Method for electrocatalytic preparation of arsine using gray arsenic as arsenic source

Abstract

The application discloses a method for electrocatalytic preparation of arsine by taking grey arsenic as an arsenic source, and the method comprises the following steps: taking a PdFe bimetallic alloy nanoparticle electrode loaded on a nickel foil as a working cathode, setting an anode as a counter electrode, taking grey arsenic as an arsenic source, catalytically reducing the grey arsenic in an alkaline electrolyte by a constant current electrolysis method, and obtaining arsine. In a wide current density range, the method can realize efficient synthesis of arsine, and the method takes common and easily obtained grey arsenic as the arsenic source, takes a PdFe / NF electrode prepared by electrodepositing in a simple manner as a catalytic working cathode, and has mild reaction conditions, and the method does not need high temperature and high pressure and a chemical reducing agent, and the electrocatalyst can be repeatedly used, so that the method provides a green, safe and efficient method for synthesis of arsine.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of arsine synthesis, and particularly relates to a method for electrocatalytic preparation of arsine by taking gray arsenic as an arsenic source. BACKGROUND

[0002] Arsine is a key dopant in the semiconductor industry, especially in the manufacture of III-V compound semiconductors (such as gallium arsenide). By using arsine in gas-phase epitaxy and molecular beam epitaxy processes, the arsenic content in semiconductor materials can be precisely controlled to adjust their electrical properties. This control capability makes arsine play a crucial role in high-tech fields such as semiconductor manufacturing, flat panel display production, and photovoltaic cell manufacturing.

[0003] Currently, the preparation of arsine mainly relies on the thermochemical reduction method. This production process requires a large amount of chemical reducing agent and generates a large amount of waste liquid, which not only does not conform to the concept of green development, but also has a great safety hazard. In recent years, electrochemical technology has become a powerful green and efficient tool in chemical synthesis. Electrochemistry realizes the reduction and oxidation of substances through electron gain and loss, avoiding the need for oxidizing agents and reducing agents in traditional chemical reactions. The current and potential in the electrochemical process can be arbitrarily controlled, with the advantages of simple operation, green environmental protection, and mild conditions. Therefore, the application of electrochemical methods in the preparation of arsine has broad prospects. SUMMARY

[0004] The application provides a method for electrocatalytic preparation of arsine by taking gray arsenic as an arsenic source at room temperature. Currently, the preparation methods of arsine mainly include chemical reduction method, gas phase reaction method, etc. Although these methods can prepare arsine, there are problems such as incomplete reaction, many by-products, and low safety. In the application, a PdFe bimetallic alloy nanoparticle electrode loaded on a nickel foil is used as a working cathode, gray arsenic is used as an arsenic source, and a constant current electrolysis method is used to catalytically reduce gray arsenic in an alkaline electrolyte at room temperature. In a wide range of current density, efficient synthesis of arsine can be achieved. Common and easily obtained gray arsenic is used as an arsenic source, and a PdFe / NF electrode prepared by simple electrodeposition is used as a catalytic working cathode. The reaction conditions are mild, and high temperature and pressure and chemical reducing agents are not required. The electrocatalyst can be reused. The application provides a green, safe, and efficient method for the synthesis of arsine.

[0005] The object of the application is achieved by the following technical solutions.

[0006] The method for electrocatalytic preparation of arsine by taking gray arsenic as an arsenic source uses a PdFe bimetallic alloy nanoparticle electrode loaded on a nickel foil as a working cathode, and sets an anode as a counter electrode. Gray arsenic is used as an arsenic source, and a constant current electrolysis method is used to catalytically reduce gray arsenic in an alkaline electrolyte to prepare arsine.

[0007] Further, the method for electrocatalytic preparation of arsine by using grey arsenic as arsenic source specifically comprises the following steps:

[0008] 1) using PdFe bimetallic alloy nanoparticles electrode loaded on nickel foil as working cathode, carbon or Pt sheet as counter electrode anode, and using proton membrane to separate the cathode chamber and anode chamber of the electrolytic cell;

[0009] 2) adding grey arsenic and alkaline electrolyte in the cathode chamber, adding alkaline electrolyte in the anode chamber, and stirring the electrolyte in the cathode chamber to make the grey arsenic fully dispersed;

[0010] 3) connecting the working cathode and the counter electrode anode with the electrochemical workstation through wires respectively, and performing constant current electrolysis on the electrolytic system, wherein the current density of the constant current is 5-40 mA / cm 2 , and arsine is prepared.

[0011] Further, in step 2), the alkaline electrolyte is an aqueous solution of one or more of sodium carbonate, potassium carbonate, potassium hydroxide, and sodium hydroxide, and the concentration is 0.1-1.5 M, preferably 0.5-1 M.

[0012] Further, in step 2), the amount of grey arsenic added in the cathode chamber electrolyte is 300-800 g / L, preferably 600-700 g / L.

[0013] Further, the electrocatalytic reaction time is 5-100 h, preferably 10-20 h.

[0014] Further, the PdFe bimetallic alloy nanoparticles electrode loaded on nickel foil is marked as PdFe / NF electrode, and the preparation method thereof comprises the following steps:

[0015] S1: pretreating the nickel foil to remove the surface oxide layer and impurities;

[0016] S2: placing the nickel foil obtained in step S1 in a mixed aqueous solution containing Fe salt and Pd salt, and performing electrodeposition in a standard three-electrode system, wherein the nickel foil serves as a cathode working electrode, a Pt sheet serves as a counter electrode, and a saturated calomel electrode serves as a reference electrode; during the electrodeposition process, Pd and Fe elements are deposited onto the nickel foil, and after the process is completed, the electrode is rinsed and dried for standby use;

[0017] S3: calcining the electrode obtained in step S2 in an inert gas atmosphere at 400-600℃ for 1-4 h, and cooling to room temperature to obtain the PdFe / NF electrode.

[0018] Further, the step of pre-treatment in step S1 is: placing the nickel foil in a 2-4M hydrochloric acid solution for ultrasonic treatment for 2-20min to remove the surface oxide layer, then rinsing the surface acid solution with deionized water, placing it in acetone for ultrasonic treatment to remove the surface residual organic matter, and finally rinsing it with deionized water and drying, i.e. the treatment is completed.

[0019] Further, in step S2, the Pd salt is one of K2PdCl4, Na2PdCl4, PdCl2 and K2PdCl6, and the concentration of the Pd salt in the mixed aqueous solution is 0.1-1M; the Fe salt is one of FeCl3, Fe2(SO4)3 and Fe(NO3)3, and the concentration of the Fe salt in the mixed aqueous solution is 0.1-1M, preferably 0.5M.

[0020] Further, in step S2, the concentration of the Pd salt in the mixed aqueous solution is 0.1-0.3M, preferably 0.2M. When performing the electrodeposition, the deposition is stopped when the charge reaches 300-1500C, preferably when the charge reaches 400-500C.

[0021] Further, in step S2, a Co salt is also added to the mixed aqueous solution, the Co salt is one of a chloride, a sulfate or a nitrate of Co, and the concentration of the Co salt in the mixed aqueous solution is 0.1-1M, preferably 0.5M, and the finally prepared catalyst is a PdFeCo / NF multi-metal electrode doped with Co.

[0022] The beneficial effects of the present application are:

[0023] 1) The present application realizes the electro-catalytic preparation of arsine using gray arsenic as an arsenic source at room temperature, and realizes the efficient synthesis of arsine in a wide range of current density, and the concentration of arsine can reach 43.1% in a wide range of current density.

[0024] 2) The present application uses PdFe bimetallic alloy nanoparticles supported on a nickel foil as an electro-catalyst, and does not need high temperature and high pressure and chemical reducing agents, and the reaction conditions are mild and the operation is simple, and the catalyst can be repeatedly used and easily recovered, effectively avoiding the problems of complex process, low safety and large waste liquid pollution in other synthesis methods.

[0025] 3) The durability and stability of the working electrode of the present application are good, and it can be used repeatedly. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Figure 2 is a TEM image of the cathode working electrode PdFe / NF of Example 1 of the present application. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with specific examples, but the protection scope of the present application is not limited thereto.

[0028] The size of the nickel foil in the embodiment of the application is 10x10 cm 2 .

[0029] Example 1: Synthesis of arsine

[0030] 1) Preparation of cathode working electrode

[0031] Step 1: The nickel foil was placed in a 3M hydrochloric acid solution and ultrasonicated for 10 min to remove the surface oxide layer; then the surface acid solution was washed with deionized water, and then placed in acetone and ultrasonicated for 10 min to remove the surface residual organic matter; finally, it was washed with deionized water and dried for use;

[0032] Step 2: The nickel foil obtained in step 1 was placed in a mixed aqueous solution containing 0.5M Fe(NO3)3 and 0.2M K2PdCl4, and electrodeposition was carried out in a standard three-electrode system at a current of 20mA, with the nickel foil as the cathode working electrode, a Pt sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. During the electrodeposition process, Pd and Fe elements were deposited on the nickel foil, and the deposition was stopped when the charge reached 500C. The electrode was washed and dried for use;

[0033] Step 3: The electrode obtained in step 2 was calcined at 500℃ for 3h in an Ar atmosphere, and after cooling to room temperature, it was washed with deionized water and dried to obtain a PdFe / NF electrode. The TEM image of the PdFe / NF electrode is shown in Figure 1 , and there are uniformly dispersed PdFe nanoparticles on the surface of the nickel foil substrate.

[0034] 2) Preparation of arsine by constant current electrolysis method for catalytic reduction of gray arsenic

[0035] A double-chamber standard flow electrolysis cell with an effective area of 10x10 cm 2 was used as the container, and a proton exchange membrane (Nafion 117) was used to separate the cathode chamber and the anode chamber. 1L of 1M KOH alkaline aqueous solution was added to the cathode chamber, and 1L of 1M KOH alkaline aqueous solution was added to the anode chamber. Then 700g of gray arsenic was added to the cathode chamber, and a magnet was added to the cathode chamber and placed on a magnetic stirrer to stir the electrolyte in the cathode chamber. PdFe / NF was used as the cathode working electrode, a Pt sheet was used as the counter electrode, and a Hg / HgO (1.0M KOH) electrode was used as the reference electrode. The cathode and anode electrodes were connected to the electrochemical workstation through wires, and a constant current of 1A-5A was selected for the reaction. After 5h / 10h of reaction, the concentration of arsine was analyzed by gas chromatography.

[0036] According to the above operation process, tests were carried out at different constant currents, and the results are shown in Table 1.

[0037] In the experiment of preparing arsine by catalytic reduction of gray arsenic by constant current electrolysis method, the cathode output only has two kinds, which are arsenic hydrogen product (arsine AsH3) and hydrogen, and the arsine concentration in Table 1 refers to the volume fraction of arsine in the mixed system of arsine and hydrogen. In the experiment, the gas outlet of the cathode chamber is connected to the tail gas treatment device (a plurality of absorption tanks containing saturated potassium permanganate aqueous solution connected in series), and when sampling and analysis, the valve of the gas outlet is switched to connect the gas chromatograph to determine the concentration of arsine in the mixed gas.

[0038] Table 1. Arsine concentration (%) under different currents

[0039]

[0040]

[0041] As shown in Table 1, under different current test conditions, the concentration of arsine produced by the cathode can exceed 20%. Especially under the action of 3A current, after 10 hours of test, the concentration of arsine reaches 43.1%. When the current is low, the conversion rate of gray arsenic is slow; with the further increase of the current, due to the competition of hydrogen evolution reaction, the concentration of arsine decreases.

[0042] Example 2: Regulating electrolyte concentration

[0043] The experimental conditions of Example 2 are repeated in Example 1, the only difference is that in step 2), the concentration of KOH alkaline aqueous solution is replaced by 0.5M, 1M, 1.5M, 2M, 2.5M or 3M, the concentration of KOH alkaline aqueous solution in the cathode chamber and the anode chamber is the same, and the selected constant current is 3A for reaction, and other conditions remain unchanged, and the concentration of arsine is analyzed by gas chromatography after reaction for 5h / 10h.

[0044] According to the above operation process, tests are carried out under different electrolyte concentrations, and the results are shown in Table 2.

[0045] Table 2. Arsine concentration (%) under different electrolyte concentrations

[0046]

[0047]

[0048] As shown in Table 2, the test results under different concentrations of electrolyte show that the concentration of electrolyte has a great influence on arsine, showing a volcanic curve, specifically, when the concentration of electrolyte is 1M or less, the concentration of arsine can reach more than 30%; when the concentration of electrolyte is increased (1.5-3M), the concentration of arsine decreases rapidly, which is due to the increase of ion transport flux in the electrolyte, the faster rate of competitive reaction hydrogen evolution reaction, and the insufficient active hydrogen in the solution to convert into arsine.

[0049] Example 3: Preparation of cathode electrode by regulating Pd salt concentration

[0050] In this Example 3, the Pd salt concentration in the PdFe / NF electrode was regulated to control the ratio of Pd and Fe. The preparation steps of the PdFe / NF electrode were repeated as in Example 1, except that the concentration of K2PdCl4in the mixed aqueous solution in Step 2 was replaced by X M (X refers to the concentration of K2PdCl4) in the preparation steps of the cathode working electrode. Other conditions remained unchanged, and finally the PdFe / NF electrode was prepared.

[0051] The PdFe / NF electrode of Example 3 was subjected to the constant current electrolysis method for catalytic reduction of gray arsenic to prepare arsine. The experimental steps were repeated as in Example 1, and a constant current of 3 A was selected for the reaction. Other conditions remained unchanged. After 5 hours / 10 hours of reaction, the arsine concentration was analyzed by gas chromatography, and the test results are shown in Table 3.

[0052] Table 3. Arsine yield under different Pd salt concentrations

[0053]

[0054] As shown in Table 3, the content of Pd has a significant impact on the efficiency of the conversion of gray arsenic to arsine. By regulating the content of Pd precursor, the content of Pd in the cathode working electrode can be controlled. Specifically, as the content of Pd increases, the concentration of arsine first increases and then decreases (reaching the optimum at 0.2 M K2PdCl4). This phenomenon may be due to the good adsorption capacity of Pd for active hydrogen produced by cathode electrolysis. When the content of adsorbed hydrogen reaches a certain level, it is easier to convert into hydrogen gas, thereby affecting the yield of arsine.

[0055] Example 4: Optimization of multi-metal doped electrode

[0056] Example 4 further regulates the electronic state of the active component Pd by multi-metal doping to optimize the electrode. The specific steps for preparing the cathode working electrode of Example 4 are as follows:

[0057] Step 1: Place the nickel foil in a 3 M hydrochloric acid solution and ultrasonicate for 10 min to remove the surface oxide layer. Then rinse the surface acid solution with deionized water, and then place it in acetone and ultrasonicate for 10 min to remove the surface residual organic matter. Finally, rinse it with deionized water and dry it for use;

[0058] Step 2, the nickel foil obtained in step 1 was placed in a mixed aqueous solution containing 0.5M Fe(NO3)3, 0.5M Z (Z refers to another nitrate salt) and 0.2M K2PdCl4, and electrodeposition was carried out in a standard three-electrode system at a current of 20mA, with the nickel foil serving as the cathode working electrode, a Pt sheet serving as the counter electrode, and a saturated calomel electrode serving as the reference electrode; the deposition was stopped when the charge reached 500C, and the electrode was washed and dried for later use;

[0059] Step 3, the electrode obtained in step 2 was calcined at 500°C for 3h under an Ar atmosphere, and after cooling to room temperature, it was washed with deionized water and dried to obtain a PdFeZ / NF multi-metal electrode.

[0060] In Example 4, the PdFeZ / NF electrode doped with multiple metals was used to prepare arsine by catalytic reduction of gray arsenic through galvanostatic electrolysis, and the experimental steps were repeated in Example 1. A constant current of 3A was selected for the reaction, and other conditions remained unchanged. After 5h / 10h of reaction, the arsine concentration was analyzed by gas chromatography, and the test results are shown in Table 4.

[0061] Table 4. Arsine concentration (%) synthesized by multi-metal doped electrodes

[0062]

[0063]

[0064] As shown in Table 4, the performance test results of the multi-metal doped electrode show that the Co element has a significant electronic regulation effect on Pd. Specifically, the PdFeCo / NF electrode synthesized by adding a Co precursor to the deposition solution has an arsine concentration of 48.8%, which is significantly better than that of the pure PdFe / NF electrode. This result shows that the doping of Co element significantly promotes the synthesis of arsine and improves the catalytic performance of the electrode.

[0065] Comparative Example 1: Preparation of a cathode working electrode using other metals doped with Pd

[0066] Step 1, the nickel foil was placed in a 3M hydrochloric acid solution and ultrasonicated for 10min to remove the surface oxide layer; then the surface acid solution was washed with deionized water, and then the nickel foil was placed in acetone and ultrasonicated for 10min to remove the surface residual organic matter; finally, the nickel foil was washed with deionized water and dried for later use;

[0067] Step 2, the nickel foil obtained in step 1 was placed in a mixed aqueous solution containing 0.5M Y (Y refers to another nitrate salt) and 0.2M K2PdCl4, and electrodeposition was carried out in a standard three-electrode system at a current of 20mA, with the nickel foil serving as the cathode working electrode, a Pt sheet serving as the counter electrode, and a saturated calomel electrode serving as the reference electrode; the deposition was stopped when the charge reached 500C, and the electrode was washed and dried for later use;

[0068] Step 3: The electrode obtained in Step 2 was calcined at 500°C for 3h under Ar atmosphere, and after cooling to room temperature, it was washed with deionized water and dried to obtain a PdY / NF electrode.

[0069] The PdY / NF electrode obtained in Step 2 was calcined at 500°C for 3h under Ar atmosphere, and after cooling to room temperature, it was washed with deionized water and dried to obtain a PdY / NF electrode.

[0070] Table 5. Arsenane concentration (%) synthesized by different metal-doped Pd electrodes

[0071]

[0072] As shown in Table 5, the performance test results of different metal-doped Pd electrodes show that Fe element has a unique electronic regulation effect on Pd, which can inhibit the hydrogen evolution reaction to a certain extent.

[0073] Comparative Example 2: Preparation of PdFe / Z electrode using different substrate materials

[0074] The preparation steps of the cathode working electrode in Comparative Example 2 were repeated in Example 1, except that "nickel foil was replaced by a substrate material Z (Z refers to other substrate materials, selected from nickel foam, titanium foam, copper foil, nickel foil or platinum sheet) of the same size", and other conditions were unchanged. Finally, a PdFe / Z electrode was obtained.

[0075] The PdFe / Z electrode prepared using different substrate materials in Comparative Example 2 was used to catalytically reduce gray arsenic to prepare arsenane by constant current electrolysis. The experimental steps were repeated in Example 1, and a constant current of 3A was selected for the reaction, and other conditions were unchanged. After 5h / 10h of reaction, the arsenane concentration was analyzed by gas chromatography, and the test results are shown in Table 6.

[0076] Table 6. Arsenane concentration (%) synthesized by electrodes prepared using different substrate materials

[0077]

[0078] As shown in Table 6, the performance test results of the PdFe / Z electrode prepared by electrodeposition using different substrate materials show that nickel substrate material has outstanding performance in synthesizing arsenane due to its good weak hydrogen evolution property, and nickel foil as a substrate is the best.

[0079] Comparative Example 3: Synthesis of arsenane using different arsenic sources

[0080] A 10x10cm 2The effective area of the double-chamber standard flow electrolytic cell is a container, the cathode chamber and the anode chamber are separated by a proton exchange membrane (Nafion 117), 1L of 1M KOH alkaline aqueous solution is added to the cathode chamber, 1L of 1M KOH alkaline aqueous solution is added to the anode chamber, then 700g of different arsenic sources (see Table 7 for details) are added to the cathode and stirred by a magnetic sub, the PdFe / NF prepared in Example 1 is used as the cathode working electrode, a Pt sheet is used as the counter electrode, and a Hg / HgO (1.0M KOH) electrode is used as the reference electrode. The anode and cathode electrodes are connected to the electrochemical workstation through wires, a constant current of 3A is selected for the reaction, and the arsine concentration is analyzed by gas chromatography after 5 hours / 10 hours of reaction. The test results are shown in Table 7.

[0081] Table 7. Arsine concentration (%) synthesized by using different arsenic sources

[0082]

[0083] As shown in Table 7, the performance test results of synthesizing arsine by using different arsenic sources show that gray arsenic has the best performance of producing arsine, which is due to the zero-valent chemical state of gray arsenic; in addition, gray arsenic has better conductivity than other arsenic sources, and this good electron transmission capacity has a significant impact on the production of arsine.

[0084] The content described in the specification is only a list of forms of the inventive concept, and the protection scope of the present application should not be regarded as limited to the specific forms stated in the examples.

Claims

1. A method for electrocatalytically preparing arsine from arsenic gray as the arsenic source, characterized in that, Using a PdFe bimetallic alloy nanoparticle electrode loaded on nickel foil as the working cathode and a counter electrode anode, arsenic was prepared by catalytic reduction of arsenic in an alkaline electrolyte via constant current electrolysis using arsenic as the arsenic source. The alkaline electrolyte is an aqueous solution of one or more of sodium carbonate, potassium carbonate, potassium hydroxide, and sodium hydroxide, with a concentration of 0.5-1M.

2. The method for electrocatalytically preparing arsine using gray arsenic as the arsenic source as described in claim 1, characterized in that, Specifically, the following steps are included: 1) The working cathode is a PdFe bimetallic alloy nanoparticle electrode loaded on nickel foil, and the counter electrode is a carbon or Pt sheet. The cathode chamber and anode chamber of the electrolytic cell are separated by a proton exchange membrane. 2) Add arsenic and alkaline electrolyte to the cathode chamber and add alkaline electrolyte to the anode chamber. Stir the electrolyte in the cathode chamber to fully disperse the arsenic. 3) The working cathode and the counter anode are connected to the electrochemical workstation via wires. The electrolysis system undergoes constant current electrolysis with a current density of 5-40 mA / cm². 2 Arsine was prepared.

3. The method for electrocatalytically preparing arsine using gray arsenic as the arsenic source as described in claim 2, characterized in that, In step 2), the amount of gray arsenic added to the electrolyte in the cathode chamber is 300-800 g / L.

4. The method for electrocatalytically preparing arsine using gray arsenic as the arsenic source as described in claim 3, characterized in that, In step 2), the amount of gray arsenic added to the electrolyte in the cathode chamber is 600-700 g / L.

5. The method for electrocatalytically preparing arsine using gray arsenic as the arsenic source as described in claim 2, characterized in that, The electrocatalytic reaction time is 5-100 h.

6. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 5, characterized in that, The electrocatalytic reaction time is 10-20 h.

7. The method for electrocatalytically preparing arsine from arsenic using arsenic as an arsenic source as described in claim 1, characterized in that, The PdFe bimetallic alloy nanoparticle electrode loaded on nickel foil is labeled as a PdFe / NF electrode, and its preparation method includes the following steps: S1: Pre-treat the nickel foil to remove the surface oxide layer and impurities; S2: The nickel foil obtained in step S1 is placed in a mixed aqueous solution containing Fe salt and Pd salt, and electrodeposition is performed in a standard three-electrode system. The nickel foil serves as the cathode working electrode, the Pt sheet serves as the counter electrode, and the saturated calomel electrode serves as the reference electrode. During the electrodeposition process, Pd and Fe elements are deposited onto the nickel foil. After the process is completed, the foil is rinsed and dried for later use. S3: The electrode obtained in step S2 is calcined in an inert gas atmosphere at 400-600℃ for 1-4 h, and then cooled to room temperature to obtain the PdFe / NF electrode.

8. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 7, characterized in that, The pretreatment steps in step S1 are as follows: place the nickel foil in a 2-4 M hydrochloric acid solution and sonicate for 2-20 min to remove the surface oxide layer. Then rinse the surface with deionized water to remove the acidic solution. Next, place it in acetone and sonicate to remove residual organic matter on the surface. Finally, rinse it with deionized water and dry it to complete the treatment.

9. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 7, characterized in that, In step S2, the Pd salt is one of K2PdCl4, Na2PdCl4, PdCl2 and K2PdCl6, and its concentration in the mixed aqueous solution is 0.1-1 M; the Fe salt is one of FeCl3, Fe2(SO4)3 and Fe(NO3)3, and its concentration in the mixed aqueous solution is 0.1-1 M.

10. The method for electrocatalytically preparing arsine from arsenic using arsenic as an arsenic source as described in claim 9, characterized in that, The concentration of Fe salt in the mixed aqueous solution is 0.5 M.

11. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 9, characterized in that, In step S2, the concentration of Pd salt in the mixed aqueous solution is 0.1-0.3 M.

12. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 11, characterized in that, In step S2, the concentration of Pd salt in the mixed aqueous solution is 0.2 M.

13. The method for electrocatalytically preparing arsine using gray arsenic as the arsenic source as described in claim 7, characterized in that, In step S2, a Co salt is also added to the mixed aqueous solution. The Co salt is a chloride, sulfate, or nitrate of Co, and its concentration in the mixed aqueous solution is 0.1-1 M. The final catalyst is a Co-doped PdFeCo / NF multimetal electrode.

14. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 13, characterized in that, The concentration of Co salt in the mixed aqueous solution is 0.5 M.

15. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 7, characterized in that, When performing electrodeposition, deposition is stopped when the charge reaches 300-1500 C.

16. The method for electrocatalytically preparing arsine from arsenic using gray arsenic as the arsenic source as described in claim 15, characterized in that, When performing electrodeposition, deposition is stopped when the charge reaches 400-500 C.

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