Catalytic material and preparation method thereof, water electrolysis hydrogen evolution catalytic electrode and water electrolysis hydrogen evolution method

Abstract

The invention relates to the technical field of water electrolysis catalysts, and discloses a catalytic material and a preparation method thereof, a water electrolysis hydrogen evolution catalytic electrode and a water electrolysis hydrogen evolution method, the catalytic material comprises a carrier and an active metal component loaded on the carrier; wherein the carrier is transition metal sulfide containing S vacancy, and at least part of the transition metal sulfide is a 1T phase; the active metal component is selected from at least one of VIII group metal and IB group metal. The catalytic material has excellent HER catalytic performance and good catalytic stability.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolyzed water catalysts, and particularly relates to a catalytic material, a preparation method thereof, an electrolyzed water hydrogen evolution catalytic electrode, and a method for electrolyzed water hydrogen evolution. Background Art

[0002] Traditional noble metals and a small amount of non-noble metals have excellent catalytic performance for HER. However, their scarcity, high cost, and low dispersion have hindered their widespread application. Doping a small amount of metal on a carrier with strong electron coupling to obtain a highly active HER catalyst is an effective way to solve the above problems. Through the strong interaction between the metal and the carrier, the electron transfer / mass exchange is promoted, the size of the active metal is effectively adjusted, and the dispersion of the active metal is improved, so as to maximize the atomic utilization efficiency of the metal.

[0003] Transition metal sulfides with a typical two-dimensional (2D) layered structure can become a promising carrier material due to their unique structure. However, the low electrical conductivity, strong aggregation tendency, and inert basal plane of transition metal sulfides limit the electrocatalytic hydrogen evolution performance. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problem of insufficient catalytic activity of the catalyst material in the electrocatalytic hydrogen evolution reaction (HER) existing in the prior art, and to provide a catalytic material, a preparation method thereof, an electrolyzed water hydrogen evolution catalytic electrode, and a method for electrolyzed water hydrogen evolution. This catalytic material has good conductivity and high HER catalytic performance.

[0005] To achieve the above purpose, the first aspect of the present invention provides a catalytic material, which includes a carrier and an active metal component supported on the carrier;

[0006] Wherein, the carrier is a transition metal sulfide containing S vacancies, and at least part of the transition metal sulfide is in the 1T phase; the active metal component is selected from at least one of Group VIII metals and Group IB metals.

[0007] The second aspect of the present invention provides a preparation method of a catalytic material, and the preparation method includes:

[0008] (1) Contacting a transition metal sulfide with a reducing agent to obtain a transition metal sulfide containing S vacancies;

[0009] (2) Mixing a precursor of the active metal component, the transition metal sulfide containing S vacancies with a solvent for impregnation, and then drying;

[0010] (3) Roasting the product obtained in step (2) in a hydrogen-containing atmosphere;

[0011] Among them, the solvent is an alcohol compound, preferably at least one of ethanol, isopropanol, methanol, isoamyl alcohol and n-butanol.

[0012] The third aspect of the present invention provides a catalytic material prepared by the above preparation method.

[0013] The fourth aspect of the present invention provides an electrolytic water hydrogen evolution catalytic electrode, which includes a conductive substrate and a catalytic material composite on the surface of the conductive substrate. The catalytic material is the catalytic material described in the first aspect or the third aspect.

[0014] The fifth aspect of the present invention provides a method for electrolytic water hydrogen evolution, which includes: under the conditions of electrolytic water, using the electrolytic water hydrogen evolution catalytic electrode described in the fourth aspect as the working electrode to carry out electrolytic water reaction.

[0015] Through the above technical solutions, the catalytic material provided by the present invention uses a transition metal sulfide containing vacancy defects as a carrier. By introducing active metal components, it can induce a phase transformation of the transition metal sulfide, so that at least part of the transition metal sulfide is in the 1T phase, thereby activating the inert basal plane of the transition metal sulfide and improving the HER catalytic performance. On the other hand, the vacancy defects in the carrier can enhance the metal-support (EMSI) effect, contribute to improving the metal dispersion and increasing the atomic utilization rate.

[0016] The preparation method of the catalytic material provided by the present invention induces vacancy defects in the transition metal sulfide through a reducing agent, thereby exposing more active sites, enabling the active metal components to adjust the electronic structure of the transition metal sulfide during the impregnation process, inducing phase transformation, and improving its conductivity. The preparation method has low energy consumption and good catalytic stability. Description of the Drawings

[0017] Figure 1 (a) is the XPS diagram of Mo element in the sulfur vacancy-containing transition metal sulfide (Sv-MoS 2 -2) and MoS 2 raw material prepared in Example 1 of the present invention;

[0018] Figure 1 (b) is the XPS diagram of S element in the sulfur vacancy-containing transition metal sulfide (Sv-MoS 2 -2) and MoS 2 raw material prepared in Example 1 of the present invention;

[0019] Figure 2 (a) is the cyclic voltammetry test curve of the catalytic material Pt / Sv-MoS 2 -2 prepared in Example 1 of the present invention under a long-time cycle;

[0020] Figure 2(b) The chrono - stability voltage curve of the catalytic material Pt / Sv - MoS 2 -2 prepared in Example 1 of the present invention. Detailed implementation manners

[0021] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0022] The first aspect of the present invention provides a catalytic material, which includes a carrier and an active metal component supported on the carrier;

[0023] Wherein, the carrier is a transition metal sulfide containing S vacancies, and at least part of the transition metal sulfide is in the 1T phase; the active metal component is selected from at least one of Group VIII metals and Group IB metals.

[0024] The inventors of the present invention found in the research that using the surface vacancy defects of the transition metal sulfide carrier can enhance the active metal - carrier effect, can achieve the precise anchoring of the active metal and form stable active metal - S coordination bonds; and the introduction of the active metal component can regulate the electronic structure, and then induce a phase transformation of the carrier with vacancy defects. The reason is that the phase transformation of the transition metal sulfide can directly affect the electronic structure of the metal active center, thereby improving the conductivity of the transition metal sulfide, significantly improving the influence of the inert 2D transition metal sulfide on HER. At the same time, the vacancy defects can modify the electron density, conductivity, coordination environment, surface interaction, molecular adsorption / desorption energy and band gap of the transition metal sulfide, thereby improving the HER performance.

[0025] In the present invention, at least part of the transition metal sulfide is in the 1T phase. The present invention has no special limitation on the content of the 1T phase, as long as the 1T phase exists. In addition to the 1T phase, the transition metal sulfide may also contain the 2H phase. The "1T phase" and "2H phase" have the conventional definitions in the art. Among them, the "1T phase" refers to the trigonal phase, and the "2H phase" refers to the hexagonal phase. In the present invention, the phase structure of the transition metal sulfide is determined by Raman spectroscopy test and analysis.

[0026] In the present invention, vacancy defects in the support are characterized by electron paramagnetic resonance spectroscopy (EPR). The instrument used for electron paramagnetic resonance spectroscopy (EPR) is a Bruker band continuous wave EPR spectrometer. The specific test parameters are as follows: central magnetic field 3500.00 G; sweep field width 200.00 G; sweep field time 30.00 s; microwave power 19.45 mW; modulation amplitude 1.000 G; conversion time 40.00 ms. The sample to be tested is placed in a rectangular cavity resonator with a frequency of 9.852508 GHz. The reflected microwave enters the detector through the circulator, and the resonance information can be calculated based on the absorption amount of the microwave radiation.

[0027] According to some preferred embodiments of the present invention, the mass ratio of the support to the active metal component in terms of elements is 10 - 1000:1. For example, it can be 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1, 900:1, 1000:1 and other typical but non-limiting mass ratios. Preferably, the mass ratio of the support to the active metal component in terms of elements is 20 - 100:1. In the above preferred composition case, it is beneficial to further exert the synergistic effect between the active metal component and the support, further enhance the metal-support interaction (EMSI) effect, induce phase transformation of the support with vacancy defects, and thus improve the catalytic activity of the catalytic material.

[0028] The selection range of the active metal component in the present invention is relatively wide, and it can be selected from at least one of Group VIII metals and Group IB metals, and can be noble metals and / or non-noble metals. Preferably, the active metal component is selected from at least one of Pt, Pd, Co, Ni, and Cu, more preferably Pt and / or Pd, and even more preferably Pt. Using the above preferred active metal component is beneficial to further improve the catalytic activity of the catalytic material.

[0029] The selection range of the transition metal in the transition metal sulfide containing S vacancies in the present invention is relatively wide, and any transition metal sulfide known in the art that can be used in the hydrogen evolution reaction (HER) of electrocatalysts can be applied to the present invention. Preferably, the transition metal in the transition metal sulfide is Mo and / or W. Using the above preferred support composition is beneficial to further exert the synergistic effect between the support and the active metal component, and thus improve the HER activity of the catalytic material.

[0030] In the present invention, in the catalytic material, at least a part of the active metal component exists in the elemental form. It can be understood that there may also be an active metal component in the oxide form. There is no particular limitation on the content of the two in the present invention. As long as there is an active metal component in the elemental form, the HER activity of the catalytic material can be further improved.

[0031] In the present invention, the active metal component has excellent dispersibility on the surface of the carrier, and the particle size of the active metal component is small. Preferably, the average particle size of the active metal component is 1 - 10 nm, more preferably 1 - 5 nm. In the present invention, the average particle size of the active metal component is measured by transmission electron microscopy (TEM).

[0032] The second aspect of the present invention provides a preparation method of a catalytic material, and the preparation method includes:

[0033] (1) Contacting a transition metal sulfide with a reducing agent to obtain a transition metal sulfide containing S vacancies;

[0034] (2) Mixing a precursor of the active metal component, the transition metal sulfide containing S vacancies with a solvent for impregnation, and then drying;

[0035] (3) Roasting the product obtained in step (2) in a hydrogen-containing atmosphere;

[0036] Wherein, the solvent is an alcohol compound, preferably at least one of ethanol, isopropanol, methanol, isoamyl alcohol and n-butanol.

[0037] In the present invention, by contacting the transition metal sulfide with the reducing agent, the transition metal element in the transition metal oxide is reduced, so that S vacancies are generated in the transition metal sulfide. The selection range of the reducing agent in the present invention is relatively wide and can be a conventional selection in the art.

[0038] According to some preferred embodiments of the present invention, the reducing agent is at least one of oxalic acid, potassium borohydride, sodium borohydride and lithium aluminum hydride.

[0039] Preferably, the reducing agent is provided by a reducing agent solution, and the concentration of the reducing agent solution is 0.5 - 3.5 mol / L, for example, it can be specific non-limiting concentration values such as 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, or any range between any two of them.

[0040] Preferably, the solvent in the reducing agent solution is an alcohol, preferably at least one of ethanol, isopropanol, methanol, isoamyl alcohol and n-butanol.

[0041] Preferably, the contacting in step (1) is carried out under ultrasonic conditions, the temperature of the contacting is 20-40 °C, and the time of the contacting is 20-120 min.

[0042] According to some preferred embodiments of the present invention, the preparation method further includes: washing and drying the product obtained by the contacting. The washing and drying can be carried out in a conventional manner in the art, and the present invention has no particular limitation thereon.

[0043] The present invention has no particular limitation on the manner of mixing the precursor of the active metal component, the transition metal sulfide containing S vacancies and the solvent, as long as each component is uniformly dispersed in the solvent. The present invention also has no particular limitation on the amount of the solvent used, and also as long as each component is uniformly dispersed in the solvent.

[0044] According to some preferred embodiments of the present invention, the mixing includes: first dispersing the transition metal sulfide containing S vacancies in the solvent, and then adding the precursor of the active metal component. By adopting the above preferred embodiment, it is beneficial to the dispersion of the transition metal sulfide containing S vacancies, improves the dispersion degree and utilization rate of the active metal, and thus improves the HER activity of the prepared catalytic material.

[0045] Preferably, the amount of the precursor solution of the active metal component is such that the mass ratio of the transition metal sulfide containing S vacancies to the precursor of the active metal component in terms of elements is 10-1000:1, preferably 20-100:1.

[0046] The present invention has a relatively wide selection range for the active metal component, which can be selected from at least one of Group VIII metals and Group IB metals, and can be noble metals and / or non-noble metals. Preferably, the active metal component is selected from at least one of Pt, Pd, Co, Ni and Cu, more preferably Pt and / or Pd, and even more preferably Pt. By adopting the above preferred active metal component, it is beneficial to further improve the catalytic activity of the catalytic material.

[0047] The present invention has a relatively wide selection range for the precursor of the active metal component, and can use soluble compounds of conventional active metal elements in the art. For example, it can be at least one of nitrates, chlorides and metal acid compounds of the active metal.

[0048] The present invention has no particular limitation on the source of the transition metal sulfide, which can be prepared by a conventional method in the art. For example, it can be prepared by a hydrothermal reaction of a transition metal oxide and a sulfur source, which is well known to those skilled in the art and will not be elaborated herein.

[0049] The present invention has a wide range of choices for the transition metals in the transition metal sulfide, and any known transition metal sulfide in the art that can be used in the electrocatalytic hydrogen evolution reaction (HER) can be applied to the present invention. Preferably, the transition metal in the transition metal sulfide is Mo and / or W. Using the above preferred carrier composition is beneficial to further exert the synergistic effect of the carrier and the active metal component, thereby improving the HER activity of the catalytic material.

[0050] According to the present invention, the surface vacancy defects of the transition metal sulfide carrier can enhance the active metal and carrier effects. During the impregnation process, in the presence of an alcohol compound, precise anchoring of the active metal and the formation of a stable active metal-S coordination bond can be achieved; and the introduction of the active metal component can regulate the electronic structure, thereby inducing a phase transformation in the carrier with vacancy defects to form a 1T phase structure. Thus, the prepared catalytic material has excellent HER activity.

[0051] According to some preferred embodiments of the present invention, the temperature of the impregnation is 30 - 100 °C, for example, it can be 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C and other specific but non-limiting temperatures or the range between them, and the time of the impregnation is 3 - 20 h, for example, it can be 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 10 h, 15 h, 20 h and other specific but non-limiting times or the range between them.

[0052] The present invention has no special limitation on the drying conditions, and it is based on removing the solvent in the impregnated product. Conventional drying conditions and equipment in the art can be used. Preferably, the drying is carried out under vacuum conditions. Preferably, the temperature of the drying is 40 - 100 °C, for example, it can be 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C and other specific but non-limiting temperatures or the range between them, and the time of the drying is 5 - 24 h, for example, it can be 5 h, 6 h, 7 h, 8 h, 10 h, 15 h, 20 h, 22 h, 24 h and other specific but non-limiting times or the range between them.

[0053] According to some preferred embodiments of the present invention, the temperature of the calcination is 100 - 500 °C, for example, it can be 100 °C, 110 °C, 120 °C, 150 °C, 180 °C, 200 °C, 230 °C, 250 °C, 300 °C, 350 °C, 400 °C, 450 °C, 500 °C and other specific but non-limiting calcination temperatures or the range between them, and the time of the calcination is 1 - 6 h, for example, it can be 1 h, 2 h, 3 h, 4 h, 5 h, 6 h and other specific calcination times.

[0054] In the present invention, preferably, the hydrogen-containing atmosphere is provided by hydrogen or a mixture of hydrogen and an inert gas, and the inert gas can be nitrogen and / or argon. Preferably, the volume content of hydrogen in the hydrogen-containing atmosphere is not higher than 20 vol%, preferably 3-15 vol%.

[0055] The third aspect of the present invention provides a catalytic material prepared by the above preparation method.

[0056] The fourth aspect of the present invention provides an electrolytic water hydrogen evolution catalytic electrode, which includes a conductive substrate and a catalytic material composite on the surface of the conductive substrate, and the catalytic material is the catalytic material described in the first aspect or the third aspect;

[0057] The present invention has a wide selection range for the conductive substrate, and any conductive substrate that can be used for electrolytic water electrodes in the art can be applied to the present invention. Preferably, the conductive substrate is selected from modified or unmodified carbon paper. The modified carbon paper can be hydrophobic modified carbon paper or hydrophilic modified carbon paper, such as at least one of 20% hydrophobic carbon paper, 5% hydrophobic carbon paper, 5% hydrophilic carbon paper, and 20% hydrophilic carbon paper.

[0058] Preferably, based on the surface area of the electrode, the loading amount of the catalytic material is 0.5-3 mg / cm 2 , preferably 1-2 mg / cm 2 .

[0059] Preferably, the electrode includes a conductive substrate, and a catalytic material and a diaphragm composite on the surface of the conductive substrate. The present invention has no special requirements for the specific selection of the diaphragm, and those skilled in the art can select according to actual needs. For example, it can be a Nafion membrane. The present invention also has no special limitation on the thickness of the diaphragm.

[0060] According to some preferred embodiments of the present invention, the preparation method of the electrolytic water hydrogen evolution catalytic electrode includes: dispersing the catalytic material and the diaphragm in an organic solvent to obtain a dispersion; then loading the dispersion on the surface of the conductive substrate and drying.

[0061] Preferably, the organic solvent is alcohol, preferably ethanol. The present invention has no special limitation on the concentration of the dispersion, as long as the catalytic material and the diaphragm are fully dispersed, and those skilled in the art can select according to actual needs. Preferably, the dispersion is carried out under ultrasonic conditions.

[0062] According to the present invention, the method of loading the dispersion on the surface of the conductive substrate can be, for example, dropping, spraying, etc., and the present invention has no special limitation on this. The loading can also be carried out once or multiple times to meet the loading amount of the catalytic material.

[0063] According to the present invention, preferably, the drying is carried out under the irradiation of an infrared lamp.

[0064] A fifth aspect of the present invention provides a method for hydrogen evolution by electrolyzing water, the method comprising: under the condition of electrolyzing water, using the electrolytic water hydrogen evolution catalytic electrode described in the fourth aspect as the working electrode to carry out the electrolytic water reaction.

[0065] The present invention will be described in detail below through examples.

[0066] The characterization methods adopted in the present invention include transmission electron microscopy characterization (TEM), X-ray photoelectron spectroscopy characterization (XPS), and electron spin resonance spectroscopy (EPR). The test methods are as follows:

[0067] The microstructure of the sample is observed by TEM, and high-resolution TEM (HRTEM) is used to analyze the microstructure and morphology of the sample, and the high-resolution lattice image is used to analyze the composition of the sample; in order to obtain the content and distribution of each component in the sample, the sample is analyzed by mapping. Sample preparation method: Take a small amount of the sample and add it to a volumetric tube containing absolute ethanol, and make the solvent uniformly dispersed by ultrasonic treatment. Then, drop the uniformly dispersed solvent onto a copper mesh with a pipette and dry it before testing.

[0068] The bonding situation and chemical valence states of elements in the material are tested by XPS photoelectron spectroscopy. Test conditions: Use an X-ray source of Al-Kα, with a photoelectron energy of 1486.6 eV, a working voltage of 15 kV, and a power of 120 mW.

[0069] The instrument used is a Bruker band continuous wave EPR spectrometer. The specific test parameters are as follows: central magnetic field 3500.00 G; sweep field width 200.00 G; sweep field time 30.00 s; microwave power 19.45 mW; modulation amplitude 1.000 G; conversion time 40.00 ms. The paramagnetic sample is placed in a rectangular dielectric resonator with a frequency of 9.852508 GHz. The reflected microwave enters the detector through the circulator, and the resonance information can be calculated according to the absorption amount of the microwave radiation.

[0070] The phase composition of the carrier in the catalytic material is determined by Raman spectroscopy. The specific conditions include: laser light source wavelength 532 nm, spectral scanning range 100 - 2000 cm -1 . Sample preparation method: Take a small amount of the sample and place it at the center of the glass slide, and then flatten the test sample with a glass slide before testing.

[0071] Example 1

[0072] (1) Disperse the MoS 2 nanotube material into 0.5 mol / L NaBH 4in an ethanol solution, ultrasonicate for 20 min at room temperature, wash the obtained product thoroughly, and place it in a vacuum dryer overnight to obtain Sv-MoS with S vacancies 2 nanotube material.

[0073] Disperse the Sv-MoS 2 and the raw material MoS 2 for EPR spectroscopic testing. It can be seen that there are S vacancies in Sv-MoS 2 .

[0074] (2) Disperse the Sv-MoS 2 nanotube material in absolute ethanol. Add the required loading amount of H 2 PtCl 6 to the above homogeneous solution (the mass ratio of Sv-MoS 2 to Pt is 100:1). Immerse at 30 °C for 5 h, and then directly place the product in a vacuum dryer at 40 °C for 5 h.

[0075] (3) Finally, calcine the sample in a tube furnace. The atmosphere is 5 vol% H 2 / N 2 , the reduction temperature is 200 °C, and the reduction time is 1 h. Cool to room temperature to obtain the Pt / Sv-MoS 2 catalytic material, denoted as Pt / Sv-MoS 2 -2.

[0076] Test the phase composition of the support in the catalytic material by Raman spectroscopy. Significant peaks are shown at 146, 278, and 332 cm -1 , and these peaks are related to the 1T-MoS 2 mode, indicating that the introduction of Pt induces the phase transformation of 2H-MoS 2 to the 1T phase on the support with vacancy defects.

[0077] Perform XPS analysis on the prepared catalytic material. The deconvolution results of Mo and S elements are shown in Figure 1 (a) and Figure 1 (b) respectively. It can be seen that the etching produces the existence of S vacancies, resulting in the reduction of Mo(IV) to Mo(III).

[0078] Use TEM to observe the structure and morphology of the catalytic material. It can be seen that Pt on the surface of the support has good dispersion, and the Pt particle size is small, with an average particle size of about 1.3 nm.

[0079] Example 2

[0080] (1) Disperse the preliminarily synthesized MoS 2The nanotubes were separately dispersed into an ethanol solution of 1 mol / L oxalic acid and sonicated for 40 min at room temperature. The obtained product was washed clean and placed in a vacuum for drying overnight to obtain Sv-MoS nanotube materials with S vacancies. 2 nanotube materials.

[0081] (2) To obtain Sv-MoS nanotubes with S vacancies, 2 the nanotubes were dispersed in isopropanol, and PdCl with the required loading amount 2 was added to the above homogeneous solution (the mass ratio of Sv-MoS 2 to Pd was 50:1). It was impregnated for 8 h at a temperature of 40 °C, and then the product was directly placed in a vacuum at 50 °C for drying for 8 h;

[0082] (3) Finally, the sample was calcined in a tube furnace. The atmosphere was 3 vol% H 2 / N 2 , the reduction temperature was 250 °C, and the reduction time was 2 h. After cooling to room temperature, the Pd / Sv-MoS 2 catalytic material was obtained. The phase composition of the carrier in the catalytic material was tested by Raman spectroscopy, and the generation of 1T-phase molybdenum disulfide was observed.

[0083] Example 3

[0084] (1) The preliminarily synthesized MoS 2 nanotubes were separately dispersed into an isopropanol solution of 1.5 mol / L potassium borohydride and sonicated for 60 min at room temperature. The obtained product was washed clean and placed in a vacuum for drying overnight to obtain Sv-MoS 2 nanotube materials.

[0085] (2) To obtain Sv-MoS nanotubes with S vacancies, 2 the nanotubes were dispersed in methanol, and Cu(NO 3 ) 2 with the required loading amount was added to the above homogeneous solution (the mass ratio of Sv-MoS 2 to Cu was 20:1). It was impregnated for 11 h at a temperature of 50 °C, and then the product was directly placed in a vacuum at 60 °C for drying for 11 h;

[0086] (3) Finally, the sample was calcined in a tube furnace. The atmosphere was 10 vol% H 2 / N 2 , the reduction temperature was 300 °C, and the reduction time was 3 h. After cooling to room temperature, the Cu / Sv-MoS 2 catalytic material was obtained.

[0087] The phase composition of the carrier in the catalytic material was tested by Raman spectroscopy, and the generation of 1T-phase molybdenum disulfide was observed.

[0088] Example 4

[0089] (1) Disperse the preliminarily synthesized WS 2 nanotubes into the ethanol solution of lithium aluminum hydride at 2.5 mol / L, ultrasonicate for 120 min at room temperature, wash the obtained product thoroughly, and place it in vacuum drying overnight to obtain the Sv-WS 2 nanotube material with S vacancies.

[0090] (2) Disperse the Sv-WS 2 nanotubes with S vacancies in n-butanol, and add the required loading amount of Ni(NO 3 ) 2 to the above homogeneous solution (the mass ratio of Sv-WS 2 to Ni is 40:1), impregnate at 80 °C for 16 h, and then directly place the product in vacuum drying at 60 °C for 11 h;

[0091] (3) Finally, calcine the sample in a tube furnace, with the atmosphere being 5 vol% H 2 / N 2 , the reduction temperature is 300 °C, and the reduction time is 6 h. Cool to room temperature to obtain the Ni / Sv-WS 2 catalytic material.

[0092] Example 5

[0093] (1) Disperse the preliminarily synthesized WS 2 nanotubes into the isopropanol solution of lithium aluminum hydride at 2.5 mol / L, ultrasonicate for 120 min at room temperature, wash the obtained product thoroughly, and place it in vacuum drying overnight to obtain the Sv-WS 2 nanotube material with S vacancies.

[0094] (2) Disperse the Sv-WS 2 nanotubes with S vacancies in isopentanol, and add the required loading amount of Co(NO 3 ) 2 to the above homogeneous solution (the mass ratio of Sv-WS 2 to Co is 60:1), impregnate at 100 °C for 20 h, and then directly place the product in vacuum drying at 60 °C for 11 h;

[0095] (3) Finally, calcine the sample in a tube furnace, with the atmosphere being 15 vol% H 2 / N 2 , the reduction temperature is 500 °C, and the reduction time is 1 h. Cool to room temperature to obtain the Co / Sv-WS 2 catalytic material.

[0096] Example 6

[0097] According to the method of Example 1, except that Sv-MoS 2 nanotube material and H 2 PtCl 6 The addition of makes the mass ratio of Sv-MoS 2 to Pt 10:1.

[0098] Comparative Example 1

[0099] According to the method of Example 5, except that step (1) is not carried out, and WS 2 nanotubes are directly dispersed in absolute ethanol, and the required loading amount of Co(NO 3 ) 2 is added to the above homogeneous solution (the mass ratio of WS 2 to Co is 60:1), impregnated at a temperature of 100 °C for 20 h, and then the product is directly placed in a vacuum dryer at 60 °C for 11 h. Finally, the sample is calcined in a tube furnace, and the atmosphere is 15 vol% H 2 / N 2 , the reduction temperature is 500 °C, and the reduction time is 1 h. After cooling to room temperature, the Co / WS 2 catalytic material is obtained.

[0100] The catalytic materials prepared in Example 5 and Comparative Example 1 were subjected to TEM tests. The Co particle size in the catalytic material prepared in Comparative Example 1 was large and prone to aggregation.

[0101] Comparative Example 2

[0102] The Sv-MoS 2 prepared in step (1) of Example 1 was directly used as a catalyst.

[0103] Test Example:

[0104] The electrochemical tests used in the present invention were all carried out on a VSP-300 type electrochemical workstation in a three-electrode system. Among them, the carbon paper, graphite electrode, and calomel electrode (SCE) loaded with the sample were used as the working electrode, counter electrode, and reference electrode in the three electrodes, respectively.

[0105] Preparation of the working electrode: First, weigh 4 mg of the sample material with a balance and put it into a small volumetric flask. Secondly, use a pipette to take 360 μL of absolute ethanol and add it to the volumetric flask of the sample. Ultrasonic it in an ultrasonic cleaner for several minutes to make it evenly dispersed. Add 40 μL of Nafion membrane solution and continue ultrasonic until the sample is evenly dispersed in the solution. Finally, use a pipette to take 50 μL of ink and gradually drop it on a 1×1 cm carbon paper, a total of 6 times, and dry it under an infrared lamp for standby. The loading amount is 1.5 mg / cm 2 .

[0106] The test methods used to evaluate the catalytic performance of the samples in this invention include: linear sweep voltammetry (LSV) and chronopotentiometry (CP) electrocatalytic test methods.

[0107] (1) The linear sweep (LSV) test is the variation of voltage with current over a certain period during the hydrogen evolution reaction (HER) test. Test conditions: The scanning voltage range is 0 - 1V, and the scanning rate is 2 mV / s. The overpotentials of the catalytic materials prepared in the above examples and comparative examples are shown in Table 1.

[0108] The LSV curve of the catalytic material Sv - MoS 2 -2 prepared in Example 1 is as Figure 2 (a) shown. It can be seen that the polarization curve results after 1000 cycles show no obvious change in overpotential.

[0109] Table 1

[0110] Number Overpotential mV Example 1 26 Example 2 65 Example 3 115 Example 4 129 Example 5 137 Example 6 97 Comparative Example 1 151 Comparative Example 2 164

[0111] (2) The chronopotentiometry test (CP) is used to test the electrochemical stability of the material; in the electrolyte, at a certain overpotential, it runs continuously for a certain period of time, and the change in voltage is observed. The chronopotentiometry curve of the catalytic material Pt / Sv - MoS 2 -2 prepared in Example 1 is as Figure 2 (b) shown. It can be seen that for the catalytic material prepared in the example of this invention, at a current of 10 mA·cm -2 , after 24 hours of testing, no change in voltage is observed, indicating that the catalytic material has excellent catalytic stability.

[0112] Combined with the above characterization results, it can be seen that the catalytic materials prepared in the examples of this invention have lower overpotentials, higher HER catalytic performance, and good catalytic stability compared to the comparative examples.

[0113] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A catalytic material, characterized in that: The catalytic material includes a carrier and an active metal component supported on the carrier; The carrier is a transition metal sulfide containing S vacancies, and at least a portion of the transition metal sulfide is a 1T phase; the active metal component is selected from at least one of Group VIII metals and Group IB metals.

2. The catalytic material according to claim 1, wherein The mass ratio of the carrier to the active metal component in terms of element is 10-1000:1, preferably 20-100:1; Preferably, the active metal component is selected from at least one of Pt, Pd, Co, Ni and Cu; Preferably, the transition metal in the transition metal sulfide is Mo and / or W.

3. The catalytic material according to claim 1 or 2, wherein: At least part of the active metal component is present in elemental form; Preferably, the average particle size of the active metal component particles is 1-10 nm, preferably 1-5 nm.

4. A method for preparing a catalytic material, characterized in that: The preparation method comprises: (1) contacting a transition metal sulfide with a reducing agent to obtain a transition metal sulfide containing a S vacancy; (2) mixing a precursor of an active metal component, a transition metal sulfide containing sulfur vacancies and a solvent for impregnation, and then drying; (3) calcining the product obtained in step (2) under a hydrogen-containing atmosphere; Wherein, the solvent is an alcohol compound, preferably at least one of ethanol, isopropanol, methanol, isopentanol and n-butanol.

5. The preparation method according to claim 4, wherein The reducing agent is at least one of oxalic acid, potassium borohydride, sodium borohydride and lithium aluminum hydride; Preferably, the reducing agent is provided by a reducing agent solution, and the concentration of the reducing agent solution is 0.5-3.5 mol / L; Preferably, the solvent in the reducing agent solution is an alcohol, preferably at least one of ethanol, isopropanol, methanol, isopentanol and n-butanol; Preferably, the contacting in step (1) is carried out under ultrasonic conditions, the contacting temperature is 20-40° C., and the contacting time is 20-120 min.

6. The preparation method according to claim 4 or 5, wherein: The mass ratio of the transition metal sulfide containing S vacancies to the precursor of the active metal component in terms of element is 10-1000:1, preferably 20-100:1; Preferably, the active metal component is selected from at least one of Pt, Pd, Co, Ni and Cu; Preferably, the transition metal in the transition metal sulfide is Mo and / or W; Preferably, the immersion temperature is 30-100°C and the immersion time is 3-20h; Preferably, the drying temperature is 40-100° C. and the drying time is 5-24 hours.

7. The preparation method according to any one of claims 4 to 6, wherein: The hydrogen-containing atmosphere is provided by hydrogen or a mixture of hydrogen and an inert gas; Preferably, the calcination temperature is 100-500° C. and the calcination time is 1-6 h.

8. The catalytic material obtained by the preparation method according to any one of claims 4 to 7.

9. A catalytic electrode for hydrogen evolution by water electrolysis, characterized in that: The electrode comprises a conductive substrate, and a catalytic material composited on the surface of the conductive substrate, wherein the catalytic material is the catalytic material according to any one of claims 1 to 3 and 8; Preferably, the conductive substrate is selected from modified or unmodified carbon paper; the modified carbon paper is preferably at least one of 20% hydrophobic carbon paper, 5% hydrophobic carbon paper, 5% hydrophilic carbon paper and 20% hydrophilic carbon paper; Preferably, based on the surface area of ​​the electrode, the loading amount of the catalytic material is 0.5-3 mg / cm 2 , preferably 1-2 mg / cm 2 .

10. A method for hydrogen evolution by electrolysis of water, characterized in that: The method comprises: under water electrolysis conditions, using the water electrolysis hydrogen evolution catalytic electrode according to claim 9 as a working electrode to perform a water electrolysis reaction.

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