Preparation method of titanium-based cathode material for hydrogen production by electrolysis of water

Abstract

This invention discloses a method for preparing a titanium-based cathode material for hydrogen production via water electrolysis, belonging to the field of titanium electrode technology. The method involves coating the surface of titanium or titanium alloys with a coating solution. The coating solution comprises: 0.19-0.21 mol / L molybdenum source, 0.09-0.11 mol / L tantalum source, and 0.63-0.67 mol / L sulfur source. The solvent is one or more of anhydrous ethanol, n-butanol, and isopropanol. Then, oxidation is performed under an inert gas atmosphere to obtain a Ti / MoS2-TaS2 electrolytic hydrogen production cathode material with excellent stability. The Ti / MoS2-TaS2 electrolytic hydrogen production cathode material obtained by this invention exhibits significantly increased and finer grains on its surface, a low hydrogen evolution overpotential, good electrochemical stability, and a simple preparation process with low production costs, making it suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of titanium electrode technology, and more specifically, relates to a titanium electrode for hydrogen production by electrolysis, and more particularly to a method for preparing a titanium-based cathode material for hydrogen production by water electrolysis. Background Technology

[0002] With the advancement of the green hydrogen industry, low-cost, low-energy-consumption electrolytic hydrogen production cathode materials will become a crucial factor in the development of hydrogen energy. Currently, the cathode materials for water electrolysis to produce hydrogen are mainly porous titanium plated with platinum and nickel alloys. Pt is a precious metal with a high price, while nickel alloys have a high hydrogen evolution potential and high energy consumption. Metal sulfides are currently considered as potential replacements for Pt and nickel alloys, with MoS2 showing the greatest potential. However, its preparation process is complex, and its structural stability is poor. Therefore, developing a stable and low-cost electrolytic hydrogen production cathode material is particularly important. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention aims to provide a method for preparing a titanium-based cathode material for hydrogen production by water electrolysis. The resulting cathode material exhibits low hydrogen evolution overpotential, good electrochemical stability, and low production cost, thereby overcoming the shortcomings of the prior art.

[0004] To achieve the above-mentioned technical objectives, the inventors have prepared Ti / MoS2-TaS2 electrolytic hydrogen production cathode material by screening suitable sulfur sources and creatively introducing tantalum sources, using a high-temperature sulfidation method, which effectively solves the aforementioned technical problems.

[0005] Specifically, the technical solution to achieve the technical objective of this invention is as follows: A method for preparing a titanium-based cathode material for hydrogen production by water electrolysis, the method comprising the following steps:

[0006] (1) Select titanium or titanium alloy as the substrate, and after removing oil stains from the surface of the substrate, perform sandblasting and acid etching treatment.

[0007] (2) Coating the substrate treated in step (1) with a coating solution, wherein the coating solution is composed of: molybdenum source 0.19-0.21 mol / L, tantalum source 0.09-0.11 mol / L, sulfur source 0.63-0.67 mol / L, and the solvent is one or more of anhydrous ethanol, n-butanol and isopropanol.

[0008] (3) Place the material coated in step (2) in an inert gas furnace and keep it at 500-900℃ for 10-20 minutes;

[0009] (4) Repeat steps (2) and (3) 8-20 times to obtain the titanium-based cathode material for hydrogen production by water electrolysis of Ti / MoS2-TaS2.

[0010] More preferably, in the preparation method of the titanium-based cathode material for hydrogen production by water electrolysis as described above, the acid etching treatment in step (1) is as follows: immersion in an oxalic acid solution with a mass fraction of 8-12% at 90-95°C for 2-4 hours.

[0011] More preferably, in the preparation method of titanium-based cathode material for hydrogen production by water electrolysis as described above, the molybdenum source in step (2) is molybdenum pentachloride.

[0012] More preferably, in the preparation method of titanium-based cathode material for hydrogen production by water electrolysis as described above, the tantalum source in step (2) is tantalum pentachloride.

[0013] More preferably, in the preparation method of titanium-based cathode material for hydrogen production by water electrolysis as described above, the sulfur source in step (2) is ammonium sulfide.

[0014] In a preferred embodiment of the present invention, the coating solution in step (2) is composed of: 0.2 mol / L molybdenum pentachloride, 0.1 mol / L tantalum pentachloride, 0.65 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

[0015] More preferably, in the preparation method of titanium-based cathode material for hydrogen production by water electrolysis as described above, the temperature of heat preservation in step (3) is 500-700℃, and even more preferably 640-660℃.

[0016] More preferably, in the method for preparing titanium-based cathode material for hydrogen production by water electrolysis as described above, the number of cycles for steps (2) and (3) in step (4) is 8-12 times.

[0017] Compared with the prior art, the preparation method of titanium-based cathode material for hydrogen production by water electrolysis provided by the present invention has the following advantages and significant progress:

[0018] (1) The preparation process is simple and the production cost is low, making it suitable for large-scale industrial production.

[0019] (2) The obtained Ti / MoS2-TaS2 electrolytic hydrogen production cathode material has significantly increased and finer grains on its surface, low hydrogen evolution overpotential, and good electrochemical stability. Attached Figure Description

[0020] Figure 1 SEM image of the Ti / MoS2-TaS2 cathode material prepared in Example 1;

[0021] Figure 2 SEM image of the Ti / MoS2-TaS2 cathode material prepared in Example 2;

[0022] Figure 3SEM image of the Ti / MoS2-TaS2 cathode material prepared in Example 3;

[0023] Figure 4 SEM image of the Ti / MoS2-TaS2 cathode material prepared in Example 4;

[0024] Figure 5 SEM image of the Ti / MoS2-TaS2 cathode material prepared in Example 5;

[0025] Figure 6 SEM image of the Ti / MoS2-TaS2 cathode material prepared in Example 6;

[0026] Figure 7 The image shows a SEM image of the Ti / MoS2-TiS2-TaS2 cathode material prepared in Example 7. Detailed Implementation

[0027] The technical solutions and effects of the present invention will be clearly and completely described below with reference to embodiments. These embodiments are for illustrative purposes only and should not be considered as limiting the scope of protection of the present invention. Furthermore, unless specific technical operation steps or conditions are specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0028] Example 1

[0029] S1. After removing oil and dirt from the surface of the titanium substrate, it is sandblasted and acid-etched for later use.

[0030] Titanium matrix: TA1 sheet.

[0031] Sandblasting process: Emery particle size 120-150µm, air pressure 3.5-4×10⁻⁶. 5 Sandblasting was performed at a pressure of 45 degrees and a pressure of 100 Pa. After sandblasting, the surface was rinsed with plenty of tap water and then cleaned with deionized water.

[0032] Acid etching process: Immerse in a 10% oxalic acid solution at 90-95℃ for 3 hours.

[0033] S2. Coat the pretreated titanium substrate surface with the prepared solution. The solution composition is: 0.2 mol / L molybdenum pentachloride, 0.1 mol / L tantalum pentachloride, 0.6 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

[0034] S3. Place the coated sample from step 2 into an argon gas protective furnace and keep it at 600℃ for 15 minutes.

[0035] S4. Repeat steps 2 and 3 10 times to obtain the Ti / MoS2-TaS2 electrolysis water production cathode material.

[0036] Example 2

[0037] S1. After removing oil and dirt from the surface of the titanium substrate, it is sandblasted and acid-etched for later use (process parameters are the same as step 1 of Example 1);

[0038] S2. Coat the pretreated titanium substrate surface with the prepared solution. The solution composition is: 0.2 mol / L molybdenum pentachloride, 0.1 mol / L tantalum pentachloride, 0.65 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

[0039] S3. Place the coated sample from step 2 into an argon gas protective furnace and keep it at 600℃ for 15 minutes.

[0040] S4. Repeat steps 2 and 3 10 times to obtain the Ti / MoS2-TaS2 electrolysis water production cathode material.

[0041] Example 3

[0042] S1. After removing oil and dirt from the surface of the titanium substrate, it is sandblasted and acid-etched for later use (process parameters are the same as step 1 of Example 1);

[0043] S2. Coat the pretreated titanium substrate surface with the prepared solution. The solution composition is: 0.2 mol / L molybdenum pentachloride, 0.1 mol / L tantalum pentachloride, 0.7 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

[0044] S3. Place the coated sample from step 2 into an argon gas protective furnace and keep it at 600℃ for 15 minutes.

[0045] S4. Repeat steps 2 and 3 10 times to obtain the Ti / MoS2-TaS2 electrolytic water production cathode material.

[0046] Table 1: Effect of ammonium sulfide molar concentration on Ti / MoS2-TaS2 cathode material for water electrolysis hydrogen production

[0047]

[0048] As can be seen from Table 1, when the molar concentration of ammonium sulfide is 0.65 mol, the cathode material has the lowest hydrogen evolution overpotential and good stability.

[0049] Example 4

[0050] S1. After removing oil and dirt from the surface of the titanium substrate, it is sandblasted and acid-etched for later use (process parameters are the same as step 1 of Example 1);

[0051] S2. Coat the pretreated titanium substrate surface with the prepared solution. The solution composition is: 0.1 mol / L molybdenum pentachloride, 0.05 mol / L tantalum pentachloride, 0.33 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

[0052] S3. Place the coated sample from step 2 into an argon gas protective furnace and keep it at 600℃ for 15 minutes.

[0053] S4. Repeat steps 2 and 3 20 times to obtain the Ti / MoS2-TaS2 electrolytic water production cathode material.

[0054] Test results show that, compared with Example 2, the Ti / MoS2-TaS2 electrolytic water hydrogen production cathode material prepared in Example 4 has fewer surface cracks and fewer grains, a hydrogen evolution overpotential of 112mV, and an electrochemical stability of more than 10 days.

[0055] Example 5

[0056] S1. After removing oil and dirt from the surface of the titanium substrate, it is sandblasted and acid-etched for later use (process parameters are the same as step 1 of Example 1);

[0057] S2. Coat the pretreated titanium substrate surface with the prepared solution. The solution composition is: 0.1 mol / L molybdenum pentachloride, 0.05 mol / L tantalum pentachloride, 0.33 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

[0058] S3. Place the coated sample from step 2 into an argon gas protective furnace and keep it at 650℃ for 15 minutes.

[0059] S4. Repeat steps 2 and 3 20 times to obtain the Ti / MoS2-TaS2 electrolytic water production cathode material.

[0060] Test results show that, compared with Example 4, the Ti / MoS2-TaS2 electrolytic water production hydrogen cathode material prepared in Example 5 has more grains on its surface, a hydrogen evolution overpotential of 103 mV, and an electrochemical stability of more than 10 days.

[0061] Example 6

[0062] S1. After removing oil and dirt from the surface of the titanium substrate, it is sandblasted and acid-etched for later use (process parameters are the same as step 1 of Example 1);

[0063] S2. Coat the pretreated titanium substrate surface with the prepared solution. The solution composition is: 0.2 mol / L molybdenum pentachloride, 0.1 mol / L tantalum pentachloride, 0.65 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

[0064] S3. Place the coated sample from step 2 into an argon gas protective furnace and keep it at 650℃ for 15 minutes.

[0065] S4. Repeat steps 2 and 3 10 times to obtain the Ti / MoS2-TaS2 electrolytic water production cathode material.

[0066] Test results show that, compared with Examples 5 and 2, the Ti / MoS2-TaS2 electrolytic hydrogen production cathode material prepared in Example 6 has significantly more and finer grains on its surface, a hydrogen evolution overpotential of 92mV, and an electrochemical stability of more than 10 days.

[0067] Example 7

[0068] S1. After removing oil and dirt from the surface of the titanium substrate, it is sandblasted and acid-etched for later use (process parameters are the same as step 1 of Example 1);

[0069] S2. Coat the pretreated titanium substrate surface with the prepared solution. The solution composition is: molybdenum pentachloride 0.2 mol / L, tantalum pentachloride 0.05 mol / L, tetrabutyl titanate 0.05 mol / L, ammonium sulfide 0.65 mol / L, and anhydrous ethanol as the solvent.

[0070] S3. Place the coated sample from step 2 into an argon gas protective furnace and keep it at 650℃ for 15 minutes.

[0071] S4. Repeat steps 2 and 3 10 times to obtain the Ti / MoS2-TiS2-TaS2 electrolytic water hydrogen production cathode material.

[0072] Test results show that, compared with Example 6, the Ti / MoS2-TiS2-TaS2 electrolytic hydrogen production cathode material prepared in Example 7 has significantly more and finer grains on its surface, but the hydrogen evolution overpotential is 156mV and the electrochemical stability is greater than 10 days.

Claims

1. A method for preparing a titanium-based cathode material for hydrogen production by water electrolysis, characterized in that, The method includes the following steps: (1) Select titanium or titanium alloy as the substrate, and after removing oil stains from the surface of the substrate, perform sandblasting and acid etching treatment. (2) Coating the substrate treated in step (1) with a coating solution, wherein the coating solution is composed of: molybdenum pentachloride 0.19-0.21 mol / L, tantalum pentachloride 0.09-0.11 mol / L, ammonium sulfide 0.63-0.67 mol / L, and the solvent is one or more of anhydrous ethanol, n-butanol and isopropanol; (3) Place the coated material from step (2) in an inert gas furnace and keep it at 640-660℃ for 10-20 minutes; (4) Repeat steps (2) and (3) 8-12 times to obtain the titanium-based cathode material for hydrogen production by water electrolysis of Ti / MoS2-TaS2.

2. The method for preparing the titanium-based cathode material for hydrogen production by water electrolysis according to claim 1, characterized in that, The acid etching process described in step (1) is as follows: immersion in an oxalic acid solution with a mass fraction of 8-12% at 90-95°C for 2-4 hours.

3. The method for preparing the titanium-based cathode material for hydrogen production by water electrolysis according to claim 1, characterized in that, The coating solution described in step (2) consists of: 0.2 mol / L molybdenum pentachloride, 0.1 mol / L tantalum pentachloride, 0.65 mol / L ammonium sulfide, and anhydrous ethanol as the solvent.

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