Method for recovering by-product silicon tetrachloride in silicon industry based on gallium electrode electrodeposition

Abstract

The invention discloses a method for recycling silicon industry by-product silicon tetrachloride based on gallium electrode electro-deposition, which is used for solving the problems of low solubility and crystal structure in the process of preparing silicon by an electro-deposition method. According to the method, a deep eutectic solvent system composed of 1, 3-dimethyl-2-imidazolinone and 1, 3-dimethylurea is adopted to efficiently absorb silicon tetrachloride in a green manner and prepare the electrolyte, and the electrolyte is converted into high-purity, uniform and compact silicon crystals by using a liquid gallium electrode electrodeposition technology, so that effective conversion from wastes to high-added-value materials is realized. Meanwhile, the low-toxicity eutectic solvent which is easy to prepare and has good biodegradability is adopted to replace traditional ionic liquid or other chemical reagents, so that the safety, the environmental protection property and the sustainability of the process are remarkably improved, and the treatment cost and the environmental burden are reduced at the same time.

Description

Technical Field

[0001] The present invention belongs to the fields of metallurgical engineering and materials science and technology, and particularly relates to a method for electro-depositing and recovering silicon tetrachloride, a by-product of the silicon industry, based on a gallium electrode. Background Art

[0002] Silicon tetrachloride (SiCl4) is one of the main by-products of the silicon industry and is widely used in optical fiber manufacturing, chemical vapor deposition (CVD), and the preparation of high-purity silicon materials. However, due to the rapid development of the silicon industry, a large amount of silicon tetrachloride by-products are generated every year, and a part of them is difficult to be directly reused, resulting in increasingly serious problems of environmental pollution and resource waste.

[0003] Currently, the recycling of silicon tetrachloride mainly involves hydrolysis, hydrogenation, or chemical reactions to produce siloxanes, silanes, or other derivatives. However, these traditional methods usually have the following problems:

[0004] 1. High energy consumption: High temperature or pressure conditions are required, increasing production costs.

[0005] 2. Environmental risks: By-products such as hydrogen chloride gas or other toxic waste may be generated during the treatment process, posing potential hazards to the environment.

[0006] 3. Complex processes: Multiple reaction and separation processes are required, which not only reduce economic efficiency but also limit the popularization of the technology.

[0007] Therefore, there is an urgent need to develop a green and efficient technology to directly convert silicon tetrachloride into high-value-added products, thereby achieving the efficient recycling of resources. In the prior art, the invention with the publication number CN104746130A proposed a method for directly electrolyzing and preparing crystalline silicon at low temperature in an ionic liquid. An ionic liquid was used as the electrolyte, and a liquid metal (such as gallium, manganese, tin, etc.) was used as the cathode. The electrodeposition temperature was 90°C to 120°C, and the voltage range was -1.8V to -3.2V. Although this method achieved the preparation of crystalline silicon at low temperature, the cost of the ionic liquid was high and its stability was poor. Side reactions might occur during the electrolysis of the electrolyte, increasing the cost and operation complexity, and affecting the feasibility of its industrial application. In addition, the high viscosity of the ionic liquid might affect the migration efficiency of silicon ions in the electrolysis reaction, affecting the deposition rate and film quality. The invention with the publication number CN115537882A proposed a method for electrodepositing a silicon film using an organic solvent. Although the reaction temperature was relatively low, the stability of the electrolyte was poor, the deposition efficiency was low, and the quality of the prepared silicon film was limited, making it difficult to meet the requirements of high-performance silicon materials. The invention with the publication number CN118207602A deposited silicon by using a solid-state electrode in a deep eutectic solvent. Although the characterization results showed that crystalline silicon could be obtained, due to the use of a traditional solid-state electrode, the deposition interface was unstable, easily leading to non-uniform growth of the silicon layer, and there was a problem of coexistence of amorphous silicon and silicon dioxide, affecting the overall purity and structural integrity of the deposited layer. There were also deficiencies in the repeatability and controllability of the preparation results. Summary of the Invention

[0008] In view of the problems existing in the prior art for treating silicon tetrachloride, such as low recovery rate, high environmental pollution risk, and insufficient resource utilization efficiency, the present invention proposes an efficient recovery method based on a deep eutectic solvent system. This method mainly utilizes electrodeposition technology to recover and treat silicon tetrachloride through a liquid gallium electrode under precise electrochemical conditions, converting it into a silicon film with relatively high purity, which is applicable to various material application fields, thereby achieving the effective utilization of resources and environmentally friendly production. The present invention significantly improves the recovery efficiency of silicon tetrachloride, reduces the environmental pollution risk, and has good economic benefits and sustainable development potential. Especially in the fields of semiconductor manufacturing, organic synthesis, materials science, and glass manufacturing, the present invention provides an innovative and efficient technical path for the resource utilization of silicon tetrachloride, making a positive contribution to promoting environmentally friendly production.

[0009] The present invention uses a deep eutectic solvent as the electrolyte. This system can efficiently dissolve silicon tetrachloride. The solubility of silicon tetrachloride in this deep eutectic solvent system is 4 g SiCl4 / 100 g solvent at 25 °C. As the temperature rises to 40 °C, 60 °C, 80 °C, and 100 °C, the solubility increases to 6 g / 100 g, 8 g / 100 g, 15 g / 100 g, 16.5 g / 100 g respectively, and stabilizes at 16.5 g / 100 g. To ensure the efficient progress of electrodeposition, the present invention optimizes the conditions for electrodeposition, especially in the selection of voltage. Through multiple experiments and combined with cyclic voltammogram (CV) analysis, in the voltage range of -3 V to -5 V, obvious reduction peaks are shown in the experimental results. When the voltage is lower than -3 V, the deposition rate decreases significantly, and the silicon deposition effect is not ideal; while when the voltage is higher than -5 V, hydrogen evolution or other side reactions may be triggered in the electrolysis reaction, affecting the deposition efficiency and the purity of the product. Finally, the present invention determines that the voltage range of -3 V to -5 V is the optimal electrodeposition voltage range, which can ensure the high purity and stability of the silicon thin film. During the entire electrodeposition process, silicon ions in the solution are directly deposited on the liquid gallium electrode, depositing a silicon thin film with a uniform structure and good compactness. The whole process is simple and efficient, realizing the efficient conversion from silicon tetrachloride to silicon thin film.

[0010]

[0011] The present invention provides a method for electrodepositing and recovering silicon tetrachloride, a by-product of the silicon industry, based on a gallium electrode. It uses a deep eutectic solvent composed of 1,3-dimethyl-2-imidazolidinone and 1,3-dimethylurea. The deep eutectic solvent system absorbing silicon tetrachloride is used as the electrolyte, and liquid metal gallium is used as the working electrode. A three-electrode system is used for potentiostatic electrodeposition reaction. After the electrodeposition product is washed and separated, the main component is crystalline silicon, which has the characteristics of a crystalline structure, indicating that this method can effectively achieve the deposition and enrichment of silicon.

[0012] In the present invention, the molar ratio of 1,3-dimethyl-2-imidazolidinone to 1,3-dimethylurea is 2:1 to 2.5:1.

[0013] In the present invention, when preparing the electrolyte, at a temperature of 60 - 100 °C, the deep eutectic solvent system absorbs silicon tetrachloride, and the amount of silicon tetrachloride dissolved in every 100 g of the deep eutectic solvent is between 8 g and 16.5 g.

[0014] In the present invention, the deep eutectic solvent system absorbing silicon tetrachloride is used as the electrolyte after being pretreated by drying.

[0015] In the present invention, in the three-electrode system, the counter electrode is a graphite electrode, and the auxiliary electrode is a silver / saturated calomel electrode.

[0016] In the present invention, during the electrodeposition reaction, the electrodeposition temperature is 80 - 100 °C, the working voltage is -3 to -5 V, and the deposition time is 2 - 4 h.

[0017] In the present invention, the electrodeposited product is washed with acetone to remove the eutectic solvent remaining on the surface of liquid metal gallium.

[0018] In the present invention, after the electrodeposited product is washed, the tetrafluoro container containing liquid metal gallium is immersed in an anhydrous ethanol bath and frozen in a -20 °C freezer for 10 - 20 h. Through the freezing treatment, the viscosity of liquid metal gallium increases, and the adhesion between the solidified gallium layer and the crystalline silicon thin film weakens, thus promoting the separation of the silicon deposit from the liquid gallium electrode. After freezing, a tetrafluoroethylene scraper is used to gently scrape the frozen silicon thin film to achieve the separation of crystalline silicon.

[0019] As described above, the present invention uses liquid metal gallium as the working electrode to construct a stable and uniform deposition interface, and combines the good dissolution ability of the eutectic solvent system for SiCl4, significantly improving the stability and controllability of the electrodeposition process. Under the optimized potentiostatic electrolysis conditions (voltage -3 to -5 V), a stable and efficient silicon deposition reaction can be achieved. The present invention not only maintains the advantage of low-temperature operation, but also shows better performance in terms of deposition efficiency, crystal quality, electrode stability and reaction repeatability, providing a more industrialized technical path for the resource utilization and high-value utilization of silicon tetrachloride.

[0020] Compared with the prior art, the beneficial effects obtained by the present invention are mainly as follows:

[0021] 1. Improve the recovery rate of silicon tetrachloride

[0022] The present invention significantly improves the recovery rate of silicon tetrachloride by absorbing silicon tetrachloride in the eutectic solvent system and using an electrochemical method for electrodeposition. This method not only reduces the loss of silicon tetrachloride, but also improves the utilization efficiency of its resources, which is of great significance for industrial production.

[0023] 2. Improve the quality of electrodeposited silicon thin films

[0024] The present invention uses liquid metal gallium as the working electrode and can effectively control the reaction conditions during the electrodeposition process, thereby improving the uniformity and denseness of the electrodeposited silicon thin film. The silicon thin film prepared by this method has good mechanical strength and chemical stability and is suitable for various high-performance material applications.

[0025] 3. Improve resource utilization efficiency and reduce production costs

[0026] The present invention recovers silicon tetrachloride by electrochemical means and prepares silicon thin films, which can significantly reduce the use of high energy consumption and high consumption of chemicals in traditional methods and reduce the overall production cost. In addition, the electrodeposition method has relatively low energy consumption during the reaction process, further improving the resource utilization efficiency.

[0027] In summary, the present invention proposes a method for absorbing silicon tetrachloride based on a deep eutectic solvent system and further preparing silicon thin films by electrodeposition, which significantly improves the recovery rate of silicon tetrachloride and realizes green and sustainable development. The present invention uses liquid metal gallium as the working electrode to construct a stable and uniform deposition interface, and combines the better dissolution ability of the deep eutectic solvent system for SiCl4, significantly improving the stability and controllability of the electrodeposition process. Under optimized constant potential electrolysis conditions (voltage -3 to -5V), a stable and efficient silicon deposition reaction can be achieved. Compared with CN118207602A, the present invention not only maintains the advantage of low-temperature operation, but also shows better performance in terms of deposition efficiency, crystal quality, electrode stability and reaction repeatability, providing a more industrialized technical path for the resource utilization and high-value utilization of silicon tetrachloride. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a technical flow chart for the present invention to recover silicon by-products silicon tetrachloride through electrodeposition using a liquid gallium electrode.

[0029] Figure 2 It is the cyclic voltammetry curve (CV diagram) of the deposited silicon in Example 1.

[0030] Figure 3 It is the SEM morphology diagram of the deposited silicon in Example 1.

[0031] Figure 4 It is the EDS elemental analysis of the deposited silicon in Example 1.

[0032] Figure 5 It is the XRD analysis of Example 1.

[0033] Figure 6 It is the XPS analysis of Example 1.

[0034] Figure 7 It is a comparison diagram of the liquid gallium electrode before and after deposition in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0035] The present invention will be described in detail below with reference to the drawings and embodiments.

[0036] The present invention uses pure liquid gallium as the working electrode, replacing the traditional multi-component liquid metal alloy. Liquid gallium has a low melting point (about 29.76 °C), remains liquid at the electrodeposition temperature of 80 °C, and has good electrical conductivity and chemical stability. The electrode design is simpler, easier to operate and maintain, suitable for large-scale industrial production. At the same time, during the electrodeposition process, the reaction conditions can be effectively controlled to deposit high-quality, uniform and dense silicon thin films, significantly improving the electrodeposition efficiency and product quality. In addition, the present invention uses a deep eutectic solvent (1,3-dimethyl-2-imidazolidinone and 1,3-dimethylurea) as the electrolyte, replacing the traditional ionic liquid. The deep eutectic solvent has the advantages of low toxicity, easy preparation, good biodegradability, etc., significantly reducing the production cost and improving the environmental protection and sustainability of the process.

[0037] A method for electrodepositing and recycling silicon tetrachloride, a by-product of the silicon industry, based on a gallium electrode provided by the present invention comprises the following specific steps:

[0038] First, prepare a deep eutectic solvent in a vacuum glove box, that is, select 1,3-dimethyl-2-imidazolidinone and 1,3-dimethylurea with a molar ratio of 2:1.

[0039] Next, heat the prepared deep eutectic solvent to 60 °C and stir for 10 min, then put it into a vacuum drying oven, set the temperature to 100 °C, and the drying time to 24 h to remove the moisture in the system.

[0040] Secondly, put the dried deep eutectic solvent into a vacuum glove box, and at a temperature of 60 °C - 100 °C, fully dissolve a certain amount of SiCl4 in the deep eutectic solvent and stir evenly.

[0041] Finally, use an electrochemical device with a three-electrode system. Its working electrode is liquid gallium, which is installed in a customized tetrafluoro container and connected with a platinum wire electrode sleeved with a tetrafluoro tube. The counter electrode is a graphite electrode, and the auxiliary electrode is a silver / saturated calomel electrode. Carry out the electrodeposition reaction under precisely controlled electrochemical conditions. Its working voltage is -3V to -5V, the deposition temperature is 80 °C, and the deposition time is 2 - 4 h. After the electrodeposition is completed, take out the liquid metal gallium in the glove box. Add 20 mL of acetone to the electrodeposited liquid gallium and ultrasonically clean it 3 times (5 min each time), then immerse it in an anhydrous ethanol bath and freeze it at -20 °C for 12 h, and scrape the silicon product with a polytetrafluoroethylene scraper.

[0042] Example 1

[0043] The deep eutectic solvent was prepared in a vacuum glove box. First, 22.83 g of 1,3-dimethyl-2-imidazolidinone and 8.81 g of 1,3-dimethylurea were weighed and added to a 100 mL Erlenmeyer flask to form the deep eutectic solvent. Then, the prepared deep eutectic solvent was heated to 60 °C and stirred for 10 min, and then placed in a vacuum drying oven for drying. The drying temperature was set at 100 °C and the drying time was 24 h. After drying was completed, the deep eutectic solvent was quickly transferred to a vacuum glove box filled with argon, and experiments were carried out in an environment with a water content and an oxygen content less than 1 ppm.

[0044] The dried deep eutectic solvent was heated to 80 °C, and SiCl4 was added dropwise to the deep eutectic solvent to saturation using a pipette with a specification of 1000 μL. After the solution was stirred evenly and the temperature was stable, an electrochemical device with a three-electrode system was used. The working electrode was a liquid metal gallium electrode (the liquid gallium was contained in a tetrafluoro container and connected to the liquid gallium through a platinum wire sleeved with a tetrafluoro tube). The counter electrode was a graphite electrode with a diameter of 5 mm × a height of 90 mm, and the auxiliary electrode was a silver / saturated calomel electrode. Before using the electrodes, the platinum wire electrode and the graphite electrode needed to be polished and ground. After grinding, they were ultrasonically cleaned with absolute ethanol for 10 min, taken out and then ultrasonically cleaned with deionized water for 10 min. After the electrode device was dried, it could be loaded and used. The electrodeposition reaction was carried out under precisely controlled electrochemical conditions. The deposition temperature was 80 °C, the working voltage was -4 V, and the current density was 16.9 A / dm ². After depositing for 2 h under this three-electrode system, the electrodeposited liquid metal gallium electrode was taken, 20 mL of acetone was added, and it was ultrasonically cleaned 3 times, with each cleaning time being 5 minutes, to ensure the removal of the residual deep eutectic solvent on the surface. Subsequently, the cleaned liquid metal gallium electrode was immersed in an absolute ethanol bath and frozen at -20 °C for 12 h to make the deposited silicon product easier to separate. After freezing, the silicon film was gently scraped off with a polytetrafluoroethylene scraper and collected. Finally, the silicon product was put into a sample bag for storage to ensure its stability at low temperature. 2 Figure 11 is the cyclic voltammogram (CV diagram) of Example 1. It can be observed from the figure that there are obvious reduction peaks in a specific voltage range, and this peak reflects the reduction reaction characteristics of SiCl4 in the deep eutectic solvent system.

[0045] Figure 2 Figure 12 is the SEM morphology diagram of the deposited silicon in Example 1. It can be observed from the SEM diagram that the surface morphology of the deposited layer is relatively dense and uniform. Figure 3 Figure 13 is the EDS elemental analysis of the deposited silicon in Example 1. Combining the elemental analysis results, the silicon content in the deposit is relatively high, and a trace amount of gallium element is detected by EDS analysis, indicating that there is some residual liquid metal gallium when scraping the silicon film. Figure 4 Figure 14 is the XRD pattern of the deposited silicon in Example 1. Figure 5The XRD analysis of Example 1 further verified the crystal structure characteristics of silicon. Obvious diffraction peaks of silicon (Si) can be seen in the figure, indicating that the electrodeposited product is mainly crystalline silicon. Figure 6 For the XPS analysis of Example 1, the signal of crystalline silicon is located at a binding energy of 99.3 eV. Figure 7 Regarding the state change of the liquid gallium electrode before and after electrodeposition in Example 1, it can be seen that there is an obvious black silicon deposition layer attached to the electrode surface after deposition.

[0046] Example 2

[0047] Prepare a deep eutectic solvent in a vacuum glove box. That is, weigh 46.80 g of 1,3-dimethyl-2-imidazolidinone and 17.62 g of 1,3-dimethylurea and add them to a 500 mL Erlenmeyer flask to form a deep eutectic solvent. Then heat the prepared deep eutectic solvent to 60 °C and stir for 10 min, and then put it into a vacuum drying oven. Set the drying temperature to 100 °C and the drying time to 24 h. After the dried deep eutectic solvent is cooled, quickly transfer the solvent to the vacuum glove box and conduct experiments in an environment with a water content and an oxygen content less than 1 ppm.

[0048] Heat the dried deep eutectic solvent to 80 °C, and use a pipette gun with a specification of 1000 μL to add SiCl4 until the deep eutectic solvent is saturated. After the solution is stirred evenly and the temperature is stable, use an electrochemical device with a three-electrode system. Its working electrode is a liquid metal gallium electrode (the liquid gallium is contained in a tetrafluoro container and is connected to the liquid gallium through a platinum wire sleeved with a tetrafluoro tube). The counter electrode is a graphite electrode with a diameter of 5 mm × a height of 90 mm, and the auxiliary electrode is a silver / saturated calomel electrode. Before using the electrodes, the platinum wire electrode and the graphite electrode need to be polished. After polishing, ultrasonically clean them with anhydrous ethanol for 10 min, take them out and then ultrasonically clean them with deionized water for 10 min. After the electrode device is dried, it can be loaded and used. Conduct an electrodeposition reaction under precisely controlled electrochemical conditions. The deposition temperature is 80 °C, the working voltage is -3 V, and the current density is 20.2 A / dm 2. The deposition time is 2 h. After depositing for 2 h under this three-electrode system, take the electrodeposited liquid gallium electrode, add 20 mL of acetone, and ultrasonically clean it 3 times, with each cleaning time being 5 minutes to ensure the removal of the residual deep eutectic solvent on the surface. Subsequently, immerse the cleaned liquid gallium electrode in an anhydrous ethanol bath and freeze it at -20 °C for 12 h to make the deposited silicon product easier to separate. After freezing, gently scrape the silicon film with a polytetrafluoroethylene spatula and collect it. Finally, put the silicon product into a sample bag for storage to ensure its stability at low temperature. 2 After depositing for 2 h under this three-electrode system, take the electrodeposited liquid gallium electrode, add 20 mL of acetone, and ultrasonically clean it 3 times, with each cleaning time being 5 minutes to ensure the removal of the residual deep eutectic solvent on the surface. Subsequently, immerse the cleaned liquid gallium electrode in an anhydrous ethanol bath and freeze it at -20 °C for 12 h to make the deposited silicon product easier to separate. After freezing, gently scrape the silicon film with a polytetrafluoroethylene spatula and collect it. Finally, put the silicon product into a sample bag for storage to ensure its stability at low temperature.

[0049] Example 3

[0050] Prepare the deep eutectic solvent in a vacuum glove box. That is, weigh 23.40 g of 1,3-dimethyl-2-imidazolidinone and 8.81 g of 1,3-dimethylurea and add them to a 100 mL Erlenmeyer flask to form the deep eutectic solvent. Then heat the prepared deep eutectic solvent to 60 °C, stir for 10 min, and then place it in a vacuum drying oven. Set the drying temperature to 100 °C and the drying time to 24 h. After the dried and cooled deep eutectic solvent is quickly transferred to the vacuum glove box, conduct experiments in an environment with a water content and an oxygen content of less than 1 ppm.

[0051] Heat the dried deep eutectic solvent to 80 °C, and use a pipette with a specification of 1000 μL to add SiCl4 dropwise to the deep eutectic solvent until it is saturated. After the solution is stirred evenly and the temperature is stable, use an electrochemical device with a three-electrode system. Its working electrode is a liquid metal gallium electrode (the liquid gallium is contained in a tetrafluoro container and is connected to the liquid gallium through a platinum wire sleeved with a tetrafluoro tube). The counter electrode is a graphite electrode with a diameter of 5 mm and a height of 90 mm, and the auxiliary electrode is a silver / saturated calomel electrode. Before using the electrodes, the platinum wire electrode and the graphite electrode need to be polished. After polishing, ultrasonically clean them with absolute ethanol for 10 min, take them out and then ultrasonically clean them with deionized water for 10 min. After the electrode device is dried, it can be loaded and used. Conduct the electrodeposition reaction under precisely controlled electrochemical conditions. The deposition temperature is 80 °C, the working voltage is -5 V, and the current density is 23.3 A / dm After depositing for 4 h under this three-electrode system, take the electrodeposited liquid metal gallium electrode, add 20 mL of acetone, and ultrasonically clean it 3 times, with each cleaning time being 5 minutes to ensure the removal of the residual deep eutectic solvent on the surface. Subsequently, immerse the cleaned liquid metal gallium electrode in an absolute ethanol bath and freeze it at -20 °C for 12 h to make the deposited silicon product easier to separate. After freezing, gently scrape the silicon film with a polytetrafluoroethylene spatula and collect it. Finally, put the silicon product into a sample bag for storage to ensure its stability at low temperature. 2

[0052] As mentioned above, the present invention innovatively combines the deep eutectic solvent with the liquid metal gallium electrode, and proposes an efficient electrochemical reduction and silicon deposition method for the recovery and conversion of silicon tetrachloride. By optimizing the ratio of the deep eutectic solvent and the electrochemical parameters, the present invention can efficiently deposit crystalline silicon, significantly improving the purity and quality of the deposited product. This method not only provides a green and sustainable solution, but also opens up a new technical path for the efficient recovery and resource utilization of silicon by-products, and has broad application prospects and significant economic and environmental benefits.​

Claims

1. A method for electroplating and recovering silicon tetrachloride, a by-product of the silicon industry, based on a gallium electrode, characterized in that, It uses 1,3-dimethyl-2-imidazolidinone and 1,3-dimethylurea to form a deep eutectic solvent. The deep eutectic solvent system that has absorbed silicon tetrachloride is used as the electrolyte, and liquid metal gallium is used as the working electrode. A three-electrode system is used for the potentiostatic electrodeposition reaction. The electrodeposited product is washed and separated to obtain crystalline silicon.

2. The method according to claim 1, wherein The molar ratio of 1,3-dimethyl-2-imidazolidinone to 1,3-dimethylurea is 2:1 to 2.5:

1.

3. The method according to claim 1, wherein When preparing the electrolyte, at a temperature of 60 - 100 °C, the deep eutectic solvent system is used to absorb silicon tetrachloride, and the amount of silicon tetrachloride dissolved in every 100 g of the deep eutectic solvent is between 8 g and 16.5 g.

4. The method according to claim 1, wherein The deep eutectic solvent system that has absorbed silicon tetrachloride is used as the electrolyte after being pretreated by drying.

5. The method according to claim 1, characterized in that, In the three-electrode system, the counter electrode is a graphite electrode, and the auxiliary electrode is a silver / saturated silver chloride electrode.

6. The method according to claim 1, characterized in that, During the electrodeposition reaction, the electrodeposition temperature is 80 - 100 °C, the working voltage is -3 V to -5 V, and the deposition time is 2 - 4 h.

7. The method according to claim 1, wherein The electrodeposited product is washed with acetone to wash away the deep eutectic solvent remaining on the surface of the liquid metal gallium.

8. The method according to claim 1, wherein The separation method is as follows: The washed liquid metal gallium is immersed in an anhydrous ethanol bath and frozen at -20 °C for 10 - 20 h, and then the silicon product is scraped off using a polytetrafluoroethylene spatula.

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