阅读说明：本技术 一种三维泡沫铜负载碱式钒酸钴功能材料电解水催化剂的制备方法 (Preparation method of three-dimensional foam copper-loaded basic cobalt vanadate functional material electrolytic water catalyst ) 是由 徐平 胡静 张彬 韩喜江 杜耘辰 于 2021-08-30 设计创作，主要内容包括：一种三维泡沫铜负载碱式钒酸钴功能材料电解水催化剂的制备方法,本发明涉及电催化材料的制备方法技术领域。本发明要解决现有催化剂的催化活性低,并且贵金属成本高的技术问题。方法：一、制备前驱体纳米球；二、清洗,烘干；三、在载体三维泡沫铜上合成碱式钒酸钴空心纳米球。本发明制备得到的三维泡沫铜负载碱式钒酸钴电极材料在HER和OER方面均表现出优越的催化性能,作为双功能催化剂时,仍然具有优异的电化学性能和稳定性,在电催化分解水电极材料技术领域将具有广泛的应用前景。本发明方法制备的三维泡沫铜负载碱式钒酸钴电解水催化剂用于电催化材料技术领域,改善能源与环境问题。(The invention discloses a preparation method of a three-dimensional foamy copper-loaded basic cobaltous vanadate functional material electrolytic water catalyst, and relates to the technical field of preparation methods of electrocatalytic materials. The invention aims to solve the technical problems of low catalytic activity and high cost of noble metal of the existing catalyst. The method comprises the following steps: firstly, preparing precursor nanospheres; secondly, cleaning and drying; thirdly, synthesizing the basic cobalt vanadate hollow nanospheres on the carrier three-dimensional foam copper. The three-dimensional foam copper loaded basic cobalt vanadate electrode material prepared by the invention has excellent catalytic performance in the aspects of HER and OER, still has excellent electrochemical performance and stability when being used as a bifunctional catalyst, and has wide application prospect in the technical field of electrocatalytic decomposition water electrode materials. The three-dimensional foam copper-loaded basic cobaltous vanadate electrolytic water catalyst prepared by the method is used in the technical field of electrocatalytic materials, and can be used for improving the energy and environmental problems.)

1. A preparation method of a three-dimensional foam copper-loaded basic cobalt vanadate functional material electrolytic water catalyst is characterized by comprising the following steps:

step one, preparing precursor nanospheres:

rapidly stirring and mixing sodium metavanadate and ultrapure water at constant temperature and magnetically to obtain a sodium metavanadate solution; quickly stirring and mixing cobalt nitrate hexahydrate and ultrapure water at constant temperature and by magnetic force to obtain a cobalt nitrate solution; cooling to room temperature;

loading a cobalt nitrate solution into a micro-sample injector, slowly dripping the cobalt nitrate solution into a sodium metavanadate solution, and stirring the solution in the adding process to obtain a suspension;

step two, carrying out ultrasonic cleaning on the carrier three-dimensional foamy copper by adopting acetone, hydrochloric acid, absolute ethyl alcohol and ultrapure water, and then drying in vacuum;

and step three, simultaneously putting the suspension obtained in the step one and the carrier three-dimensional foam copper treated in the step two into a hydrothermal reaction kettle, carrying out Ostwald ripening reaction, controlling the temperature and time of the hydrothermal reaction, synthesizing basic cobaltous vanadate hollow nanospheres on the carrier three-dimensional foam copper, then sequentially adopting ultrapure water and absolute ethyl alcohol for rinsing, drying, obtaining the three-dimensional foam copper-loaded basic cobaltous vanadate functional material electrolytic water catalyst, and finishing the preparation.

2. The preparation method of the three-dimensional foam copper supported basic cobalt vanadate functional material electrolytic water catalyst according to claim 1, wherein in the step one, the mass ratio of the cobalt nitrate hexahydrate to the sodium metavanadate is 3: 2; the volume ratio of the ultrapure water for preparing the cobalt nitrate solution to the ultrapure water for preparing the sodium metavanadate solution is 2: 7.

3. The preparation method of the three-dimensional foamy copper supported basic cobaltous vanadate functional material electrolytic water catalyst according to claim 1, characterized in that in the first step, the rapid constant temperature magnetic stirring rotation speed is controlled to 2000rpm, the time is 30 minutes, and the temperature is 80 ℃.

4. The preparation method of the three-dimensional foamy copper supported basic cobaltous vanadate functional material electrolytic water catalyst according to claim 1, characterized in that the dropping speed of the microsyringe is controlled to be 100mL/h in the first step.

5. The method for preparing the catalyst for electrolyzing water by using the three-dimensional foamy copper loaded with the basic cobalt vanadate functional material according to claim 1, wherein the size of the carrier three-dimensional foamy copper in the second step is 1 cm x 2 cm, and the thickness is 2 mm.

6. The preparation method of the three-dimensional foam copper-loaded basic cobaltous vanadate functional material electrolytic water catalyst according to claim 1, wherein the ultrasonic cleaning process in the second step is to sequentially clean the catalyst once by acetone and hydrochloric acid, and then alternately clean the catalyst 3 times by absolute ethyl alcohol and ultrapure water.

7. The preparation method of the three-dimensional foam copper-loaded basic cobalt vanadate functional material electrolytic water catalyst according to claim 1, wherein the vacuum drying in the second step is performed by using a vacuum drying oven, the temperature is controlled to be 60 ℃, and the drying time is 6 hours.

8. The preparation method of the three-dimensional foam copper supported basic cobalt vanadate functional material electrolytic water catalyst according to claim 1, wherein the capacity of the inner container of the hydrothermal reaction kettle in the step three is 50mL, and the addition amount of the suspension is 30 mL.

9. The preparation method of the three-dimensional foamy copper supported basic cobaltous vanadate functional material electrolytic water catalyst according to claim 1, wherein in the third step, the carrier three-dimensional foamy copper is immersed in the suspension.

10. The preparation method of the catalyst for electrolyzing water by using the three-dimensional foamy copper-loaded basic cobalt vanadate functional material according to claim 1, wherein the reaction temperature of the three-dimensional control water heating is 150 ℃ and the reaction time is 7 hours.

Technical Field

The invention relates to the technical field of preparation methods of electrocatalytic materials.

Background

In recent years, the technology of hydrogen production by water electrolysis can effectively utilize sustainable energy and convert the sustainable energy into hydrogen energy with stable output; hydrogen with extremely high purity can be prepared; but also has a completely clean preparation route. Therefore, the utility model is favored and widely attended by researchers. The key problem of electrochemical water decomposition is to find a catalytic material which has high activity, low cost, good stability and easy availability. Although noble metal catalysts have a high catalytic activity, they are correspondingly expensive, thus limiting the sustainable development of water electrolysis technology. A large number of reports have demonstrated that the performance of catalytic reactions depends on the physicochemical properties of the catalyst surface, mainly on the catalytic material active sites, with the greater the number of active sites, the better the conductivity and the better the catalytic performance. Theories and experiments prove that the transition metal-based compound has very good electric, optical and catalytic properties. Researches find that the transition metal cobalt-based compound has rich active sites and is beneficial to catalytic reaction. How to increase the number of active sites of the catalytic material and the electrical conductivity of the material to improve the catalytic performance of the existing catalyst is a problem to be solved urgently.

Disclosure of Invention

The invention provides a preparation method of a three-dimensional foam copper-loaded basic cobalt vanadate functional material electrolytic water catalyst, aiming at solving the technical problems of low catalytic activity and high noble metal cost of the existing catalyst.

A preparation method of a three-dimensional foam copper-loaded basic cobalt vanadate functional material electrolytic water catalyst specifically comprises the following steps:

step one, preparing precursor nanospheres:

rapidly stirring and mixing sodium metavanadate and ultrapure water at constant temperature and magnetically to obtain a sodium metavanadate solution; quickly stirring and mixing cobalt nitrate hexahydrate and ultrapure water at constant temperature and by magnetic force to obtain a cobalt nitrate solution; cooling to room temperature;

loading a cobalt nitrate solution into a micro-sample injector, slowly dripping the cobalt nitrate solution into a sodium metavanadate solution, and stirring the solution in the adding process to obtain a suspension;

step two, carrying out ultrasonic cleaning on the carrier three-dimensional foamy copper by adopting acetone, hydrochloric acid, absolute ethyl alcohol and ultrapure water, and then drying in vacuum;

and step three, simultaneously putting the suspension obtained in the step one and the carrier three-dimensional foam copper treated in the step two into a hydrothermal reaction kettle, carrying out Ostwald ripening reaction, controlling the temperature and time of the hydrothermal reaction, synthesizing basic cobaltous vanadate hollow nanospheres on the carrier three-dimensional foam copper, then sequentially adopting ultrapure water and absolute ethyl alcohol for rinsing, drying, obtaining the three-dimensional foam copper-loaded basic cobaltous vanadate functional material electrolytic water catalyst, and finishing the preparation.

Further, the mass ratio of the cobalt nitrate hexahydrate to the sodium metavanadate in the first step is 3: 2; the volume ratio of the ultrapure water for preparing the cobalt nitrate solution to the ultrapure water for preparing the sodium metavanadate solution is 2: 7.

Further, the hydrothermal reaction temperature in the third step is 150 ℃, and the reaction time is 7 hours.

Wherein the suspension obtained in the first step is a precursor nanosphere with the diameter of about 100 nanometers.

The hollow spherical nano material loaded by the three-dimensional conductive carrier prepared by the invention has the advantages that the loaded hollow spherical catalyst can expose more active sites, has larger specific surface area and has good surface permeability, so that the combination of the three-dimensional conductive carrier can provide higher loading capacity and smaller resistance.

The Oswald ripening process adopted by the invention is a process that small crystal particles are gradually dissolved and deposited on large crystal particles again to form a hollow framework along with the change of time in the liquid phase reaction process. The invention synthesizes the hollow nano-sphere particles based on a template-free method of an Ostwald curing process, and can regulate and control the active sites of the catalytic material in a certain range by controlling the hollow degree of the nano-sphere particles. The method for synthesizing the hollow sphere is simple to operate, can control the size of a product to a certain extent, can semi-quantitatively regulate and control the number of catalytic activity sites, and is a means for synthesizing the water electrolysis catalyst.

The invention has the beneficial effects that:

the invention utilizes the Oswald curing process to form a defect-rich catalytic material, combines the excellent conductivity and large specific surface area of the carrier three-dimensional conductive foam copper, and constructs the difunctional electrolytic water catalyst with a rapid electron transmission path, high loading capacity, high exposed active sites and high reaction activity.

The three-dimensional foam copper loaded basic cobaltous vanadate electrocatalytic material prepared by the method can promote electron transfer and reduce overpotential of electrocatalytic decomposition water due to the fact that the loaded hollow spherical catalyst can expose more active sites, has larger specific surface area and good surface permeability, and is combined with high loading capacity and smaller resistance which can be provided by a three-dimensional conductive carrier, and the method is a novel effective strategy for improving electrocatalytic activity.

The three-dimensional foamy copper loaded basic cobaltous vanadate electrocatalytic material prepared by the method has higher catalytic performance and excellent long-term stability, and has better application prospect in the technical field of electrocatalytic materials.

Proved by verification, the three-dimensional foamy copper-loaded basic cobalt vanadate electrode material prepared by the invention has excellent catalytic performance in both HER and OER aspects, and still has excellent electrochemical performance and stability when being used as a bifunctional catalyst.

The three-dimensional foam copper-loaded basic cobaltous vanadate electrolytic water catalyst prepared by the method is used in the technical field of electrocatalytic materials, and can be used for improving the energy and environmental problems.

Drawings

FIG. 1 is a scanning electron microscope (10 μm) of an electrolytic water catalyst of a three-dimensional foam copper-supported basic cobalt vanadate functional material prepared in the first embodiment;

FIG. 2 is a scanning electron microscope (1 μm) of an electrolytic water catalyst of the three-dimensional foam copper-supported basic cobalt vanadate functional material prepared in the first embodiment;

FIG. 3 is a transmission diagram of an electrolyzed water catalyst of a three-dimensional foamy copper-supported basic cobalt vanadate functional material prepared in the first embodiment, wherein a scale 51/nm, a scale b is 200nm, a scale c is 100nm, and a scale d is 100 nm;

FIG. 4 is a Raman spectrum of an electrolyzed water catalyst comprising a three-dimensional copper foam supported basic cobalt vanadate functional material prepared according to the first example, wherein ● represents a lattice vibration peak, ^ represents a V-O bond vibration peak, ■ represents a Co-O bond vibration peak, and ^ a represents a V-O-V bond vibration peak;

FIG. 5 is an x-ray powder diffraction pattern of an electrolytic water catalyst of the three-dimensional foam copper-supported basic cobalt vanadate functional material prepared in the first embodiment;

FIG. 6 is a performance diagram of the three-dimensional foamy copper-supported basic cobalt vanadate functional material water electrolysis catalyst prepared in the first embodiment for electrocatalytic hydrogen evolution reaction, wherein ■ represents Co₃(OH)₂V₂O₇·2H₂O/CF,. diamond-solid represents pure foamy copper,. tangle-solidup represents Pt/C/CF;

FIG. 7 is a graph of performance of the three-dimensional copper foam supported basic cobalt vanadate functional material water electrolysis catalyst prepared in the first embodiment in an electrocatalytic decomposition water-oxygen evolution reaction;

FIG. 8 is a performance diagram of the three-dimensional copper foam supported basic cobalt vanadate functional material electrolytic water catalyst prepared in the first embodiment for full water hydrolysis reaction.

Detailed Description

The technical solution of the present invention is not limited to the specific embodiments listed below, and includes any combination of the specific embodiments.

The first embodiment is as follows: the embodiment of the invention relates to a preparation method of a three-dimensional foamy copper-loaded basic cobalt vanadate functional material electrolytic water catalyst, which specifically comprises the following steps:

step one, preparing precursor nanospheres:

rapidly stirring and mixing sodium metavanadate and ultrapure water at constant temperature and magnetically to obtain a sodium metavanadate solution; quickly stirring and mixing cobalt nitrate hexahydrate and ultrapure water at constant temperature and by magnetic force to obtain a cobalt nitrate solution; cooling to room temperature;

loading a cobalt nitrate solution into a micro-sample injector, slowly dripping the cobalt nitrate solution into a sodium metavanadate solution, and stirring the solution in the adding process to obtain a suspension;

step two, carrying out ultrasonic cleaning on the carrier three-dimensional foamy copper by adopting acetone, hydrochloric acid, absolute ethyl alcohol and ultrapure water, and then drying in vacuum;

and step three, simultaneously putting the suspension obtained in the step one and the carrier three-dimensional foam copper treated in the step two into a hydrothermal reaction kettle, carrying out Ostwald ripening reaction, controlling the temperature and time of the hydrothermal reaction, synthesizing basic cobaltous vanadate hollow nanospheres on the carrier three-dimensional foam copper, then sequentially adopting ultrapure water and absolute ethyl alcohol for rinsing, drying, obtaining the three-dimensional foam copper-loaded basic cobaltous vanadate functional material electrolytic water catalyst, and finishing the preparation.

The second embodiment is as follows: the first difference between the present embodiment and the specific embodiment is: in the first step, the mass ratio of the cobalt nitrate hexahydrate to the sodium metavanadate is 3: 2; the volume ratio of the ultrapure water for preparing the cobalt nitrate solution to the ultrapure water for preparing the sodium metavanadate solution is 2: 7. The rest is the same as the first embodiment.

The third concrete implementation mode: the present embodiment differs from the first or second embodiment in that: step one, controlling the rotating speed of the rapid constant-temperature magnetic stirring to be 2000rpm, the time to be 30 minutes and the temperature to be 80 ℃. The other is the same as in the first or second embodiment.

The fourth concrete implementation mode: the difference between this embodiment mode and one of the first to third embodiment modes is: step one, the dropping speed of the microsyringe is controlled to be 100 mL/h. The others are the same as in one of the first to third embodiments.

The fifth concrete implementation mode: the difference between this embodiment and one of the first to fourth embodiments is: and step two, the size of the carrier three-dimensional foam copper is 1 cm multiplied by 2 cm, and the thickness is 2 mm. The other is the same as one of the embodiments to four.

The sixth specific implementation mode: the difference between this embodiment and one of the first to fifth embodiments is: and step two, the ultrasonic cleaning process comprises the steps of sequentially cleaning the substrate once by using acetone and hydrochloric acid, and then alternately cleaning the substrate for 3 times by using absolute ethyl alcohol and ultrapure water. The other is the same as one of the first to fifth embodiments.

The seventh embodiment: the difference between this embodiment and one of the first to sixth embodiments is: and step two, vacuum drying is carried out by adopting a vacuum drying oven, the temperature is controlled to be 60 ℃, and the drying time is 6 hours. The other is the same as one of the first to sixth embodiments.

The specific implementation mode is eight: the present embodiment differs from one of the first to seventh embodiments in that: and step three, the capacity of the inner container of the hydrothermal reaction kettle is 50mL, and the adding amount of the suspension is 30 mL. The other is the same as one of the first to seventh embodiments.

The specific implementation method nine: the present embodiment differs from the first to eighth embodiments in that: and step three, immersing the carrier three-dimensional foam copper in the suspension. The rest is the same as the first to eighth embodiments.

The detailed implementation mode is ten: the present embodiment differs from one of the first to ninth embodiments in that: and the hydrothermal reaction temperature is 150 ℃, and the reaction time is 7 h. The other is the same as one of the first to ninth embodiments.

The following examples were used to demonstrate the beneficial effects of the present invention:

the first embodiment is as follows:

the embodiment of the invention provides a preparation method of a three-dimensional foam copper-loaded basic cobalt vanadate functional material electrolytic water catalyst, which is characterized by comprising the following steps of:

step one, preparing precursor nanospheres:

1.4g of cobalt nitrate hexahydrate and 20mL of ultrapure water are quickly stirred and mixed at constant temperature and magnetic force to obtain a cobalt nitrate solution; rapidly stirring and mixing 0.39g of sodium metavanadate and 70mL of ultrapure water at constant temperature and magnetically to obtain a sodium metavanadate solution; cooling to room temperature; loading a cobalt nitrate solution into a micro-sample injector, slowly dripping the cobalt nitrate solution into a sodium metavanadate solution, and stirring the solution in the adding process to obtain a suspension;

step two, carrying out ultrasonic cleaning on the carrier three-dimensional foamy copper by adopting acetone, hydrochloric acid, absolute ethyl alcohol and ultrapure water, then drying in vacuum, and adopting a vacuum drying oven, controlling the temperature to be 60 ℃ and the drying time to be 6 hours; the size of the carrier three-dimensional foam copper is 1 cm multiplied by 2 cm, and the thickness is 2 mm;

and step three, simultaneously putting 30mL of the suspension obtained in the step one and the carrier three-dimensional foam copper treated in the step two into a hydrothermal reaction kettle, carrying out Ostwald ripening reaction, controlling the hydrothermal reaction temperature at 150 ℃ and the reaction time at 7h, synthesizing basic cobaltous vanadate hollow nanospheres on the carrier three-dimensional foam copper, then sequentially adopting ultrapure water and absolute ethyl alcohol for rinsing, and drying to obtain the three-dimensional foam copper-loaded basic cobaltous vanadate functional material electrolytic water catalyst, thus completing the preparation.

Step one, controlling the rotating speed of the rapid constant-temperature magnetic stirring to be 2000rpm, the time to be 30 minutes and the temperature to be 80 ℃.

Step one, the dropping speed of the microsyringe is controlled to be 100 mL/h.

And step two, the ultrasonic cleaning process comprises the steps of sequentially cleaning the substrate once by using acetone and hydrochloric acid, and then alternately cleaning the substrate for 3 times by using absolute ethyl alcohol and ultrapure water.

And step three, the capacity of the inner container of the hydrothermal reaction kettle is 50 mL.

And thirdly, obliquely leaning the carrier three-dimensional foam copper on the inner container wall of the reaction kettle, and immersing the carrier three-dimensional foam copper in the suspension.

FIG. 1 is a scanning electron microscope (10 μm) of an electrolytic water catalyst of the three-dimensional copper foam loaded basic cobalt vanadate functional material prepared in the first embodiment, and FIG. 2 is a scanning electron microscope (1 μm) of an electrolytic water catalyst of the three-dimensional copper foam loaded basic cobalt vanadate functional material prepared in the first embodiment; as can be seen from fig. 1 and fig. 2, the overall structure of the three-dimensional copper foam supported basic cobalt vanadate catalytic material prepared by the invention is in the shape of a hollow nanosphere, and the hollow structure grown in situ on the three-dimensional conductive substrate can promote the contact between the electrolyte and the functional material, thereby accelerating the electrochemical reaction.

FIG. 3 is a transmission diagram of an electrolyzed water catalyst of a three-dimensional foamy copper-supported basic cobalt vanadate functional material prepared in the first embodiment, wherein a scale a is 51 nm, a scale b is 200nm, a scale c is 100nm, and a scale d is 100 nm; as shown in FIG. 3, the diameter of the single spherical particle of the prepared three-dimensional foam copper-supported basic cobalt vanadate catalytic material is about 200 nm.

FIG. 4 is a Raman spectrum of an electrolyzed water catalyst of three-dimensional foam copper-supported basic cobalt vanadate functional material prepared in the first example, wherein ● represents a lattice vibration peak,Major axis is Y-O bond peak, major axis is ■ Co-O bond peak, major axis is tangle-solidup root is V-O-V bond peak; as can be seen from fig. 4, the prepared samples exhibited the corresponding characteristic raman peaks. The material is Co₃(OH)₂V₂O₇·2H₂O。

FIG. 5 is an x-ray powder diffraction pattern of the three-dimensional foam copper-supported basic cobalt vanadate functional material electrolytic water catalyst prepared in the first embodiment, and it can be known from FIG. 5 that the obtained product is a basic cobalt vanadate material, and the characteristic peak position of the product is matched with a standard PDF card (card number: 50-0570).

FIG. 6 is a performance diagram of the three-dimensional foamy copper-supported basic cobalt vanadate functional material water electrolysis catalyst prepared in the first embodiment for electrocatalytic hydrogen evolution reaction, wherein ■ represents Co₃(OH)₂V₂O₇·2H₂O/CF,. diamond-solid represents pure foamy copper,. tangle-solidup represents Pt/C/CF; as shown in fig. 6, the three-dimensional copper foam supported basic cobalt vanadate catalytic material exhibits excellent performance of electrocatalytic decomposition of water and hydrogen evolution.

Fig. 7 is a performance graph of the three-dimensional copper foam supported basic cobalt vanadate functional material electrolytic water catalyst prepared in the first example for electrocatalytic decomposition water oxygen evolution reaction, and as shown in fig. 7, the three-dimensional copper foam supported basic cobalt vanadate catalytic material exhibits excellent electrocatalytic decomposition water oxygen evolution performance.

FIG. 8 is a performance diagram of the three-dimensional copper foam supported basic cobalt vanadate functional material electrolytic water catalyst prepared in the first embodiment for full water hydrolysis reaction.