阅读说明：本技术 一种MoS2/S-NiCoCr-LDH复合材料的制备方法 (MoS2Preparation method of/S-NiCoCr-LDH composite material ) 是由 葛宗义 庄建国 于 2020-11-18 设计创作，主要内容包括：本发明公开了一种MoS_2/S-NiCoCr-LDH复合材料的制备方法,包括下述步骤：首先将硝酸铬、硝酸镍、硝酸钴和尿素溶解在去离子水中,之后滴加氢氧化钠调节pH,反应后与硫化钠水热反应,之后再与钼酸钠、硫代乙酰胺反应得到MoS_2/S-NiCoCr-LDHs复合材料,制备的MoS_2/S-NiCoCr-LDHs复合材料应用于电化学合成氨电催化剂。(The invention discloses a MoS 2 The preparation method of the/S-NiCoCr-LDH composite material comprises the following steps: firstly, dissolving chromium nitrate, nickel nitrate, cobalt nitrate and urea in deionized water, then dropwise adding sodium hydroxide to adjust the pH value, reacting with sodium sulfide for thermal reaction, and then reacting with sodium molybdate and thioacetamide to obtain MoS 2 (S) -NiCoCr-LDHs composite material and prepared MoS 2 the/S-NiCoCr-LDHs composite material is applied to an electro-catalyst for electrochemically synthesizing ammonia.)

1. MoS₂The preparation method of the/S-NiCoCr-LDH composite material is characterized by comprising the following steps of:

(1) adding chromium nitrate, cobalt nitrate, nickel nitrate and urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L NaOH solution, adjusting the pH value of the solution to 10, stirring in an oil bath, then washing with deionized water to be neutral, and drying at the constant temperature of 80 ℃;

(2) adding the product of the step (1) into 50ml of deionized water, and adding Na₂S, stirring for 30min, transferring to a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction, washing with deionized water after the reaction is finished, and carrying out vacuum drying at 60 ℃;

(3) adding the product of the step (2) into 100ml of deionized waterAdding sodium molybdate, thioacetamide and hexadecyl trimethyl ammonium bromide, performing ultrasonic treatment for 30min, transferring the solution into a polytetrafluoroethylene reaction kettle, performing hydrothermal reaction, performing centrifugal washing after the reaction is finished, and drying to obtain MoS₂the/S-NiCoCr-LDH composite material.

2. A MoS according to claim 1₂The preparation method of the/S-NiCoCr-LDH composite material is characterized in that in the step (1), the molar ratio of chromium nitrate to cobalt nitrate to nickel nitrate to urea is 1 mmol: (0.5-2) mmol: (0.5-2) mmol: (2-3) mmol.

3. A MoS according to claim 1₂The preparation method of the/S-NiCoCr-LDH composite material is characterized in that in the step (1), the oil bath temperature is 80-120 ℃, and the oil bath time is 18-32 h.

4. A MoS according to claim 1₂The preparation method of the/S-NiCoCr-LDH composite material is characterized in that in the step (2), the product of the step (1) and Na₂The mass ratio of S is 1 mg: (0.5-1) mg.

5. A MoS according to claim 1₂The preparation method of the/S-NiCoCr-LDH composite material is characterized in that in the step (2), the hydrothermal reaction temperature is 100-150 ℃, and the reaction time is 16-32 h.

6. A MoS according to claim 1₂The preparation method of the/S-NiCoCr-LDH composite material is characterized in that in the step (3), the mass ratio of the product in the step (2) to sodium molybdate, thioacetamide and hexadecyl trimethyl ammonium bromide is 1 mg: (1-2) mg: (0.5-1.5) mg: (0.2-0.8) mg.

7. A MoS according to claim 1₂The preparation method of the/S-NiCoCr-LDH composite material is characterized in that in the step (3), the hydrothermal reaction temperature is 150-200 ℃, and the reaction time is 24-48 h.

8. A MoS according to any of claims 1 to 7₂The preparation method of the/S-NiCoCr-LDH composite material is characterized in that the MoS is prepared by adopting a method of mixing the MoS and the NiCoCr-LDH composite material₂The composite material prepared by the preparation method of the/S-NiCoCr-LDH composite material is applied to an electro-catalyst for electrochemically synthesizing ammonia.

Technical Field

The invention relates to the field of electrochemical synthesis ammonia electrocatalyst, in particular to MoS₂A preparation method of a/S-NiCoCr-LDH composite material.

Background

Ammonia is an important chemical production raw material and chemical product, and the yield of ammonia is the largest among all chemical products worldwide because it is one of the indispensable raw materials in the manufacture of nitrogen fertilizers and the production of various compound fertilizers. Thus, it can be said that ammonia plays a foundation in the advancement and prosperity of human economy and civilization. In addition, the hydrogen content in ammonia molecules is very high, and can reach 17.6%, and compared with liquid hydrogen, liquid ammonia has the advantages of safety, stability, convenience in transportation and the like, so that the ammonia can be used as a medium for storing energy and hydrogen. The modern ammonia synthesis technology originates from the 'haber reaction' proposed by haber of german chemist 1905, i.e. the synthesis of ammonia on the surface of a chromium-containing solid catalyst at high temperature and high pressure by using nitrogen and hydrogen as raw materials. The 'haber reaction' makes artificial nitrogen fixation possible and accelerates the development of global agriculture. But based on the "haber reaction" synthesisThe ammonia technology needs to be carried out at high temperature and high pressure, the energy consumption is huge and accounts for about 1 to 2 percent of the annual global energy consumption, and a large amount of greenhouse gas CO can be discharged in the reaction process₂Therefore, the search of a new synthetic method for replacing the Huppe method has important significance.

The electrochemical synthesis of ammonia can be carried out at normal temperature and normal pressure, and the ammonia is synthesized by electrocatalytic nitrogen reduction (NRR), wherein the raw material is N which is easily obtained₂And H₂And O, in addition, electric energy is used as a renewable energy source, so that the dependence of a synthesis process on fossil energy is greatly reduced, and the harm to the environment can be effectively reduced, so that the electrochemical ammonia synthesis technology has great application potential. However, many problems still exist in the current electrochemistry and need to be solved. First, N₂Stable property, the cracking energy of the first bond in N ≡ N is up to 410 kJ.mol^-1This makes NRR kinetics slow and has a large overpotential. Secondly, the theoretical potential of the electrocatalytic hydrogen production reaction in the water phase is smaller than that of NRR, and the catalyst is easier to react with H₂O is bound, which makes H₂The main by-product in NRR is formed, and the faradaic efficiency of the reaction is greatly reduced, so that the development of an NRR electrocatalyst with high efficiency, stability and good selectivity is a research hotspot at the present stage.

The transition metal LDH material is a catalyst which is applied more in the field of electrochemical synthesis of ammonia at present due to the layered structure and the high specific surface area, but the conductivity is poor, so that the further development of the transition metal LDH material is influenced, and the Mo-based material is an important catalyst in the field of nitrogen fixation, but the stability of the Mo-based material applied to the field of electrochemical synthesis of ammonia is poor, so that the catalyst is difficult to be fixed on an electrode for carrying out efficient catalytic reaction.

Disclosure of Invention

The invention aims to provide a MoS₂Preparation method of/S-NiCoCr-LDH composite material and MoS₂the/S-NiCoCr-LDH composite material comprises the following raw materials: chromium nitrate, nickel nitrate, cobalt nitrate, urea, sodium sulfide, sodium molybdate, thioacetamide and hexadecyltrimethylammonium bromide. The preparation method comprises the following steps:

(1) adding chromium nitrate, cobalt nitrate, nickel nitrate and urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L NaOH solution, adjusting the pH of the solution to 10, then stirring in an oil bath, then washing with deionized water to be neutral, and drying at the constant temperature of 80 ℃;

(2) adding the product of the step (1) into 50ml of deionized water, and adding Na₂S, stirring for 30min, transferring to a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction, washing with deionized water after the reaction is finished, and carrying out vacuum drying at 60 ℃;

(3) adding the product obtained in the step (2) into 100ml of deionized water, adding sodium molybdate, thioacetamide and hexadecyl trimethyl ammonium bromide, carrying out ultrasonic treatment for 30min, transferring the solution into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction, carrying out centrifugal washing after the reaction is finished, and drying to obtain MoS₂the/S-NiCoCr-LDH composite material.

Preferably, in the step (1), the molar ratio of the chromium nitrate to the cobalt nitrate to the nickel nitrate to the urea is 1 mmol: (0.5-2) mmol: (0.5-2) mmol: (2-3) mmol.

Preferably, in the step (1), the oil bath temperature is 80-120 ℃, and the oil bath time is 18-32 h.

Preferably, in the step (2), the product obtained in the step (1) and Na₂The mass ratio of S is 1 mg: (0.5-1) mg.

Preferably, in the step (2), the hydrothermal reaction temperature is 100-150 ℃, and the reaction time is 16-32 h.

Preferably, in the step (3), the mass ratio of the product of the step (2) to the sodium molybdate, thioacetamide and hexadecyl trimethyl ammonium bromide is 1 mg: (1-2) mg: (0.5-1.5) mg: (0.2-0.8) mg.

Preferably, in the step (3), the hydrothermal reaction temperature is 150-.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a MoS₂The preparation method of the/S-NiCoCr-LDH composite material has very simple process, and the obtained MoS₂the/S-NiCoCr-LDH composite material has excellent electrocatalytic performance. The NiCoCr-LDH has a layered structure and a large specific surface area, can be used as an ammonia catalyst for electrochemical synthesis,but the further development of the product is influenced by poor conductivity, MoS₂The conductivity of the NiCoCr-LDH is improved and the electrocatalytic performance of the NiCoCr-LDH is enhanced by doping the S element in the/S-NiCoCr-LDH. Meanwhile, the Mo-based material has excellent electro-catalytic nitrogen reduction performance, so that MoS is obtained₂The composite material is compounded with S-NiCoCr-LDH, so that the electrocatalytic nitrogen reduction performance of the material is further improved.

The invention has simple raw materials, is easy to obtain and is environment-friendly.

Test method

The nitrogen reduction test was performed in a typical H-cell, with two cells separated by a perfluorosulfonic acid 211 membrane, and all electrochemical tests were performed at ambient temperature and pressure. The two cells were separated and all electrochemical tests were performed at ambient temperature and pressure. The perfluorosulfonic acid 211 membrane was first pretreated prior to testing. Firstly, treating a perfluorosulfonic acid 211 membrane in boiling distilled water for 1 h; secondly, putting the mixture into a hydrogen peroxide aqueous solution with the volume fraction of 5 percent for treatment for 1h at the temperature of 80 ℃; third, the film was then placed in 0.5M H₂SO₄Treating in the solution at 80 deg.C for 3 h; and fourthly, soaking the treated membrane in distilled water for 6 hours. The electrochemical experiment is carried out on an electrochemical workstation with the model number of CHI 660E, a three-electrode system is adopted, a glassy carbon electrode modified by a catalyst is used as a working electrode, a graphite electrode is used as a counter electrode, and an Ag/AgCl electrode is used as a reference electrode. Nitrogen reduction was tested at 0.1M Na saturated with nitrogen₂SO₄Potentiostatic tests were carried out in solution.

Product NH₃The concentration of (b) was determined by indophenol blue spectrophotometry. 2ml of Na are taken out of the cathode cell₂SO₄Electrolyte is put into a 10ml centrifuge tube, then 2ml sodium hydroxide solution mixed with 5 percent of salicylic acid and sodium citrate is added, and finally 1ml sodium hypochlorite solution with 0.05M and 0.2ml sodium nitrosochromide solution with 1 percent of mass are added. The UV test was performed after 2h in a dark room.

Faraday efficiency (CR) of nitrogen reduction reactions was defined as the synthesis of NH₃The required amount of charge divided by the amount of charge passing through the electrode during electrolysisOf the charge of (c). The Faraday efficiency calculation formula is as follows:

rate of ammonia production (v)_NH3) The calculation formula is as follows:

wherein F is the Faraday constant, [ NH ]₃]For measuring the resulting NH₃Concentration, V is the collected NH₃Na of (2)₂SO₄Volume of electrolyte, total amount of charge passed through the electrodes during electrolysis of Q, t is reduction time, m_cat.Is the catalyst mass. The invention collects NH₃Na of (2)₂SO₄The electrolyte volume V is 40ml, the reduction time is 2h, the catalyst mass is 10mg, and the Faraday efficiency is 96485C/mol.

Drawings

FIG. 1 is a MoS prepared according to example 1 of the present invention₂Scanning Electron Microscope (SEM) picture of/S-NiCoCr-LDH composite material.

FIG. 2 is a MoS prepared according to example 1 of the present invention₂And the electrocatalytic nitrogen reduction performance diagram of the/S-NiCoCr-LDH composite material.

FIG. 3 is a MoS prepared according to example 1 of the present invention₂Circulation stability performance diagram of/S-NiCoCr-LDH composite material

Detailed description of the preferred embodiments

Example 1:

MoS₂the/S-NiCoCr-LDH composite material specifically comprises the following preparation steps:

(1) adding 1mmol of chromium nitrate, 1.5mmol of cobalt nitrate, 1.5mmol of nickel nitrate and 2mmol of urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L of NaOH solution, adjusting the pH value of the solution to 10, then stirring in an oil bath at 100 ℃ for 24h, then washing with deionized water to be neutral, and drying at constant temperature of 80 ℃;

(2) 200mg of the product of the step (1)Adding into 50ml deionized water, adding 100mg Na₂S, stirring for 30min, transferring to a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction for 24h at 120 ℃, washing with deionized water after the reaction is finished, and carrying out vacuum drying at 60 ℃;

(3) adding 200mg of the product obtained in the step (2) into 100ml of deionized water, adding 300mg of sodium molybdate, 200mg of thioacetamide and 100mg of hexadecyl trimethyl ammonium bromide, carrying out ultrasonic treatment for 30min, transferring the solution into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction for 36h at 180 ℃, carrying out centrifugal washing after the reaction is finished, and drying to obtain MoS₂the/S-NiCoCr-LDH composite material.

As shown in FIG. 1, the MoS prepared according to the method of example 1 of the present invention₂the/S-NiCoCr-LDH composite material is a layered nanosheet.

MoS prepared by the method described in example 1 of the invention₂NH measured by/S-NiCoCr-LDH composite material₃The concentration was 7.82. mu.g/ml, and after the end of the test, the total amount of charge Q passed through the electrodes during electrolysis at a voltage of-0.3V was read from the computer as 0.4037C. And calculating the ammonia yield and the Faraday efficiency according to a formula, and drawing a performance diagram of the ammonia yield and the Faraday efficiency. As can be seen from FIG. 2, Na is present at 0.1M₂SO₄Under neutral conditions, the MoS prepared according to the method described in example 1 of the invention₂When the/S-NiCoCr-LDH is used as an electro-catalyst for the electrochemical synthesis of ammonia, the maximum ammonia yield and Faraday efficiency are achieved when the voltage is-0.3V, and the maximum ammonia yield is 15.64 mu g h^-1mg^-1cat, the maximum faradaic efficiency is 13.19%.

FIG. 3 is a MoS prepared according to the method described in example 1 of the present invention₂The cycle stability performance diagram of the/S-NiCoCr-LDH composite material shows that the ammonia yield and the Faraday efficiency of the sample are not obviously reduced after 5 times of continuous tests at a voltage of-0.3V from figure 3, which indicates that the MoS prepared by the method of the embodiment 1 of the invention₂the/S-NiCoCr-LDH composite material has good stability.

Example 2:

MoS₂the/S-NiCoCr-LDH composite material specifically comprises the following preparation steps:

(1) adding 1mmol of chromium nitrate, 0.5mmol of cobalt nitrate, 2.5mmol of nickel nitrate and 1.5mmol of urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L of NaOH solution, adjusting the pH value of the solution to 10, then stirring in an oil bath at 80 ℃ for 18h, then washing with deionized water to be neutral, and drying at constant temperature of 80 ℃;

(2) adding 200mg of the product of step (1) to 50ml of deionized water, and adding 50mg of Na₂S, stirring for 30min, transferring to a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction for 16h at 100 ℃, washing with deionized water after the reaction is finished, and carrying out vacuum drying at 60 ℃;

(3) adding 200mg of the product obtained in the step (2) into 100ml of deionized water, adding 200mg of sodium molybdate and 100mg of thioacetamide 40mg of hexadecyl trimethyl ammonium bromide, carrying out ultrasonic treatment for 30min, transferring the solution into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction at 150 ℃ for 24h, carrying out centrifugal washing after the reaction is finished, and drying to obtain MoS₂the/S-NiCoCr-LDH composite material.

MoS prepared by the method described in example 2 of the invention₂NH measured by/S-NiCoCr-LDH composite material₃MoS prepared by the method of example 2 of the invention at a concentration of 7.34. mu.g/ml and a total amount of charge Q passed through the electrodes during electrolysis at a voltage of-0.3V of 0.4252C₂When the/S-NiCoCr-LDH is used as an electro-catalyst for the electrochemical synthesis of ammonia, the maximum ammonia yield and Faraday efficiency are achieved when the voltage is-0.3V, and the maximum ammonia yield is 13.12 mu g h^-1mg^-1cat, the maximum faraday efficiency is 9.82%.

Example 3:

MoS₂the/S-NiCoCr-LDH composite material specifically comprises the following preparation steps:

(1) adding 1mmol of chromium nitrate, 2.5mmol of cobalt nitrate, 0.5mmol of nickel nitrate and 3mmol of urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L of NaOH solution, adjusting the pH value of the solution to 10, then stirring in an oil bath at 120 ℃ for 32h, then washing with deionized water to be neutral, and drying at constant temperature of 80 ℃;

(2) adding 200mg of the product of step (1) to 50ml of deionized water, and adding 200mg of Na₂S, stirring for 30min, transferring to a polytetrafluoroethylene reaction kettle, and carrying out water treatment at 150 DEG CCarrying out thermal reaction for 36h, washing with deionized water after the reaction is finished, and carrying out vacuum drying at 60 ℃;

(3) adding 200mg of the product obtained in the step (2) into 100ml of deionized water, adding 400mg of sodium molybdate, 300mg of thioacetamide and 150mg of hexadecyl trimethyl ammonium bromide, carrying out ultrasonic treatment for 30min, transferring the solution into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction for 48h at 200 ℃, carrying out centrifugal washing after the reaction is finished, and drying to obtain MoS₂the/S-NiCoCr-LDH composite material.

MoS prepared by the method described in example 3 of the invention₂NH measured by/S-NiCoCr-LDH composite material₃The concentration was 5.98. mu.g/ml, and the total amount of charge Q passed through the electrodes during electrolysis at a voltage of-0.3V was 0.4246C. MoS prepared by the method described in example 3 of the invention₂When the/S-NiCoCr-LDH is used as an electro-catalyst for the electrochemical synthesis of ammonia, the maximum ammonia yield and Faraday efficiency are achieved when the voltage is-0.3V, and the maximum ammonia yield is 11.98 mu g h^-1mg^-1cat, the maximum faraday efficiency is 8.43%.

Example 4:

MoS₂the/S-NiCoCr-LDH composite material specifically comprises the following preparation steps:

(1) adding 1mmol of chromium nitrate, 0.5mmol of cobalt nitrate, 2.5mmol of nickel nitrate and 2mmol of urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L of NaOH solution, adjusting the pH value of the solution to 10, then stirring in an oil bath at 100 ℃ for 24h, then washing with deionized water to be neutral, and drying at constant temperature of 80 ℃;

(2) adding 200mg of the product of step (1) to 50ml of deionized water, and adding 100mg of Na₂S, stirring for 30min, transferring to a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction for 24h at 120 ℃, washing with deionized water after the reaction is finished, and carrying out vacuum drying at 60 ℃;

(3) adding 200mg of the product obtained in the step (2) into 100ml of deionized water, adding 300mg of sodium molybdate, 200mg of thioacetamide and 100mg of hexadecyl trimethyl ammonium bromide, carrying out ultrasonic treatment for 30min, transferring the solution into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction for 36h at 180 ℃, carrying out centrifugal washing after the reaction is finished, and drying to obtain MoS₂/S-NiCoCr-LDH composite material。

MoS prepared by the method described in example 1 of the invention₂NH measured by/S-NiCoCr-LDH composite material₃The concentration was 5.36. mu.g/ml, and the total amount of charge Q passed through the electrodes during electrolysis at a voltage of-0.3V was 0.5105C. MoS prepared by the method described in example 4 of the invention₂When the/S-NiCoCr-LDH is used as an electro-catalyst for the electrochemical synthesis of ammonia, the maximum ammonia yield and Faraday efficiency are achieved when the voltage is-0.3V, and the maximum ammonia yield is 10.71 mu g h^-1mg^-1cat, maximum faraday efficiency is 7.15%.

Comparative example 1:

(1) adding 1mmol of chromium nitrate, 1.5mmol of cobalt nitrate, 1.5mmol of nickel nitrate and 2mmol of urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L of NaOH solution, adjusting the pH value of the solution to 10, then stirring in an oil bath at 100 ℃ for 24h, then washing with deionized water to be neutral, and drying at constant temperature of 80 ℃;

(2) adding 200mg of the product obtained in the step (1) into 100ml of deionized water, adding 300mg of sodium molybdate, 200mg of thioacetamide and 100mg of hexadecyl trimethyl ammonium bromide, carrying out ultrasonic treatment for 30min, transferring the solution into a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction at 180 ℃ for 36h, carrying out centrifugal washing after the reaction is finished, and drying to obtain MoS₂a/NiCoCr-LDH composite material.

MoS prepared according to the method of comparative example 1 of the invention₂NH measured by/S-NiCoCr-LDH composite material₃The concentration was 3.47. mu.g/ml, and the total amount of charge Q passed through the electrodes during electrolysis at a voltage of-0.3V was 0.5435C. MoS prepared according to the method of comparative example 1 of the invention₂When the/NiCoCr-LDH is used as an electro-catalyst for the electrochemical synthesis of ammonia, the maximum ammonia yield and Faraday efficiency are achieved when the voltage is-0.3V, and the maximum ammonia yield is 6.95 mu g h^-1mg^-1cat, the maximum faraday efficiency is 4.43%. MoS prepared by the method described in comparative example 1₂The ammonia yield and Faraday efficiency of the/NiCoCr-LDH composite material are obviously lower than those of the examples 1-4, which shows that the electrocatalytic performance of the composite material is obviously improved by doping the S element.

Comparative example 2:

(1) adding 1mmol of chromium nitrate, 1.5mmol of cobalt nitrate, 1.5mmol of nickel nitrate and 2mmol of urea into 200ml of deionized water, magnetically stirring for 30min, then dropwise adding 1mol/L of NaOH solution, adjusting the pH value of the solution to 10, then stirring in an oil bath at 100 ℃ for 24h, then washing with deionized water to be neutral, and drying at constant temperature of 80 ℃;

(2) adding 200mg of the product of step (1) to 50ml of deionized water, and adding 100mg of Na₂And S, stirring for 30min, transferring to a polytetrafluoroethylene reaction kettle, carrying out hydrothermal reaction at 120 ℃ for 24h, washing with deionized water after the reaction is finished, and carrying out vacuum drying at 60 ℃.

MoS prepared according to the method of comparative example 2 of the invention₂NH measured by/S-NiCoCr-LDH composite material₃The concentration was 2.75. mu.g/ml, and the total amount of charge Q passed through the electrodes during electrolysis at a voltage of-0.3V was 0.5124C. When the S-NiCoCr-LDH prepared by the method in the embodiment 3 of the invention is used as an electro-catalyst for the electrochemical synthesis of ammonia, the maximum ammonia yield and Faraday efficiency are obtained when the voltage is-0.3V, and the maximum ammonia yield is 5.49 mu g h^-1mg^-1cat, the maximum faraday efficiency is 3.67%.

The ammonia production and Faraday efficiency of S-NiCoCr-LDH composite materials prepared by the method described in comparative example 2 are significantly lower than those of examples 1-4, indicating that MoS₂The load of the composite material obviously improves the electrocatalytic performance of the composite material.