and after mixing, it is stirred at room temperature for 30 min, and then transferred into a 50 mL high-pressure reaction kettle, and reacted at 160°C for 4 h, and the obtained solution has a pH value of 10.
[0034] S4: After reaction, the sample is washed with deionized water and ethanol for multiple times, and dried in an oven at 40°C for 6 h, and the powder product is recovered, and the obtained solution has a pH value of 9.
[0035] Example 2 A preparation method of a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: a mmol of Co(NO3)2 and b mmol of Cu(NO3)2 (a:b = 4:1) and 0.3 g of PVP are respectively ultrasonically dissolved in 30 mL of deionized water to obtain solution A, and solution A is stirred at room temperature for 30 min.
[0036] S2: 3.76 mmol of NaOH and 1.875 mmol of trisodium citrate are ultrasonically dissolved in 30 mL of deionized water to obtain solution B.
[0037] S3: Solution A is transferred into solution B, and after mixing, it is stirred at room temperature for 30 min, and then transferred into a 50 mL high-pressure reaction kettle, and reacted at 160°C for 4 h, and the obtained solution has a pH value of 10.
[0038] S4: After reaction, the sample is washed with deionized water and ethanol for multiple times, and dried in an oven at 40°C for 6 h, and the powder product is recovered, and the obtained solution has a pH value of 9.
[0039] S5: 4 mg of the composite catalyst CuCo2O4@Cu2O was weighed and dissolved in 950 μL of an ethanol solution, followed by 50 μL of a solution of low valence, and ultrasonic treatment for 10 min. 400 μL of the above sample was dropped on a glassy carbon electrode, and the dried glassy carbon electrode sample was further used for performance testing of electrocatalytic water decomposition OER. In the OER test, the CuCo2O4@Cu2O composite catalyst as an anode oxygen evolution reaction catalytic material can effectively improve the OER performance of electrocatalytic water.
[0040] Example 3 A preparation method of a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: a mmol of Co(NO3)2 and b mmol of Cu(NO3)2 (a:b = 2:1) and 0.3 g of PVP were respectively ultrasonically dissolved in 30 mL of deionized water to obtain solution A, and solution A was stirred at room temperature for 30 min.
[0041] S2: 3.76 mmol of NaOH and 1.875 mmol of trisodium citrate were ultrasonically dissolved in 30 mL of deionized water to obtain solution B.
[0042] S3: Solution A was transferred into solution B, and after mixing, it was stirred at room temperature for 30 min, and then transferred into a 100 mL high-pressure reaction kettle, and reacted at 160℃ for 4 h, and the pH value of the obtained solution was 10.
[0043] S4: After the reaction, the sample was washed with deionized water and ethanol several times, and dried in an oven at 40℃ for 6 h, and the powder product was recovered, and the pH value of the obtained solution was 9.
[0044] S5: 4 mg of the composite catalyst CuCo2O4@Cu2O was weighed and dissolved in 950 μL of an ethanol solution, followed by 50 μL of a solution of low valence, and ultrasonic treatment for 10 min. 400 μL of the above sample was dropped on a glassy carbon electrode, and the dried glassy carbon electrode sample was further used for performance testing of electrocatalytic water decomposition OER. In the OER test, the CuCo2O4@Cu2O composite catalyst as an anode oxygen evolution reaction catalytic material can effectively improve the OER performance of electrocatalytic water.
[0045] Example 4 A preparation method of a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: a mmol of Co(NO3)2 and b mmol of Cu(NO3)2 (a:b = 2:1) and 0.3 g of PVP were respectively ultrasonically dissolved in 30 mL of deionized water to obtain solution A, and solution A was stirred at room temperature for 30 min.
[0046] S2: 3.76 mmol NaOH and 1.875 mmol trisodium citrate were ultrasonically dissolved in 30 mL of deionized water to obtain solution B.
[0047] S3: Solution A was transferred into solution B, mixed and stirred at room temperature for 30 min, and then transferred into a 100 mL high-pressure reaction kettle, reacted at 160°C for 4 h, and the obtained solution had a pH value of 10.
[0048] S4: After reaction, the sample was washed with deionized water and ethanol for multiple times, dried in an oven at 40°C for 6 h, and the powder product was recovered, and the obtained solution had a pH value of 9.
[0049] S5: 4 mg of the composite catalyst CuCo2O4@Cu2O was weighed and dissolved in 950 μL of an ethanol solution, and then 50 μL of a solution was added, and ultrasonically treated for 10 min. 400 μL of the above sample was dropped and coated on a glassy carbon electrode, and the dried glassy carbon electrode sample was further used for performance test of electrocatalytic water splitting OER. In the OER test, the CuCo2O4@Cu2O composite catalyst as an anode oxygen evolution reaction catalytic material can effectively improve the OER performance of electrocatalytic water splitting.
[0050] Example 5 A preparation method of a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: a mmol of Co(NO3)2 and b mmol of Cu(NO3)2 (a:b = 1:2) and 0.3 g of PVP were ultrasonically dissolved in 30 mL of deionized water to obtain solution A, and solution A was stirred at room temperature for 30 min.
[0051] S2: 3.76 mmol NaOH and 1.875 mmol trisodium citrate were ultrasonically dissolved in 30 mL of deionized water to obtain solution B.
[0052] S3: Solution A was transferred into solution B, mixed and stirred at room temperature for 30 min, and then transferred into a 100 mL high-pressure reaction kettle, reacted at 160°C for 4 h, and the obtained solution had a pH value of 10.
[0053] S4: After reaction, the sample was washed with deionized water and ethanol for multiple times, dried in an oven at 40°C for 6 h, and the powder product was recovered, and the obtained solution had a pH value of 8.
[0054] S5: 4 mg of the composite catalyst CuCo2O4@Cu2O was weighed and dissolved in 950 μL of an ethanol solution, followed by 50 μL of a solution of low valence, and ultrasonic treatment for 10 min. 400 μL of the above sample was dropped on a glassy carbon electrode, and the dried glassy carbon electrode sample was further used for performance testing of electrocatalytic water decomposition OER. In the OER test, the CuCo2O4@Cu2O composite catalyst as an anode oxygen evolution reaction catalytic material can effectively improve the OER performance of electrocatalytic water.
[0055] Example 6 A method for preparing a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: a mmol of Co(NO3)2 and b mmol of Cu(NO3)2 (a:b = 1:3) and 0.3 g of PVP were respectively ultrasonically dissolved in 30 mL of deionized water to obtain solution A, and solution A was stirred at room temperature for 30 min.
[0056] S2: 3.76 mmol of NaOH and 1.875 mmol of trisodium citrate were ultrasonically dissolved in 30 mL of deionized water to obtain solution B.
[0057] S3: Solution A was transferred into solution B, and after mixing, it was stirred at room temperature for 30 min, and then transferred into a 100 mL high-pressure reaction kettle, and reacted at 160℃ for 4 h, and the pH value of the obtained solution was 10.
[0058] S4: After the reaction, the sample was washed with deionized water and ethanol several times, and dried in an oven at 40℃ for 6 h, and the powder product was recovered, and the pH value of the obtained solution was 8.
[0059] S5: 4 mg of the composite catalyst CuCo2O4@Cu2O was weighed and dissolved in 950 μL of an ethanol solution, followed by 50 μL of a solution of low valence, and ultrasonic treatment for 10 min. 400 μL of the above sample was dropped on a glassy carbon electrode, and the dried glassy carbon electrode sample was further used for performance testing of electrocatalytic water decomposition OER. In the OER test, the CuCo2O4@Cu2O composite catalyst as an anode oxygen evolution reaction catalytic material can effectively improve the OER performance of electrocatalytic water.
[0060] Example 7 A method for preparing a CuCo2O4@Cu2O composite catalyst, comprising the following steps: S1: a mmol of Co(NO3)2 and b mmol of Cu(NO3)2 (a:b = 1:4) and 0.3 g of PVP were respectively ultrasonically dissolved in 30 mL of deionized water to obtain solution A, and solution A was stirred at room temperature for 30 min.
[0061] S2: Dissolve 3.76 mmol NaOH and 1.875 mmol trisodium citrate in 30 mL deionized water to obtain solution B.
[0062] S3: Transfer solution A into solution B, mix and stir at room temperature for 30 min, then transfer into a 100 mL high-pressure reactor and react at 160°C for 4 h, and the obtained solution has a pH value of 10.
[0063] S4: After reaction, the sample is washed with deionized water and ethanol for several times, and dried in an oven at 40°C for 6 h, and the powder product is recovered, and the obtained solution has a pH value of 8.
[0064] S5: Weigh 4 mg of composite catalyst CuCo2O4@Cu2O, dissolve in 950 μL of ethanol solution, then add 50 μL of solution, and ultrasonic for 10 min. Take 400 μL of the above sample and drop it on a glassy carbon electrode, and the dried glassy carbon electrode sample is further used for performance test of electrocatalytic water splitting OER. In the OER test, the CuCo2O4@Cu2O composite catalyst as an anode oxygen evolution reaction catalytic material can effectively improve the OER performance of electrocatalytic water splitting.
[0065] The synthesis ratio of the solution in examples 1-7 is shown in Table 1: Table 1 Synthesis ratio
[0066] The CuCo2O4@Cu2O prepared by examples 1-7 is taken as the research object, and the present application adopts scanning electron microscope (SEM) and X-ray diffraction (XRD) technology to characterize the phase structure of the nanomaterial, as follows: (1) Morphology characterization The structure of the prepared CuCo2O4@Cu2O is detected by S-4800 type SEM instrument, and the results are shown in Figure 1 –4. As can be seen from Figure 2 –8, the morphology of the material is Cu2O cubic surface distributed with CuCo2O4 particles.
[0067] (2) Structure characterization The structure of the prepared nanomaterial is characterized by Bruker D8 Advance type XRD, and the results are shown in Figure 5 –8. As can be seen from Figure 9–10It can be seen that the pure copper source synthesized material is Cu2O, and the card used is JCPDS No. 05-0667. The pure Co source synthesized product is Co(OH)2, and the card used is JCPDS No. 30-0443. The products synthesized by different ratios of Co source and Cu source are all composite CuCo2O4@Cu2O, and the corresponding cards are JCPDS No. 37-0878 and JCPDS No. 05-0667, indicating that the CuCo2O4 and Cu2O materials are successfully prepared.
[0068] (3) Linear sweep voltammetry (LSV) test The urea oxidation performance of NiFe-PBA was tested in a three-electrode system with the prepared CuCo2O4@Cu2O powder sample as the working electrode material, a saturated calomel electrode as the reference electrode, and a carbon rod as the counter electrode. The electrolyte was 1.0 mol dm -3 KOH. Figure 11 The test of OER performance of electrocatalytic water decomposition was carried out in a three-electrode system by linear sweep voltammetry (LSV). The LSV test was used to evaluate the electrode material, and the results are shown in Figure 11 The results show that the composite catalyst CuCo2O4@Cu2O has excellent OER performance, and the CuCo2O4@Cu2O synthesized under the ratio of 1.25 mmol Co(NO3)2 and 0.63 mmol Cu(NO3)2 has the best performance, and the required potential is 1.59 V and 1.69 V under the current density of 10 mA cm ‒2 and 50 mA cm ‒2 .
[0069] (4) Tafel slope test Figure 13 The composite CuCo2O4@Cu2O prepared in Examples 1-7 was used as the research object, and according to the corresponding Tafel value, it can be known that the material has a fast chemical reaction rate.
[0070] (5) AC impedance test Figure 14 The composite CuCo2O4@Cu2O prepared in Examples 1-7 was used as the research object, and the material prepared by loading the powder sample on a glassy carbon electrode was directly used as the working electrode material for electrocatalytic water oxidation. The EIS test still used a three-electrode system. The electrochemical impedance spectrum was used to further evaluate the ion transmission rate and transfer impedance of the prepared active electrode material CuCo2O4@Cu2O. The CuCo2O4@Cu2O synthesized under the ratio of 1.25 mmol Co(NO3)2 and 0.63 mmol Cu(NO3)2 has the lowest charge transfer impedance, proving that the material has a better charge mass transfer rate.
[0071] The above are preferred embodiments of the present application, not to limit the protection scope of the present application, equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.
Claims
1. A method for preparing a CuCo2O4@Cu2O composite catalyst, characterized in that: The steps include: S1: a mmol Co(NO3)2, b mmol Cu(NO3)2 and 0.3 g PVP were ultrasonically dissolved in 30 mL deionized water to obtain solution A, which was stirred at room temperature for 30 min; S2: 3.76 mmol NaOH and 1.875 mmol trisodium citrate were ultrasonically dissolved in 30 mL deionized water to obtain solution B; S3: Solution A was transferred into solution B, mixed and stirred at room temperature for 30 min, then transferred into a 100 mL autoclave and reacted at 160°C for 4 h. The pH value of the obtained solution was 10. S4: After the reaction, the sample was washed with deionized water and ethanol for multiple times, dried in an oven at 40°C for 6 h, and a powder product was recovered. The pH value of the obtained solution was 8-9.
2. A method for preparing a glassy carbon electrode sample, characterized in that: 4 mg of the CuCo2O4@Cu2O composite catalyst prepared by the preparation method of claim 1 was weighed and dissolved in 950 μL of ethanol solution. 50 μL of naphthol solution was then added dropwise. The mixture was ultrasonicated for 10 min. 400 μL of the above solution was then dropped onto the glassy carbon electrode. After drying, a glassy carbon electrode sample was obtained. The loading amount was 0.014 mg cm -2 .