Preparation method of three-dimensional electrolytic composite hydrogen evolution material
阅读说明：本技术 一种三维电解复合析氢材料的制备方法 (Preparation method of three-dimensional electrolytic composite hydrogen evolution material ) 是由 曾令平 刘佳兴 贾友禄 肖逸锋 于 2020-12-15 设计创作，主要内容包括：本发明公开了一种三维电解复合析氢材料的制备方法,属于析氢材料技术领域；本发明先采用化学镀工艺制备了镍钴磷粉末,并对其进行聚乙烯醇浸渍改性处理,同时制备了氧化铜粉末和石墨-镍钴磷前驱体,之后烧结制备得到石墨-镍钴磷-氧化铜三维复合析氢材料；本发明制备方法简单,制备成本低廉,可大范围推广；石墨-镍钴磷-氧化铜三维复合析氢材料结合强度高,机械强度大,使用寿命长,具有良好的电催化析氢性能,重复使用性能好。(The invention discloses a preparation method of a three-dimensional electrolytic composite hydrogen evolution material, belonging to the technical field of hydrogen evolution materials; firstly, preparing nickel-cobalt-phosphorus powder by adopting a chemical plating process, carrying out polyvinyl alcohol impregnation modification treatment on the nickel-cobalt-phosphorus powder, simultaneously preparing copper oxide powder and a graphite-nickel-cobalt-phosphorus precursor, and then sintering to prepare a graphite-nickel-cobalt-phosphorus-copper oxide three-dimensional composite hydrogen evolution material; the preparation method is simple, the preparation cost is low, and the preparation method can be popularized in a large range; the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material has high bonding strength, high mechanical strength, long service life, good electrocatalytic hydrogen evolution performance and good reusability.)
1. A preparation method of a three-dimensional electrolytic composite hydrogen evolution material is characterized by comprising the following steps:
(1) pretreatment of graphite powder:
firstly, adding graphite powder with the average particle size of 0.5 mu m into a container filled with distilled water, wherein the mass ratio of the graphite powder to the distilled water is 1: 30, heating and boiling for 5 hours, naturally cooling the suspension to room temperature, and filtering and collecting graphite powder;
secondly, preparing a nitric acid solution with the mass percentage concentration of 15%, adding the graphite powder obtained in the step I into the nitric acid solution, and soaking for 30min, wherein the mass ratio of the graphite powder to the nitric acid solution is 1: 8, centrifugally separating the graphite powder, and centrifugally washing the graphite powder by using distilled water until the washing water is neutral; then, the washed graphite powder is placed in a drying oven to be dried at the temperature of 80 ℃, and after the graphite powder is dried, the graphite powder is ground into superfine powder with the average grain diameter of 0.5 mu m;
(2) preparing chemical plating solution for preparing nickel-phosphorus powder:
chemical raw materials used are as follows: the nickel sulfate, sodium hypophosphite, citric acid, succinic acid, sodium acetate and ammonium bifluoride are used in the following mass proportion relationship: nickel sulfate: sodium hypophosphite: citric acid: succinic acid: sodium acetate: 25-30% of ammonium bifluoride: 10-15: 10-15: 3-5: 3-5: 3-5;
preparing a chemical nickel and phosphorus plating solution:
firstly, sequentially adding nickel sulfate, citric acid, succinic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 50-60 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, carrying out magnetic stirring, adjusting the pH value of the solution in the container to be 4.4-4.8, and slowly carrying out magnetic stirring on the solution for 20-30 min to prepare the chemical plating solution for preparing the nickel-phosphorus powder;
(3) preparing chemical plating solution for preparing cobalt powder:
chemical raw materials used are as follows: the material comprises cobalt chloride, acetic acid, malonic acid, sodium acetate, ammonium bifluoride and sodium hypophosphite, wherein the dosage of the material is in the following mass proportion relation: cobalt chloride: acetic acid: malonic acid: sodium acetate: ammonium acid fluoride: 25-30% of sodium hypophosphite: 10-15: 3-5: 3-5: 10 to 15.
Preparing a chemical cobalt plating solution:
firstly, sequentially adding cobalt chloride, acetic acid, malonic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 30-50 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, carrying out magnetic stirring, adjusting the pH value of the solution in the container to be 4.4-4.8, and slowly carrying out magnetic stirring on the solution for 20-30 min to prepare the chemical plating solution for preparing cobalt powder;
(4) preparation and treatment of nickel-phosphorus-cobalt powder:
firstly, preparing chemical alkaline washing liquid:
sequentially adding sodium phosphate, sodium carbonate and sodium hydroxide into a beaker filled with 1L of distilled water according to the mass ratio of 7:5:1, and stirring to fully dissolve the sodium phosphate, the sodium carbonate and the sodium hydroxide; after the sodium phosphate, the sodium carbonate and the sodium hydroxide are fully dissolved, slowly stirring the solution at room temperature for 30min to obtain chemical alkaline washing liquid; heating the prepared chemical alkaline cleaning solution to 60-70 ℃ for later use;
pretreating a stainless steel test piece for chemical plating:
the stainless steel test piece for preparing the chemical nickel-cobalt-phosphorus plating layer comprises the following chemical components in percentage by mass: 0.08% of carbon, 0.03% of sulfur, 0.045% of phosphorus, 1.0% of silicon, 2.0% of manganese, 8.0% of nickel, 18.0% of chromium and the balance of iron;
a. firstly, carrying out primary polishing on a stainless steel test piece by using abrasive cloths with specifications of 60#, 120# and 280# in sequence to remove impurities such as dirt, oxide skin and the like on the surface of the test piece, then finely polishing the test piece by using water sand paper with specification of 400#, wherein after the test piece is polished, the surface of the test piece is smooth and has no macroscopic defect, scratch or sand hole;
b. cleaning a stainless steel test piece with distilled water, then placing the stainless steel test piece into a chemical alkaline washing solution at the temperature of 60-70 ℃ for oil removal treatment, taking the stainless steel test piece out of the alkaline washing solution after 5min, firstly washing the stainless steel test piece with flowing tap water, and then cleaning the stainless steel test piece with distilled water;
c. placing the stainless steel test piece which is degreased and cleaned in a hydrochloric acid solution with the mass percentage concentration of 10% for activation treatment, wherein the activation temperature is room temperature, taking out the test piece from the hydrochloric acid solution after 3-5 min of activation, and washing the residual hydrochloric acid solution on the surface of the test piece by using distilled water;
plating the stainless steel test piece and preparing nickel, cobalt and phosphorus powder:
mixing a chemical plating solution for preparing nickel-phosphorus powder and a chemical plating solution for preparing cobalt powder, placing the mixture in a container, keeping the temperature at 83-88 ℃, then placing the pretreated stainless steel test piece into the container, then placing a fine iron wire with the diameter of 0.5mm, the front end and the surface of which are polished by abrasive paper, into the plating solutions, and enabling the front end of the fine iron wire to be fully contacted with the stainless steel test piece; after a large amount of bubbles are generated and separated out on the surface of the stainless steel test piece, taking the stainless steel test piece out of the chemical plating solution, controlling the temperature of a container containing the plating solution by adopting water bath heating, controlling the plating time to be 60-90 min, taking the stainless steel test piece out of the plating solution, washing the surface of the stainless steel test piece by using flowing tap water, cleaning the surface of the stainless steel test piece by using distilled water, and drying the surface of the stainless steel test piece by blowing; scraping the nickel-cobalt-phosphorus coating on the surface of the stainless steel test piece by using a scraper, and grinding the nickel-cobalt-phosphorus coating in a high-energy ball mill to obtain nickel-cobalt-phosphorus powder with the average particle size of 7 mu m;
soaking pretreatment of nickel cobalt phosphorus powder:
preparing a polyvinyl alcohol aqueous solution with the mass percentage concentration of 0.3-0.5% by using polyvinyl alcohol with the polymerization degree of 1750 and the alcoholysis degree of 89%, placing the nickel-cobalt-phosphorus powder subjected to ball milling in the polyvinyl alcohol aqueous solution, soaking at room temperature for 60-90 min, taking out, placing in an oven, drying at the temperature of 80 ℃, and grinding into fine powder with the average particle size of 8 microns;
(5) treatment of copper oxide powder
Firstly, taking a copper sheet as a precursor, firstly, ultrasonically cleaning the copper sheet in 0.1mol/L HCl solution for 5 minutes, then washing the copper sheet with deionized water, then soaking the copper sheet in acetone solution for 1 minute, and finally washing the copper sheet with deionized water;
secondly, placing a part of the cleaned copper sheet in an alkaline aqueous solution, exposing the other part of the cleaned copper sheet in the air, wherein the alkaline aqueous solution contains 1mol/LKOH, 0.1mol/LLIOH and 0.01mol/LKCl, and after reacting for 5 days at room temperature, the whole surface of the copper sheet turns black; taking out the copper sheet, washing the copper sheet by using deionized water, and then drying the copper sheet;
thirdly, carrying out heat treatment on the dried copper sheet at 300 ℃ for 5 hours in an air atmosphere to obtain the copper sheet with the surface coated with the copper oxide;
scraping the copper oxide on the surface of the copper sheet by using a scraper, and grinding the scraped copper oxide in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 3-5 h to prepare copper oxide powder with the average particle size of 7 microns;
(6) preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Firstly, preparing graphite-nickel cobalt phosphorus precursor
According to the ratio of 1.5-2.3 mmol: 2.5-3.2 mmol: adding graphite powder and nickel cobalt phosphorus powder into deionized water according to the molar volume ratio of 10.8-15.4 mL, stirring, and then adding 2mmol of urea and 0.5mmol of NH4F, continuing stirring; adding the mixed solution obtained by stirring and sodium chloride accounting for 2% of the mass of the mixed solution into a reaction kettle, preserving the heat at 180 ℃ for 5 hours to obtain a graphite-nickel cobalt phosphorus precursor, and grinding the graphite-nickel cobalt phosphorus precursor into powder with the particle size of 8 mu m;
② preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Uniformly mixing the graphite-nickel cobalt phosphorus precursor and copper oxide powder, adding the mixture into a porcelain boat, putting the porcelain boat into an upper air inlet of a tube furnace, heating the porcelain boat to 300 ℃ in an argon atmosphere, preserving heat for 7 hours, then heating the porcelain boat to 450 ℃ at the speed of 3 ℃/min, and preserving heat for 2 hours; taking out, immediately washing with room-temperature deionized water for 3 times, soaking in ethanol for 10min, soaking in deionized water for 20min, and washing with deionized water for 2 times to obtain the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material.
2. The preparation method of the three-dimensional composite hydrogen evolution material according to claim 1, characterized in that the concentration of HCl solution used for treating the copper oxide powder is 0.1mol/L, the temperature for heat treatment of the copper sheet is 200-500 ℃, and the time for heat treatment is 5-10 hours.
3. The preparation method of the three-dimensional electrolytic composite hydrogen evolution material according to claim 1, characterized in that the rotation speed of a ball mill in the copper oxide powder treatment process is 1346rpm/min, the ball-to-material ratio is 40:1, and the grinding time is 3-5 h.
4. The method for preparing the three-dimensional electrolytic composite hydrogen evolution material according to claim 1, wherein the graphite-nickel cobalt phosphorus precursor and the copper oxide powder are mixed in a mass ratio of 1.5:1.3 during the preparation of the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material.
Technical Field
The invention relates to the technical field of hydrogen evolution materials, in particular to a preparation method of a three-dimensional electrolytic composite hydrogen evolution material.
Background
Recently, humans are facing increasingly severe environmental pollution and energy crisis, and the development and utilization of clean and efficient energy is currently one of the important challenges to solve the current crisis. From the perspective of energy cleanness and recyclability, hydrogen energy as a high-efficiency, clean and environment-friendly secondary energy has the characteristics of rich resources, high heat value, environmental protection, no pollution, various utilization forms and the like, is generally considered as an ideal new energy, and has incomparable huge advantages and infinite wide application prospects. However, how to obtain relatively cheap hydrogen energy through an effective way is one of the main contents of research of researchers at present, water resources on the earth are abundant, obtaining hydrogen through electrolysis of water is one of the effective ways, but low conversion efficiency of electrolysis energy of water is one of the factors restricting the industrial production of the hydrogen, so that designing and developing a high-performance catalyst for electrolyzing water has extremely important significance.
There are many methods for preparing hydrogen, and the most environmentally friendly method is to electrolyze water to prepare hydrogen-HER. Currently, the most efficient electrolytic water hydrogen evolution catalyst is a platinum group catalyst, but the practical application of the platinum group catalyst is limited by the expensive price and limited resources. Various non-noble metal catalysts are vigorously researched to replace platinum group catalysts for electrolyzing water to generate hydrogen, and metal phosphide attracts people's attention due to excellent electrochemical performance, and methods such as hetero atom doping, compounding with carbon materials and the like are used for improving HER catalytic activity of the metal phosphide. Since Ni has autocatalytic properties like Co, and Ni and Co act synergistically, NixCoyPz ternary phosphide was demonstrated to be comparable to the corresponding binary metal phosphide Ni2P and CoP have more excellent HER catalytic performance, but the existing catalytic activity and poor stability of the P and CoP cannot meet the actual requirement. The graphite has the advantages of wide sources, good stability, low price, good electrochemical performance and the like, has wide application in the fields of catalyst carriers, energy storage, electrocatalysis and the like, can adjust the electronic arrangement, the charge density, the generation defects and the formation of rich electrocatalytic active sites of carbon by doping nitrogen, sulfur, phosphorus and other heteroatoms in carbon groups, and has important application in the aspects of lithium ion batteries, electrochemical hydrogen evolution and oxygen evolution reactions, electrocatalytic oxygen reduction and the like. Graphite is combined with NixCoyPz ternary phosphide to improve the catalytic activity and stability of the catalyst, but the problems of incapability of being reused, poor mechanical strength, short service life and the like still exist. At present, no research report about a graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material is found.
Disclosure of Invention
The invention aims to provide a preparation method of a three-dimensional electrolytic composite hydrogen evolution material, which aims to solve the problems in the prior art.
In order to achieve the purpose, the invention provides the following scheme:
the invention provides a preparation method of a three-dimensional electrolytic composite hydrogen evolution material, which comprises the following steps:
1. a preparation method of a three-dimensional electrolytic composite hydrogen evolution material is characterized by comprising the following steps:
(1) pretreatment of graphite powder:
firstly, adding graphite powder with the average particle size of 0.5 mu m into a container filled with distilled water, wherein the mass ratio of the graphite powder to the distilled water is 1: 30, heating and boiling for 5 hours, naturally cooling the suspension to room temperature, and filtering and collecting graphite powder;
secondly, preparing a nitric acid solution with the mass percentage concentration of 15%, adding the graphite powder obtained in the step I into the nitric acid solution, and soaking for 30min, wherein the mass ratio of the graphite powder to the nitric acid solution is 1: 8, centrifugally separating the graphite powder, and centrifugally washing the graphite powder by using distilled water until the washing water is neutral; then, the washed graphite powder is placed in a drying oven to be dried at the temperature of 80 ℃, and after the graphite powder is dried, the graphite powder is ground into superfine powder with the average grain diameter of 0.5 mu m;
(2) preparing chemical plating solution for preparing nickel-phosphorus powder:
chemical raw materials used are as follows: the nickel sulfate, sodium hypophosphite, citric acid, succinic acid, sodium acetate and ammonium bifluoride are used in the following mass proportion relationship: nickel sulfate: sodium hypophosphite: citric acid: succinic acid: sodium acetate: 25-30% of ammonium bifluoride: 10-15: 10-15: 3-5: 3-5: 3-5;
preparing a chemical nickel and phosphorus plating solution:
firstly, sequentially adding nickel sulfate, citric acid, succinic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 50-60 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, carrying out magnetic stirring, adjusting the pH value of the solution in the container to be 4.4-4.8, and slowly carrying out magnetic stirring on the solution for 20-30 min to prepare the chemical plating solution for preparing the nickel-phosphorus powder;
(3) preparing chemical plating solution for preparing cobalt powder:
chemical raw materials used are as follows: the material comprises cobalt chloride, acetic acid, malonic acid, sodium acetate, ammonium bifluoride and sodium hypophosphite, wherein the dosage of the material is in the following mass proportion relation: cobalt chloride: acetic acid: malonic acid: sodium acetate: ammonium acid fluoride: 25-30% of sodium hypophosphite: 10-15: 3-5: 3-5: 10-15;
preparing a chemical cobalt plating solution:
firstly, sequentially adding cobalt chloride, acetic acid, malonic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 30-50 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, carrying out magnetic stirring, adjusting the pH value of the solution in the container to be 4.4-4.8, and slowly carrying out magnetic stirring on the solution for 20-30 min to prepare the chemical plating solution for preparing cobalt powder;
(4) preparation and treatment of nickel-phosphorus-cobalt powder:
firstly, preparing chemical alkaline washing liquid:
sequentially adding sodium phosphate, sodium carbonate and sodium hydroxide into a beaker filled with 1L of distilled water according to the mass ratio of 7:5:1, and stirring to fully dissolve the sodium phosphate, the sodium carbonate and the sodium hydroxide; after the sodium phosphate, the sodium carbonate and the sodium hydroxide are fully dissolved, slowly stirring the solution at room temperature for 30min to obtain chemical alkaline washing liquid; heating the prepared chemical alkaline cleaning solution to 60-70 ℃ for later use;
pretreating a stainless steel test piece for chemical plating:
the stainless steel test piece for preparing the chemical nickel-cobalt-phosphorus plating layer comprises the following chemical components in percentage by mass: 0.08% of carbon, 0.03% of sulfur, 0.045% of phosphorus, 1.0% of silicon, 2.0% of manganese, 8.0% of nickel, 18.0% of chromium and the balance of iron;
a. firstly, carrying out primary polishing on a stainless steel test piece by using abrasive cloths with specifications of 60#, 120# and 280# in sequence to remove impurities such as dirt, oxide skin and the like on the surface of the test piece, then finely polishing the test piece by using water sand paper with specification of 400#, wherein after the test piece is polished, the surface of the test piece is smooth and has no macroscopic defect, scratch or sand hole;
b. cleaning a stainless steel test piece with distilled water, then placing the stainless steel test piece into a chemical alkaline washing solution at the temperature of 60-70 ℃ for oil removal treatment, taking the stainless steel test piece out of the alkaline washing solution after 5min, firstly washing the stainless steel test piece with flowing tap water, and then cleaning the stainless steel test piece with distilled water;
c. placing the stainless steel test piece which is degreased and cleaned in a hydrochloric acid solution with the mass percentage concentration of 10% for activation treatment, wherein the activation temperature is room temperature, taking out the test piece from the hydrochloric acid solution after 3-5 min of activation, and washing the residual hydrochloric acid solution on the surface of the test piece by using distilled water;
plating the stainless steel test piece and preparing nickel, cobalt and phosphorus powder:
mixing a chemical plating solution for preparing nickel-phosphorus powder and a chemical plating solution for preparing cobalt powder, placing the mixture in a container, keeping the temperature at 83-88 ℃, then placing the pretreated stainless steel test piece into the container, then placing a fine iron wire with the diameter of 0.5mm, the front end and the surface of which are polished by abrasive paper, into the plating solutions, and enabling the front end of the fine iron wire to be fully contacted with the stainless steel test piece; after a large amount of bubbles are generated and separated out on the surface of the stainless steel test piece, taking the stainless steel test piece out of the chemical plating solution, controlling the temperature of a container containing the plating solution by adopting water bath heating, controlling the plating time to be 60-90 min, taking the stainless steel test piece out of the plating solution, washing the surface of the stainless steel test piece by using flowing tap water, cleaning the surface of the stainless steel test piece by using distilled water, and drying the surface of the stainless steel test piece by blowing; scraping the nickel-cobalt-phosphorus coating on the surface of the stainless steel test piece by using a scraper, and grinding the nickel-cobalt-phosphorus coating in a high-energy ball mill to obtain nickel-cobalt-phosphorus powder with the average particle size of 7 mu m;
soaking pretreatment of nickel cobalt phosphorus powder:
preparing a polyvinyl alcohol aqueous solution with the mass percentage concentration of 0.3-0.5% by using polyvinyl alcohol with the polymerization degree of 1750 and the alcoholysis degree of 89%, placing the nickel-cobalt-phosphorus powder subjected to ball milling in the polyvinyl alcohol aqueous solution, soaking at room temperature for 60-90 min, taking out, placing in an oven, drying at the temperature of 80 ℃, and grinding into fine powder with the average particle size of 8 microns;
(5) treatment of copper oxide powder
Firstly, taking a copper sheet as a precursor, firstly, ultrasonically cleaning the copper sheet in 0.1mol/L HCl solution for 5 minutes, then washing the copper sheet with deionized water, then soaking the copper sheet in acetone solution for 1 minute, and finally washing the copper sheet with deionized water;
secondly, placing a part of the cleaned copper sheet in an alkaline aqueous solution, exposing the other part of the cleaned copper sheet in the air, wherein the alkaline aqueous solution contains 1mol/LKOH, 0.1mol/LLIOH and 0.01mol/LKCl, and after reacting for 5 days at room temperature, the whole surface of the copper sheet turns black; taking out the copper sheet, washing the copper sheet by using deionized water, and then drying the copper sheet;
thirdly, carrying out heat treatment on the dried copper sheet at 300 ℃ for 5 hours in an air atmosphere to obtain the copper sheet with the surface coated with the copper oxide;
scraping the copper oxide on the surface of the copper sheet by using a scraper, and grinding the scraped copper oxide in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 3-5 h to prepare copper oxide powder with the average particle size of 7 microns;
(6) preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Firstly, preparing graphite-nickel cobalt phosphorus precursor
According to the ratio of 1.5-2.3 mmol: 2.5-3.2 mmol: adding graphite powder and nickel cobalt phosphorus powder into deionized water according to the molar volume ratio of 10.8-15.4 mL, stirring, and then adding 2mmol of urea and 0.5mmol of NH4F, continuing stirring; adding the mixed solution obtained by stirring and sodium chloride with the mass of 2 percent of the mixed solution into a reaction kettle together, and preserving the heat at 180 DEG C5h, obtaining a graphite-nickel cobalt phosphorus precursor, and grinding the graphite-nickel cobalt phosphorus precursor into powder with the particle size of 8 mu m;
② preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Uniformly mixing the graphite-nickel cobalt phosphorus precursor and copper oxide powder, adding the mixture into a porcelain boat, putting the porcelain boat into an upper air inlet of a tube furnace, heating the porcelain boat to 300 ℃ in an argon atmosphere, preserving heat for 7 hours, then heating the porcelain boat to 450 ℃ at the speed of 3 ℃/min, and preserving heat for 2 hours; taking out, immediately washing with room-temperature deionized water for 3 times, soaking in ethanol for 10min, soaking in deionized water for 20min, and washing with deionized water for 2 times to obtain the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material.
Preferably, the concentration of HCl solution adopted for treating the copper oxide powder is 0.1mol/L, the temperature for heat treatment of the copper sheet is 200-500 ℃, and the time for heat treatment is 5-10 hours.
Preferably, the rotating speed of the ball mill in the process of treating the copper oxide powder is 1346rpm/min, the ball-material ratio is 40:1, and the grinding time is 3-5 h.
Preferably, in the preparation process of the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material, the graphite-nickel cobalt phosphorus precursor and the copper oxide powder are mixed according to the mass ratio of 1.5: 1.3.
The beneficial technical effects are as follows: as Ni and Co have autocatalysis performance, cobalt ions can be introduced on the basis of the Ni-P alloy to form a Ni-Co-P ternary alloy plating layer. The Ni-Co-P ternary alloy coating can refine the crystallization compared to the Ni-P coating, so that the NixCoyPz ternary phosphide is compared with the corresponding binary metal phosphide Ni2P and CoP have more excellent HER catalytic performance; when the graphite-nickel cobalt phosphorus precursor is used in a high-temperature environment, the interface bonding state of graphite and a copper oxide matrix can be improved, so that the interface bonding is firmer and tighter, and the mechanical property of the three-dimensional composite hydrogen evolution material is obviously improved. The preparation method is simple, the preparation cost is low, and the preparation method can be popularized in a large range; the prepared graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material has good electrocatalytic hydrogen evolution performance, good reusability, large mechanical strength, long service life and high bonding strength.
Detailed Description
Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.
It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.
It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The specification and examples are exemplary only.
As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.
Example 1
A preparation method of a three-dimensional electrolytic composite hydrogen evolution material comprises the following steps:
(1) pretreatment of graphite powder:
firstly, adding graphite powder with the average particle size of 0.5 mu m into a container filled with distilled water, wherein the mass ratio of the graphite powder to the distilled water is 1: 30, heating and boiling for 5 hours, naturally cooling the suspension to room temperature, and filtering and collecting graphite powder;
secondly, preparing a nitric acid solution with the mass percentage concentration of 15%, adding the graphite powder obtained in the step I into the nitric acid solution, and soaking for 30min, wherein the mass ratio of the graphite powder to the nitric acid solution is 1: 8, centrifugally separating the graphite powder, and centrifugally washing the graphite powder by using distilled water until the washing water is neutral; then, the washed graphite powder is placed in a drying oven to be dried at the temperature of 80 ℃, and after the graphite powder is dried, the graphite powder is ground into superfine powder with the average grain diameter of 0.5 mu m;
(2) preparing chemical plating solution for preparing nickel-phosphorus powder:
chemical raw materials used are as follows: the nickel sulfate, sodium hypophosphite, citric acid, succinic acid, sodium acetate and ammonium bifluoride are used in the following mass proportion relationship: nickel sulfate: sodium hypophosphite: citric acid: succinic acid: sodium acetate: ammonium acid fluoride ═ 28: 13: 12: 4: 4: 4;
preparing a chemical nickel and phosphorus plating solution:
firstly, sequentially adding nickel sulfate, citric acid, succinic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 55 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; then dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, magnetically stirring, adjusting the pH value of the solution in the container to be 4.6, and slowly magnetically stirring the solution for 25min to prepare the chemical plating solution for preparing the nickel-phosphorus powder;
(3) preparing chemical plating solution for preparing cobalt powder:
chemical raw materials used are as follows: the material comprises cobalt chloride, acetic acid, malonic acid, sodium acetate, ammonium bifluoride and sodium hypophosphite, wherein the dosage of the material is in the following mass proportion relation: cobalt chloride: acetic acid: malonic acid: sodium acetate: ammonium acid fluoride: sodium hypophosphite 27: 13: 4: 4: 12;
preparing a chemical cobalt plating solution:
firstly, sequentially adding cobalt chloride, acetic acid, malonic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 40 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; then dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, magnetically stirring, adjusting the pH value of the solution in the container to be 4.6, and slowly magnetically stirring the solution for 25min to prepare the chemical plating solution for preparing cobalt powder;
(4) preparation and treatment of nickel-phosphorus-cobalt powder:
firstly, preparing chemical alkaline washing liquid:
sequentially adding sodium phosphate, sodium carbonate and sodium hydroxide into a beaker filled with 1L of distilled water according to the mass ratio of 7:5:1, and stirring to fully dissolve the sodium phosphate, the sodium carbonate and the sodium hydroxide; after the sodium phosphate, the sodium carbonate and the sodium hydroxide are fully dissolved, slowly stirring the solution at room temperature for 30min to obtain chemical alkaline washing liquid; heating the prepared chemical alkaline cleaning solution to 65 ℃ for later use;
pretreating a stainless steel test piece for chemical plating:
the stainless steel test piece for preparing the chemical nickel-cobalt-phosphorus plating layer comprises the following chemical components in percentage by mass: 0.08% of carbon, 0.03% of sulfur, 0.045% of phosphorus, 1.0% of silicon, 2.0% of manganese, 8.0% of nickel, 18.0% of chromium and the balance of iron;
a. firstly, carrying out primary polishing on a stainless steel test piece by using abrasive cloths with specifications of 60#, 120# and 280# in sequence to remove impurities such as dirt, oxide skin and the like on the surface of the test piece, then finely polishing the test piece by using water sand paper with specification of 400#, wherein after the test piece is polished, the surface of the test piece is smooth and has no macroscopic defect, scratch or sand hole;
b. cleaning a stainless steel test piece by using distilled water, then placing the stainless steel test piece into chemical alkaline washing liquid at the temperature of 65 ℃ for oil removal treatment, taking the stainless steel test piece out of the alkaline washing liquid after 5min, firstly washing the stainless steel test piece by using flowing tap water, and then cleaning the stainless steel test piece by using distilled water;
c. placing a stainless steel test piece which is degreased and cleaned in a hydrochloric acid solution with the mass percentage concentration of 10% for activation treatment, wherein the activation temperature is room temperature, taking out the test piece from the hydrochloric acid solution after activation for 4min, and cleaning the residual hydrochloric acid solution on the surface of the test piece by using distilled water;
plating the stainless steel test piece and preparing nickel, cobalt and phosphorus powder:
a. firstly, placing the stainless steel test piece in the step II in a container filled with the chemical plating solution in the steps (2) and (3) at the temperature of 86 ℃, then placing a thin iron wire with the diameter of 0.5mm, the front end and the surface of which are polished by sand paper, in the plating solution, and making the front end of the thin iron wire fully contact with the stainless steel test piece; after a large amount of bubbles are generated and separated out on the surface of the stainless steel, taking out the iron wire from the chemical plating solution, and controlling the temperature of a container containing the plating solution by adopting water bath heating for 80 min;
b. after plating for 80min, taking out the stainless steel test piece from the plating solution, firstly washing the surface of the stainless steel test piece by using running tap water, then cleaning the stainless steel test piece by using distilled water, and drying the surface of the stainless steel test piece by blowing;
c. scraping the nickel-cobalt-phosphorus coating on the surface of the stainless steel test piece by using a scraper, and grinding the nickel-cobalt-phosphorus coating in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 4h to prepare nickel-cobalt-phosphorus powder with the average particle size of 7 microns;
soaking pretreatment of nickel cobalt phosphorus powder:
preparing a polyvinyl alcohol aqueous solution with the mass percentage concentration of 0.4% by using polyvinyl alcohol with the polymerization degree of 1750 and the alcoholysis degree of 89%, placing the nickel-cobalt-phosphorus powder subjected to ball milling into the polyvinyl alcohol aqueous solution, soaking at room temperature for 70min, taking out, placing in an oven, drying at the temperature of 80 ℃, and grinding into fine powder with the average particle size of 8 mu m;
(5) treatment of copper oxide powder
Firstly, taking a copper sheet as a precursor, firstly, ultrasonically cleaning the copper sheet in 0.1mol/L HCl solution for 5 minutes, then washing the copper sheet with deionized water, then soaking the copper sheet in acetone solution for 1 minute, and finally washing the copper sheet with deionized water;
secondly, placing a part of the cleaned copper sheet in an alkaline aqueous solution, exposing the other part of the cleaned copper sheet in the air, wherein the alkaline aqueous solution contains 1mol/LKOH, 0.1mol/LLIOH and 0.01mol/LKCl, and after reacting for 5 days at room temperature, the whole surface of the copper sheet turns black; taking out the copper sheet, washing the copper sheet by using deionized water, and then drying the copper sheet;
thirdly, carrying out heat treatment on the dried copper sheet at 300 ℃ for 5 hours in an air atmosphere to obtain the copper sheet with the surface coated with the copper oxide;
scraping the copper oxide on the surface of the copper sheet coated with the copper oxide by using a scraper, and grinding the scraped copper oxide in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 3-5 h to obtain copper oxide powder with the average particle size of 7 microns;
(6) preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Firstly, preparing graphite-nickel cobalt phosphorus precursor
According to the weight ratio of 1.8mmol to 2.9 mmol: adding graphite powder and nickel cobalt phosphorus powder into deionized water according to the molar volume ratio of 13.6mL, stirring, and then adding 2mmol of urea and 0.5mmol of NH4F, continuing stirring; adding the mixed solution obtained by stirring and sodium chloride accounting for 2% of the mass of the mixed solution into a reaction kettle, preserving the heat at 180 ℃ for 5 hours to obtain a graphite-nickel cobalt phosphorus precursor, and grinding the graphite-nickel cobalt phosphorus precursor into powder with the particle size of 8 mu m;
② preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Uniformly mixing the graphite-nickel cobalt phosphorus precursor and copper oxide powder according to the mass ratio of 1.5:1.3, adding the mixture into a porcelain boat, putting the porcelain boat into an upper air inlet of a tube furnace, heating to 300 ℃ in an argon atmosphere, preserving heat for 7 hours, then heating to 450 ℃ at the speed of 3 ℃/min, and preserving heat for 2 hours; taking out, immediately washing with room-temperature deionized water for 3 times, soaking in ethanol for 10min, soaking in deionized water for 20min, and washing with deionized water for 2 times to obtain the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material.
The method is characterized in that a molybdenum disulfide-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material is used as a working electrode, a platinum electrode is used as a counter electrode, a silver/silver chloride electrode is used as a reference electrode, the scanning speed is 2mV/s, the potential scanning interval is-0.4-0.6V, the electrode potential is calibrated to be the electrode potential relative to a reversible hydrogen electrode, and the electrolyte is 1.0mol/L of sodium hydroxide solution. The results showed that the cathodic hydrogen evolution current density was 165.62mA/cm when the cathodic potential was-100 mV2The cathode has high hydrogen evolution current density and good electrochemical hydrogen evolution performance.
Example 2
A preparation method of a three-dimensional electrolytic composite hydrogen evolution material comprises the following steps:
(1) pretreatment of graphite powder:
firstly, adding graphite powder with the average particle size of 0.5 mu m into a container filled with distilled water, wherein the mass ratio of the graphite powder to the distilled water is 1: 30, heating and boiling for 5 hours, naturally cooling the suspension to room temperature, and filtering and collecting graphite powder;
secondly, preparing a nitric acid solution with the mass percentage concentration of 15%, adding the graphite powder obtained in the step I into the nitric acid solution, and soaking for 30min, wherein the mass ratio of the graphite powder to the nitric acid solution is 1: 8, centrifugally separating the graphite powder, and centrifugally washing the graphite powder by using distilled water until the washing water is neutral; then, the washed graphite powder is placed in a drying oven to be dried at the temperature of 80 ℃, and after the graphite powder is dried, the graphite powder is ground into superfine powder with the average grain diameter of 0.5 mu m;
(2) preparing chemical plating solution for preparing nickel-phosphorus powder:
chemical raw materials used are as follows: the nickel sulfate, sodium hypophosphite, citric acid, succinic acid, sodium acetate and ammonium bifluoride are used in the following mass proportion relationship: nickel sulfate: sodium hypophosphite: citric acid: succinic acid: sodium acetate: ammonium bifluoride 30: 10: 15: 3: 5: 3;
preparing a chemical nickel and phosphorus plating solution:
firstly, sequentially adding nickel sulfate, citric acid, succinic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 60 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; then dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, magnetically stirring, adjusting the pH value of the solution in the container to be 4.4, and slowly magnetically stirring the solution for 30min to prepare the chemical plating solution for preparing the nickel-phosphorus powder;
(3) preparing chemical plating solution for preparing cobalt powder:
chemical raw materials used are as follows: the material comprises cobalt chloride, acetic acid, malonic acid, sodium acetate, ammonium bifluoride and sodium hypophosphite, wherein the dosage of the material is in the following mass proportion relation: cobalt chloride: acetic acid: malonic acid: sodium acetate: ammonium acid fluoride: sodium hypophosphite 30: 10: 5: 3: 15;
preparing a chemical cobalt plating solution:
firstly, sequentially adding cobalt chloride, acetic acid, malonic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 30 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; then dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, magnetically stirring, adjusting the pH value of the solution in the container to be 4.8, and slowly magnetically stirring the solution for 20min to prepare the chemical plating solution for preparing cobalt powder;
(4) preparation and treatment of nickel-phosphorus-cobalt powder:
firstly, preparing chemical alkaline washing liquid:
sequentially adding sodium phosphate, sodium carbonate and sodium hydroxide into a beaker filled with 1L of distilled water according to the mass ratio of 7:5:1, and stirring to fully dissolve the sodium phosphate, the sodium carbonate and the sodium hydroxide; after the sodium phosphate, the sodium carbonate and the sodium hydroxide are fully dissolved, slowly stirring the solution at room temperature for 30min to obtain chemical alkaline washing liquid; heating the prepared chemical alkaline cleaning solution to 70 ℃ for later use;
pretreating a stainless steel test piece for chemical plating:
the stainless steel test piece for preparing the chemical nickel-cobalt-phosphorus plating layer comprises the following chemical components in percentage by mass: 0.08% of carbon, 0.03% of sulfur, 0.045% of phosphorus, 1.0% of silicon, 2.0% of manganese, 8.0% of nickel, 18.0% of chromium and the balance of iron;
a. firstly, carrying out primary polishing on a stainless steel test piece by using abrasive cloths with specifications of 60#, 120# and 280# in sequence to remove impurities such as dirt, oxide skin and the like on the surface of the test piece, then finely polishing the test piece by using water sand paper with specification of 400#, wherein after the test piece is polished, the surface of the test piece is smooth and has no macroscopic defect, scratch or sand hole;
b. cleaning a stainless steel test piece with distilled water, then placing the stainless steel test piece into a chemical alkaline washing solution at the temperature of 60-70 ℃ for oil removal treatment, taking the stainless steel test piece out of the alkaline washing solution after 5min, firstly washing the stainless steel test piece with flowing tap water, and then cleaning the stainless steel test piece with distilled water;
c. placing a stainless steel test piece which is degreased and cleaned in a hydrochloric acid solution with the mass percentage concentration of 10% for activation treatment, wherein the activation temperature is room temperature, taking out the test piece from the hydrochloric acid solution after 3min of activation, and cleaning the residual hydrochloric acid solution on the surface of the test piece by using distilled water;
plating the stainless steel test piece and preparing nickel, cobalt and phosphorus powder:
a. firstly, placing the stainless steel test piece in the step II in a container filled with the chemical plating solution in the steps (2) and (3) at the temperature of 88 ℃, then placing a thin iron wire with the diameter of 0.5mm, the front end and the surface of which are polished by sand paper, in the plating solution, and making the front end of the thin iron wire fully contact with the stainless steel test piece; after a large amount of bubbles are generated and separated out on the surface of the stainless steel, taking out the iron wire from the chemical plating solution, and controlling the temperature of a container containing the plating solution by adopting water bath heating for 60 min;
b. after plating for 60min, taking out the stainless steel test piece from the plating solution, firstly washing the surface of the stainless steel test piece by using running tap water, then cleaning the stainless steel test piece by using distilled water, and drying the surface of the stainless steel test piece by blowing;
c. scraping the nickel-cobalt-phosphorus coating on the surface of the stainless steel test piece by using a scraper, and grinding the nickel-cobalt-phosphorus coating in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 5 hours to obtain nickel-cobalt-phosphorus powder with the average particle size of 7 microns;
soaking pretreatment of nickel cobalt phosphorus powder:
preparing a polyvinyl alcohol aqueous solution with the mass percentage concentration of 0.3% by using polyvinyl alcohol with the polymerization degree of 1750 and the alcoholysis degree of 89%, placing the nickel-cobalt-phosphorus powder subjected to ball milling into the polyvinyl alcohol aqueous solution, soaking for 90min at room temperature, taking out the nickel-cobalt-phosphorus powder, placing the nickel-cobalt-phosphorus powder into an oven, drying the nickel-cobalt-phosphorus powder at the temperature of 80 ℃, and grinding the nickel-cobalt-phosphorus powder into fine powder with the average particle size of 8 mu m;
(5) treatment of copper oxide powder
Firstly, taking a copper sheet as a precursor, firstly, ultrasonically cleaning the copper sheet in 0.1mol/L HCl solution for 5 minutes, then washing the copper sheet with deionized water, then soaking the copper sheet in acetone solution for 1 minute, and finally washing the copper sheet with deionized water;
secondly, placing a part of the cleaned copper sheet in an alkaline aqueous solution, exposing the other part of the cleaned copper sheet in the air, wherein the alkaline aqueous solution contains 1mol/LKOH, 0.1mol/LLIOH and 0.01mol/LKCl, and after reacting for 5 days at room temperature, the whole surface of the copper sheet turns black; taking out the copper sheet, washing the copper sheet by using deionized water, and then drying the copper sheet;
thirdly, carrying out heat treatment on the dried copper sheet at 300 ℃ for 5 hours in an air atmosphere to obtain the copper sheet with the surface coated with the copper oxide;
scraping the copper oxide on the surface of the copper sheet coated with the copper oxide by using a scraper, and grinding the scraped copper oxide in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 3h to prepare copper oxide powder with the average particle size of 7 microns;
(6) preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Firstly, preparing graphite-nickel cobalt phosphorus precursor
According to the weight ratio of 1.5mmol to 3.2 mmol: adding graphite powder and nickel cobalt phosphorus powder into deionized water according to the molar volume ratio of 15.4mL,stirring, adding 2mmol of urea and 0.5mmol of NH4F, continuing stirring; adding the mixed solution obtained by stirring and sodium chloride accounting for 2% of the mass of the mixed solution into a reaction kettle, preserving the heat at 180 ℃ for 5 hours to obtain a graphite-nickel cobalt phosphorus precursor, and grinding the graphite-nickel cobalt phosphorus precursor into powder with the particle size of 8 mu m;
② preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Uniformly mixing the graphite-nickel cobalt phosphorus precursor and copper oxide powder according to the mass ratio of 1.5:1.3, adding the mixture into a porcelain boat, putting the porcelain boat into an upper air inlet of a tube furnace, heating to 300 ℃ in an argon atmosphere, preserving heat for 7 hours, then heating to 450 ℃ at the speed of 3 ℃/min, and preserving heat for 2 hours; taking out, immediately washing with room-temperature deionized water for 3 times, soaking in ethanol for 10min, soaking in deionized water for 20min, and washing with deionized water for 2 times to obtain the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material.
Example 3
A preparation method of a three-dimensional electrolytic composite hydrogen evolution material comprises the following steps:
(1) pretreatment of graphite powder:
firstly, adding graphite powder with the average particle size of 0.5 mu m into a container filled with distilled water, wherein the mass ratio of the graphite powder to the distilled water is 1: 30, heating and boiling for 5 hours, naturally cooling the suspension to room temperature, and filtering and collecting graphite powder;
secondly, preparing a nitric acid solution with the mass percentage concentration of 15%, adding the graphite powder obtained in the step I into the nitric acid solution, and soaking for 30min, wherein the mass ratio of the graphite powder to the nitric acid solution is 1: 8, centrifugally separating the graphite powder, and centrifugally washing the graphite powder by using distilled water until the washing water is neutral; then, the washed graphite powder is placed in a drying oven to be dried at the temperature of 80 ℃, and after the graphite powder is dried, the graphite powder is ground into superfine powder with the average grain diameter of 0.5 mu m;
(2) preparing chemical plating solution for preparing nickel-phosphorus powder:
chemical raw materials used are as follows: the nickel sulfate, sodium hypophosphite, citric acid, succinic acid, sodium acetate and ammonium bifluoride are used in the following mass proportion relationship: nickel sulfate: sodium hypophosphite: citric acid: succinic acid: sodium acetate: ammonium bifluoride 25: 15: 10: 5: 3: 5;
preparing a chemical nickel and phosphorus plating solution:
firstly, sequentially adding nickel sulfate, citric acid, succinic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 50 ℃ and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; then dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, magnetically stirring, adjusting the pH value of the solution in the container to be 4.8, and slowly and magnetically stirring the solution for 20min to prepare the chemical plating solution for preparing the nickel-phosphorus powder;
(3) preparing chemical plating solution for preparing cobalt powder:
chemical raw materials used are as follows: the material comprises cobalt chloride, acetic acid, malonic acid, sodium acetate, ammonium bifluoride and sodium hypophosphite, wherein the dosage of the material is in the following mass proportion relation: cobalt chloride: acetic acid: malonic acid: sodium acetate: ammonium acid fluoride: sodium hypophosphite 25: 15: 3: 5: 10;
preparing a chemical cobalt plating solution:
firstly, sequentially adding cobalt chloride, acetic acid, malonic acid, sodium acetate and ammonium bifluoride into a container containing 1L of distilled water, placing the container on a magnetic stirrer, heating to ensure that the temperature of the solution is 50 ℃, and completely dissolving the added reagent; after the reagents are dissolved, adding sodium hypophosphite into the solution, stirring to dissolve the sodium hypophosphite, and naturally cooling the solution to room temperature after the sodium hypophosphite is completely dissolved; then dropwise adding an ammonia water solution with the mass percentage concentration of 25% into the solution by using a dropper, magnetically stirring, adjusting the pH value of the solution in the container to be 4.4, and slowly magnetically stirring the solution for 30min to prepare the chemical plating solution for preparing the cobalt powder;
(4) preparation and treatment of nickel-phosphorus-cobalt powder:
firstly, preparing chemical alkaline washing liquid:
sequentially adding sodium phosphate, sodium carbonate and sodium hydroxide into a beaker filled with 1L of distilled water according to the mass ratio of 7:5:1, and stirring to fully dissolve the sodium phosphate, the sodium carbonate and the sodium hydroxide; after the sodium phosphate, the sodium carbonate and the sodium hydroxide are fully dissolved, slowly stirring the solution at room temperature for 30min to obtain chemical alkaline washing liquid; heating the prepared chemical alkaline cleaning solution to 60-70 ℃ for later use;
pretreating a stainless steel test piece for chemical plating:
the stainless steel test piece for preparing the chemical nickel-cobalt-phosphorus plating layer comprises the following chemical components in percentage by mass: 0.08% of carbon, 0.03% of sulfur, 0.045% of phosphorus, 1.0% of silicon, 2.0% of manganese, 8.0% of nickel, 18.0% of chromium and the balance of iron;
a. firstly, carrying out primary polishing on a stainless steel test piece by using abrasive cloths with specifications of 60#, 120# and 280# in sequence to remove impurities such as dirt, oxide skin and the like on the surface of the test piece, then finely polishing the test piece by using water sand paper with specification of 400#, wherein after the test piece is polished, the surface of the test piece is smooth and has no macroscopic defect, scratch or sand hole;
b. cleaning a stainless steel test piece by using distilled water, then placing the stainless steel test piece into chemical alkaline washing liquid at the temperature of 60 ℃ for oil removal treatment, taking the stainless steel test piece out of the alkaline washing liquid after 5min, firstly washing the stainless steel test piece by using flowing tap water, and then cleaning the stainless steel test piece by using distilled water;
c. placing a stainless steel test piece which is degreased and cleaned in a hydrochloric acid solution with the mass percentage concentration of 10% for activation treatment, wherein the activation temperature is room temperature, taking out the test piece from the hydrochloric acid solution after 5min of activation, and cleaning the residual hydrochloric acid solution on the surface of the test piece by using distilled water;
plating the stainless steel test piece and preparing nickel, cobalt and phosphorus powder:
a. firstly, placing the stainless steel test piece in the step II in a container filled with the chemical plating solution in the steps (2) and (3) at the temperature of 83 ℃, then placing a thin iron wire with the diameter of 0.5mm, the front end and the surface of which are polished by sand paper, in the plating solution, and making the front end of the thin iron wire fully contact with the stainless steel test piece; after a large amount of bubbles are generated and separated out on the surface of the stainless steel, taking out the iron wire from the chemical plating solution, and controlling the temperature of a container containing the plating solution by adopting water bath heating for 90 min;
b. taking out the stainless steel test piece from the plating solution after plating for 90min, firstly washing the surface of the stainless steel test piece by using running tap water, then cleaning the stainless steel test piece by using distilled water, and drying the surface of the stainless steel test piece by blowing;
c. scraping the nickel-cobalt-phosphorus coating on the surface of the stainless steel test piece by using a scraper, and grinding the nickel-cobalt-phosphorus coating in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 3h to obtain nickel-cobalt-phosphorus powder with the average particle size of 7 microns;
soaking pretreatment of nickel cobalt phosphorus powder:
preparing a polyvinyl alcohol aqueous solution with the mass percentage concentration of 0.5% by using polyvinyl alcohol with the polymerization degree of 1750 and the alcoholysis degree of 89%, placing the nickel-cobalt-phosphorus powder subjected to ball milling into the polyvinyl alcohol aqueous solution, soaking for 60min at room temperature, taking out the nickel-cobalt-phosphorus powder, placing the nickel-cobalt-phosphorus powder into an oven, drying the nickel-cobalt-phosphorus powder at the temperature of 80 ℃, and grinding the nickel-cobalt-phosphorus powder into fine powder with the average particle size of 8 mu m;
(5) treatment of copper oxide powder
Firstly, taking a copper sheet as a precursor, firstly, ultrasonically cleaning the copper sheet in 0.1mol/L HCl solution for 5 minutes, then washing the copper sheet with deionized water, then soaking the copper sheet in acetone solution for 1 minute, and finally washing the copper sheet with deionized water;
secondly, placing a part of the cleaned copper sheet in an alkaline aqueous solution, exposing the other part of the cleaned copper sheet in the air, wherein the alkaline aqueous solution contains 1mol/LKOH, 0.1mol/LLIOH and 0.01mol/LKCl, and after reacting for 5 days at room temperature, the whole surface of the copper sheet turns black; taking out the copper sheet, washing the copper sheet by using deionized water, and then drying the copper sheet;
thirdly, carrying out heat treatment on the dried copper sheet at 300 ℃ for 5 hours in an air atmosphere to obtain the copper sheet with the surface coated with the copper oxide;
scraping the copper oxide on the surface of the copper sheet coated with the copper oxide by using a scraper, and grinding the scraped copper oxide in a high-energy ball mill at the rotating speed of 1346rpm/min at the ball-to-material ratio of 40:1 for 5 hours to prepare copper oxide powder with the average particle size of 7 microns;
(6) preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Firstly, preparing graphite-nickel cobalt phosphorus precursor
According to a ratio of 2.3mmol:2.5 mmol: adding graphite powder and nickel cobalt phosphorus powder into deionized water according to the molar volume ratio of 10.8mL, stirring, and then adding 2mmol of urea and 0.5mmol of NH4F, continuing stirring; adding the mixed solution obtained by stirring and sodium chloride accounting for 2% of the mass of the mixed solution into a reaction kettle, preserving the heat at 180 ℃ for 5 hours to obtain a graphite-nickel cobalt phosphorus precursor, and grinding the graphite-nickel cobalt phosphorus precursor into powder with the particle size of 8 mu m;
② preparation of graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material
Uniformly mixing the graphite-nickel cobalt phosphorus precursor and copper oxide powder according to the mass ratio of 1.5:1.3, adding the mixture into a porcelain boat, putting the porcelain boat into an upper air inlet of a tube furnace, heating to 300 ℃ in an argon atmosphere, preserving heat for 7 hours, then heating to 450 ℃ at the speed of 3 ℃/min, and preserving heat for 2 hours; taking out, immediately washing with room-temperature deionized water for 3 times, soaking in ethanol for 10min, soaking in deionized water for 20min, and washing with deionized water for 2 times to obtain the graphite-nickel cobalt phosphorus-copper oxide three-dimensional composite hydrogen evolution material.
The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.