Preparation method of manganese sulfide electrode material and application of electrode material

Abstract

The invention discloses a preparation method of a manganese sulfide electrode material and application of the electrode material. The preparation method comprises the following steps: S1, polishing a diameter glassy carbon electrode on chamois by using aluminum oxide powder; s2, manganese sulfide powder is weighed and placed in a weighing bottle, and absolute ethyl alcohol, a naphthol solution, polyvinyl alcohol and ethylene glycol are added; s3, ultrasonic dispersion; and S4, transferring the solution by using a pipette, coating the solution on the surface of a glassy carbon electrode, and naturally forming a film to obtain a manganese sulfide electrode sample. The sample can be subjected to an electrochemical test under conventional experiment conditions to obtain an electrochemical test result of manganese sulfide. The manganese sulfide electrode can be used for evaluating pitting corrosion behavior tendency of stainless steel in various service environments, corrosion behavior research of the stainless steel in different service environments can be carried out more conveniently, and theoretical guidance is provided for stainless steel components and production design.

Description

Technical Field

[0001] The invention relates to the field of preparation of manganese sulfide electrodes, in particular to a method for preparing a manganese sulfide electrode material and application of the electrode material. Background Art

[0002] With the widespread use of steel materials, their corrosion resistance has received extensive attention and research. Stainless steel will automatically generate a passivation film with good protection in the natural environment. However, when it is exposed to a chloride ion environment, the surface passivation film will be destroyed by chloride ion corrosion, causing pitting corrosion of stainless steel. The inclusion phase manganese sulfide in the material is usually the initiation site of pitting corrosion. A large number of studies have been conducted to obtain mature conclusions on the process and mechanism of manganese sulfide-induced pitting corrosion of stainless steel, and the electrochemical parameters of manganese sulfide. However, most of these studies use micro-area technology to test and obtain the electrochemical parameters of manganese sulfide inclusions from a microscopic perspective. The micro-area testing technology has high requirements and costs for sample preparation, and often does not obtain the electrochemical parameters of pure manganese sulfide inclusions, which reduces the accuracy of the research. In addition, stainless steel usually forms inclusions of different sizes and shapes during the refining process, which affects the corrosion resistance of stainless steel in different environments. The evaluation of the pitting behavior tendency of stainless steel is closely related to the corrosion behavior of inclusions in different environments. Most of the current evaluation methods test stainless steel as a whole, and cannot actually monitor the corrosion behavior of inclusions in the steel, nor can they separate the stainless steel matrix from the inclusions for research. This increases the difficulty of stainless steel pitting evaluation and reduces the accuracy of the evaluation method.

[0003] Therefore, preparing electrochemical samples that meet the requirements of conventional electrochemical testing to assist in the evaluation of stainless steel pitting behavior to improve the accuracy of the research not only has urgent research value, but also can save experimental costs and provide certain theoretical guidance for stainless steel production design. This is the driving force and basis for the completion of the present invention. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and to provide a method for preparing a manganese sulfide electrode material and the application of the electrode material.

[0005] The technical problem solved by the present invention is to provide a method for preparing a conventional electrochemical test manganese sulfide electrochemical sample and its application, to evaluate the pitting behavior of stainless steel in different service environments, and to provide certain theoretical guidance for the production design of stainless steel.

[0006] In order to solve the above technical problems, the technical solution of the present invention is:

[0007] Provided is a method for preparing a manganese sulfide electrode material and an application of the electrode material, which comprises the following steps:

[0008] S1, polishing the glassy carbon electrode on suede with aluminum oxide powder;

[0009] S2, weighing manganese sulfide powder and placing it in a weighing bottle, and adding anhydrous ethanol, naphthol solution, polyvinyl alcohol, and ethylene glycol;

[0010] S3, ultrasonic dispersion;

[0011] S4, using a pipette to transfer the above solution to the surface of the glassy carbon electrode, forming a film naturally to obtain a manganese sulfide electrode sample.

[0012] Preferably, a glassy carbon electrode with a diameter of 2.5-5 mm is used.

[0013] Preferably, aluminum oxide powder with a particle size of 0.05 μm is used for grinding and polishing.

[0014] Preferably, in step S2, the amount of manganese sulfide powder added is 1-4 mg, the amount of anhydrous ethanol added is 100-250 μL, the concentration of naphthol solution is 5%, the amount added is 20-30 μL, the amount of polyvinyl alcohol added is 0.1-0.5 mg, and the amount of ethylene glycol added is 5-10 μL. The naphthol solution and polyvinyl alcohol ensure the film-forming property of the solution, and the ethylene glycol ensures the dispersibility of the solution.

[0015] Preferably, the ultrasonic dispersion time in step S3 is 15-30 min.

[0016] Preferably, in step S4, the amount of the mixed solution transferred by the pipette is 2-5 μL, and is dotted on the surface of the glassy carbon electrode.

[0017] Preferably, the natural film forming temperature in step S4 is 25°C.

[0018] The electrode material of the present invention, namely, the manganese sulfide electrochemical sample is evenly coated on the surface of the glassy carbon electrode.

[0019] The manganese sulfide electrochemical sample provided by the present invention is a manganese sulfide electrochemical test sample obtained by the above preparation method.

[0020] The beneficial effects of the present invention are:

[0021] The electrochemical parameters of manganese sulfide under conventional electrochemical test conditions can be obtained, and can be used to assist in evaluating the pitting behavior tendency of stainless steel materials under different service environments, providing theoretical guidance for stainless steel composition and production design.

[0022] The electrochemical test sample has a simple structure and a simple preparation method, which shortens the time for electrochemical testing of manganese sulfide inclusions. At the same time, due to the simple preparation, it will not cause damage to the steel sample, and truly realizes the electrochemical test of manganese sulfide inclusions. Pure manganese sulfide powder is used to prepare the sample to avoid electrochemical test errors caused by the matrix part. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0024] Figure 1 Schematic diagram of the test of electrochemical samples containing manganese sulfide inclusions;

[0025] Figure 2 Electrochemical test sample diagram completed in the embodiment;

[0026] Figure 3 Electrochemical parameter diagram obtained in the examples; Figure 4 Example: Figure 1. Potentiodynamic polarization test results of manganese sulfide. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with specific examples. However, the uses and purposes of these exemplary embodiments are only for illustration and do not constitute any form of limitation on the actual protection scope of the present invention, let alone limit the protection scope of the present invention to them.

[0028] Example

[0029] A method for preparing an electrochemical test sample of manganese sulfide inclusions comprises the following steps:

[0030] S1, polishing a glassy carbon electrode with a diameter of 2.5 mm on suede with aluminum oxide powder with a particle size of 0.05 μm;

[0031] S2, weigh 4 mg of manganese sulfide powder and place it in a weighing bottle, and add 250 μL of anhydrous ethanol, 30 μL of naphthol solution (5%), 0.1 mg of polyvinyl alcohol, and 10 μL of ethylene glycol to ensure the film-forming property of the solution and the dispersibility of the manganese sulfide powder;

[0032] S3, ultrasonic dispersion for 15 min to make the solution fully mixed;

[0033] S4. Use a pipette to transfer 5 μL of the above solution and apply it on the surface of the glassy carbon electrode. A film is formed naturally at 25°C to obtain a manganese sulfide electrochemical test sample.

[0034] Test method:

[0035] The electrochemical test was started after the manganese sulfide electrochemical test sample formed a film naturally. The test was carried out using a classic three-electrode system, that is, a saturated calomel electrode was used as the reference electrode, a platinum sheet was used as the auxiliary electrode, and the manganese sulfide electrochemical test sample was used as the working electrode. The electrochemical experiments were all carried out on a Gamry electrochemical workstation. During the electrochemical test, the manganese sulfide test sample and the platinum sheet were immersed in a sodium chloride solution. After the electrochemical system was stabilized, the manganese sulfide test sample was polarized from -500mV to +300mV by a potentiodynamic polarization test at a relative corrosion potential of 5mV / s. The ohmic drop between the working electrode and the reference electrode can be automatically compensated by the instrument. This test can obtain three electrochemical parameter values: corrosion potential, self-corrosion current density, and current density at different polarization potentials.

[0036] Data Analysis:

[0037] The results of the potentiodynamic polarization test of the manganese sulfide electrode prepared in this example are as follows: Figure 3 As shown in the literature, the results of the potentiodynamic polarization test of manganese sulfide obtained using micro-area testing technology are as follows Figure 4 The results show that the manganese sulfide electrode test results obtained by this embodiment are similar to the micro-area test results (corrosion potential), and the change rules are also similar. In addition, the operation of this embodiment is simpler and can be used under conventional test conditions, avoiding various costs of micro-area sample preparation and testing.

[0038] Matters not covered by the present invention are known technologies.

Claims

1. A method for preparing a manganese sulfide electrode material, characterized in that: The steps include: S1, polishing the glassy carbon electrode on suede with aluminum oxide powder; S2, weighing manganese sulfide powder and placing it in a weighing bottle, and adding anhydrous ethanol, naphthol solution, ethylene glycol, and polyvinyl alcohol; S3, ultrasonic dispersion; S4, using a pipette to transfer the above solution to the surface of the glassy carbon electrode, forming a film naturally to obtain a manganese sulfide electrode sample.

2. The method for preparing a manganese sulfide electrode material according to claim 1, characterized in that: In step S1, the diameter of the glassy carbon electrode is 2.5-5 mm, and the particle size of the aluminum oxide used is 0.05 μm.

3. The method for preparing a manganese sulfide electrode material according to claim 1, characterized in that: In the step S2, the amount of manganese sulfide powder added is 1-4 mg, the amount of anhydrous ethanol added is 100-250 μL, the concentration of the naphthol solution is 5%, the amount added is 20-30 μL, the amount of polyvinyl alcohol added is 0.1-0.5 mg, and the amount of ethylene glycol added is 5-10 μL; the naphthol solution and polyvinyl alcohol ensure the film-forming property of the solution, and the ethylene glycol ensures the dispersibility of the solution.

4. The method for preparing a manganese sulfide electrode material according to claim 1, characterized in that: The ultrasonic dispersion time in step S3 is 15-30 min.

5. The method for preparing a manganese sulfide electrode material according to claim 1, characterized in that: In step S4, the amount of the mixed solution transferred by the pipette is 2-5 μL, and is dotted on the surface of the glassy carbon electrode.

6. The method for preparing a manganese sulfide electrode material according to claim 1, characterized in that: The natural film forming temperature in step S4 is 25°C.

7. An electrode material, characterized in that: The electrode material is prepared by the method for preparing a manganese sulfide electrode material and the application of the electrode material as described in any one of claims 1 to 6.

8. Use of the electrode material as claimed in claim 7 in electrochemical testing.

9. The use according to claim 8, characterized in that: The electrochemical parameters of the manganese sulfide electrode in conventional electrochemical tests can be obtained.

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