A method for preparing nano-scale high-purity germanium dioxide

Abstract

The present invention belongs to the technical field of preparation of high-purity rare metal materials, and specifically relates to a method for preparing nano-scale high-purity germanium dioxide. High-purity germanium tetrachloride, polyvinyl alcohol solution and water are prepared, mixed and stirred to form a mixed solution, and then germanium dioxide is extracted through a hydrolysis reaction. The generated high-purity germanium dioxide is then strengthened by ultrasonic waves to prepare nano-scale germanium dioxide, thereby obtaining high-purity germanium dioxide with smaller particle size.

Description

Technical Field

[0001] The invention belongs to the technical field of rare metal high-purity material preparation, and in particular relates to a device for preparing nano-level high-purity germanium dioxide. Background Art

[0002] Germanium dioxide (GeO2) is an important oxide of germanium with special chemical properties. The smaller the particle size of nano-scale germanium dioxide, the larger the specific surface area and the stronger the surface activity. Therefore, it has greater application value in some fields. For example, in the field of catalysis, nano-scale germanium dioxide has high catalytic activity. As the particle size decreases, its catalytic performance is improved. In the field of optics, nano-scale germanium dioxide has a high refractive index and extinction coefficient. In the "Lightemission from Ge and GeO 2 The paper "Nanocrystals" mentions that nano-sized germanium dioxide is an excellent blue-light-emitting material, with emission peak energy centers located at 3.1 eV (400 nm) and 2.2 eV (563.6 nm). Its optical properties improve as the particle size decreases. In the biomedical field, nano-sized germanium dioxide has low toxicity and good biocompatibility. As the particle size decreases, its application in fields such as bioimaging, drug delivery, and tumor therapy becomes more effective. In the sensor field, nano-sized germanium dioxide can be used to manufacture highly sensitive gas sensors and humidity sensors. As the particle size decreases, its surface activity increases, allowing it to interact with more gas molecules. In the field of electronic devices, nano-sized germanium dioxide has excellent electrical conductivity. As the particle size decreases, it has potential applications in the manufacture of electronic devices such as field-effect transistors and solar cells. In short, the smaller the particle size of nano-sized germanium dioxide, the more effective its application in fields such as catalysis, optics, biomedicine, sensors, and electronic devices. However, it should be noted that when using germanium dioxide with a small particle size, its purity and stability should be ensured to avoid negative effects.

[0003] To address the technical challenges of preparing nanoscale, high-purity germanium dioxide, Zhu Jing et al. produced GeO2 nanowires with diameters less than 100 nm at atmospheric pressure by heating a mixture of germanium powder, carbon nanotubes, and Si-SiO2, using the carbon nanotubes as templates to restrict GeO2 growth. However, the product contained a small amount of SiO2. Tang Yuanhong et al. used elemental germanium as a target and laser ablation under low vacuum conditions to produce GeO2 nanowires with a proportional diameter and length. Iswanathamurthi et al. prepared polycrystalline GeO2 fibers using germanium isopropoxide by electrospinning and heat treatment. Wu Hongping et al. prepared GeO2 nanocubes using a reverse micelle method in the presence of hexadecyltrimethylammonium bromide and oleylamine. Chemical methods for preparing nano-germanium dioxide offer simpler reactions, lower experimental requirements, and higher yields, but they use expensive raw materials and are complex and difficult to operate. Each of these methods has limitations, making industrial production difficult.

[0004] The patent application number is "201810057038.0", and the patent name is "Method for preparing nano-scale germanium dioxide powder". It discloses a method for preparing nano-scale germanium dioxide, which utilizes the ability of GeO2 to dissolve in alkaline solution and to form GeO3 2- The form exists in the solution and GeO3 2- It is easy to be reduced to GeO in solution; first prepare a certain concentration of GeO3 2- By controlling the drop rate and molar amount of the reducing agent NaBH4 solution, the GeO3 2- It is quickly converted into GeO, nucleates and grows in the solution, and finally a non-hollow structured nano-scale GeO2 powder is obtained by heat treatment in air.

[0005] The above scheme is difficult to industrialize because the product contains some amorphous structure and other components, and the purity is difficult to reach the use requirement of more than 99.999%. It is difficult to develop efficient preparation technology. Summary of the Invention

[0006] In view of the problems existing in the background technology, the present invention provides a method for preparing nano-scale high-purity germanium dioxide.

[0007] To achieve the above objectives, the following technical solution is adopted to prepare nano-scale high-purity germanium dioxide, and the steps are as follows:

[0008] S1: Prepare raw materials by taking 50-500 mL of high-purity germanium tetrachloride; prepare a 5% polyvinyl alcohol solution, and take 0.05-0.10 mL of the 5% polyvinyl alcohol solution and 50 mL of high-purity water, mix and stir to prepare a mixed solution;

[0009] S2: hydrolysis reaction, first adding 100-1000 mL of high-purity water into the hydrolysis reactor, then adding high-purity germanium tetrachloride and the mixed solution into the hydrolysis reactor at a volume ratio of 1:7-21, respectively. The addition rate of high-purity germanium tetrachloride is 1-2 mL / min, and the addition rate of the mixed solution is 7-21 times the addition rate of high-purity germanium tetrachloride. The addition process is fully stirred at a stirring rate of 70-80 r / min, and a jacket is set outside the hydrolysis reactor to ensure that the temperature of the solution in the hydrolysis reactor is controlled at 35-45°C;

[0010] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0011] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0012] S5: Secondary vacuum filtration, the solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0013] S6: Further purification: rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50 mL-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a blast drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0014] The method for preparing nano-scale high-purity germanium dioxide of the present invention has the following advantages:

[0015] By adding the surfactant polyvinyl alcohol to the hydrolysis of high-purity germanium tetrachloride to produce high-purity germanium dioxide, the formation of large germanium dioxide particles and molecular agglomeration are suppressed. The resulting high-purity germanium dioxide is then enhanced with ultrasound to produce nano-scale germanium dioxide, resulting in smaller particles of high-purity germanium dioxide. The addition of the surfactant modifies the molecular interface physical properties, preventing the formation of larger particles. The ultrasound enhancement disperses some of the aggregated molecular clusters, thereby suppressing the formation of large particles of high-purity germanium dioxide. DETAILED DESCRIPTION

[0016] Example 1: The preparation steps are as follows:

[0017] S1: Prepare the raw materials by placing 50 mL of high-purity germanium tetrachloride in a 2000 mL container. Prepare a 5% polyvinyl alcohol solution by dissolving 5 g of polyvinyl alcohol in 10 mL of water and then adding 90 mL of water. After the solution is complete, take 0.05 mL of the 5% polyvinyl alcohol solution and 50 mL of high-purity water, mix and stir to form a mixed solution, and place the mixed solution in another 2000 mL container.

[0018] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and the mixed solution into the hydrolysis reactor at a volume ratio of 1:7. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 7 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0019] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0020] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0021] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0022] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0023] Example 2: The preparation steps are as follows:

[0024] S1: Prepare the raw materials by placing 50 mL of high-purity germanium tetrachloride in a 2000 mL container. Prepare a 5% polyvinyl alcohol solution by dissolving 5 g of polyvinyl alcohol in 10 mL of water and then adding 90 mL of water. After the solution is complete, take 0.05 mL of the 5% polyvinyl alcohol solution and 50 mL of high-purity water, mix and stir to form a mixed solution, and place the mixed solution in another 2000 mL container.

[0025] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and the mixed solution into the hydrolysis reactor at a volume ratio of 1:14. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 14 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0026] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0027] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0028] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0029] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0030] Example 3: The preparation steps are as follows:

[0031] S1: Prepare the raw materials by placing 50 mL of high-purity germanium tetrachloride in a 2000 mL container. Prepare a 5% polyvinyl alcohol solution by dissolving 5 g of polyvinyl alcohol in 10 mL of water and then adding 90 mL of water. After the solution is complete, take 0.05 mL of the 5% polyvinyl alcohol solution and 50 mL of high-purity water, mix and stir to form a mixed solution, and place the mixed solution in another 2000 mL container.

[0032] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and the mixed solution into the hydrolysis reactor at a volume ratio of 1:21. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 21 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0033] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0034] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0035] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0036] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0037] Example 4: The preparation steps are as follows:

[0038] S1: Prepare the raw materials by placing 50 mL of high-purity germanium tetrachloride in a 2000 mL container. Prepare a 5% polyvinyl alcohol solution by dissolving 5 g of polyvinyl alcohol in 10 mL of water and then adding 90 mL of water. After the solution is complete, take 0.05 mL of the 5% polyvinyl alcohol solution and 50 mL of high-purity water, mix and stir to form a mixed solution, and place the mixed solution in another 2000 mL container.

[0039] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and the mixed solution into the hydrolysis reactor at a volume ratio of 1:7. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 7 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0040] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0041] S4: Drying: Dry the high-purity germanium dioxide obtained by filtration and washing in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-grade high-purity germanium dioxide with a purity of 99.999%.

[0042] Implementation Method Example 1 Example 2 Example 3 Example 4 Germanium dioxide particle size 500-600nm 550-630nm 600-650nm 10-50um

[0043] Comparative Example 1: The preparation steps are as follows:

[0044] S1: Prepare raw materials by placing 50 mL of high-purity germanium tetrachloride in a 2000 mL container without adding surfactant.

[0045] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride into the hydrolysis reactor at a rate of 1 mL / min. Stir thoroughly during the addition process at a stirring rate of 70-80 r / min. During the hydrolysis process, the temperature of the solution in the hydrolysis reactor needs to be kept at 40°C.

[0046] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0047] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0048] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0049] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0050] Comparative Example 2: The preparation steps are as follows:

[0051] S1: Prepare raw materials: take 50 mL of high-purity germanium tetrachloride and place it in a 2000 mL container; take anhydrous ethanol and place it in a 2000 mL container;

[0052] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and anhydrous ethanol into the hydrolysis reactor at a volume ratio of 1:7. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 7 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0053] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0054] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0055] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0056] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0057] Comparative Example 3: The preparation steps are as follows:

[0058] S1: Prepare the raw materials: take 50 mL of high-purity germanium tetrachloride and place it in a 2000 mL container; take sodium dodecylbenzenesulfonate and place it in a 2000 mL container;

[0059] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and anhydrous ethanol into the hydrolysis reactor at a volume ratio of 1:7. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 7 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0060] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0061] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0062] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0063] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0064] Comparative Example 4: The preparation steps are as follows:

[0065] S1: Prepare raw materials: take 50 mL of high-purity germanium tetrachloride and place it in a 2000 mL container; take tetra-n-butyl titanate and place it in a 2000 mL container;

[0066] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and anhydrous ethanol into the hydrolysis reactor at a volume ratio of 1:7. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 7 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0067] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0068] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0069] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0070] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0071] Comparative Example 5: The preparation steps are as follows:

[0072] S1: Prepare the raw materials: take 50 mL of high-purity germanium tetrachloride and place it in a 2000 mL container; take polyvinyl alcohol and place it in a 2000 mL container;

[0073] S2: Hydrolysis reaction: first add 100 mL into the hydrolysis reactor, then add high-purity germanium tetrachloride and anhydrous ethanol into the hydrolysis reactor at a volume ratio of 1:7. The addition rate of high-purity germanium tetrachloride is 1 mL / min, and the addition rate of the mixed solution is 7 mL / min. The addition process is fully stirred at a stirring rate of 70-80 r / min. The temperature of the solution in the hydrolysis reactor needs to be kept at about 40°C during the hydrolysis process.

[0074] S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing;

[0075] S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution.

[0076] S5: Secondary vacuum filtration: The solution containing germanium dioxide after ultrasonic treatment is filtered using a vacuum pump to separate high-purity germanium dioxide.

[0077] S6: Further purification: Rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a forced air drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.

[0078] Implementation Method Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Germanium dioxide particle size 74-200um 70-150um 50-120um 40-60 um 10-50 um

[0079] The exploratory experimental results show that the addition of the four surfactants can reduce the particle size of germanium dioxide during hydrolysis. It can be seen that surfactants play a significant role in the preparation of nano-scale high-purity germanium dioxide. Among the four surfactants, polyvinyl alcohol has the best activation and dispersing effect. Therefore, polyvinyl alcohol is selected as the surfactant in the present invention.

Claims

1. A method for preparing nano-scale high-purity germanium dioxide, characterized in that The steps include: S1: Prepare raw materials by taking 50-500 mL of high-purity germanium tetrachloride; prepare a 5% polyvinyl alcohol solution, and take 0.05-0.10 mL of the 5% polyvinyl alcohol solution and 50 mL of high-purity water, mix and stir to prepare a mixed solution; S2: hydrolysis reaction, first adding 100-1000 mL of high-purity water into the hydrolysis reactor, then adding high-purity germanium tetrachloride and the mixed solution into the hydrolysis reactor at a volume ratio of 1:7-21, respectively. The addition rate of high-purity germanium tetrachloride is 1-2 mL / min, and the addition rate of the mixed solution is 7-21 times the addition rate of high-purity germanium tetrachloride. The addition process is fully stirred at a stirring rate of 70-80 r / min, and a jacket is set outside the hydrolysis reactor to ensure that the temperature of the solution in the hydrolysis reactor is controlled at 35-45°C; S3: Extract germanium dioxide, filter the reaction product, and separate the generated germanium dioxide from the hydrolysis mother liquor; rinse the separated germanium dioxide 2-3 times with 20 ℃ high-purity water, using 50-60 mL of water each time, and filter it clean after each washing; S4: Ultrasonic strengthening: The germanium dioxide obtained after filtration and washing is placed in an ultrasonic intensifier and strengthened with ultrasonic waves at a frequency of 50 to 500 kHz for 15 to 30 minutes. The high-frequency vibration of the ultrasonic waves causes large particles to be broken down into small particles and dispersed in the solution. S5: secondary vacuum filtration, filtering the solution containing germanium dioxide after ultrasonic treatment with a vacuum pump to separate high-purity germanium dioxide; S6: Further purification: rinse the separated high-purity germanium dioxide with 20°C high-purity water for 2-3 times, using 50 mL-60 mL of water each time, and filter it clean after each washing; dry the filtered and washed high-purity germanium dioxide in a blast drying oven at 120°C; finally, calcine it in a muffle furnace at 600°C to obtain nano-scale high-purity germanium dioxide with a purity of 99.999%.