Composite alkaline hydrogen evolution electrode, preparation method thereof, and water electrolysis device

Abstract

The present application provides a composite alkaline hydrogen evolution electrode, a preparation method thereof, and a water electrolysis device, relating to the field of electrodes for water electrolysis. The composite alkaline hydrogen evolution electrode comprises a porous metal substrate, a V-VI group compound semiconductor layer, and a transition metal sulfide compound layer arranged in a stacked manner. The present application uses a combination of a porous metal substrate, a V-VI group compound semiconductor layer, and a transition metal sulfide compound layer as an electrode, which increases the roughness of the electrode surface and the electrochemically active surface area of the electrode. The electrode of the present application has high catalytic activity for hydrogen evolution reaction. Moreover, the electrode of the present application also has high resistance to high temperature and strong alkali.

Description

Technical Field

[0001] The present application relates to the field of electrodes for water electrolysis, and in particular to a composite alkaline hydrogen evolution electrode, a preparation method thereof, and a water electrolysis device. Background Art

[0002] Hydrogen is a clean and non-polluting energy source. Water electrolysis is considered to be one of the simplest and most effective methods for producing hydrogen, powered by renewable energy such as solar energy, wind energy, and wave energy. H * ) close to zero and possessing excellent conductivity, making them the best electrodes for hydrogen evolution. However, the high cost, limited reserves, and other factors have significantly hindered the commercial application of Pt-based electrodes. Therefore, the development of low-cost, low-overpotential, and long-term stable non-precious metal electrode materials is crucial for hydrogen production from water electrolysis.

[0003] Existing nickel-molybdenum-based water electrolysis electrodes have problems such as complicated process steps and poor catalytic effect. Summary of the Invention

[0004] The purpose of this application is to provide a composite alkaline hydrogen evolution electrode and a preparation method thereof and a water electrolysis device to solve the above problems.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] A composite alkaline hydrogen evolution electrode comprises a porous metal substrate, a V-VI group compound semiconductor layer, and a transition metal sulfide compound layer which are stacked.

[0007] According to an embodiment of the present application, the porous metal substrate includes any one of foamed molybdenum nickel, foamed iron, foamed copper, and foamed nickel.

[0008] According to an embodiment of the present application, the material forming the V-VI group compound semiconductor layer includes any one of Sb2Te3, Sb2Se3, Sb2S3, Bi2Te3, Bi2Se3, and Bi2S3;

[0009] And / or, the thickness of the Group V-VI compound semiconductor layer is 0.5 to 2 μm.

[0010] According to an embodiment of the present application, the material forming the transition metal chalcogenide layer includes any one of MoS2, MoSe2, SnSe2, and WS2;

[0011] And / or, the thickness of the transition metal chalcogenide compound layer is 1 to 2.5 μm.

[0012] The present application also provides a method for preparing the composite alkaline hydrogen evolution electrode as described above, comprising:

[0013] Mixing a porous metal substrate, a Group V-VI compound semiconductor precursor, and water, and performing a first hydrothermal reaction in a reactor to obtain a porous metal substrate loaded with a Group V-VI compound semiconductor layer;

[0014] The porous metal substrate carrying the Group V-VI compound semiconductor layer, a transition metal sulfide compound precursor and water are mixed, and a second hydrothermal reaction is carried out in a reactor to obtain a composite alkaline hydrogen evolution electrode.

[0015] According to an embodiment of the present application, the V-VI group compound semiconductor precursor includes a group V element-containing substance and a group VI element-containing substance, the group V element-containing substance includes any one of an antimony source and a bismuth source, and the group VI element-containing substance includes a tellurium source;

[0016] And / or, the antimony source includes at least one of potassium antimony tartrate, antimony trichloride, and antimony oxide; the tellurium source includes at least one of sodium tellurate, potassium tellurate, tellurium powder, and tellurium oxide; and the bismuth source includes Bi2O3;

[0017] and / or, the molar ratio of the substance containing Group V elements to the substance containing Group VI elements is 1:(3-4.5);

[0018] And / or, when the Group V element-containing substance includes an antimony source, during the first hydrothermal reaction, the method further comprises adding glucose and ethylenediamine to the reaction system, wherein the molar ratio of the antimony source to the glucose is 1:(14-16); and the content ratio of the antimony source to the ethylenediamine is 0.135:(18-22) g / ml;

[0019] And / or, when the substance containing group V elements includes a bismuth source, when performing the first hydrothermal reaction, the method further includes adding PVP and sodium hydroxide to the reaction system, the mass ratio of the bismuth source to the PVP is 0.233: (0.4-0.6), and the molar ratio of the bismuth source to the sodium hydroxide is 1: (18-22).

[0020] According to an embodiment of the present application, the temperature of the first hydrothermal reaction is 170-190°C;

[0021] And / or, the first hydrothermal reaction time is 11-24 hours.

[0022] According to an embodiment of the present application, the transition metal chalcogenide precursor includes a molybdenum source and a sulfur source;

[0023] And / or, the molybdenum source includes at least one of ammonium molybdate and sodium molybdate, and the sulfur source includes at least one of thioacetamide and thiourea;

[0024] and / or, the molar ratio of the molybdenum source to the sulfur source is 1:(2.1-2.7);

[0025] and / or, the molar ratio of the antimony source to the molybdenum source is 1:(8-9);

[0026] And / or, the concentration of the molybdenum source in the reaction system is 0.04-0.08 mol / L.

[0027] According to an embodiment of the present application, the temperature of the second hydrothermal reaction is 170-190°C;

[0028] And / or, the second hydrothermal reaction time is 19-21 hours.

[0029] The present application also provides a water electrolysis device, which includes a cathode and an anode, and the cathode includes the composite alkaline hydrogen evolution electrode described above or includes the composite alkaline hydrogen evolution electrode prepared by the preparation method described above.

[0030] Compared with the prior art, the advantages of this application include:

[0031] This application utilizes a combination of a porous metal substrate, a Group V-VI compound semiconductor layer, and a transition metal chalcogenide layer as an electrode, increasing the roughness of the electrode surface and the electrochemically active surface area of the electrode. The electrode of this application exhibits high catalytic activity in the hydrogen evolution reaction. Furthermore, the electrode of this application has a hierarchical heterogeneous structure, which gives the electrode of this application high catalytic activity. Furthermore, the electrode of this application also exhibits high resistance to high temperatures and strong alkalis.

[0032] The present invention only requires a two-step hydrothermal method to prepare an electrode with high catalytic activity. The method of the present invention has the advantages of simple process, easy process control, and short cycle, which is conducive to large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0034] Figure 1 Schematic diagram of the structure of the composite alkaline hydrogen evolution electrode prepared in Example 1;

[0035] Figure 2 This is a SEM image of the composite alkaline hydrogen evolution electrode prepared in Example 1;

[0036] Figure 3 This is an SEM image of the layered structure of the composite alkaline hydrogen evolution electrode prepared in Example 1;

[0037] Figure 4 LSV curve of the composite alkaline hydrogen evolution electrode prepared in Example 1;

[0038] Figure 5 LSV curve of MoS2-Bi2Te3@NMF prepared in Example 2;

[0039] Figure 6 This is an SEM image of the raw material molybdenum nickel foam NMF of Comparative Example 1;

[0040] Figure 7 is the SEM image of Sb2Te3@NMF prepared in Comparative Example 1;

[0041] Figure 8 is the LSV curve of Sb2Te3@NMF prepared in comparative example 1;

[0042] Figure 9 LSV curve of MoS2@NMF prepared in comparative example 2;

[0043] Figure 10 LSV curve of Sb2Te3-MoS2@NMF prepared in comparative example 3;

[0044] Figure 11 This is the SEM image of MoS2-Sb2Te3@NMF-2 prepared in Comparative Example 4;

[0045] Figure 12 LSV curve of MoS2-Sb2Te3@NMF-2 prepared in comparative example 4;

[0046] Figure 13 This is the SEM image of MoS2-Sb2Te3@NMF-3 prepared in Comparative Example 5;

[0047] Figure 14 LSV curve of MoS2-Sb2Te3@NMF-3 prepared in comparative example 5;

[0048] Figure 15 1 is a comparison diagram of the hydrogen evolution overpotential of the electrodes prepared in Example 1, Comparative Example 4 and Comparative Example 5;

[0049] Figure 16 Comparison of electrochemical impedance spectroscopy (EIS) of electrodes prepared from NMF, Example 1, and Comparative Examples 1-3;

[0050] Figure 17 Comparison of polarization curves of electrodes prepared from NMF, Example 1, and Comparative Examples 1-3;

[0051] Figure 181 is a comparison of Tafel curves of electrodes prepared from NMF, Example 1, and Comparative Examples 1-3;

[0052] Figure 19 This is the chronopotentiometry curve of the composite alkaline hydrogen evolution electrode prepared in Example 1. DETAILED DESCRIPTION

[0053] As used herein:

[0054] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0055] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0056] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.

[0057] In these examples, parts and percentages are by mass unless otherwise indicated.

[0058] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike parts by mass, the sum of the mass of all components is not limited to 100 parts.

[0059] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0060] The present application provides a composite alkaline hydrogen evolution electrode, which includes a porous metal substrate, a V-VI group compound semiconductor layer, and a transition metal sulfide compound layer that are stacked.

[0061] According to an embodiment of the present application, the porous metal substrate includes any one of foamed molybdenum nickel, foamed iron, foamed copper, and foamed nickel.

[0062] According to some embodiments of the present application, the pore count of the porous metal substrate is 13 to 120 PPI, wherein each endpoint value of the pore count may allow a deviation of ±5 to ±10; the surface density of the porous metal substrate is 280 to 300 g / m 2 , wherein each endpoint value of the surface density may allow a deviation of ±30; the thickness of the porous metal substrate is 0.5 to 10 mm, wherein each endpoint value of the thickness may allow a deviation of ±0.05 to ±1.0.

[0063] The number of pores of the porous metal substrate used in the examples of the present application is 13 to 120 PPI, and the surface density of the porous metal substrate is 280 to 300 g / m 2 , the thickness of the porous metal substrate is 0.5 to 10 mm.

[0064] According to an embodiment of the present application, the material forming the V-VI group compound semiconductor layer includes any one of Sb2Te3, Sb2Se3, Sb2S3, Bi2Te3, Bi2Se3, and Bi2S3;

[0065] And / or, the thickness of the Group V-VI compound semiconductor layer is 0.5 to 2 μm.

[0066] For example, the thickness of the Group V-VI compound semiconductor layer may be 0.5 μm, 1 μm, 1.5 μm, 2 μm, or any value between 0.5 and 2 μm.

[0067] According to an embodiment of the present application, the material forming the transition metal chalcogenide layer includes any one of MoS2, MoSe2, SnSe2, and WS2;

[0068] And / or, the thickness of the transition metal chalcogenide compound layer is 1 to 2.5 μm.

[0069] For example, the thickness of the transition metal chalcogenide layer may be 1 μm, 1.5 μm, 2 μm, 2.5 μm, or any value between 1 and 2.5 μm.

[0070] The present application also provides a method for preparing the composite alkaline hydrogen evolution electrode as described above, comprising:

[0071] Mixing a porous metal substrate, a Group V-VI compound semiconductor precursor, and water, and performing a first hydrothermal reaction in a reactor to obtain a porous metal substrate loaded with a Group V-VI compound semiconductor layer;

[0072] The porous metal substrate carrying the Group V-VI compound semiconductor layer, a transition metal sulfide compound precursor and water are mixed, and a second hydrothermal reaction is carried out in a reactor to obtain a composite alkaline hydrogen evolution electrode.

[0073] According to an embodiment of the present application, the V-VI group compound semiconductor precursor includes a group V element-containing substance and a group VI element-containing substance, the group V element-containing substance includes any one of an antimony source and a bismuth source, and the group VI element-containing substance includes a tellurium source;

[0074] And / or, the antimony source includes at least one of potassium antimony tartrate, antimony trichloride, and antimony oxide; the tellurium source includes at least one of sodium tellurate, potassium tellurate, tellurium powder, and tellurium oxide; and the bismuth source includes Bi2O3;

[0075] and / or, the molar ratio of the substance containing Group V elements to the substance containing Group VI elements is 1:(3-4.5);

[0076] For example, the molar ratio of the substance containing the Group V element to the substance containing the Group VI element can be 1:3, 1:3.5, 1:4, 1:4.5, or any value between 1:(3-4.5).

[0077] And / or, when the Group V element-containing substance includes an antimony source, during the first hydrothermal reaction, the method further comprises adding glucose and ethylenediamine to the reaction system, wherein the molar ratio of the antimony source to the glucose is 1:(14-16); and the content ratio of the antimony source to the ethylenediamine is 0.135:(18-22) g / ml;

[0078] For example, the molar ratio of the antimony source to glucose can be 1:14, 1:15, 1:16 or any value between 1:(14-16), and the content ratio of the antimony source to ethylenediamine can be 0.135:18 g / ml, 0.135:19 g / ml, 0.135:20 g / ml, 0.135:21 g / ml, 0.135:22 g / ml or any value between 0.135:(18-22) g / ml.

[0079] And / or, when the substance containing group V elements includes a bismuth source, when performing the first hydrothermal reaction, the method further includes adding PVP and sodium hydroxide to the reaction system, the mass ratio of the bismuth source to the PVP is 0.233: (0.4-0.6), and the molar ratio of the bismuth source to the sodium hydroxide is 1: (18-22).

[0080] For example, the mass ratio of the bismuth source to the PVP can be any value between 0.233:0.4, 0.233:0.5, 0.233:0.6 or 0.233:(0.4-0.6), and the molar ratio of the bismuth source to the sodium hydroxide can be any value between 1:18, 1:19, 1:20, 1:21, 1:22 or 1:(18-22).

[0081] According to an embodiment of the present application, the temperature of the first hydrothermal reaction is 170-190°C; for example, the temperature of the first hydrothermal reaction can be 170°C, 180°C, 190°C or any value between 170-190°C.

[0082] And / or, the first hydrothermal reaction time is 11-24 hours. For example, the first hydrothermal reaction time can be 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours or any value between 11 and 24 hours.

[0083] According to an embodiment of the present application, the transition metal chalcogenide precursor includes a molybdenum source and a sulfur source;

[0084] And / or, the molybdenum source includes at least one of ammonium molybdate and sodium molybdate, and the sulfur source includes at least one of thioacetamide and thiourea;

[0085] The molar ratio of the molybdenum source to the sulfur source is 1:(2.1-2.7); for example, the molar ratio of the molybdenum source to the sulfur source can be 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7 or any value between 1:(2.1-2.7).

[0086] And / or, the molar ratio of the antimony source to the molybdenum source is 1:(8-9). For example, the molar ratio of the antimony source to the molybdenum source can be 1:8, 1:8.1, 1:8.2, 1:8.3, 1:8.4, 1:8.5, 1:8.6, 1:8.7, 1:8.8, 1:8.9, 1:9, or any value in between 1:(8-9).

[0087] And / or, the concentration of the molybdenum source in the reaction system is 0.04-0.08 mol / L. For example, the concentration of the molybdenum source in the reaction system can be 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, or any value between 0.04 and 0.08 mol / L.

[0088] According to an embodiment of the present application, the temperature of the second hydrothermal reaction is 170-190°C; for example, the temperature of the second hydrothermal reaction can be 170°C, 180°C, 190°C or any value between 170-190°C.

[0089] And / or, the second hydrothermal reaction time is 19-21 hours. For example, the second hydrothermal reaction time can be 19 hours, 20 hours, 21 hours, or any value between 19 and 21 hours.

[0090] The present application also provides a water electrolysis device, which includes a cathode and an anode, and the cathode includes the composite alkaline hydrogen evolution electrode described above or includes the composite alkaline hydrogen evolution electrode prepared by the preparation method described above.

[0091] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0092] Example 1

[0093] Example 1 provides a method for preparing a composite alkaline hydrogen evolution electrode MoS2-Sb2Te3@NMF-1, comprising the following steps:

[0094] a. First, cut a 2cm x 2cm piece of molybdenum nickel foam. Then, ultrasonically clean it in 1M HCl solution, anhydrous ethanol, and deionized water for 15 minutes to remove oxides, oil, and impurities from the surface. After cleaning, dry the foam and set aside.

[0095] b. Dissolve 0.135g potassium antimony tartrate, 0.1825g sodium tellurite, 0.6g glucose, and 20ml ethylenediamine in 10ml deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the cleaned molybdenum nickel foam and precursor solution to a 50ml microreactor, which is then placed in an electric heated air drying oven at 180°C for 12 hours. After the reaction, remove the molybdenum nickel foam, rinse it several times with anhydrous ethanol, and dry it for 2 hours to obtain a molybdenum nickel foam loaded with a three-dimensional Sb2Te3 nanoarray structure.

[0096] c. Dissolve 0.37g of ammonium molybdate and 0.335g of thioacetamide in 30ml of deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the molybdenum nickel foam loaded with three-dimensional Sb2Te3 nanoarray structures and the precursor solution to a 50ml microreactor. The microreactor is then placed in an electric forced air drying oven and reacted at 180°C for 20 hours. After the reaction, remove the molybdenum nickel foam, rinse it several times with anhydrous ethanol, and dry it for 2 hours. This yields the molybdenum nickel foam MoS2-Sb2Te3@NMF-1 loaded with MoS2 spherical nanostructures, a composite alkaline hydrogen evolution electrode.

[0097] refer to Figure 1 The composite alkaline hydrogen evolution electrode includes MoS2, Sb2Te3 and foam molybdenum nickel metal support NMF, and MoS2 and Sb2Te3 grow uniformly on the surface of the foam molybdenum nickel metal support NMF.

[0098] The SEM of MoS2-Sb2Te3@NMF-1 prepared in Example 1 is as follows: Figure 2 As shown, Figure 2 The SEM images of MoS2-Sb2Te3@NMF-1 at different magnifications are shown in FIG. Figure 2 As can be seen in the figure, after a two-step hydrothermal treatment, nanoscale spherical catalytically active MoS2 is uniformly grown on the surface of the three-dimensional Sb2Te3 nanoarray. Upon magnification, nanospheres with a diameter of approximately 200 nm are observed, growing densely and obscuring the original three-dimensional nanoarray morphology. This increases the electrochemically active surface area of the electrode, thereby improving electrocatalytic performance. Figure 3 The SEM image of the layered structure of MoS2-Sb2Te3@NMF-1 is shown in the figure. The thickness of the Sb2Te3 layer can reach 0.5~2μm, and the thickness of the MoS2 layer can reach 1~2.5μm.

[0099] The three-dimensional Sb2Te3 nanoarray structure in the electrode of Example 1 increases the roughness of the electrode surface, and the MoS2 nanosphere structure increases the electrochemically active surface area of the electrode, which plays an important role in maintaining high catalytic activity at high current density.

[0100] In order to test the activity of the corresponding materials, the electrode prepared in this application was used as the working electrode, a graphite rod and a Hg / HgO electrode were used as the counter electrode and the reference electrode, respectively, and a hydrogen evolution reaction test (linear sweep voltammetry, LSV) was carried out in 1M KOH electrolyte at room temperature using a three-electrode system.

[0101] The LSV curve of MoS2-Sb2Te3@NMF-1 prepared in Example 1 is as follows: Figure 4 As shown in Figure 1, the MoS2-Sb2Te3@NMF-1 electrode prepared in Example 1 exhibits excellent electrocatalytic hydrogen evolution performance in a 1M KOH aqueous solution. When the current density is 10 mA / cm 2 , 50mA / cm 2 , 100mA / cm 2 When the overpotentials are 2 mV, 176 mV, and 206 mV, respectively, the MoS2-Sb2Te3@NMF-1 prepared in Example 1 exhibits excellent hydrogen evolution performance.

[0102] Example 2

[0103] Example 2 provides a method for preparing a composite alkaline hydrogen evolution electrode MoS2-Bi2Te3@NMF, comprising the following steps:

[0104] a. First, cut a 2cm x 2cm piece of molybdenum nickel foam. Then, ultrasonically clean it in 1M HCl solution, anhydrous ethanol, and deionized water for 15 minutes to remove oxides, oil, and impurities from the surface. After cleaning, dry the foam and set aside.

[0105] b. Weigh 0.5g of PVP and dissolve it in 33ml of ethylene glycol, stirring continuously for 20 minutes. Weigh 0.233g of Bi2O3, 0.239g of TeO2, and 0.4g of NaOH and add them to the stirred solution. Stir continuously for 3 hours to form a homogeneous solution, thus obtaining the precursor solution for the hydrothermal reaction. Add the cleaned molybdenum nickel foam and precursor solution to a 50ml microreactor, which is then placed in an electric heated blast drying oven at 180°C for 24 hours. After the reaction is complete, remove the molybdenum nickel foam and rinse it several times with anhydrous ethanol, then dry it for 2 hours to obtain a molybdenum nickel foam loaded with a Bi2Te3 nanolayered structure.

[0106] c. Dissolve 0.37g of ammonium molybdate and 0.335g of thioacetamide in 30ml of deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the molybdenum nickel foam loaded with a three-dimensional Bi2Te3 nanoarray structure and the precursor solution to a 50ml microreactor. The microreactor is then placed in an electric forced air drying oven and reacted at 180°C for 20 hours. After the reaction, remove the molybdenum nickel foam, rinse it several times with anhydrous ethanol, and dry it for 2 hours. This yields a molybdenum nickel foam loaded with MoS2 nanolayered structures, MoS2-Bi2Te3@NMF, a composite alkaline hydrogen evolution electrode.

[0107] The LSV curve of the hydrogen evolution reaction catalyzed by MoS2-Bi2Te3@NMF prepared in Example 2 in 1M KOH at room temperature is as follows: Figure 5 As shown in Figure 2, it exhibits excellent electrocatalytic hydrogen evolution performance in a 1M KOH aqueous solution. When the current density is 10 mA / cm 2 , 50mA / cm 2 , 100mA / cm 2 When the overpotentials are 22 mV, 226 mV, and 318 mV, respectively, the MoS2-Bi2Te3@NMF prepared in Example 2 exhibits excellent hydrogen evolution performance.

[0108] Comparative Example 1

[0109] Comparative Example 1 provides a method for preparing Sb2Te3@NMF, comprising the following steps:

[0110] a. First, cut a 2cm x 2cm piece of molybdenum nickel foam. Then, ultrasonically clean it in 1M HCl solution, anhydrous ethanol, and deionized water for 15 minutes to remove oxides, oil, and impurities from the surface. After cleaning, dry the foam and set aside.

[0111] b. Dissolve 0.135g potassium antimony tartrate, 0.1825g sodium telluride, 0.6g glucose, and 20ml ethylenediamine in 10ml deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the cleaned molybdenum nickel foam and precursor solution to a 50ml microreactor, which is then placed in an electric heated air drying oven at 180°C for 12 hours. After the reaction, remove the molybdenum nickel foam, rinse it several times with deionized water, and dry it for 2 hours to obtain a molybdenum nickel foam loaded with a three-dimensional Sb2Te3 nanoarray structure.

[0112] The SEM of Sb2Te3@NMF prepared in Comparative Example 1 is as follows: Figure 7 As shown, Figure 7 There are two SEM images of Sb2Te3@NMF at different magnifications. Figure 7It can be seen that after hydrothermal treatment, the three-dimensional Sb2Te3 nanoarray grows evenly on the surface of the molybdenum nickel foam. After magnification, it can be observed that the surface of the three-dimensional Sb2Te3 nanoarray is very smooth, and although it grows very densely on the surface of the molybdenum nickel foam, there are large gaps between the rods. Figure 7 and Figure 6 Comparing the SEM images of the foamed molybdenum nickel metal substrate, it can be seen that the three-dimensional Sb2Te3 nanoarray makes the surface of the NMF rougher, thereby increasing the contact area between the nanoarray and the electrolyte.

[0113] The LSV curve of the hydrogen evolution reaction catalyzed by the Sb2Te3@NMF electrode prepared in Comparative Example 1 in 1M KOH at room temperature is shown in Figure 2. Figure 8 As shown by Figure 8 It can be seen that the electrocatalytic hydrogen evolution performance of Sb2Te3@NMF prepared in comparative example 1 in a 1M KOH aqueous solution is very good when the current density is 10 mA / cm 2 , 50mA / cm 2 When , the overpotentials are 254mV and 404mV respectively.

[0114] Comparative Example 2

[0115] Comparative Example 2 provides a method for preparing MoS2@NMF, comprising the following steps:

[0116] a. First, cut a 2cm x 2cm piece of molybdenum nickel foam. Then, ultrasonically clean it in 1M HCl solution, anhydrous ethanol, and deionized water for 15 minutes to remove oxides, oil, and impurities from the surface. After cleaning, dry the foam and set aside.

[0117] b. Dissolve 0.37g of ammonium molybdate and 0.335g of thioacetamide in 30ml of deionized water to form a homogeneous solution, obtaining the precursor solution for the hydrothermal reaction. Add the cleaned molybdenum nickel foam and precursor solution to a 50ml microreactor. Place the microreactor in an electric heated air drying oven and react at 180°C for 20h. After the reaction, remove the molybdenum nickel foam and rinse several times with anhydrous ethanol, then dry for 2h to obtain the MoS2@NMF hydrogen evolution electrode.

[0118] The LSV curve of the MoS2@NMF prepared in comparative example 2 catalyzed hydrogen evolution reaction in 1M KOH at room temperature is as follows: Figure 9 As shown by Figure 9 It can be seen that the electrocatalytic hydrogen evolution performance of MoS2@NMF prepared in comparative example 2 in a KOH aqueous solution with a concentration of 1 M is good when the current density is 10 mA / cm 2 , 50mA / cm 2When , the overpotentials are 62mV and 208mV respectively.

[0119] Comparative Example 3

[0120] Comparative Example 3 provides a method for preparing Sb2Te3-MoS2@NMF, comprising the following steps:

[0121] a. First, cut a 2cm x 2cm piece of molybdenum nickel foam. Then, ultrasonically clean it in 1M HCl solution, anhydrous ethanol, and deionized water for 15 minutes to remove oxides, oil, and impurities from the surface. After cleaning, dry the foam and set aside.

[0122] b. Dissolve 0.37g of ammonium molybdate and 0.335g of thioacetamide in 30ml of deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the cleaned molybdenum nickel foam and precursor solution to a 50ml microreactor, which is then placed in an electric heated blast drying oven at 180°C for 20h. After the reaction, remove the molybdenum nickel foam and rinse it several times with anhydrous ethanol, then dry it for 2h to obtain a molybdenum nickel foam loaded with MoS2 nanostructures.

[0123] c. Dissolve 0.135g potassium antimony tartrate, 0.1825g sodium tellurite, 0.6g glucose, and 20ml ethylenediamine in 10ml deionized water to form a homogeneous solution, obtaining the precursor solution for the hydrothermal reaction. Add the molybdenum nickel foam loaded with MoS2 nanostructures and the precursor solution to a 50mL microreactor. The microreactor is then placed in an electric forced-air drying oven and reacted at 180°C for 12 hours. After the reaction, remove the molybdenum nickel foam, rinse it several times with anhydrous ethanol, and dry it for 2 hours to obtain the Sb2Te3-MoS2@NMF hydrogen evolution electrode.

[0124] The LSV curve of the hydrogen evolution reaction catalyzed by Sb2Te3-MoS2@NMF prepared in comparative example 3 in 1M KOH at room temperature is shown as follows: Figure 10 As shown by Figure 10 It can be seen that the electrocatalytic hydrogen evolution performance of Sb2Te3-MoS2@NMF prepared in comparative example 3 in a 1M KOH aqueous solution is very good when the current density is 10 mA / cm 2 , 50mA / cm 2 When , the overpotentials are 118mV and 204mV respectively.

[0125] Comparative Example 4

[0126] Comparative Example 4 provides a method for preparing a composite alkaline hydrogen evolution electrode MoS2-Sb2Te3@NMF-2, comprising the following steps:

[0127] a. First, cut a 2cm x 2cm piece of molybdenum nickel foam. Then, ultrasonically clean it in 1M HCl solution, anhydrous ethanol, and deionized water for 15 minutes to remove oxides, oil, and impurities from the surface. After cleaning, dry the foam and set aside.

[0128] b. Dissolve 0.27g potassium antimony tartrate, 0.365g sodium telluride, 0.6g glucose, and 20ml ethylenediamine in 10ml deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the cleaned molybdenum nickel foam and precursor solution to a 50ml microreactor, which is then placed in an electric heated air drying oven at 180°C for 24h. After the reaction, remove the molybdenum nickel foam, rinse it several times with anhydrous ethanol, and dry it for 2h to obtain a molybdenum nickel foam loaded with Sb2Te3 nanostructures.

[0129] c. Dissolve 0.74g of ammonium molybdate and 0.67g of thioacetamide in 30ml of deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the molybdenum nickel foam loaded with Sb2Te3 nanostructures and the precursor solution to a 50mL microreactor. The microreactor is then placed in an electric forced-air drying oven and reacted at 180°C for 20h. After the reaction, remove the molybdenum nickel foam and rinse several times with anhydrous ethanol, then dry for 2h to obtain the MoS2 nanostructure-loaded molybdenum nickel foam MoS2-Sb2Te3@NMF-2, a composite alkaline hydrogen evolution electrode.

[0130] The SEM images of the layered structure of MoS2-Sb2Te3@NMF-2 prepared in Comparative Example 4 are as follows: Figure 11 As shown in the figure, after two-step hydrothermal treatment, the thickness of the Sb2Te3 layer can reach 3-4 μm, and the thickness of the MoS2 layer can reach 3-5 μm.

[0131] The LSV curve of the hydrogen evolution reaction catalyzed by MoS2-Sb2Te3@NMF-2 prepared in comparative example 4 in 1M KOH at room temperature is shown as follows: Figure 12 As shown, Figure 12 It can be seen that the electrocatalytic hydrogen evolution performance in a 1M KOH aqueous solution is good when the current density is 10mA / cm 2 , 50mA / cm 2 , 100mA / cm 2 When , the overpotentials are 57mV, 326mV, and 555mV respectively.

[0132] Comparative Example 5

[0133] Comparative Example 5 provides a preparation method of a composite alkaline hydrogen evolution electrode MoS2-Sb2Te3@NMF-3, comprising the following steps:

[0134] a. First, cut a 2cm x 2cm piece of molybdenum nickel foam. Then, ultrasonically clean it in 1M HCl solution, anhydrous ethanol, and deionized water for 15 minutes to remove oxides, oil, and impurities from the surface. After cleaning, dry the foam and set aside.

[0135] b. Dissolve 0.0675g potassium antimony tartrate, 0.0913g sodium telluride, 0.6g glucose, and 20ml ethylenediamine in 10ml deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the cleaned molybdenum nickel foam and precursor solution to a 50ml microreactor, which is then placed in an electric heated air drying oven at 180°C for 10 hours. After the reaction, remove the molybdenum nickel foam, rinse it several times with anhydrous ethanol, and dry it for 2 hours to obtain a molybdenum nickel foam loaded with Sb2Te3 nanostructures.

[0136] c. Dissolve 0.135g of ammonium molybdate and 0.17g of thioacetamide in 30ml of deionized water to form a homogeneous solution, obtaining a precursor solution for the hydrothermal reaction. Add the molybdenum nickel foam loaded with Sb2Te3 nanostructures and the precursor solution to a 50mL microreactor. The microreactor is then placed in an electric forced-air drying oven and reacted at 180°C for 15h. After the reaction, remove the molybdenum nickel foam and rinse several times with anhydrous ethanol, then dry for 2h to obtain the MoS2-Sb2Te3@NMF-3 composite alkaline hydrogen evolution electrode.

[0137] The SEM images of the layered structure of MoS2-Sb2Te3@NMF-3 prepared in Comparative Example 5 are as follows: Figure 13 As shown in the figure, after two-step hydrothermal treatment, the thickness of the Sb2Te3 layer can reach 0.1~0.4μm, and the thickness of the MoS2 layer can reach 0.1~0.8μm.

[0138] The LSV curve of the hydrogen evolution reaction catalyzed by MoS2-Sb2Te3@NMF-3 prepared in comparative example 5 in 1M KOH at room temperature is shown as follows: Figure 14 As shown, Figure 14 It can be seen that the electrocatalytic hydrogen evolution performance in a 1M KOH aqueous solution is good when the current density is 10mA / cm 2 , 50mA / cm 2 When , the overpotentials are 423mV and 768mV respectively.

[0139] Example 1, Comparative Example 4 and Comparative Example 5 were respectively subjected to a current density of 10 mA / cm 2 , 50mA / cm 2 The overpotential when , is compared, as Figure 15 As shown by Figure 15It can be seen that the overpotential of the electrode of Example 1 at the same current density is significantly lower than that of Comparative Example 4 and Comparative Example 5, indicating that the electrode of Example 1 has a better hydrogen evolution ability. This is because too thick and too thin two-dimensional material nanostructure layers will hinder the transfer of electrons and reduce the electrochemical active surface area. Example 1 has the lowest overpotential and the better hydrogen evolution ability, indicating that the preferred thickness of the Sb2Te3 layer is 0.5 to 2 μm, and the preferred thickness of the MoS2 layer is 1 to 2.5 μm.

[0140] Electrochemical impedance spectroscopy (EIS) is mainly used to analyze and test the electrochemical impedance of materials. It is an important means to understand the catalytic performance of materials and the reasons behind them. This application conducted EIS tests on NMF, MoS2-Sb2Te3@NMF-1 prepared in Example 1, Sb2Te3@NMF prepared in Comparative Example 1, MoS2@NMF prepared in Comparative Example 2, and Sb2Te3-MoS2@NMF prepared in Comparative Example 3. The results are as follows: Figure 16 As shown. Figure 16 It can be found that NMF has the smallest electron transfer resistance (Rct) of 10.74Ω, indicating the fastest electron transfer rate; while MoS2-Sb2Te3@NMF-1 has the largest Rct of 1.626E+9Ω. Despite the larger Rct, the electrode MoS2-Sb2Te3@NMF-1 has highly exposed active sites that can effectively promote hydrogen generation.

[0141] Figure 17 The polarization curves of the electrodes prepared from NMF, Example 1, and Comparative Examples 1-3 are shown in Figure 1. As can be seen from the figure, the MoS2-Sb2Te3@NMF-1 prepared in Example 1 exhibits excellent electrocatalytic hydrogen evolution performance in a 1M KOH aqueous solution. When the current density is 10 mA / cm 2 , 50mA / cm 2 , 100mA / cm 2 When the overpotential is 2mV, 176mV, and 206mV, respectively, it is significantly better than the electrodes prepared by NMF and Comparative Examples 1-3, and is also better than the existing electrodes for water electrolysis that have been reported.

[0142] Depend on Figure 18 It can be seen that the Tafel slope (16 mV / dec) of the MoS2-Sb2Te3@NMF-1 electrode prepared in Example 1 is smaller than the Tafel slope of the electrodes prepared in Comparative Examples 1-3, indicating that the MoS2-Sb2Te3@NMF-1 electrode prepared in Example 1 is more efficient in promoting the hydrogen evolution reaction.

[0143] The composite alkaline hydrogen evolution electrode prepared in Example 1 was subjected to a voltage-time test under high temperature and strong alkali (60°C, 6M KOH). The results are as follows: Figure 19As shown. Figure 19 It can be seen that at 50 mA cm 2 Under the current density, after 24 hours of testing, the composite alkaline hydrogen evolution electrode prepared in Example 1 has good performance stability and a relatively smooth curve. After 24 hours of testing, the overpotential increases by 50 mV, indicating that the electrode of the present application has high high temperature and strong alkali resistance.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These 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 application.

[0145] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and to form distinct embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this application and should not be construed as an admission or any implication that such information constitutes prior art known to those skilled in the art.

Claims

1. A composite alkaline hydrogen evolution electrode, characterized in that The composite alkaline hydrogen evolution electrode comprises a porous metal substrate, a V-VI group compound semiconductor layer, and a transition metal sulfide compound layer which are stacked; The porous metal substrate is foamed molybdenum nickel; The material forming the V-VI group compound semiconductor layer is Sb2Te3; The thickness of the V-VI group compound semiconductor layer is 0.5 to 2 μm; The material forming the transition metal chalcogenide layer is MoS2; The thickness of the transition metal chalcogenide compound layer is 1-2.5 μm.

2. A method for preparing the composite alkaline hydrogen evolution electrode according to claim 1, characterized in that: include: Mixing a porous metal substrate, a Group V-VI compound semiconductor precursor, and water, and performing a first hydrothermal reaction in a reactor to obtain a porous metal substrate loaded with a Group V-VI compound semiconductor layer; The porous metal substrate carrying the Group V-VI compound semiconductor layer, a transition metal sulfide compound precursor and water are mixed, and a second hydrothermal reaction is carried out in a reactor to obtain a composite alkaline hydrogen evolution electrode.

3. The method for preparing the composite alkaline hydrogen evolution electrode according to claim 2, wherein: The V-VI group compound semiconductor precursor includes a substance containing a group V element and a substance containing a group VI element, wherein the substance containing the group V element is an antimony source and the substance containing the group VI element is a tellurium source; The antimony source includes at least one of potassium antimony tartrate, antimony trichloride, and antimony oxide; the tellurium source includes at least one of sodium tellurate, potassium tellurate, tellurium powder, and tellurium oxide; The molar ratio of the substance containing the group V element to the substance containing the group VI element is 1:(3-4.5); When the Group V element-containing substance is an antimony source, during the first hydrothermal reaction, the method further includes adding glucose and ethylenediamine to the reaction system, wherein the molar ratio of the antimony source to the glucose is 1:(14-16); and the content ratio of the antimony source to the ethylenediamine is 0.135:(18-22) g / ml.

4. The method for preparing the composite alkaline hydrogen evolution electrode according to claim 3, wherein: The temperature of the first hydrothermal reaction is 170-190°C; And / or, the first hydrothermal reaction time is 11-24 hours.

5. The method for preparing the composite alkaline hydrogen evolution electrode according to claim 3, wherein: The transition metal chalcogenide precursor is a molybdenum source and a sulfur source; The molybdenum source includes at least one of ammonium molybdate and sodium molybdate, and the sulfur source includes at least one of thioacetamide and thiourea; The molar ratio of the molybdenum source to the sulfur source is 1:(2.1-2.7); The molar ratio of the antimony source to the molybdenum source is 1:(8-9); The concentration of the molybdenum source in the reaction system is 0.04-0.08 mol / L.

6. The method for preparing the composite alkaline hydrogen evolution electrode according to claim 5, wherein: The temperature of the second hydrothermal reaction is 170-190°C; And / or, the second hydrothermal reaction time is 19-21 hours.

7. A water electrolysis device, characterized in that: The water electrolysis device comprises a cathode and an anode, wherein the cathode comprises the composite alkaline hydrogen evolution electrode according to claim 1 or the composite alkaline hydrogen evolution electrode prepared by the preparation method according to any one of claims 2 to 6.

Images