Preparation method of high-efficiency two-dimensional sulfide nanocatalyst

Abstract

The application discloses a kind of two-dimensional multivariate sulfide nanosheet catalyst preparation method, according to following steps implementation: step 1, porous foam nickel is cut; Step 2, prepare hydrothermal reaction solution in polytetrafluoroethylene high-pressure reaction kettle;Step 3, the foam nickel obtained in step 1 is placed in dilute nitric acid, and ultrasonic cleaning is carried out, then it is washed with deionized water, then vacuum drying is carried out;Step 4, the prepared hydrothermal reaction solution is placed in ultrasonic machine and subjected to first ultrasonic treatment, so that the hydrothermal reaction solution is uniformly mixed, then the foam nickel obtained in step 3 is placed in the hydrothermal reaction solution, and second ultrasonic treatment is carried out;Step 5, the high-pressure reaction kettle obtained in step 4 is placed in a blast drying oven for reaction;Step 6, after the high-pressure reaction kettle obtained in step 5 is reduced to room temperature, the high-pressure reaction kettle is opened, and the product is washed with deionized water, and then the product is dried in an oven to obtain a high-efficiency two-dimensional sulfide nanocatalyst.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalytic material preparation, and particularly relates to a preparation method of a high-efficiency two-dimensional sulfide nanocatalyst. BACKGROUND

[0002] Hydrogen is widely used in petroleum, chemical industry, electronics, metallurgy, aerospace, light industry and other fields due to its unique properties, and the demand is increasing day by day. At present, China mainly uses fossil energy to produce hydrogen and industrial by-product to produce hydrogen. Such process has high energy consumption, limited raw materials, low product purity and high carbon emission; compared with the above, the water electrolysis hydrogen production process is simple, has high product purity, and is easy to combine with renewable energy (solar energy, wind energy and water energy, etc.), and is the most potential and promising green hydrogen production technology.

[0003] However, the current water electrolysis hydrogen production technology still has the key technical problems of low efficiency and high cost, which restricts its industrialization process. This is mainly due to the high overpotential and slow kinetics of the anode oxygen evolution reaction in the water electrolysis process, resulting in high energy consumption, and the expensive catalyst. Therefore, developing a high-activity and low-cost anode catalyst to reduce energy consumption and cost is one of the effective means to promote the industrialization process of water electrolysis. SUMMARY

[0004] The purpose of the application is to provide a preparation method of a high-efficiency two-dimensional sulfide nanocatalyst, which solves the problem of high cost of the existing anode catalyst for electrolysis of hydrogen.

[0005] In order to solve the above technical problems, the application discloses a preparation method of a high-efficiency two-dimensional sulfide nanocatalyst, which is specifically implemented according to the following steps:

[0006] Step 1, cutting a porous foam nickel;

[0007] Step 2, preparing a hydrothermal reaction solution in a high-pressure reaction kettle of polytetrafluoroethylene;

[0008] Step 3, placing the foam nickel obtained in step 1 in dilute nitric acid and performing ultrasonic cleaning, then rinsing with deionized water, and then performing vacuum drying;

[0009] Step 4, placing the prepared hydrothermal reaction solution in an ultrasonic machine for first ultrasonic treatment to make the hydrothermal reaction solution uniformly mixed, and then placing the foam nickel obtained in step 3 in the hydrothermal reaction solution for second ultrasonic treatment;

[0010] Step 5, placing the high-pressure reaction kettle obtained in step 4 into a blast drying oven for reaction;

[0011] After the high-pressure reactor obtained in step 5 is cooled to room temperature, the high-pressure reactor is opened, and the product is washed with deionized water, and then the product is placed in an oven for drying, to obtain a high-efficiency two-dimensional sulfide nanocatalyst.

[0012] The technical scheme of the present application also has the following characteristics:

[0013] As a preferred scheme of the present application, in the step 1, the shape of the cut foam nickel is a square of 1cm 2 .

[0014] As a preferred scheme of the present application, in the step 2, the hydrothermal reaction solution comprises thiourea, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and deionized water; the molar ratio of the thiourea, cobalt nitrate hexahydrate and nickel nitrate hexahydrate is 3:1-5:3:6, and 50ml of deionized water is configured for every 0.003mol of thiourea.

[0015] As a preferred scheme of the present application, in the step 3: the concentration of the dilute nitric acid is 0.1mol / L-0.5mol / L.

[0016] As a preferred scheme of the present application, in the step 3: the cleaning power of the ultrasonic cleaning is 100W-150W, and the cleaning time is 5min-10min.

[0017] As a preferred scheme of the present application, in the step 4, the temperature of the second ultrasonic treatment is 20℃-28℃, and the time is 5min-10min.

[0018] As a preferred scheme of the present application, in the step 5, the temperature of the reaction in the air blowing drying box is 160℃-180℃, and the reaction time is 6h-8h.

[0019] As a preferred scheme of the present application, in the step 6, the temperature of the drying in the oven is 60℃-65℃, and the time is 5h-6h

[0020] As a preferred scheme of the present application, the obtained high-efficiency two-dimensional sulfide nanocatalyst is used for preparing an anode electrode.

[0021] Compared with the prior art, (1) the preparation method of the high-efficiency two-dimensional sulfide nanocatalyst of the present application utilizes the synergistic effect of multiple metals, adjusts and optimizes the catalytic activity in the water electrolysis oxygen evolution process, improves the water electrolysis efficiency, and saves the power cost in the hydrogen production process; (2) the preparation method of the high-efficiency two-dimensional sulfide nanocatalyst of the present application, the prepared anode electrode has a two-dimensional nanosheet structure, which is grown in situ on the foam nickel substrate by a hydrothermal method, improves the conductivity, has a large specific surface area, and promotes the electron conduction and mass transfer process in the oxygen evolution catalysis process; (3) the preparation method of the high-efficiency two-dimensional sulfide nanocatalyst of the present application adopts a one-step hydrothermal method, which is simple to operate, and improves the stability and conductivity of the catalyst by growing in situ on the foam nickel; (4) the preparation method of the high-efficiency two-dimensional sulfide nanocatalyst of the present application, the prepared anode electrode is suitable for a strong alkali electrolyte system, which reduces the maintenance cost caused by the corrosion of the equipment in the acid environment during water electrolysis; (5) the preparation method of the high-efficiency two-dimensional sulfide nanocatalyst of the present application, the catalytic material is a non-noble metal element, which is widely available, low in cost, can be prepared in large quantities, and easy to produce. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings described herein are used to provide further understanding of the present application, constitute a part of the present application, and the illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 The scanning electron microscope microstructure of Example 1;

[0024] Figure 2 The scanning electron microscope microstructure of Example 4;

[0025] Figure 3 The scanning electron microscope microstructure of Comparative Example 1;

[0026] Figure 4 The alkaline water electrolysis efficiency activity test of the electrodes of Example 1, 4 and Comparative Examples 1, 2, 3 and 4, and the electrolyte is 1M KOH. DETAILED DESCRIPTION

[0027] The technical solutions of the present application are further described in detail in combination with the drawings.

[0028] Example 1

[0029] The preparation method of the high-efficiency two-dimensional sulfide nanocatalyst of the present application is specifically implemented as follows:

[0030] Step 1, cut the foam nickel (1x1cm 2), the cut foam nickel is weighed and placed;

[0031] Step 2, 0.003 mol of cobalt nitrate hexahydrate, 0.005 mol of nickel nitrate hexahydrate and 0.005 mol of thiourea are weighed and added to 50 mL of deionized water in a high-pressure reaction kettle lined with polytetrafluoroethylene;

[0032] Step 3, take 1*1cm 2 of foam nickel, sequentially ultrasonic cleaning with dilute nitric acid, deionized water, wherein the ultrasonic cleaning power is 100W, the cleaning time is 10min, vacuum drying, and weighing;

[0033] Step 4, the prepared reaction solution is placed in an ultrasonic machine for ultrasonic, so that the solution is uniformly mixed, and the foam nickel treated in step 3 is placed in the reaction solution and continues to be ultrasonic. In this process, special attention should be paid to controlling the temperature of the ultrasonic machine to be 20℃, and the second ultrasonic time is 10min;

[0034] Step 5, after the lining of polytetrafluoroethylene in step 4 is transferred to the outer lining, it is placed in a forced air drying oven, the reaction temperature is set to 160℃, and the reaction is carried out for 8 hours;

[0035] Step 6, after the temperature drops to room temperature, the reaction kettle is opened, the sample is taken out, and the sample is washed with deionized water three times to obtain a cobalt-nickel sulfide sample grown on the foam nickel. The sample is placed in a 60℃ oven and dried for 6 hours, then the sample is loaded and sealed for storage.

[0036] Example 2

[0037] The preparation method of the high-efficiency two-dimensional sulfide nanocatalyst according to the application is specifically implemented in the following manner:

[0038] Step 1, cut a foam nickel (1*1cm 2 ) of a certain size, weigh the cut foam nickel and place it;

[0039] Step 2, 0.003 mol of cobalt nitrate hexahydrate, 0.0001 mol of nickel nitrate hexahydrate and 0.003 mol of thiourea are weighed and added to 50 mL of deionized water in a high-pressure reaction kettle lined with polytetrafluoroethylene;

[0040] Step 3, take 1*1cm 2 of foam nickel, sequentially ultrasonic cleaning with dilute nitric acid, deionized water, wherein the ultrasonic cleaning power is 135W, the cleaning time is 8min, vacuum drying, and weighing;

[0041] Step 4, the prepared reaction solution is placed in an ultrasonic machine for ultrasonic treatment to mix the solution uniformly, and then the foam nickel treated in step 3 is placed in the reaction solution for continuous ultrasonic treatment. In this process, special attention should be paid to controlling the temperature of the ultrasonic machine to be 24 DEG C, and the second ultrasonic treatment time is 8 min;

[0042] Step 5, after the inner liner of the high-pressure reaction kettle in step 4 is transferred to the outer liner, it is placed in a forced air drying oven, a reaction temperature of 170 DEG C is set, and reaction is carried out for 7 hours;

[0043] Step 6, after the temperature drops to room temperature, the reaction kettle is opened, the sample is taken out, and the sample is washed with deionized water three times to obtain a cobalt-nickel sulfide sample grown on the foam nickel, which is placed in an oven at 63 DEG C and dried for 5.5 hours before being loaded and sealed for storage.

[0044] Example 3

[0045] The preparation method of the high-efficiency two-dimensional sulfide nanocatalyst according to the present application is specifically implemented in the following manner:

[0046] Step 1, cut a foam nickel of a certain size (1x1cm 2 ), weigh the cut foam nickel and place it;

[0047] Step 2, weigh 0.003 mol of cobalt nitrate hexahydrate, 0.0005 mol of nickel nitrate hexahydrate, and 0.0035 mol of thiourea, and add 50 mL of deionized water into a high-pressure reaction kettle with a polytetrafluoroethylene inner liner;

[0048] Step 3, take a foam nickel of 1x1cm 2 , and sequentially ultrasonically clean it with dilute nitric acid and deionized water, wherein the cleaning power of the ultrasonic cleaning is 150 W, the cleaning time is 5 min, and the foam nickel is vacuum dried and weighed;

[0049] Step 4, the prepared reaction solution is placed in an ultrasonic machine for ultrasonic treatment to mix the solution uniformly, and then the foam nickel treated in step 3 is placed in the reaction solution for continuous ultrasonic treatment. In this process, special attention should be paid to controlling the temperature of the ultrasonic machine to be 24 DEG C, and the second ultrasonic treatment time is 8 min;

[0050] Step 5, after the inner liner of the high-pressure reaction kettle in step 4 is transferred to the outer liner, it is placed in a forced air drying oven, a reaction temperature of 170 DEG C is set, and reaction is carried out for 7 hours;

[0051] Step 6, after the temperature drops to room temperature, the reaction kettle is opened, the sample is taken out, and the sample is washed with deionized water three times to obtain a cobalt-nickel sulfide sample grown on the foam nickel, which is placed in an oven at 63 DEG C and dried for 5.5 hours before being loaded and sealed for storage.

[0052] Comparative Example 1

[0053] Preparation of cobalt sulfide catalytic electrode:

[0054] 1. Cut the nickel foam (1 x 1 cm 2 ) to a certain size, weigh the cut nickel foam, and place it;

[0055] 2. Weigh 0.003 mol of cobalt nitrate hexahydrate and 0.005 mol of thiourea, and add them to 50 mL of deionized water in a high-pressure reaction kettle lined with polytetrafluoroethylene;

[0056] 3. Take 1 x 1 cm 2 of nickel foam, and sequentially ultrasonically clean it with dilute nitric acid and deionized water, wherein the ultrasonic cleaning power is 150 W, the cleaning time is 5 min, vacuum drying is performed, and the weight is measured;

[0057] 4. Place the prepared reaction solution in an ultrasonic machine to ultrasonically mix the solution, and then place the clean nickel foam of step (3) in the reaction solution and continue ultrasonic treatment. In this process, special attention should be paid to controlling the ultrasonic machine temperature to be 20°C, and the second ultrasonic treatment time is 10 min;

[0058] 5. After the second ultrasonic treatment, transfer the high-pressure reaction kettle lined with polytetrafluoroethylene in step (4) to the outer lining, and place it in a forced air drying oven, set the reaction temperature to 160°C, and react for 6 hours;

[0059] 6. After the temperature drops to room temperature, open the reaction kettle, take out the sample, and wash the sample with deionized water three times to obtain a cobalt sulfide sample grown on the nickel foam. Place the sample in an oven at 60°C, dry it for 5-6 hours, and then seal and store the sample.

[0060] Comparative Example 2

[0061] Preparation of cobalt-nickel catalytic electrode:

[0062] 1. Cut the nickel foam (1 x 1 cm 2 ) to a certain size, weigh the cut nickel foam, and place it;

[0063] 2. Weigh 0.003 mol of cobalt nitrate hexahydrate and 0.005 mol of nickel nitrate hexahydrate, and add them to 50 mL of deionized water in a high-pressure reaction kettle lined with polytetrafluoroethylene;

[0064] 3. Take 1 x 1 cm 2 of nickel foam, and sequentially ultrasonically clean it with dilute nitric acid and deionized water, wherein the ultrasonic cleaning power is 150 W, the cleaning time is 5 min, vacuum drying is performed, and the weight is measured;

[0065] 4. Place the prepared reaction solution in an ultrasonic machine and sonicate to mix the solution evenly. Then place the cleaned nickel foam from step (3) into the reaction solution and continue sonicating. During this process, pay special attention to controlling the ultrasonic machine temperature to 28℃ and the second sonication time to 5 minutes.

[0066] 5. After transferring the high-pressure reactor with polytetrafluoroethylene lining from step (4) to the outer lining, place it in a forced-air drying oven, set the reaction temperature to 160℃, and react for 6 hours.

[0067] 6. After the temperature drops to room temperature, open the reactor, take out the sample, and wash the sample three times with deionized water to obtain the cobalt-nickel sample grown on the nickel foam. Place it in an oven at 60°C and dry for 6 hours. Then pack the sample and seal it for storage.

[0068] Comparative Example 3

[0069] Preparation of nickel foam catalytic electrode:

[0070] 1. Cut a piece of nickel foam to a certain size (1×1cm). 2 Weigh the cut nickel foam and place it in a container.

[0071] 2. Take 1×1cm 2 The foamed nickel was ultrasonically cleaned sequentially with dilute nitric acid and deionized water. The ultrasonic cleaning power was 150W and the cleaning time was 5 minutes. The product was then vacuum dried and weighed.

[0072] 3. Place it in an oven at 60℃ and dry for 6 hours before loading the sample into a sealed container.

[0073] Application Example 1

[0074] The electrochemical oxygen evolution activity of the catalytic electrodes obtained in Example 1 and Comparative Examples 1-3 was evaluated under alkaline conditions.

[0075] 1. The analysis was performed using a standard three-electrode electrochemical voltammetry method. The electrolyte was a 1M KOH solution, and the effective exposed area of ​​the electrode was 1×1cm. 2 The solution resistance was compensated for at 1.8Ω, and the voltammetric curve scan rate was 5mV·s. -1 Test temperature: 25℃;

[0076] 2. Its oxygen evolution performance in water electrolysis is as follows: Figure 4 As shown: Nickel sulfide electrode (Example 1) > Cobalt sulfide electrode (Comparative Example 1) > Cobalt-nickel electrode (Comparative Example 2) > Nickel foam (Comparative Example 3);

[0077] The present invention can regulate the catalyst activity by adjusting the components, concentration, reaction temperature, and time of the hydrothermal precursor.

Claims

1. A method for preparing a high-efficiency two-dimensional sulfide nanocatalyst, characterized in that, Specifically, the following steps are implemented: Step 1, cutting the porous nickel foam; Step 2, preparing a hydrothermal reaction solution in a high-pressure reaction kettle of polytetrafluoroethylene; Step 3, placing the nickel foam obtained in step 1 in dilute nitric acid and performing ultrasonic cleaning, then rinsing with deionized water, and then vacuum drying; Step 4, placing the prepared hydrothermal reaction solution in an ultrasonic machine for first ultrasonic treatment to mix the hydrothermal reaction solution uniformly, and then placing the nickel foam obtained in step 3 in the hydrothermal reaction solution for second ultrasonic treatment; Step 5, placing the high-pressure reaction kettle obtained in step 4 into a blast drying oven for reaction; Step 6, after the high-pressure reaction kettle obtained in step 5 is cooled to room temperature, opening the high-pressure reaction kettle, and washing the product with deionized water, then drying the product in an oven to obtain a high-efficiency two-dimensional sulfide nanocatalyst; In the step 1, the shape of the foamed nickel after cutting is a square of 1 cm 2 . In the step 2, the hydrothermal reaction solution comprises thiourea, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and deionized water; the molar ratio of the cobalt nitrate hexahydrate, the nickel nitrate hexahydrate and the thiourea is 3:5:5 or 3:0.1:3 or 3:0.5:3.5, and 50 mL of deionized water is configured for every 0.003 mol of cobalt nitrate hexahydrate; In the step 3: the concentration of the dilute nitric acid is 0.1 mol L -1 -0.5 mol L -1 ; In the step 3, the cleaning power of the ultrasonic cleaning is 100 W-150 W, and the cleaning time is 5 min-10 min; In the step 4, the temperature of the second ultrasonic treatment is 20℃-28℃, and the time is 5 min-10 min; In the step 5, the temperature of the reaction in the blast drying oven is 160℃-180℃, and the reaction time is 6 h-8 h; In the step 6, the temperature of the drying in the oven is 60℃-65℃, and the time is 5 h-6 h.

2. The method for preparing the high-efficiency two-dimensional sulfide nanocatalyst according to claim 1, characterized in that, The obtained high-efficiency two-dimensional sulfide nanocatalyst is used to prepare an anode electrode.

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