CN113122873B

CN113122873B - Electrocatalytic material and preparation method thereof

Info

Publication number: CN113122873B
Application number: CN202110408832.7A
Authority: CN
Inventors: 常彬; 周伟家; 袁海凤; 刘震; 赵莉莉; 姜迪
Original assignee: University of Jinan
Current assignee: University of Jinan
Priority date: 2021-04-16
Filing date: 2021-04-16
Publication date: 2022-05-24
Anticipated expiration: 2041-04-16
Also published as: CN113122873A

Abstract

The invention discloses an electrocatalytic material and a preparation method thereof. The method comprises the following steps: and immersing the substrate in a metal solution by taking the metal sheet as the substrate, starting laser to etch the substrate, and obtaining the electro-catalytic material after etching. The invention can be used for preparing the electrocatalytic material for electrocatalytic ammonia synthesis: a noble metal-mixed phase titanium dioxide multi-stage electrocatalytic material; the multifunctional integrated electrocatalysis material for electrocatalysis hydrogen production can be prepared. The precious metal-mixed phase titanium dioxide multi-stage electro-catalysis synthetic ammonia material prepared by the invention can realize optimization of a gas-liquid-solid three-phase reaction interface and anchoring load of dominant active components by a laser micro-processing process one-step method, and has obvious effect when being used for electro-catalysis synthetic ammonia. The multifunctional integrated electrocatalytic material prepared by the invention has the capabilities of solution circulation, gas diffusion and current collection and excellent and stable electrocatalytic hydrogen production activity.

Description

Electrocatalytic material and preparation method thereof

Technical Field

The invention relates to the technical field of electrocatalytic materials, in particular to an electrocatalytic material and a preparation method thereof.

Background

One of the most important chemical products, ammonia (NH)₃) The method occupies an indispensable position in national economic development. The birth of the Haber-Bosch ammonia synthesis method has led to the successful realization of "bread in the air". However, the Haber-Bosch process is harsh in reaction conditions and high in energy consumption, and releases a large amount of carbon dioxide during the preparation of the raw material hydrogen to cause environmental pollution. Therefore, researchers have been working on attempts to innovate the catalytic technology of synthetic ammonia in an attempt to lower the temperature and pressure of the reaction of synthetic ammonia and to improve the conversion efficiency of synthetic ammonia. Based on the nature of the synthetic ammonia: the ammonia synthesis can be realized only by a proper proton source and an electron donor, and the technology for synthesizing ammonia by electrocatalysis nitrogen fixation is generated. The technology has the advantages of mild reaction conditions, low energy consumption, environmental friendliness and the like. However, there are still many disadvantages, such as low ammonia yield, low faradaic efficiency, poor catalytic material stability, etc.

Hydrogen, a renewable energy source, has the advantage of being clean and pollution-free, and is considered one of the most potential candidates for fossil fuels. The technology for producing hydrogen by electrolysis has the advantages of cleanness, no pollution, high purity of prepared hydrogen, high efficiency and the like, and converts redundant electric energy into hydrogen energy. The key to the large-scale application of hydrogen production by water electrolysis is to further reduce the power cost of hydrogen production by water electrolysis by using a high-activity electrocatalyst. In addition, the water electrolysis hydrogen production device is composed of a cathode conductive current collector, a cathode catalyst, a proton exchange membrane, an anode catalyst, an anode conductive current collector and the like. The cathodic conductive current collector and the anodic conductive current collector function to conduct and collect current, with the grooved channels and pore structure for the passage of water and gas. The cathode catalyst and the anode catalyst are usually coated on both sides of the proton exchange membrane using a binder, but this supported material is liable to cause catalyst peeling after a long test. Secondly, the conductive current collector and the electrocatalyst are made of two parts, increasing the complexity of the cell element.

Therefore, a simple and low-energy-consumption preparation method is needed for preparing the electrocatalytic material, so that the electrocatalytic material can be used for electrocatalytic ammonia synthesis or electrocatalytic hydrogen production.

Disclosure of Invention

In view of the above prior art, the present invention aims to provide an electrocatalytic material and a preparation method thereof. The precious metal-mixed phase titanium dioxide multi-stage electro-catalysis synthetic ammonia material prepared by the invention can realize optimization of a gas-liquid-solid three-phase reaction interface and anchoring load of dominant active components by a laser micro-processing process one-step method, and has obvious effect when being used for electro-catalysis synthetic ammonia. The invention can also prepare a multifunctional integrated electrocatalytic material which simultaneously has the capabilities of solution circulation, gas diffusion and current collection and excellent and stable electrocatalytic hydrogen production activity.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect of the present invention, there is provided a method for preparing an electrocatalytic material, the method comprising: and immersing the substrate in a metal solution by taking the metal sheet as the substrate, starting laser to bombard the substrate, and obtaining the electrocatalytic material after the bombardment is finished.

Preferably, the substrate is titanium, and the thickness of the substrate is 0.02-2 mm; the metal solution is a noble metal solution.

More preferably, the noble metal solution is a chloroauric acid solution, a chloroplatinic acid solution, a rhodium chloride solution, a ruthenium chloride solution or a palladium chloride solution; the solution concentration of the noble metal solution is 1-20 mM.

The chloroauric acid solution, the chloroplatinic acid solution, the rhodium chloride solution, the ruthenium chloride solution or the palladium chloride solution are prepared by taking water as a solvent.

Preferably, the pulse frequency of the laser is 5-20 kHz, the wavelength is 1064nm, the energy is 2-20W, and the sweep rate is 20-1000 mm/s.

Preferably, the substrate is pretreated before being immersed in the metal solution, wherein the pretreatment is to etch the substrate by using laser to form a groove channel and a hole structure on the substrate.

Preferably, the power of the laser etching is 10-20W.

Preferably, the substrate is titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, silver, cadmium, tantalum, tungsten, platinum, gold, aluminum, indium, thallium, tin, palladium, rhodium, iridium, or alloys of the foregoing metals.

Preferably, the metal solution is a solution containing metal ions at a concentration of 2 mM.

The solution containing metal ions is prepared by using water as a solvent.

More preferably, the metal ions are one or more of titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, silver, cadmium, tantalum, tungsten, platinum, gold, aluminum, indium, thallium, tin, palladium, rhodium and iridium ions.

Preferably, the pulse frequency of the laser for bombarding the substrate is 20kHz, the wavelength is 1064nm, the laser power is 19W, and the scanning speed is 500 mm/s.

In a second aspect of the present invention, the multi-stage electrocatalytic material prepared by the above preparation method is provided, wherein the multi-stage electrocatalytic material is a three-stage electrocatalytic material, and the three-stage electrocatalytic material includes a noble metal, a mixed-phase titanium dioxide, and a noble metal-mixed-phase titanium dioxide.

In a third aspect of the present invention, there is provided the multifunctional integrated electrocatalytic material prepared by the above preparation method, wherein the electrocatalytic material comprises a substrate, the substrate is provided with a groove channel and a pore structure, and the substrate is loaded with a metal electrocatalyst; the metal electrocatalyst is a simple substance or an alloy of titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, silver, cadmium, tantalum, tungsten, platinum, gold, aluminum, indium, thallium, tin, palladium, rhodium and iridium.

In a fourth aspect of the invention, there is provided the use of the above multistage electrocatalytic material in the electrocatalytic synthesis of ammonia.

In a fifth aspect of the invention, the multifunctional integrated electrocatalytic material is applied to electrocatalytic hydrogen production.

The invention has the beneficial effects that:

1. the invention adopts the laser micromachining and etching method, and the preparation process is precise, accurate and rapid. And non-contact processing is adopted, so that mechanical extrusion or mechanical stress cannot be generated on the material. Meanwhile, the laser micromachining has the characteristics of high speed, concentrated energy, short preparation period and strong repeatability, and is easy to integrate and industrialize. The laser preparation belongs to a preparation method of a normal-temperature, normal-pressure and open system, and has the advantages of convenient operation, easy control, high dimensional precision and high processing repeatability.

2. The micro-channel structure of the precious metal-mixed phase titanium dioxide multistage electro-catalytic material prepared by the invention effectively realizes the optimization of gas-liquid-solid three-phase reaction interface, and meanwhile, the regulation and control of mixed crystal phase and the loading of active components further improve the catalytic activity of electro-catalytic synthesis of ammonia.

3. The multifunctional integrated electrocatalysis material prepared by the invention has the capabilities of solution circulation, gas diffusion and current collection and excellent and stable electrocatalysis hydrogen production activity. The conductive current collector and the electrocatalyst are unified, are integrated multifunctional electrodes, and avoid various defects of the electrocatalyst loaded on the proton exchange membrane. According to the invention, the groove channel and the hole structure are marked on the metal electrode by laser, the conductive current collector is simply and rapidly prepared, and the shape and the size of the groove channel and the hole structure of the electrode can be designed at will. The prepared electro-catalytic material is a metal electro-catalyst which is loaded on a conductive current collector in situ by laser, does not need the fixation of a binder, has good catalytic stability and can be independently loaded.

Drawings

FIG. 1 is a schematic view of the process flow of the present invention for preparing a precious metal-miscible titanium dioxide multi-stage electrocatalytic material.

FIG. 2 is an X-ray diffraction pattern of a gold-miscible titanium dioxide multi-stage electrocatalytic material prepared according to the present invention.

FIG. 3 is a front scanning electron microscope image, a front scanning electron microscope image and a back scanning electron microscope image of the gold-mixed phase titanium dioxide multi-stage electrocatalytic material prepared by the invention.

FIG. 4 is the current-time curve diagram of the synthesis of ammonia by using the gold-mixed phase titanium dioxide multi-stage electrocatalytic material prepared by the invention.

FIG. 5 is a diagram showing the catalytic performance of ammonia synthesis of gold-mixed phase titanium dioxide multi-stage electrocatalytic material prepared by the present invention, wherein a is a diagram showing the ammonia production rate, and b is a diagram showing the Faraday efficiency.

Fig. 6 is a schematic view of the multifunctional integrated electrocatalytic material prepared by the present invention, wherein 1 is a metal sheet substrate, 2 is a groove channel, 3 is a pore structure, and 4 is a supported metal electrocatalyst.

FIG. 7 is an XRD pattern of the Pt/Mo multifunctional integrated electrocatalytic material prepared in the embodiment 6 of the present invention.

Fig. 8 is a LSV curve of the Pt/Mo multifunctional integrated electrocatalytic material prepared in example 6 of the present invention at PH 0.

Fig. 9 is an i-t curve of the Pt/Mo multifunctional integrated electrocatalytic material prepared in example 6 of the present invention at PH 0.

FIG. 10 is a diagram of Pt obtained in comparative example 2₇₅Mo₂₅The LSV profile of @ graphene material at pH 0.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. 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 application belongs.

As described in the background section, semiconducting titanium dioxide has the advantages of chemical stability, strong redox properties, corrosion resistance and low cost. The mixed crystal form and the variable valence state titanium can promote the N [ identical to ] N triple bond fracture of nitrogen, and the reverse bond pi orbit of nitrogen molecule can feed back and accelerate the N [ identical to ] N fracture. Meanwhile, the gold active center receives electrons of the mixed-phase titanium dioxide to further promote the electron enrichment, so that the adsorption and the dissociation of nitrogen molecules on electron-rich active sites are accelerated. Although various types of functionalized titanium dioxide have many applications in the field of energy conversion functionalization, the preparation methods are complex or consume too much energy.

When the water is electrolyzed to produce hydrogen, the conductive current collector and the electro-catalytic material are composed of two parts, so that the complexity of the elements of the electrolytic cell is increased. The method of coating the catalytic material on the proton exchange membrane by using the binder is unstable, and the catalyst is easy to fall off after long-time testing.

Based on this, the object of the present invention is to provide an electrocatalytic material and a method for preparing the same. The invention is based on laser micromachining technology, and directly realizes the integrated and integrated preparation of the gold-mixed phase titanium dioxide composite hole electrode material for synthesizing ammonia by electro-catalysis.

The method can also be used for preparing the multifunctional integrated electrocatalytic material which simultaneously has the capabilities of solution circulation, gas diffusion and current collection and the electrocatalytic hydrogen production activity; the shape and size of the groove channel and pore structure of the electrode can be designed at will, and the metal substrate and the metal electrocatalyst required to be supported can be selected autonomously. The substrate of the invention has certain conductivity, and is beneficial to the flow of current when being used as an electrode. The substrate material can absorb laser to generate a thermal effect, so that the load of metal ions and the construction of groove channels and hole structures are facilitated. The laser etching is used, so that the metal substrate can absorb laser to generate a strong thermal effect, and metal ions are reduced into metal by heat and loaded on the metal substrate; on the other hand, a groove channel and hole structure is constructed.

In order to make the technical solutions of the present application more clearly understood by those skilled in the art, the technical solutions of the present application will be described in detail below with reference to specific embodiments.

The test materials used in the examples of the present invention are all conventional in the art and commercially available.

Example 1

The precious metal-mixed phase titanium dioxide multi-stage electrocatalytic material is prepared by adopting the process flow schematic diagram shown in figure 1.

Adding a prepared 2mM chloroauric acid solution into a reactor, immersing a titanium target with the thickness of 1mM in the prepared chloroauric acid solution, and then adjusting the optical path of a pulse laser beam on a laser processing table to focus the laser beam on the titanium target. The laser pulse frequency was set at 20kHz, the wavelength at 1064nm, the energy at 10W and the sweep rate at 200 mm/s. And starting a laser to etch the titanium target. And after the laser etching is finished, washing the electrode material with water and alcohol for 2 times respectively, and performing vacuum drying to obtain the precious metal-mixed phase titanium dioxide multi-stage electro-catalytic material. The resulting material was titanium dioxide in a mixed phase of rutile and anatase, as evidenced by the XRD spectrum (fig. 2). The size of the front surface of the electrode is 20 μm, the edges and the interior of the pores are fused and stacked by titanium dioxide, the size of the back surface of the electrode is 8 μm, and the surface is smooth (figure 3).

Example 2

The preparation method is the same as that of example 1, except that the thickness of the titanium target is 0.02mM, the noble metal solution is 1mM chloroplatinic acid solution, the laser pulse frequency is set to 5kHz, the energy is 1W, and the sweep rate is 1000 mM/s.

Example 3

The preparation method is the same as example 1, except that the thickness of the titanium target is 0.1mM, the noble metal solution is 10mM ruthenium chloride solution, the laser pulse frequency is 10kHz, the energy is 5W, and the sweep rate is 600 mM/s.

Example 4

The preparation method is the same as that of the example 1, except that the thickness of the titanium target is 0.5mM, the noble metal solution is 20mM rhodium chloride acid solution, the laser pulse frequency is 15kHz, the energy is 10W, and the sweep rate is 400 mM/s.

Example 5

The preparation method is the same as example 1, except that the thickness of the titanium target is 2mM, the noble metal solution is 50mM palladium chloride solution, the laser pulse frequency is set to be 20kHz, the energy is 20W, and the sweep rate is 200 mM/s.

Comparative example 1

According to the definition of Intermediates in Blue TiO₂Preparation of TiO Material for use in Nanotube Arrays reactions site of Nitrogen Electrocatalysis, ChemCatchem,2020,12,2760-₂A base composite material.

Test example 1

The gold-miscible phase titanium dioxide multi-stage electro-catalytic material prepared by the method is applied to nitrogen reduction synthesis of ammonia:

at 0.5mol/L Na₂SO₄In the method, a three-electrode reaction device is adopted, Pt is used as a counter electrode, Ag/AgCl is used as a reference electrode, the gold-mixed phase titanium dioxide multistage electrocatalytic material prepared in the example 1 is used as a working electrode, nitrogen is introduced at the gas flow of 10L/min, and the current time curve of synthesizing ammonia by electrocatalytic nitrogen reduction in a test solution is shown in figure 4 under the assistance of an electric field.

The gold mixture prepared in example 1 was mixedCompared with the mixed-phase titanium dioxide material and the titanium target material, the catalytic effect of the multi-stage electro-catalytic titanium dioxide material for synthesizing ammonia through electro-catalysis is shown in fig. 5. It can be seen that the catalytic activity of the gold-mixed phase titanium dioxide multi-stage electrocatalytic material is obviously improved compared with that of the mixed phase titanium dioxide material and the titanium target material, and the electrocatalytic synthesis ammonia yield is 11.7 mu gh^- ¹cm^-2(i.e., 1.92X 10)^-10mol s^-1cm^-2Corresponding to a voltage of-0.4V), corresponding to a faraday efficiency of 12.8%. The design of the hierarchical porous electrode material, the regulation and control of the mixed crystal phase and the loading of the active components enable the composite electrode material to show good performance in the aspect of electrocatalytic nitrogen fixation.

TiO prepared in comparative example 1₂The base composite test conditions differed from the above example 1 in that the electrolyte was 0.1 MKOH. The ammonia yield was 1.61X 10^-10mol s^-1cm^-2The corresponding voltage is-0.45V.

The traditional preparation of the titanium dioxide-based composite material needs high-temperature calcination and strong reducing agent reaction, and the precise repeated regulation and control of the process cannot be realized. The invention prepares the noble metal-mixed phase titanium dioxide multi-stage electro-catalysis material in one step by a laser micro-processing technology based on the energy locality and photo-thermal reduction characteristics of laser. The consistency of the structure and the standard is confirmed by powder X-ray diffraction (XRD) analysis, and the size and the morphology of the porous electrode of the multi-material are characterized by a scanning electron microscope. The obtained material is used as a working electrode and shows good performance of electrocatalytic ammonia synthesis which is superior to that of the traditional synthetic material. Therefore, the material has important application value in the field of electrocatalytic ammonia synthesis.

Example 6

The method comprises the steps of using a molybdenum sheet as a metal substrate, marking a groove channel and a hole structure by using laser in a circular arc array mode and a circular filling mode respectively, then placing the metal sheet in a chloroplatinic acid solution, and carrying out laser marking in a circular array mode to load platinum on the metal sheet, thereby finally obtaining the Pt/Mo multifunctional integrated electrocatalysis material (see figure 6).

The molybdenum sheet is an industrial pure molybdenum sheet with the purity of 99.99 percent, the length of 50mm, the width of 50mm and the thickness of 0.5 mm. The laser is a solid laser, the central wavelength of the laser is 1064nm, the pulse width is 100ns, the repetition frequency is 20KHz, and the single pulse energy is 1 mJ. Arc array pattern settings of the circle marking the groove channel: the diameter of the circle is 0.185mm, the diameter of the circle array is 3.2mm, 8mm, 12.6mm, 17.4mm, 22.2mm and 26.8mm, the number of the arrays is 720, the array angular interval is 0.5 degrees, the laser marking scanning speed is 500mm/s, the laser power is 16W, and the times are 200. Circle filling mode setting of the marking hole structure: the diameter of the circle is 0.185mm, the circle is filled in a mode of 'Hui' shape, the distance between filling lines is 0.001mm, the scanning speed of laser marking is 500mm/s, the laser power is 16W, and the laser marking passes are 100 times. The chloroplatinic acid solution was at a concentration of 2 mM. The circular array pattern of platinum loading on the metal sheet was set: the diameter of the circle is 0.3mm, the circle is filled in a 'return' shape, the space between filling lines is 0.001mm, the number of the arrays is 20 multiplied by 20, the space between circles in the arrays is 0.3mm, the scanning speed of laser marking is 500mm/s, the laser power is 19W, and the number of laser marking passes is 30.

Example 7

The difference from example 6 is that the Rh/Mo multifunctional integrated electrocatalytic material was prepared by using a molybdenum sheet as a metal substrate, placing the metal sheet in a metal ion solution, and using a rhodium chloride solution with a concentration of 2 mM.

And respectively marking a groove channel and a hole structure by using laser in a circular arc array mode and a circular filling mode, then placing the metal sheet in a rhodium chloride solution, and carrying out laser marking in the circular array mode to load rhodium on the metal sheet, thereby finally obtaining the Rh/Mo multifunctional integrated electrocatalysis material.

Example 8

The difference from example 6 is that a PtPd/Ti multifunctional integrated electrocatalytic material was prepared using a titanium sheet as a metal substrate, and the metal sheet was placed in a metal ion solution containing chloroplatinic acid at a concentration of 2mM and palladium chloride at a concentration of 2 mM.

And respectively marking a groove channel and a hole structure by using laser in a circular arc array mode and a circular filling mode, then placing the metal sheet in a palladium chloride solution containing chloroplatinic acid with the concentration of 2mM and palladium chloride with the concentration of 2mM, and carrying out laser marking in the circular array mode to load the platinum-palladium alloy on the metal sheet, thereby finally obtaining the PtPd/Ti multifunctional integrated electrocatalytic material.

Comparative example 2

Pt was prepared according to the teachings of the paper dot adsorbed PtMo nanosponge as a high hly effective and stable electrochemical reactions for hydrogen evolution in bouth acetic and alkaline media, article No. Carbon,2019,146,116-₇₅Mo₂₅The @ graphene material is prepared by the following steps:

1. 28mg of carbon dots were added to 195mL of H₂And (4) in O.

2. 20mM H was prepared₂PtCl₆And 20mM MoCl₅5mL of aqueous solution.

3. The solution of step 2 was added rapidly to the solution in step 1.

4. After 30 minutes sonication of the solution, a homogeneous solution was obtained.

5. 20mL of 50mM NaBH₄The reducing agent is slowly injected into the prepared homogeneous solution and stirred strongly.

6. Stirring was continued at 70 ℃ for 3 hours until the whole solution was black.

7. Centrifuging the mixture

8. And washing with deionized water.

9. Drying at 70 ℃ to obtain Pt₇₅Mo₂₅@graphene。

10. 1mL of a water/Isopropanol (IPA)/Nafion solution (80/20/0.02,% v) was prepared.

11. 1.8mg of prepared Pt₇₅Mo₂₅@ graphene was dispersed in 1mL of a water/isopropyl alcohol (IPA)/Nafion solution to prepare a catalyst suspension.

12. And (5) performing ultrasonic action for 1h to obtain a mixed solution.

13. And dripping 3 mu L of the mixed solution on the surface of a glassy carbon electrode, and drying.

Test example 2

The Pt/Mo integrated electrocatalytic material prepared in example 6 was subjected to X-ray powder diffraction (XRD) test, and its XRD pattern is shown in FIG. 7, which shows that the integrated electrocatalytic material isThe material has phases of molybdenum and platinum, demonstrating the successful synthesis of Pt/Mo. The electrochemical hydrogen production catalysis performance test is carried out on the Pt/Mo integrated electro-catalysis material, and the test conditions are as follows: the measurement was performed at room temperature using a three-electrode electrochemical workstation (CHI 760E) under Linear Sweep Voltammetry (LSV) at 0.5mol/L H₂SO₄LSV testing was performed in an electrolyte at PH 0 using an Ag | AgCl electrode as a reference electrode with a scan range of 0 to-2V at a scan rate of 5 mV/s. The LSV curve of the Pt/Mo integrated electrocatalytic material is shown in FIG. 8, and it can be seen that when the current density reaches 10mA/cm²When the overpotential is 1.2V, the Pt/Mo integrated electrocatalytic material has a small overpotential of 33mV, and reaches 900mA/cm²The high current density shows excellent electrocatalytic hydrogen production performance. The i-t curve obtained by performing a Chronoamperometry (Chronoamperometry) test at room temperature and an overpotential of 0.65V is shown in FIG. 9, which shows that the Pt/Mo integrated electrocatalytic material has a high current density (400 mA/cm)²) The current density remained stable for 20 hours of testing. Based on the electrochemical catalytic performance test, the prepared Pt/Mo integrated electro-catalytic material has excellent catalytic hydrogen production activity under an acidic condition and has long-term high-current test stability.

Pt prepared in comparative example 2₇₅Mo₂₅@ graphene material, test conditions: the measurement was performed at room temperature using a three-electrode electrochemical workstation (CHI 760E) under Linear Sweep Voltammetry (LSV) at 0.5mol/L H₂SO₄LSV test was performed in electrolyte (PH 0) using Ag | AgCl electrode as reference electrode. Measured Pt₇₅Mo₂₅The LSV curve of the @ graphene material is shown in FIG. 10, and it can be seen that when the current density reaches 10mA/cm²When (i) is Pt₇₅Mo₂₅The overpotential (. eta.) of @ graphene materials₁₀) Is 32mV but the current density is not very large, and the Pt/Mo multifunctional integrated electrocatalytic material prepared in the embodiment 6 of the invention reaches 900mA/cm when the overpotential is 1.2V²The high current density shows excellent electro-catalysis hydrogen production performance, and has long-time high current testStability, and is more beneficial to industrial application.

Comparative example 2 the synthesis of PtMo material was complicated and used corrosive reagents. In the step of preparing the Pt/Mo multifunctional integrated electrocatalytic material, the method has the advantages of few steps, no corrosive reagent, short time and the like. In addition, the Pt/Mo multifunctional integrated electro-catalytic material prepared by the method has the capabilities of solution circulation, gas diffusion and current collection and excellent and stable electro-catalytic hydrogen production activity.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-stage electrocatalytic material, characterized in that the multi-stage electrocatalytic material is a three-stage electrocatalytic material, the three-stage electrocatalytic material comprising a noble metal, a miscible titanium dioxide, a noble metal-miscible titanium dioxide;

the preparation method of the multi-stage electrocatalytic material comprises the following steps: immersing a metal sheet serving as a substrate in a metal solution, starting laser to bombard the substrate, and obtaining an electrocatalytic material after bombardment is finished;

the substrate is titanium, and the thickness of the substrate is 0.02-2 mm; the metal solution is a noble metal solution;

the noble metal solution is a chloroauric acid solution, a chloroplatinic acid solution, a rhodium chloride solution, a ruthenium chloride solution or a palladium chloride solution; the solution concentration of the noble metal solution is 1-20 mM; the pulse frequency of the laser is 5-20 kHz, the wavelength is 1064nm, the energy is 2-20W, and the sweep rate is 20-1000 mm/s.

2. Use of the multi-stage electrocatalytic material of claim 1 for electrocatalytic synthesis of ammonia.

3. The multifunctional integrated electrocatalytic material is characterized by comprising a substrate, wherein the substrate is provided with a groove channel and a pore structure, and a metal electrocatalyst is loaded on the substrate; the metal electrocatalyst is a simple substance or an alloy of titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, silver, cadmium, tantalum, tungsten, platinum, gold, aluminum, indium, thallium, tin, palladium, rhodium and iridium;

the preparation method of the multifunctional integrated electrocatalysis material comprises the following steps: the method comprises the following steps of (1) preprocessing a substrate before the substrate is immersed in a metal solution, wherein the preprocessing is to etch the substrate by adopting laser and form a groove channel and a hole structure on the substrate;

the substrate is titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, silver, cadmium, tantalum, tungsten, platinum, gold, aluminum, indium, thallium, tin, palladium, rhodium, iridium or an alloy of the metals; the metal solution is a solution containing metal ions;

the metal ions are one or more of titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, silver, cadmium, tantalum, tungsten, platinum, gold, aluminum, indium, thallium, tin, palladium, rhodium and iridium ions; the pulse frequency of the laser bombarding the substrate is 20kHz, the wavelength is 1064nm, the laser power is 19W, and the scanning speed is 500 mm/s.

4. The use of the multifunctional integrated electrocatalytic material of claim 3 in electrocatalytic hydrogen production.