Electrode with color change activity indication function and preparation method and application thereof

Abstract

The invention discloses a preparation method of an electrode with a color change activity indication function, which comprises the following steps: 1) dissolving a metal source precursor in a solvent, and stirring and uniformly mixing with noble metal to obtain a mixture; (2) placing a conductive substrate into the mixture in the step (1), and carrying out hydrothermal reaction to obtain a front-end product; and (3) carrying out heat treatment on the front-end product in the step (2) to obtain the electrode with the color-changing activity indication function. The electrode with the activity indication function comprises a conductive substrate, the conductive substrate is provided with transition metal oxide loaded with precious metal M. The electrode can directly reflect the dynamic process of a catalytic reaction through color change, and the catalytic reaction is more stable. And researchers are helped to systematically establish a structure-function relationship among applied voltage-electrode color-electrocatalytic activity, so that a microscopic complex water electrolysis reaction becomes transparent and visual, and electrocatalytic basic research is promoted to develop towards intelligentization and informatization directions.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy materials, and in particular relates to an electrode with a color-changing active indication function, a preparation method and an application thereof. Background Art

[0002] Hydrogen energy has attracted more and more attention from scientific research and industry due to its advantages of high combustion enthalpy and zero carbon emissions. Using renewable energy (solar energy, wind energy, hydropower, etc.) to generate electricity and drive water splitting to produce hydrogen is considered to be one of the most economical and greenest ways to produce hydrogen.

[0003] At present, the research and development work on water splitting to produce hydrogen is in the experimental stage. During the experiment, the analysis of the specific electrocatalytic process needs to rely on precise in-situ spectroscopy experiments and ideal simulation calculations. However, the complex solid-liquid interface catalytic process under the action of an external electric field is difficult to be fully simulated theoretically, which directly leads to the catalytic mechanism analysis process being very boring and the workload is extremely huge. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the main purpose of the present invention is to provide an electrode with a color-changing activity indication function, which can directly reflect the catalytic reaction process by organically integrating the electrocatalytic reaction with the color-changing technology, and the change of the electrode color under different potential loadings, so that the microscopically complex electrocatalytic process becomes highly visualized and presented with intuitive color changes; the present invention also provides a preparation method and application of the electrode with a color-changing activity indication function.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] The present invention is aimed at the basic acidic HER and OER electrocatalytic reactions involving multi-step proton-coupled electron electrochemical reactions, and the process and mechanism analysis are complex and boring; the transition metal system loads the noble metal atom integrated electrode so that the microscopic electrochemical process of acidic HER / OER can be presented through simple and intuitive visual changes; at the same time, the noble metal ions provide matching adsorption / activation sites, which can improve the catalytic activity of the electrode. Clarifying and establishing the applied voltage-electrode color-HER / OER electrocatalytic activity structure-activity relationship will promote the development of basic electrocatalytic research towards intelligence and informationization.

[0007] Specifically, a method for preparing an electrode having a color-changing active indication function comprises the following steps:

[0008] 1) dissolving a metal source precursor in a solvent, and then stirring with a noble metal to mix uniformly to obtain a mixture;

[0009] 2) placing a conductive substrate into the mixture in step 1) to perform a hydrothermal reaction to obtain a front-end product;

[0010] 3) The front-end product of step 2) is subjected to heat treatment to obtain an electrode having a color-changing active indication function.

[0011] In some specific embodiments, the metal precursor in step 1) is one or more of tungsten chloride, molybdenum chloride, iron chloride, cobalt chloride, chromium chloride, nickel chloride, and vanadium chloride; and the noble metal is one or more of Pt, Ru, or Ir.

[0012] In certain specific embodiments, the mass ratio of the metal source precursor to the noble metal is (3-5): (1-2);

[0013] In some specific embodiments, the solvent in step 1) is ethanol, deionized water or a mixture thereof.

[0014] In some specific embodiments, the conductive substrate in step 2) is one of ITO or FTO.

[0015] In certain specific embodiments, the process conditions of the hydrothermal reaction in step 2) are: heating to 140-180° C. at a heating rate of 5-10° C. / min and maintaining the reaction for 12-24 hours.

[0016] In certain specific embodiments, the process conditions of the heat treatment in step 3) are: in a reducing atmosphere or an inert atmosphere, the temperature is increased to 100-200° C. at a heating rate of 2-10° C. / min and the reaction is maintained for 1-2 hours.

[0017] In some specific embodiments, the product after the hydrothermal reaction is further subjected to washing, separation and drying treatments.

[0018] The main purpose of the present invention is to provide an electrode with a color-changing active indication function, wherein the electrode comprises a conductive substrate on which a transition metal oxide loaded with a noble metal is arranged.

[0019] The main purpose of the present invention is to provide an electrode with a color-changing activity indicating function for use in an electrochemical catalytic process.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] 1) The electrode with activity indication function provided by the present invention comprises a conductive substrate on which a transition metal oxide loaded with a noble metal M is arranged. The electrode is mainly used for acidic HER and OER catalytic reactions. The electrode can directly reflect the kinetic process of the catalytic reaction through color changes, which helps researchers to systematically establish the structure-activity relationship between applied voltage-electrode color-electrocatalytic activity, thereby making the microscopically complex water electrolysis reaction transparent and visualized, and promoting the development of basic research on electrocatalysis towards intelligence and informatization.

[0022] 2) The preparation method of the electrode with color-changing active indication function provided by the present invention has easy-to-obtain raw materials, simple process steps, and high repetitive stability. Through hydrothermal method and heat treatment, a reasonable transition metal oxide-loaded noble metal electrochromic electrode is constructed, which has high activity and good stability and is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments or the description of the prior art will be briefly introduced below.

[0024] Figure 1 This is a SEM image of the surface of the electrode having a color-changing active indication function in Example 1 of the present invention;

[0025] Figure 2 The front-end product Pt SAs@WO in Example 1 of the present invention x A physical picture of the color change of the electrode with color change activity indication function;

[0026] Figure 3 A schematic diagram of the color change principle of the electrode with color change activity indication function provided by the present invention;

[0027] Figure 4 This is a scanning linear voltammetry curve of the electrode with color-changing activity indicating function in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following embodiments are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0029] When a certain amount, concentration or other value or parameter is expressed in the form of a range, a preferred range, or a preferred upper and lower numerical limit, it should be understood that it is equivalent to specifically revealing any range by combining any pair of upper range limits or preferred numerical values ​​with any lower range limit or preferred numerical value, regardless of whether the range is specifically disclosed. Unless otherwise indicated, the numerical range values ​​listed herein include the endpoints of the range, and all integers and fractions within the range.

[0030] Unless otherwise indicated, all percentages, parts, ratios, etc. herein are by weight.

[0031] The materials, methods, and examples herein are illustrative and are not to be construed as limiting unless specifically stated.

[0032] In the following embodiments, the purity of the raw material of chloroplatinic acid (H2PtCl6·6H2O) is 99%, which is specifically purchased from Aladdin Reagent Network; the purity of the raw material of ruthenium chloride (RuCl3) is 99.95%, which is specifically purchased from Aladdin Reagent Network; the purity of the raw material of indium chloride (InCl3·4H2O) is 98%, which is specifically purchased from Aladdin Reagent Network.

[0033] Example 1

[0034] A method for preparing an electrode having a color-changing active indication function comprises the following steps:

[0035] (1) Weigh 50 mg of tungsten chloride (WCl6) and dissolve it in 30 mL of alcohol solvent, stir until it is completely dissolved, then add 10 mg of chloroplatinic acid (H2PtCl6·6H2O), stir and mix at room temperature, stir at a speed of 300 rpm for 30 minutes, and stir to obtain a uniform mixture;

[0036] (2) The mixture in step 1) was transferred to a 100 mL Teflon reactor liner, and then a piece of ITO (size 10*30*1.1 mm, with the conductive surface facing up) was placed in a stainless steel jacket, and then transferred to a hydrothermal oven, and the temperature was raised to 180°C at a rate of 5°C / min for a hydrothermal reaction for 12 hours; after the reaction was completed, it was cooled to room temperature, slowly washed with deionized water, and the product was collected and placed in a vacuum oven and dried at 50°C for 30 minutes to obtain the front-end product Pt SAs@WO3;

[0037] (3) The front-end product Pt SAs@WO3 obtained in step 2) was heat treated, placed in an alumina ceramic boat, and transferred to a tube furnace. It was cleaned with Ar for 10 min to ensure that the oxygen was completely removed. Then, a mixed gas of Ar and H2 was introduced in a mixing ratio of 200 sccm:20 sccm (10:1). The temperature was increased to 200°C at a heating rate of 5°C / min and kept at this condition for 1 h. When the annealing was completed and the temperature dropped to room temperature, the color-changing active indicator electrode was collected for morphological and phase characterization.

[0038] Example 2

[0039] (1) Weigh 50 mg of molybdenum chloride (MoCl5) and dissolve it in 30 mL of alcohol solvent, stir until it is completely dissolved, then add 10 mg of ruthenium chloride (RuCl3), stir and mix at room temperature, stir at a speed of 300 rpm for 30 minutes, and stir to obtain a uniform mixture;

[0040] (2) The mixture in step 1) was transferred to a 100 mL Teflon reactor liner, and a piece of FTO (size 10*30*1.1 mm, with the conductive surface facing up) was placed in a stainless steel jacket, and then transferred to a hydrothermal oven, and the temperature was raised to 180°C at a rate of 5°C / min for a hydrothermal reaction for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, slowly washed with deionized water, and the product was collected and placed in a vacuum oven and dried at 50°C for 30 minutes to obtain the product Ru SAs@MoO3;

[0041] (3) The front-end product Ru SAs@MoO3 obtained in step 2) was heat-treated, placed in an alumina ceramic boat, and transferred to a tube furnace. It was purged with Ar for 10 min to ensure that oxygen was completely removed. Then Ar gas was introduced and the temperature was increased to 200°C at a heating rate of 5°C / min and kept at this condition for 1 h. When the annealing was completed and the temperature dropped to room temperature, the color-changing active indicator electrode was collected for morphological and phase characterization.

[0042] Example 3

[0043] (1) Weigh 30 mg of ferric chloride (FeCl3) and dissolve it in 30 mL of a mixed solvent of alcohol and deionized water (volume ratio of 1:1), stir until it is completely dissolved, then add 10 mg of indium chloride (InCl3·4H2O), stir and mix at room temperature, stir at a rate of 300 rpm for 30 min, and stir to obtain a uniform mixture;

[0044] (2) The mixture in step 1) was transferred to a 100 mL Teflon reactor liner, and then a piece of ITO (size 10*30*1.1 mm, with the conductive surface facing up) was placed in a stainless steel jacket, and then transferred to a hydrothermal oven, and the temperature was raised to 180°C at a rate of 5°C / min for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, slowly washed with deionized water, and the product was collected and placed in a vacuum oven and dried at 50°C for 30 minutes to obtain the front-end product In SAs@Fe2O3;

[0045] (3) The front-end product In SAs@Fe2O3 obtained in step 2) was heat treated, placed in an alumina ceramic boat, and transferred to a tube furnace. It was purged with Ar for 10 min to ensure that oxygen was completely removed. Then Ar gas was introduced and the temperature was increased to 200°C at a heating rate of 5°C / min and kept at this condition for 1 h. When the annealing was completed and the temperature dropped to room temperature, the color-changing active indicator electrode was collected for morphology and phase characterization.

[0046] Example 4

[0047] (1) Weigh 50 mg of cobalt chloride (CoCl2) and dissolve it in 30 mL of alcohol solvent, stir until it is completely dissolved, then add 10 mg of chloroplatinic acid (H2PtCl6·6H2O), stir and mix at room temperature, stir at a speed of 300 rpm for 30 minutes, and stir to obtain a mixture;

[0048] (2) The mixture in step 1) was transferred to a 100 mL Teflon reactor liner, and then a piece of ITO (size 10*30*1.1 mm, with the conductive surface facing up) was placed in a stainless steel jacket, and then transferred to a hydrothermal oven, and the temperature was raised to 180°C at a rate of 5°C / min for a hydrothermal reaction for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, slowly washed with deionized water, and the product was collected and placed in a vacuum oven and dried at 50°C for 30 minutes to obtain the front-end product Pt SAs@CoO2;

[0049] (3) The front-end product Pt SAs@CoO2 obtained in step 2) was heat treated, placed in an alumina ceramic boat, and transferred to a tube furnace. It was cleaned with Ar for 10 min to ensure that the oxygen was completely removed. Then, a mixed gas of Ar and H2 was introduced in a mixing ratio of 200 sccm:20 sccm (10:1). The temperature was increased to 200°C at a heating rate of 5°C / min and kept at this condition for 1 h. When the annealing was completed and the temperature dropped to room temperature, the color-changing active indicator electrode was collected for morphological and phase characterization.

[0050] Example 5

[0051] (1) Weigh 50 mg of vanadium chloride (VCl3) and dissolve it in 30 mL of alcohol solvent, stir until it is completely dissolved, then add 10 mg of chloroplatinic acid (H2PtCl6·6H2O), stir and mix at room temperature, stir at a speed of 300 rpm for 30 minutes, and stir to obtain a uniform mixture;

[0052] (2) The mixture in step 1) was transferred to a 100 mL Teflon reactor liner, and then a piece of ITO (size 10*30*1.1 mm, with the conductive surface facing up) was placed in a stainless steel jacket, and then transferred to a hydrothermal oven, and the temperature was raised to 180°C at a rate of 5°C / min for a hydrothermal reaction for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, slowly washed with deionized water, and the product was collected and placed in a vacuum oven and dried at 50°C for 30 minutes to obtain the front-end product Pt SAs@V2O5;

[0053] (3) The front-end product Pt SAs@V2O5 obtained in step 2) was heat treated, placed in an alumina ceramic boat, and transferred to a tube furnace. It was purged with Ar for 10 min to ensure that the oxygen was completely removed. Then, a mixed gas of Ar and H2 was introduced in a mixing ratio of 200 sccm:20 sccm (10:1). The temperature was increased to 200°C at a heating rate of 5°C / min and kept at this condition for 1 h. When the annealing was completed and the temperature dropped to room temperature, the color-changing active indicator electrode was collected for morphological and phase characterization.

[0054] Example 6

[0055] (1) Weigh 50 mg of nickel chloride (NiCl2) and dissolve it in 30 mL of alcohol solvent, stir until it is completely dissolved, then add 10 mg of chloroplatinic acid (H2PtCl6·6H2O), stir and mix at room temperature, stir at a speed of 300 rpm for 30 minutes, and stir to obtain a uniform mixture;

[0056] (2) The mixture in step 1) was transferred to a 100 mL Teflon reactor liner, and then a piece of ITO (size 10*30*1.1 mm, with the conductive surface facing up) was placed in a stainless steel jacket, and then transferred to a hydrothermal oven, and the temperature was raised to 140°C at a rate of 5°C / min for 18 hours. After the reaction was completed, the mixture was cooled to room temperature, slowly washed with deionized water, and the product was collected and placed in a vacuum oven and dried at 50°C for 30 minutes to obtain the front-end product Pt SAs@NiO;

[0057] (3) The front-end product Pt SAs@NiO obtained in step 2) was heat treated, placed in an alumina ceramic boat, and transferred to a tube furnace. It was purged with Ar for 10 min to ensure that the oxygen was completely removed. Then, a mixed gas of Ar and H2 was introduced in a mixing ratio of 200 sccm:20 sccm (10:1). The temperature was increased to 200°C at a heating rate of 5°C / min and kept at this condition for 1 h. When the annealing was completed and the temperature dropped to room temperature, the color-changing active indicator electrode was collected for morphological and phase characterization.

[0058] Example 7

[0059] (1) Weigh 50 mg of chromium chloride (CrCl3) and dissolve it in 30 mL of alcohol solvent, stir until it is completely dissolved, then add 10 mg of chloroplatinic acid (H2PtCl6·6H2O), stir and mix at room temperature, stir at a speed of 300 rpm for 30 minutes, and stir to obtain a uniform mixture;

[0060] (2) The mixture in step 1) was transferred to a 100 mL Teflon reactor liner, and then a piece of ITO (size 10*30*1.1 mm, with the conductive surface facing up) was placed in a stainless steel jacket, and then transferred to a hydrothermal oven, and the temperature was raised to 180°C at a rate of 5°C / min for a hydrothermal reaction for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, slowly washed with deionized water, and the product was collected and placed in a vacuum oven and dried at 50°C for 30 minutes to obtain the front-end product Pt SAs@CrO2;

[0061] (3) The front-end product Pt SAs@CrO2 obtained in step 2) was heat treated, placed in an alumina ceramic boat, and transferred to a tube furnace. It was purged with Ar for 10 min to ensure that the oxygen was completely removed. Then, a mixed gas of Ar and H2 was introduced in a mixing ratio of 200 sccm:20 sccm (10:1). The temperature was increased to 200°C at a heating rate of 5°C / min and kept at this condition for 1 h. When the annealing was completed and the temperature dropped to room temperature, the color-changing active indicator electrode was collected for morphological and phase characterization.

[0062] The electrode with color change indicating activity indicating function provided by the present invention comprises a conductive substrate, on which a transition metal oxide loaded with a noble metal M is arranged, and is mainly used for acidic HER and OER catalytic reactions; taking Example 1 as an example, the electrode is applied to electrolysis of water for hydrogen evolution and has excellent stability and activity, and the specific electrochemical performance test is as follows:

[0063] The electrochemical tests were all conducted at room temperature using a CHI760E electrochemical workstation, using 0.5MH2SO4 (pH=0) solution as the acidic electrolyte. A three-electrode system was used in the test, the electrode prepared in the application was clamped on a platinum electrode as the working electrode, a carbon rod was used as the counter electrode, and Ag / AgCl was used as the reference electrode. A scanning linear voltammetric curve test was performed with a scanning speed of 0.01mV and a potential range of (0 to -0.8). The measured data was calibrated with a reversible hydrogen electrode (RHE) according to the equation:

[0064] E RHE =E Ag / AgCl +0.197V

[0065] The test results are as follows Figure 4As shown in the figure, it was found that the catalyst only needed an overpotential of 120 mV to generate 10 mA / cm 2 The current density is excellent.

[0066] At the same time, the present application also takes Example 1 as an example, and characterizes the morphology and phase of the intermediate product and the prepared electrochromic catalyst in the preparation method of the present application by using a field emission scanning electron microscope of Zeiss Company of Germany. The results are as follows Figure 1-Figure 3 As shown, Figure 1 This is a SEM image of the electrode surface with color-changing active indication function. Figure 2 This is the actual color change picture of the Pt SAs@WO3 color-changing electrode. Figure 3 Schematic diagram of the color-changing principle of the Pt SAs@WO3 color-changing electrode. Figure 1 and 2 It can be seen that the color of the electrochromic electrode prepared in the experiment gradually changes from colorless to dark. Figure 4 This is a scanning linear voltammetry curve of the electrode with color-changing activity indication function.

[0067] The inventors proposed a method for preparing an electrode with a color-changing active indication function. By selecting a suitable transition metal oxide source precursor and a suitable noble metal solution, and annealing under high temperature conditions, an efficient and simple method for synthesizing an electrode with a color-changing active indication function is demonstrated. This method can provide a new idea and method for electrochromic electrode materials.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for preparing an electrode having a color-changing active indication function, characterized in that: The steps include: 1) dissolving a metal source precursor in a solvent, and then stirring with a noble metal to mix uniformly to obtain a mixture; 2) placing a conductive substrate into the mixture in step 1) to perform a hydrothermal reaction to obtain a front-end product; 3) The front-end product of step 2) is subjected to heat treatment to obtain an electrode having a color-changing active indication function.

2. The method for preparing an electrode having a color-changing active indicating function according to claim 1, characterized in that: In step 1), the metal precursor is one or more of tungsten chloride, molybdenum chloride, iron chloride, cobalt chloride, chromium chloride, nickel chloride, and vanadium chloride; and the noble metal is one or more of Pt, Ru, or Ir.

3. The method for preparing an electrode having a color-changing active indicating function according to claim 1 or 2, characterized in that: The mass ratio of the metal source precursor to the noble metal is (3-5):(1-2).

4. The method for preparing an electrode having a color-changing active indication function according to claim 1, characterized in that: The solvent in step 1) is ethanol, deionized water or a mixture thereof.

5. The method for preparing an electrode having a color-changing active indicating function according to claim 4, characterized in that: The conductive substrate in step 2) is one of ITO and FTO.

6. The method for preparing an electrode having a color-changing active indicating function according to claim 5, characterized in that: The process conditions of the hydrothermal reaction in step 2) are: heating to 140-180° C. at a heating rate of 5-10° C. / min and maintaining the reaction for 12-24 hours.

7. The method for preparing an electrode having a color-changing active indicating function according to claim 5, characterized in that: The process conditions of the heat treatment in step 3) are: in a reducing atmosphere or an inert atmosphere, the temperature is increased to 100-200° C. at a heating rate of 2-10° C. / min and the reaction is maintained for 1-2 hours.

8. The method for preparing an electrode having a color-changing active indicating function according to claim 6, characterized in that: The method also includes washing, separating and drying the product after the hydrothermal reaction.

9. An electrode with color-changing active indication function prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The electrode comprises a conductive substrate, on which a transition metal oxide loaded with a noble metal is arranged.

10. Use of the electrode with color-changing activity indicating function according to claim 9 in an electrochemical catalytic process.

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