Preparation method of high-purity vanadium trioxide
By using a glucose-montmorillonite hydrothermal carbon composite material and a mixed reducing agent of graphene, the problem of preparing high-purity vanadium trioxide in the existing technology has been solved, and the preparation of high-purity and fine-particle-size vanadium trioxide has been achieved, overcoming the safety and equipment problems of traditional methods.
Patent Information
- Application Number
- CN202511268769.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-06
- Publication Date
- 2026-01-13
AI Technical Summary
Existing technologies make it difficult to prepare high-purity vanadium trioxide, and traditional reduction methods have safety hazards or high equipment requirements, making it difficult to achieve an efficient and environmentally friendly reduction process.
High-purity vanadium trioxide was prepared by using glucose-montmorillonite hydrothermal carbon composite material and graphene as a mixed reducing agent, and vanadium pentoxide was treated by hydrothermal reaction and calcination. The glucose-montmorillonite hydrothermal carbon composite material was used as a reducing agent and graphene activator to improve the reduction effect.
The preparation of vanadium trioxide with high purity (≥99.99%) and fine particle size (20-80nm) has been achieved, avoiding the safety hazards and equipment requirements of traditional methods, and improving the reduction efficiency and product purity.
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of vanadium chemical metallurgy, and particularly relates to a preparation method of high-purity vanadium trioxide. BACKGROUND
[0002] Vanadium trioxide, chemical formula: V2O3, as a typical phase change material, has wide application in the fields of thermal sensitive material, nonlinear resistance material, electrocaloric display material, etc. because the phase change process is accompanied by sudden changes in electrical, optical and magnetic properties. At present, the reduction method includes reduction by adding solid reducing agents (such as sulfur, carbon powder, graphite, etc.) and reduction by reducing gas (such as H2, CO, etc.). The method of adding graphite and carbon as reducing agents has simple production process, but the obtained powder has coarse particles and impure phase, and other low-valence vanadium oxide phases are easily generated. The reduction by H2 or CO has good reduction effect and high product purity, but there are risks of combustion, explosion or toxic gas leakage. The method of preparing vanadium trioxide by decomposing vanadate, in which ammonia gas produced by ammonium vanadate is cracked into H2 and N2 for reduction, is clean and environmentally friendly, and does not need to add any reducing agent. However, the ammonia gas cracking is not complete, the reduction is not sufficient, and the equipment requirement is high. Moreover, it is difficult to obtain high-purity vanadium trioxide by using the above methods. SUMMARY
[0003] The technical problem to be solved by the application is to overcome the deficiencies of the prior art, and provide a preparation method of high-purity vanadium trioxide, which has high purity.
[0004] The technical solution adopted by the application to solve the technical problem is a preparation method of high-purity vanadium trioxide, comprising the following steps: (1) preparing a glucose-montmorillonite hydrothermal carbon composite material; The following operations can be specifically used: montmorillonite is acidified with dilute hydrochloric acid for more than 24 hours, and then repeatedly washed with ultrapure water to wash the pH value of the acidified montmorillonite to near neutral, and then dried (preferably dried in a 105℃ oven for 24 hours), ground through a 100 mesh sieve and reserved; a certain amount of glucose is weighed, added to pure water and stirred to dissolve, then a certain amount of treated montmorillonite is weighed and added to the glucose solution, and then continuously stirred for more than 30 minutes to fully mix; the mass ratio of glucose to treated montmorillonite is 1:2-4. The mixed solution of glucose and montmorillonite is continuously reacted at 140℃-180℃ for more than 10 hours, and after complete cooling, solid-liquid separation is performed, the obtained solid material is washed with ultrapure water for more than 3 times, and then washed with anhydrous ethanol for more than 2 times, and the obtained black solid powder is dried (preferably dried at 105℃ for 24 hours); after grinding, the glucose-montmorillonite hydrothermal carbon composite material is obtained by passing through a 100 mesh sieve.
[0005] (2) mixing the vanadium pentoxide powder, graphene and the glucose-montmorillonite hydrothermal carbon composite material obtained in step (1) to react for 1-3 hours under stirring at 600-800 DEG C, then adding water to dissolve the mixture under stirring, and then filtering to remove the insoluble substances to obtain a precursor solution; The research shows that the glucose-montmorillonite hydrothermal carbon composite material and the graphene are used as the mixed reducing agent; on one hand, the glucose-montmorillonite hydrothermal carbon composite material itself can reduce the vanadium pentoxide; on the other hand, the glucose-montmorillonite hydrothermal carbon composite material is an activator or catalyst of the graphene, and can improve the reduction capacity of the graphene on the vanadium pentoxide; the mixture of the two can quickly reduce the vanadium pentoxide, and can improve the reaction degree of the vanadium pentoxide and the purity of the obtained vanadium trioxide.
[0006] (3) adding ammonia water to the precursor solution obtained in step (2) to react under stirring to produce a precipitate; until no precipitate is produced, at this time, the reaction is completed, and the pH value of the solution is 8-10; filtering and taking the precipitate.
[0007] (4) drying the precipitate obtained in step (3) to obtain a precursor; and calcining the precursor in an inert atmosphere at a temperature of 500-600 DEG C for 1-3 hours to obtain high-purity vanadium trioxide.
[0008] Further, in step (2), the purity of the vanadium pentoxide powder is ≥98%.
[0009] Further, in step (2), the mass ratio of the vanadium pentoxide powder, the graphene and the glucose-montmorillonite hydrothermal carbon composite material obtained in step (1) is 1:0.5-5:0.5-5 (preferably 1:1-2:1-2).
[0010] Further, in step (3), the mass concentration of the ammonia water is preferably 12-18%.
[0011] Further, in step (4), the inert atmosphere is argon or nitrogen.
[0012] The purity of the vanadium trioxide obtained in the application is ≥99.99%, and the particle size is 20-80 nm.
[0013] The glucose-montmorillonite hydrothermal carbon composite material and the graphene are used as the mixed reducing agent; on one hand, the glucose-montmorillonite hydrothermal carbon composite material itself can reduce the vanadium pentoxide; on the other hand, the glucose-montmorillonite hydrothermal carbon composite material is an activator or catalyst of the graphene, and can improve the reduction capacity of the graphene on the vanadium pentoxide; the mixture of the two can quickly reduce the vanadium pentoxide, and can improve the reaction degree of the vanadium pentoxide and the purity of the obtained vanadium trioxide. DETAILED DESCRIPTION
[0014] The present invention will be further described in detail below with reference to specific embodiments. Example 1
[0015] The preparation method of high-purity vanadium trioxide in this embodiment includes the following steps: (1) Preparation of glucose-montmorillonite hydrothermal carbon composite material; The specific steps are as follows: Montmorillonite is acidified with dilute hydrochloric acid for 24 hours, then repeatedly washed with ultrapure water until the pH of the acidified montmorillonite is near neutral. It is then dried (in an oven at 105℃ for 24 hours), ground, and sieved through a 100-mesh sieve for later use. A certain mass of glucose is weighed, dissolved in pure water, and then a certain mass of the treated montmorillonite is weighed and added to the glucose solution. The mixture is stirred for 30 minutes to ensure thorough mixing. The mass ratio of glucose to treated montmorillonite is 1:2. The glucose and montmorillonite mixture is reacted at 140℃ for 10 hours. After complete cooling, the solid and liquid are separated. The resulting solid material is washed three times with ultrapure water and twice with anhydrous ethanol. The resulting black solid powder is dried (at 105℃ for 24 hours). After grinding, it is sieved through a 100-mesh sieve to obtain the glucose-montmorillonite hydrothermal carbon composite material.
[0016] (2) Mix vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1), stir at 600°C for 3 hours, add water and stir to dissolve, then filter to remove insoluble matter to obtain precursor solution; In step (2), the purity of the vanadium pentoxide powder is 98%.
[0017] In step (2), the mass ratio of vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1) is 1:1:1.
[0018] (3) Add ammonia to the precursor solution obtained in step (2), stir and react to produce a precipitate; until no precipitate is produced, this is the reaction endpoint, and the pH of the solution is 8; filter and take the precipitate; In step (3), the mass concentration of ammonia is 12%.
[0019] (4) Dry the precipitate obtained in step (3) to obtain the precursor; calcine the precursor in an inert atmosphere at a temperature of 500°C for 2 hours to obtain high-purity vanadium trioxide.
[0020] In step (4), the inert atmosphere is argon.
[0021] The vanadium trioxide obtained by this invention has a purity of 99.993% and a particle size of 20–80 nm. Example 2
[0022] The preparation method of high-purity vanadium trioxide in this embodiment includes the following steps: (1) Preparation of glucose-montmorillonite hydrothermal carbon composite material; The specific steps are as follows: Montmorillonite is acidified with dilute hydrochloric acid for 24 hours, then repeatedly washed with ultrapure water until the pH of the acidified montmorillonite is near neutral. It is then dried (in an oven at 105℃ for 24 hours), ground, and sieved through a 100-mesh sieve for later use. A certain mass of glucose is weighed, dissolved in pure water, and then a certain mass of the treated montmorillonite is weighed and added to the glucose solution. The mixture is stirred continuously for 30 minutes to ensure thorough mixing. The mass ratio of glucose to treated montmorillonite is 1:4. The glucose and montmorillonite mixture is reacted at 180℃ for 12 hours. After complete cooling, the solid and liquid are separated. The resulting solid material is washed with ultrapure water at least three times, then with anhydrous ethanol at least twice. The resulting black solid powder is dried (at 105℃ for 24 hours). After grinding, it is sieved through a 100-mesh sieve to obtain the glucose-montmorillonite hydrothermal carbon composite material.
[0023] (2) Mix vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1), stir at 800°C for 1 hour, add water and stir to dissolve, then filter to remove insoluble matter to obtain precursor solution. In step (2), the purity of the vanadium pentoxide powder is 98%.
[0024] In step (2), the mass ratio of vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1) is 1:2:2.
[0025] (3) Add ammonia to the precursor solution obtained in step (2), stir and react to produce a precipitate; until no precipitate is produced, this is the reaction endpoint, and the pH of the solution is 10; filter and take the precipitate; In step (3), the mass concentration of ammonia is 18%.
[0026] (4) Dry the precipitate obtained in step (3) to obtain the precursor; calcine the precursor in an inert atmosphere at a temperature of 600°C for 1 hour to obtain high-purity vanadium trioxide.
[0027] In step (4), the inert atmosphere is nitrogen.
[0028] The vanadium trioxide obtained by this invention has a purity of 99.991% and a particle size of 20–80 nm. Example 3
[0029] The preparation method of high-purity vanadium trioxide in this embodiment includes the following steps: (1) Preparation of glucose-montmorillonite hydrothermal carbon composite material; The specific steps are as follows: Montmorillonite is acidified with dilute hydrochloric acid for 24 hours, then repeatedly washed with ultrapure water until the pH of the acidified montmorillonite is near neutral. It is then dried (in an oven at 105℃ for 24 hours), ground, and sieved through a 100-mesh sieve for later use. A certain mass of glucose is weighed, dissolved in pure water, and then a certain mass of the treated montmorillonite is weighed and added to the glucose solution. The mixture is stirred continuously for at least 30 minutes to ensure thorough mixing. The mass ratio of glucose to treated montmorillonite is 1:3. The glucose and montmorillonite mixture is reacted at 160℃ for 10 hours. After complete cooling, the solid and liquid are separated. The resulting solid material is washed three times with ultrapure water and twice with anhydrous ethanol. The resulting black solid powder is dried (at 105℃ for 24 hours). After grinding, it is sieved through a 100-mesh sieve to obtain the glucose-montmorillonite hydrothermal carbon composite material.
[0030] (2) Mix vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1), stir at 700°C for 2 hours, add water and stir to dissolve, then filter to remove insoluble matter to obtain precursor solution; In step (2), the purity of the vanadium pentoxide powder is 98%.
[0031] In step (2), the mass ratio of vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1) is 1:0.5:5.
[0032] (3) Add ammonia to the precursor solution obtained in step (2), stir and react to produce a precipitate; until no precipitate is produced, this is the reaction endpoint, and the pH of the solution is 10; filter and take the precipitate; In step (3), the mass concentration of ammonia is 18%.
[0033] (4) Dry the precipitate obtained in step (3) to obtain the precursor; calcine the precursor in an inert atmosphere at a temperature of 600°C for 2 hours to obtain high-purity vanadium trioxide.
[0034] In step (4), the inert atmosphere is argon.
[0035] The vanadium trioxide obtained by this invention has a purity of 99.992% and a particle size of 20–80 nm.
[0036] Comparative Example 1 In this comparative example, in step (1), when preparing the glucose-montmorillonite hydrothermal carbon composite material, the same mass of glucose and montmorillonite as in step (1) of Example 1 were directly mixed and reacted at 140°C for 10 hours. After grinding, the mixture was passed through a 100-mesh sieve to obtain the glucose-montmorillonite hydrothermal carbon composite material.
[0037] The other steps and operations are the same as in Example 1.
[0038] The vanadium trioxide obtained in this comparative example had a purity of 96.7%. Its particle size ranged from 400 to 1000 nm, exhibiting an uneven particle size distribution. This demonstrates that only by employing a specific method to prepare the glucose-montmorillonite hydrothermal carbon composite material can a good reduction effect be achieved.
[0039] Comparative Example 2 In this comparative example, no graphene was added in step (2), and the other steps and operations were the same as in Example 1.
[0040] The vanadium trioxide obtained in this comparative example has a purity of 97.2%. Its particle size ranges from 500 to 1200 nm, and the particle size distribution is non-uniform.
[0041] Comparative Example 3 In this comparative example, step (2) involves stirring the reaction at 500°C, while the other steps and operations are the same as in Example 1.
[0042] The purity of vanadium trioxide obtained in this comparative example was 47.2%. This indicates that the reaction temperature was too low, resulting in an incomplete reaction.
[0043] Comparative Example 4 In this comparative example, in step (2), the reaction was stirred at 500°C for 10 hours, and the other steps and operations were the same as in Example 1.
[0044] The purity of vanadium trioxide obtained in this comparative example was 67.2%. This shows that the reaction was incomplete due to the low reaction temperature. Even extending the reaction time did not guarantee a complete reaction.
[0045] Comparative Example 5 In this comparative example, step (2) involves stirring the reaction at 900°C, while the other steps and operations are the same as in Example 1.
[0046] The purity of vanadium trioxide obtained in this comparative example is 99.97%. Its particle size is 20-200 nm. It can be seen that excessively high reaction temperature does not have a positive impact on the purity of vanadium trioxide, but rather reduces its purity. This may be because overheating at high temperatures causes some hydrothermal carbon materials to agglomerate, thus affecting their reduction performance.
Claims
1. A method for preparing high-purity vanadium trioxide, characterized in that, Includes the following steps: (1) Preparation of glucose-montmorillonite hydrothermal carbon composite material; The specific steps are as follows: Montmorillonite is acidified with dilute hydrochloric acid for more than 24 hours, then repeatedly washed with ultrapure water until the pH value of the acidified montmorillonite is near neutral. It is then dried, ground, and passed through a 100-mesh sieve for later use. A certain mass of glucose is weighed, dissolved in pure water, and then a certain mass of the treated montmorillonite is weighed and added to the glucose solution. The mixture is stirred continuously for more than 30 minutes to ensure thorough mixing. The mass ratio of glucose to treated montmorillonite is 1:2–4. The glucose and montmorillonite mixture is reacted at 140℃–180℃ for more than 10 hours. After complete cooling, the solid and liquid are separated. The resulting solid material is washed with ultrapure water more than 3 times, then washed with anhydrous ethanol more than 2 times. The resulting black solid powder is dried and ground, then passed through a 100-mesh sieve to obtain the glucose-montmorillonite hydrothermal carbon composite material. (2) Mix vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1), stir and react at 600-800℃ for 1-3 hours, add water and stir to dissolve after reaction, then filter to remove insoluble matter to obtain precursor solution; (3) Add ammonia to the precursor solution obtained in step (2), stir and react to produce a precipitate; until no precipitate is produced, this is the reaction endpoint, and the pH of the solution is 8-10; filter and take the precipitate; (4) Dry the precipitate obtained in step (3) to obtain the precursor; calcine the precursor in an inert atmosphere at a temperature of 500-600℃ for 1-3 hours to obtain high-purity vanadium trioxide.
2. The method for preparing high-purity vanadium trioxide according to claim 1, characterized in that, In step (1), the pH of the acidified montmorillonite is washed to near neutral and then dried in an oven at 105°C for 24 hours.
3. The method for preparing high-purity vanadium trioxide according to claim 1 or 2, characterized in that, In step (1), the obtained black solid powder is baked at 105°C for 24 hours.
4. The method for preparing high-purity vanadium trioxide according to claim 1 or 2, characterized in that, In step (2), the purity of the vanadium pentoxide powder is ≥98%.
5. The method for preparing high-purity vanadium trioxide according to claim 1 or 2, characterized in that, In step (2), the mass ratio of vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1) is 1:0.5~5:0.5~5.
6. The method for preparing high-purity vanadium trioxide according to claim 5, characterized in that, In step (2), the mass ratio of vanadium pentoxide powder, graphene, and glucose-montmorillonite hydrothermal carbon composite material obtained in step (1) is 1:1 to 2:1 to 2.
7. The method for preparing high-purity vanadium trioxide according to claim 1 or 2, characterized in that, In step (3), the mass concentration of ammonia water is 12-18%.
8. The method for preparing high-purity vanadium trioxide according to claim 1 or 2, characterized in that, In step (4), the inert atmosphere is argon or nitrogen.