CN1277749C - Process for preparing rutile phase titanium dioxide nano-powder - Google Patents

Abstract

The invention relates to a preparation method of rutile phase titanium dioxide nanopowder, comprising the following steps: preparing titanium tetrachloride raw material into hydrosol, diluting the hydrosol with water after being aged, and then heating to hydrolyze the sol and produce precipitation, and dissolving the obtained The precipitate is filtered, washed with water and then dried to obtain the rutile phase titanium dioxide nanopowder. The advantages of the preparation technology of the rutile-phase titanium dioxide nano-powder according to the present invention are mainly reflected in: 1. The crystal structure of the nano-powder particles is all rutile phase; 2. The nano-powder particles are uniform, have good dispersibility, and have a high degree of crystallization; 3. Only titanium tetrachloride is used as the precursor, and no other reagents and seeds need to be added; 4. The yield is high, the cost is low, the process is relatively easy to control, and it is convenient for scale-up experiments; 5. The requirements for equipment are not high, suitable for in industrial production.

Description

A kind of preparation method of rutile phase titanium dioxide nanopowder

(1) Technical field

The invention relates to a preparation method of rutile phase titanium dioxide nano powder.

(2) Background technology

Titanium dioxide has three main crystal structures: brookite, anatase and rutile. Among them, rutile is a thermodynamically stable structure, which has a large dielectric constant, a high refractive index, a strong ultraviolet absorption rate and a strong crushing resistance. Due to its superior physical and chemical properties, nano rutile can be widely used in pigments, cosmetics, fine ceramics, environmental purification photocatalysis, catalyst supports and dielectric materials. Before the present invention, the preparation method of pure nanometer rutile at home and abroad is various, and each method all exists in one way or another deficiency to varying degrees. Representative methods are:

1. Traditional methods. That is, amorphous TiO ₂ or anatase TiO ₂ is calcined at a high temperature above 450°C to transform it into rutile. Although it is possible to obtain rutile particles in the range of nanometer particle size in this way, in the process of calcination, it is bound to be accompanied by agglomeration, grain growth, and reduction of specific surface area, which affects its physical and chemical properties to a certain extent, and then affects its performance in the calcination process. practical application.

2. Low-temperature hydrolysis and lipification. In this method, TiCl ₄ is hydrolyzed below 40°C, followed by lipidation for a period of time to obtain nanometer rutile particles. Low-temperature hydrolysis of TiCl ₄ can obtain rutile crystal nuclei, thereby preparing nanoparticles with finer particle size. However, when using this method to prepare nano-rutile powder, the production cost is too high because of its low yield.

3. Hydrolysis method. In this method, TiCl ₄ is hydrolyzed at different temperatures. When the hydrolysis temperature is lower than 40°C, although nano-rutile powder with a single crystal phase composition can be prepared, the yield of TiO ₂ is less than 80%; when the hydrolysis temperature of TiCl ₄ rises to 60°C and 95°C, the yield of TiO ₂ The rates rose to 84.5% and 88.9%, respectively. However, as the yield increased, the TiO ₂ nanopowders changed from a single rutile phase to a mixed phase of rutile and anatase.

4. Seed hydrolysis method. In order to increase the yield of rutile in the low-temperature hydrolysis method and reduce the production cost, a small amount of nanometer rutile seeds are added during the hydrolysis of TiCl ₄ . Although this method can increase the yield of nano-rutile, adding nano-rutile will increase the production cost, and when the hydrolysis temperature reaches 95°C, the yield of _TiO2 reaches 95.6%, and the obtained nano-titanium dioxide powder is rutile The mixture of rutile and anatase cannot obtain pure nano-rutile powder.

5. Hydrothermal method. The method is to first prepare TiCl ₄ and other raw materials into an aqueous solution of appropriate concentration, then transfer it to a high-pressure reactor, and react under a sealed condition above 150°C to prepare nano-rutile powder. Although this method can prepare pure rutile nanoparticles with different particle sizes and shapes by controlling the reaction conditions, it has high requirements for equipment, is difficult to carry out scale-up experiments, and is not conducive to industrial production.

6. Solvothermal method. This method is similar to method 4, except that raw materials such as TiCl ₄ are formulated into non-aqueous solutions or other solutions containing certain water. Although the particle size and shape of nano-rutile can be controlled by controlling the type and concentration of the solvent, this method not only has high requirements for equipment, but also has high requirements for solvents. This not only increases the production cost, but also is unfavorable for industrialized production.

(3) Contents of the invention

The purpose of the present invention is to provide a method for preparing rutile phase titanium dioxide nanopowder with high yield, low cost and easy process control.

For realizing the object of the present invention, the technical scheme adopted in the present invention is as follows:

A method for preparing titanium dioxide nano-powder in rutile phase, comprising the following steps: preparing titanium tetrachloride as a raw material into a hydrosol, diluting the hydrosol with water after aging, reheating to hydrolyze the sol and produce precipitation, and filtering the obtained precipitate , washed with water and then dried to obtain rutile phase titanium dioxide nanopowder.

The preparation method of the rutile phase titanium dioxide nanopowder is specifically carried out as follows:

(A) According to the volume ratio of titanium tetrachloride and pure water of 1:1-4, titanium tetrachloride is added dropwise into pure water at 0-40°C, and fully stirred to prepare a light yellow-green sol;

(B) Place the sol prepared in step (A) for 2 hours to 15 days to age, then dilute the sol to pure water at a volume ratio of 1:1 to 4, add water dropwise to the sol at 0 to 40°C, and fully Stir to prepare a colorless transparent solution, then adjust the temperature of the solution to 40-60°C and stir for 0.5-3 hours;

(C) keep stirring while raising the temperature of the system to 65-100° C., keep warm and stir and reflux for 0.5-4 hours to generate precipitation;

(D) Filtrating the obtained precipitate, washing and drying with water to obtain rutile phase titanium dioxide nanopowder.

The preparation method of the above rutile phase titanium dioxide nanopowder: in the step (A), the volume ratio of titanium tetrachloride to water is 1:1.5-2.5, and the stirring temperature is 0-20°C. More preferably, the volume ratio of titanium tetrachloride and water is 1:2, and the stirring temperature is 0-5°C.

Further, in the step (B), the aging time of the sol is 8 to 60 hours, and then according to the volume ratio of the sol to water 1:1.5 to 2.5, water is added dropwise to the sol at 0 to 20°C, and fully stirred to prepare It is a colorless transparent solution, and the resulting solution is stirred at 40-60°C for 1-3 hours. In the step (B), it is more preferable to place the sol for 12-48 hours for aging, add water dropwise to the sol at 0-10°C at a volume ratio of 1:2 between the sol and water, and stir thoroughly to form a colorless and transparent solution , and the resulting solution was stirred at 40-60° C. for 0.5-2 hours.

Still further, the preparation method of rutile phase titanium dioxide nanopowder, the step (C) is carried out as follows: keep stirring while raising the temperature of the system to 90-100° C., keep warm, stir and reflux for 1-3 hours, and precipitate. Most preferably, the step (C) is carried out as follows: keep stirring while raising the temperature of the system to 95° C., keep warm, stir and reflux for 2 hours, and precipitate.

Furthermore, the preparation method of the rutile phase titanium dioxide nanopowder recommended by the present invention is carried out as follows:

(A) According to the volume ratio of titanium tetrachloride and pure water 1:2, titanium tetrachloride is added dropwise into pure water at 0-40°C, fully stirred to prepare a light yellow-green sol; the pure water is Deionized or distilled water;

(B) After aging the sol prepared in step (A) for 12 hours to 48 hours, add water dropwise to the sol at 0-40°C according to the volume ratio of sol to pure water 1:2, and stir thoroughly to prepare Colorless and transparent solution; the obtained solution was kept stirring at 40°C for 0.5-1 hour, then the system was heated to 60°C, and kept stirring for 0.5-1 hour;

(C) Keep stirring while raising the temperature of the system to 95°C, keep warm and stir and reflux for 2 hours, and precipitate;

(D) Filtrate the obtained precipitate, wash with water, and dry to obtain rutile phase titanium dioxide nanopowder.

The advantages of the preparation technology of the rutile phase titanium dioxide nanopowder according to the present invention are mainly reflected in:

1. The crystal structure of nano powder particles is rutile phase;

2. The nano-powder has uniform particles, good dispersion and high degree of crystallization;

3. Only use titanium tetrachloride as the precursor, no need to add any other reagents and crystal seeds;

4. The yield is high, the cost is low, the process is relatively easy to control, and it is convenient for scale-up experiments;

5. The requirements for equipment are not high, and it is suitable for industrial production;

(4) Description of drawings

Fig. 1 is a process flow chart for preparing the rutile phase titanium dioxide nanopowder according to the present invention.

Fig. 2 is the X-ray diffraction (XRD) figure of titanium dioxide nanopowder made in embodiment 1.

3 is a transmission electron microscope (TEM) photo of titanium dioxide nanopowders prepared in Example 1.

(5) Specific implementation methods

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

Example 1

(1) Fix a three-necked bottle with a capacity of 500mL in an ice-water bath, take 200mL of pure water (H ₂ O) and put it into the three-necked bottle; install a condenser tube on the middle port of the three-necked bottle, and use tap water to condense; Install a junction thermometer on the mouth of the three-necked flask to monitor and control the temperature of the reaction system; get TiCl _100mL into a dry constant-pressure separating funnel, and install the constant-pressure separating funnel on the other side of the three-necked flask; Under the condition of ice-water bath cooling, open the switch of the constant pressure separatory funnel, slowly drop the titanium tetrachloride solution into pure water, and control the temperature of the whole dropping and mixing process at 20°C by controlling the dropping speed and the temperature of the ice-water bath Left and right; with the addition of titanium tetrachloride, the color of the system gradually changes, from colorless and transparent to light yellow-green, the viscosity of the system also gradually increases, and changes from solution to colloidal state, after the addition of titanium tetrachloride is completed After that, continue to stir for another 2 hours. At this time, the mixed system is a light yellow-green sol, which is cooled to room temperature and placed for aging;

(2) After placing the titanium tetrachloride aqueous sol for 12 hours, take 100mL of the above-mentioned sol and pack it into a 500mL three-necked bottle, and fix the three-necked bottle in a water bath; install a condenser tube on the middle port of the three-necked bottle, and use tap water to condense; Install a junction thermometer on one port of the three-necked bottle to monitor and control the temperature of the reaction system; take 200 mL of H ₂ O into a dry constant-pressure separating funnel, and install the constant-pressure separating funnel on the other side port of the three-necked bottle ; Under the conditions of magnetic stirring and ice-water bath cooling, open the switch of the constant pressure separatory funnel, slowly drop water into pure water, and make the temperature of the whole dropping and mixing process be controlled at 30°C by controlling the rate of addition and the temperature of the ice-water bath. ℃; with the addition of pure water, the mixed system gradually changes from light yellow-green to colorless and transparent, and continues to stir for 30 minutes after the addition of pure water;

(3) Slowly raise the temperature of the system to 40°C, and stabilize it at 40°C, and continue to stir for 1 hour. At this time, the color of the system is colorless and transparent; while stirring, raise the temperature of the system to 60°C, and stabilize it at 60°C. And continue to stir again 1 hour, the color of this moment system is still colorless and transparent;

(4) Raise the temperature of the system to 95°C. As the temperature rises, the system quickly changes from a colorless and transparent solution to a milky white turbid liquid. Keep the temperature of the system at 95°C and keep stirring. The prolongation of time will produce a large amount of sediment, keep warm and stir for 2 hours, filter the sediment, rinse with pure water, and then dry to get pure rutile nanopowder, its crystal phase composition is shown in Figure 2, its particle size and shape As shown in Figure 3.

Example 2

(1) Using the device described in step (1) in Example 1, get pure water (H ₂ O) 300mL into a three-necked bottle; get TiCl _100mL into a dry constant pressure separatory funnel; Under the conditions of stirring and ice-water bath cooling, open the switch of the constant pressure separatory funnel, slowly drop the titanium tetrachloride solution into pure water, and control the temperature of the whole dropping and mixing process at About 5°C; after the addition of titanium tetrachloride is completed, continue to stir for 2 hours. At this time, the mixed system is a light yellow-green sol. Cool it to room temperature and place it;

(2) Using the device described in step (2) in Example 1, after placing the titanium tetrachloride hydrosol for 50 hours, take 100mL of the above-mentioned sol and pack it into a 500mL three-necked bottle; take H ₂ O300mL and put it into a dry Inside the constant pressure separatory funnel; under the conditions of magnetic stirring and ice-water bath cooling, turn on the switch of the constant pressure separatory funnel, slowly drop the water into the pure water, and make the whole dropping and mixing by controlling the dropping speed and the temperature of the ice-water bath The temperature of the process is controlled at about 10°C; with the addition of pure water, the mixed system gradually changes from light yellow-green to colorless and transparent, and the stirring is continued for 30 minutes after the addition is completed;

(3) Slowly raise the temperature of the system to 40°C, and stabilize at 40°C, and continue to stir for 1 hour. At this time, the color of the system is colorless and transparent; while stirring, raise the temperature of the system to 50°C, and stabilize at 50°C. And continue to stir again 1 hour, the color of this moment system is still colorless and transparent;

(4) Raise the temperature of the system to 90°C. As the temperature rises, the system quickly changes from a colorless and transparent solution to a milky white turbid liquid. Keep the system temperature at 90°C and keep stirring. The prolongation of time produces a large amount of precipitates. After the temperature is stabilized and stirred for 4 hours, the precipitates are filtered, rinsed with pure water, and then dried to obtain pure rutile nanopowder.

Example 3

(1) Using the device described in step (1) in Example 1, get pure water (H ₂ O) 100mL into a three-necked bottle; get TiCl _100mL into a dry constant pressure separatory funnel; Under the conditions of stirring and ice-water bath cooling, open the switch of the constant pressure separatory funnel, slowly drop the titanium tetrachloride solution into pure water, and control the temperature of the whole dropping and mixing process at About 30°C; after the addition of titanium tetrachloride is completed, continue to stir for 2 hours. At this time, the mixed system is a light yellow-green sol. Cool it to room temperature and place it;

(2) Using the device described in step (2) in Example 1, after placing the titanium tetrachloride aqueous sol for 30 hours, take 100mL of the above-mentioned sol and pack it into a 500mL three-necked bottle; take H ₂ O350mL and put it into a dry Inside the constant pressure separatory funnel; under the conditions of magnetic stirring and ice-water bath cooling, turn on the switch of the constant pressure separatory funnel, slowly drop the water into the pure water, and make the whole dropping and mixing by controlling the dropping speed and the temperature of the ice-water bath The temperature of the process is controlled at about 35°C; with the addition of pure water, the mixed system gradually changes from light yellow-green to colorless and transparent, and the stirring is continued for 30 minutes after the addition is completed;

(3) Slowly raise the temperature of the system to 45°C, and stabilize it at 45°C, and continue to stir for 1.5 hours. At this time, the color of the system is colorless and transparent; while stirring, raise the temperature of the system to 55°C, and stabilize it at 55°C. And continue to stir again 1 hour, the color of this moment system is still colorless and transparent;

(4) Raise the temperature of the system to 97°C. As the temperature rises, the system will quickly change from a colorless and transparent solution to a milky white turbid liquid. Keep the system temperature at 97°C and continue to stir. The prolongation of time produces a large amount of precipitates. After the temperature is stabilized and stirred for 1.5 hours, the precipitates are filtered, rinsed with pure water, and then dried to obtain pure rutile nanopowder.

Claims (10)

1, a kind of preparation method of rutile phase titanium dioxide nano-powder, it is characterized in that comprising the steps: the titanium tetrachloride raw material is mixed with water sol, water sol is diluted with water after aging, reheating makes sol hydrolyze and produces precipitation, The obtained precipitate is filtered, washed with water and then dried to obtain rutile phase titanium dioxide nanopowder. 2. The method for preparing the rutile phase titanium dioxide nano-powder according to claim 1, characterized in that it is carried out as follows: (A) According to the volume ratio of titanium tetrachloride and pure water of 1:1-4, titanium tetrachloride is added dropwise into pure water at 0-40°C, and fully stirred to form a light yellow-green sol; (B) Place the sol prepared in step (A) for 2 hours to 15 days to age, then dilute the sol to pure water at a volume ratio of 1:1 to 4, add water dropwise to the sol at 0 to 40°C, and fully Stir to make a colorless and transparent solution, then adjust the temperature of the solution to 40-60°C and stir for 0.5-3 hours; (C) keep stirring while raising the temperature of the system to 65-100° C., keep warm and stir and reflux for 0.5-4 hours to generate precipitation; (D) Filtrating the obtained precipitate, washing and drying with water to obtain rutile phase titanium dioxide nanopowder. 3. The preparation method of rutile phase titanium dioxide nanopowder according to claim 2, characterized in that: in the step (A), the volume ratio of titanium tetrachloride to water is 1: 1.5～2.5, and the stirring temperature is 0～20℃. 4. The preparation method of rutile phase titanium dioxide nanopowder according to claim 3, characterized in that: in the step (A), the volume ratio of titanium tetrachloride to water is 1:2, and the stirring temperature is 0～ 5°C. 5. The method for preparing rutile-phase titanium dioxide nanopowder according to claim 2, characterized in that: in the step (B), the sol is aged for 8 to 60 hours, and then the sol and water are 1: 1.5 to 2.5. Volume ratio, water is added dropwise into the sol at 0-20°C, fully stirred to form a colorless transparent solution, and the obtained solution is stirred at 40-60°C for 1-3 hours. 6. The method for preparing rutile-phase titanium dioxide nanopowder according to claim 5, characterized in that: in the step (B), the sol is aged for 12 to 48 hours, and the volume ratio of sol to water is 1:2, Add water dropwise into the sol at 0-10°C, stir well to make a colorless transparent solution, and stir the obtained solution at 40-60°C for 1-2 hours. 7. The method for preparing rutile-phase titanium dioxide nanopowder according to any one of claims 2 to 6, characterized in that the step (C) is carried out as follows: keep stirring while raising the temperature of the system to 90-100°C, keep warm And stirred and refluxed for 1 to 3 hours, and precipitated. 8. The preparation method of rutile phase titanium dioxide nanopowder according to claim 7, characterized in that the step (C) is carried out as follows: keep stirring while raising the temperature of the system to 95 ° C, keep warm and stir and reflux for 2 hours, precipitation. 9. The method for preparing the rutile phase titanium dioxide nanopowder according to claim 2, characterized in that it is carried out as follows: (A) According to the volume ratio of titanium tetrachloride and pure water 1:2, titanium tetrachloride is added dropwise into pure water at 0-40°C, and fully stirred to form a light yellow-green sol; (B) After aging the sol prepared in step (A) for 12-48 hours, add water dropwise to the sol at 0-40°C according to the volume ratio of sol to pure water 1:2, and stir fully to form color transparent solution; the obtained solution was kept stirring at 40°C for 1 hour, then the system was heated to 60°C, and kept stirring for 1 hour; (C) Keep stirring while raising the temperature of the system to 95°C, keep warm and stir and reflux for 2 hours, and precipitate; (D) Filtrate the obtained precipitate, wash with water, and dry to obtain rutile phase titanium dioxide nanopowder. 10. The method for preparing rutile phase titanium dioxide nanopowder according to claim 9, characterized in that said pure water is deionized water.

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