CN103318949A - Low temperature solid phase preparation method of indium tin oxide nano particle powder - Google Patents

Abstract

The invention discloses a low-temperature solid-phase preparation method of indium tin oxide nanoparticle powder, which comprises dissolving metal indium with inorganic acid to form an initial solution or dissolving metal salt of indium in water to prepare an initial solution, and then adding tin metal salts to form a mixed solution, and then add a water-soluble inorganic salt to it, then add ammonia water to the mixed solution, and finally generate an indium tin oxide precursor, then dry the reaction system, and obtain a mixed powder after grinding , and then calcining the mixed powder, the calcined product is washed with water to remove inorganic salts, and then dried to finally obtain indium tin oxide nano particle powder. The method can prepare indium tin oxide nanoparticle powder at a lower calcination temperature (300-500°C), which can overcome the problems of high energy consumption and serious particle agglomeration caused by high-temperature calcination treatment, and the operation process is simple, and the raw materials used The price is low, can be recycled, and is suitable for industrial scale production.

Description

A low-temperature solid phase preparation method of indium tin oxide nanoparticle powder

technical field

The invention belongs to the technical field of fine chemicals, and relates to the preparation of indium tin oxide nanoparticle powder, in particular to a low-temperature solid-phase preparation method of indium tin oxide nanoparticle powder.

Background technique

Indium tin oxide (ITO) is a solid solution formed by doping tin oxide (SnO ₂ ) in indium oxide (In ₂ O ₃ ), and it is a highly degenerate and heavily doped semiconductor material. At present, developed countries in the world such as Japan, the United States and other countries use about 90% of indium to prepare ITO materials, which have high infrared light reflectivity (greater than 80%), high ultraviolet light absorption rate (greater than 85%), high It has excellent properties such as electrical conductivity, high hardness, wear resistance, and good chemical etching, and is widely used in solid flat panel displays, solar cells, electromagnetic shielding, transparent conductive materials, and coated glass. In practical applications, indium tin oxide is generally prepared into a film. There are many methods for preparing an indium tin oxide film, but it is necessary to prepare a large-area and high-performance indium tin oxide film. At present, the best method recognized as magnetron sputtering is to form a film by magnetron sputtering. Before forming a film, an indium tin oxide target needs to be prepared. The prepared target requires a high density, because the density of the target not only affects the deposition rate during coating, but also the coating particles. The density and discharge phenomenon of the film will also affect the electrical and optical properties of the film. The currently used magnetron indium tin oxide targets are generally formed by vacuum pressing of indium tin oxide nanopowders. The smaller the particle size of the indium tin oxide nanopowder, the higher the density of the obtained target material, which can increase the deposition rate during the magnetron sputtering film formation process, and the resistivity is more stable, preventing the appearance of black spots. However, if the particle size of indium tin oxide powder is too small, it will easily form agglomeration. Therefore, in order to obtain high-quality ITO ceramic targets, the preparation of ITO nanoparticle powder with small particle size, light agglomeration and good conductivity is the key.

The more common method for preparing indium tin oxide nanoparticle powder is the sol-gel method. The sol-gel method generally uses indium and tin alkoxides as raw materials, forms a sol by hydrolysis, then polymerizes the sol to gel, and then dries and calcines the gel. The prepared powder has good chemical uniformity, fine particles, and agglomeration. Light, but the price of raw materials used is very high, and the preparation process is complicated, so it is not suitable for industrial production. Co-precipitation method is another common method for preparing ITO nanoparticle powder. For example, Chinese patent CN 2005100106666 uses 4N or 5N indium and tin as raw materials, dissolves them with inorganic acid, and then uses ultrasonic precipitation, microwave drying, calcination, or freeze drying, and boiling reflux method to calcine, and the average particle size is 5-5. 10nm indium tin oxide nanoparticle powder. Since metal tin is extremely unstable during the dissolution process, it cannot be completely guaranteed that metal tin dissolves into tetravalent tin ions, thereby affecting the effect of tin doping. Therefore, the indium tin oxide nanoparticle powder prepared by this method is impure. In addition, this method also needs to use ultrasonic precipitation, microwave drying, and calcination, and the experimental operation process is relatively complicated. Chinese patent CN 2011100491885 discloses a method for preparing indium tin oxide nanoparticle powder. This method uses indium, tin metal or soluble indium and tin salts as raw materials to prepare a mixed solution, and adds a dispersant to the mixed solution, and reacts Ultrasonic waves are applied to the system, and after precipitation, filtration, washing, drying and calcination, indium tin oxide nanoparticle powder with good dispersibility is finally prepared. This method requires calcination at a relatively high temperature (600°C). High-temperature calcination not only consumes a lot of energy, but also causes sintering and hard agglomeration of particles; at the same time, this method requires the introduction of a dispersant and requires The initial reaction system is ultrasonically treated, and the reaction process is relatively complicated and difficult to control. Therefore, this method is not conducive to industrialized mass production.

The present invention can prepare indium tin oxide nanoparticle powder at a relatively low calcination temperature (300-500°C), which overcomes the problems of high energy consumption and serious particle agglomeration caused by high-temperature calcination treatment, and the operation process is simple, and the The raw material is cheap, can be recycled, and is suitable for industrial scale production.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and to provide a low-temperature solid-phase preparation method of indium tin oxide nanoparticle powder, which can prepare indium oxide at a relatively low calcination temperature (300-500°C). The tin nanoparticle powder can overcome the problems of high energy consumption and serious particle agglomeration caused by high-temperature calcination, and the operation process is simple, the raw materials used are cheap, can be recycled, and are suitable for industrial scale production.

The purpose of the present invention is solved by the following technical solutions:

The low-temperature solid-phase preparation method of the indium tin oxide nanoparticle powder is carried out according to the following steps:

1) Dissolving metallic indium with a purity greater than 99.99% with inorganic acid to form an initial solution, or dissolving indium metal salts in water to prepare an initial solution;

2) Add tin metal salt to the initial solution to form mixed solution A;

3) Then add a water-soluble inorganic salt into the mixed solution A, and dissolve the inorganic salt completely after stirring to obtain a mixed solution B;

4) Add ammonia water to the mixed solution B, control the pH value of the reaction between 7.0 and 10.0, and finally generate an indium tin oxide precursor;

5) Drying the reaction system in step 4) and grinding to obtain a mixed powder;

6) The mixed powder obtained in step 5) is calcined, and the calcined product is washed with water to remove inorganic salts, and then dried to obtain indium tin oxide nanoparticle powder.

Further, in the above step 1), the inorganic acid used to dissolve metal indium is one or more mixtures of concentrated nitric acid, concentrated sulfuric acid, and concentrated hydrochloric acid. The indium metal salt for preparing the initial solution is InCl ₃ , In(NO ₃ ) ₃ or In ₂ (SO ₄ ) ₃ . The In ³⁺ concentration of the configured initial solution is 0.01-1 mol/L.

Further, in the above step 2), the metal salt of tin is SnCl ₄ , Sn(NO ₃ ) ₄ or Sn(SO ₄ ) ₂ .

Further, in the above step 3), the water-soluble inorganic salt added to the mixed solution A is a mixture of one or more of NaCl, KCl, Na ₂ SO ₄ and K ₂ SO ₄ . The molar ratio of adding water-soluble inorganic salt to In ³⁺ in the mixed solution A is 5-100.

Further, in the above step 5), the calcining temperature for calcining the mixed powder is 300-500° C., and the calcining time is 2-6 hours.

The present invention has the following beneficial effects:

(1) The present invention uses water-soluble inorganic salt as the dispersant and isolation phase for the first time, which not only prevents the formation of interparticle aggregates of the indium tin oxide precursor, but also effectively prevents the growth of indium tin oxide nanoparticles during the calcination process. Formation of large and hard agglomerates. Such a process is simple to operate and low in cost.

(2) During the calcination process of the present invention, the inorganic salt particles in the system provide heterogeneous nucleation sites, so that the precursor of indium tin oxide can be transformed into a cubic phase of indium tin oxide at low temperature. Compared with the common method, The preparation temperature was reduced by nearly 300°C. The preparation method provided by the invention has the advantages of low calcination temperature and low energy consumption, and is suitable for industrial scale production.

(3) The indium tin oxide nanoparticle powder prepared by the present invention has high purity, small particle size, and light agglomeration. By increasing the molar ratio of soluble inorganic salts and In ³⁺ , the particle size can be further reduced and the dispersion of nanoparticles can be increased.

Description of drawings

Fig. 1 is the X-ray diffraction spectrum of the indium tin oxide nanoparticle powder prepared in embodiment 1;

2 is a transmission electron micrograph of indium tin oxide nanoparticles prepared in Example 1;

3 is a transmission electron micrograph of indium tin oxide nanoparticles prepared in Example 2.

Detailed ways

The low-temperature solid-phase preparation method of the indium tin oxide nanoparticle powder of the present invention is carried out according to the following steps:

1) An initial solution is formed by dissolving metallic indium with a purity greater than 99.99% with an inorganic acid, wherein the inorganic acid used to dissolve metallic indium is one or more mixtures of concentrated nitric acid, concentrated sulfuric acid, and concentrated hydrochloric acid. Alternatively, in this step, the initial solution can be prepared by dissolving the metal salt of indium in water. The indium metal salt for preparing the initial solution is InCl ₃ , In(NO ₃ ) ₃ or In ₂ (SO ₄ ) ₃ . The In ³⁺ concentration of the initial solution prepared in this step is 0.01-1 mol/L.

2) Add tin metal salt to the initial solution to form a mixed solution A, in which the mass ratio of In ₂ O ₃ /SnO ₂ is 9/1; the tin metal salt can be SnCl ₄ , Sn(NO ₃ ) ₄ or Sn( SO ₄ ) ₂ .

3) Then add a water-soluble inorganic salt to the mixed solution A, the molar ratio of the water-soluble inorganic salt to In ³⁺ is 5-100. And the water-soluble inorganic salt can be a mixture of one or more of NaCl, KCl, Na ₂ SO ₄ and K ₂ SO ₄ ; the inorganic salt is completely dissolved by stirring to obtain the mixed solution B.

4) Add ammonia water to the mixed solution B, control the pH value of the reaction between 7.0 and 10.0, and finally generate an indium tin oxide precursor;

5) Dry the reaction system in step 4) at 80-90°C, and grind to obtain mixed powder;

6) Calcining the mixed powder obtained in step 5) at 300-500°C for 2-6 hours. The calcined product is washed with water to remove inorganic salts and then dried at 80-90°C to obtain Indium tin oxide nanoparticle powder.

Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail:

Example 1

Dissolve metal indium with a purity greater than 99.99% in nitric acid to prepare a solution with an In ³⁺ concentration of 0.19 mol/L, dissolve SnCl ₄ 5H ₂ O in distilled water to prepare a solution, and then mix indium nitrate solution and tin chloride solution Prepare a mixed solution according to In ₂ O ₃ :SnO ₂ (wt%)=9:1, then add NaCl to the mixed solution, where NaCl:In ³⁺ (mol%)=10:1, and dissolve NaCl completely after stirring , then add ammonia water to the mixed solution, control the pH value of the reaction between 7.0 and 10.0, and finally generate an indium tin oxide precursor, then dry the reaction system at 80-90°C, and grind it to obtain The powder is mixed, and then the mixed powder is calcined at 400° C. for 2 hours, and the calcined product is washed with water to remove NaCl, and then dried under the condition of 80-90° C. to finally obtain indium tin oxide nano particle powder. Figure 1 is the X-ray diffraction spectrum of the prepared indium tin oxide nanoparticle powder. It can be clearly seen from Figure 1 that all the diffraction peaks are the diffraction peaks of cubic indium oxide, indicating that the powder has high purity and no impurity phase. FIG. 2 is a transmission electron micrograph of the prepared indium tin oxide nanoparticle powder. It can be seen that the average particle size of the indium tin oxide nanoparticle is about 35 nm, and the agglomeration is light.

Example 2

Dissolve metal indium with a purity greater than 99.99% in nitric acid to prepare a solution with an In ³⁺ concentration of 0.19 mol/L, dissolve SnCl ₄ 5H ₂ O in distilled water to prepare a solution, and then mix indium nitrate solution and tin chloride solution Prepare a mixed solution according to In ₂ O ₃ :SnO ₂ (wt%)=9:1, then add Na ₂ SO ₄ to the mixed solution, where Na ₂ SO ₄ :In ³⁺ (mol%)=20:1, Dissolve Na ₂ SO ₄ completely after stirring, then add ammonia water to the mixed solution, control the pH value of the reaction between 7.0 and 10.0, and finally generate the precursor of indium tin oxide, and then put the reaction system under the condition of 80-90°C Carry out drying treatment and grind to obtain mixed powder, then calcinate the mixed powder at 400°C for 2 hours, wash the calcined product with water to remove Na ₂ SO ₄ and then dry it at 80-90°C to finally obtain indium oxide Tin nanoparticle powder. FIG. 3 is a transmission electron micrograph of the prepared indium tin oxide nanoparticles. It can be seen that the average particle size of the indium tin oxide nanoparticles is about 30 nm, and there is almost no agglomeration.

Example 3

This embodiment proceeds according to the following steps:

1) Dissolve metal indium with a purity greater than 99.99% in concentrated sulfuric acid to form an initial solution, and the In ³⁺ concentration of the prepared initial solution is 0.01mol/L.

2) A tin metal salt is added to the initial solution to form a mixed solution A; the tin metal salt can be Sn(SO ₄ ) ₂ .

3) Then add a water-soluble inorganic salt to the mixed solution A, the molar ratio of the water-soluble inorganic salt to In ³⁺ is 5. In this embodiment, KCl is selected as the water-soluble inorganic salt; after stirring, the inorganic salt is completely dissolved to obtain a mixed solution B.

4) Add ammonia water to the mixed solution B, control the pH value of the reaction between 7.0 and 10.0, and finally generate an indium tin oxide precursor;

5) Dry the reaction system in step 4) at 80°C, and grind to obtain a mixed powder;

6) Put the mixed powder obtained in step 5) for calcination at 300°C for 6 hours. The calcined product is washed with water to remove inorganic salts and then dried at 90°C to finally obtain indium tin oxide nanoparticle powder body.

Example 4

This embodiment proceeds according to the following steps:

1) Dissolve metal indium with a purity greater than 99.99% in concentrated hydrochloric acid to form an initial solution, and the In ³⁺ concentration of the prepared initial solution is 1mol/L.

2) A tin metal salt is added to the initial solution to form a mixed solution A; the tin metal salt can be SnCl ₄ .

3) Then add a water-soluble inorganic salt to the mixed solution A, the molar ratio of the water-soluble inorganic salt to In ³⁺ is 100. In this embodiment, Na ₂ SO ₄ is selected as the water-soluble inorganic salt; the inorganic salt is completely dissolved by stirring, and a mixed solution B is obtained.

4) Add ammonia water to the mixed solution B, control the pH value of the reaction between 7.0 and 10.0, and finally generate an indium tin oxide precursor;

5) Dry the reaction system in step 4) at 90°C and grind to obtain a mixed powder;

6) The mixed powder obtained in step 5) was calcined at 500°C for 2 hours, and the calcined product was washed with water to remove inorganic salts and then dried at 80°C to finally obtain indium tin oxide nanoparticle powder body.

Example 5

This embodiment proceeds according to the following steps:

1) Prepare an initial solution by dissolving metal salt of indium in water, wherein the metal salt is InCl ₃ ; the In ³⁺ concentration of the prepared initial solution is 0.5mol/L.

2) A tin metal salt is added to the initial solution to form a mixed solution A; the tin metal salt can be Sn(NO ₃ ) ₄ .

3) Then add a water-soluble inorganic salt to the mixed solution A, the molar ratio of the water-soluble inorganic salt to In ³⁺ is 50. In this embodiment, K ₂ SO ₄ is selected as the water-soluble inorganic salt; the inorganic salt is completely dissolved by stirring, and a mixed solution B is obtained.

4) Add ammonia water to the mixed solution B, control the pH value of the reaction between 7.0 and 10.0, and finally generate an indium tin oxide precursor;

5) Dry the reaction system in step 4) at 85°C and grind to obtain a mixed powder;

6) The mixed powder obtained in step 5) was calcined at 400°C for 2 hours, and the calcined product was washed with water to remove inorganic salts and then dried at 85°C to finally obtain indium tin oxide nanoparticle powder body.

Claims (10)

1. the Low Temperature Solid-Phase preparation method of a tin indium oxide nano particle powder is characterized in that, carries out according to following steps:

1) purity is formed initial soln greater than 99.99% indium metal after with inorganic acid solution, perhaps with the water-soluble initial soln that is mixed with of the metal-salt of indium;

2) metal-salt of adding tin forms mixed solution A in initial soln;

3) then in mixed solution A, add water-soluble inorganic salt, through stirring the inorganic salt dissolve complete, obtain mixing solutions B;

4) add ammoniacal liquor in mixing solutions B, the pH value of control reaction generates the tin indium oxide presoma at last between 7.0～10.0;

5) reaction system of step 4) is carried out drying treatment, and after grinding, obtain mixed powder;

6) mixed powder that step 5) is obtained carries out calcination processing, and calcinate carries out drying treatment after inorganic salt are removed in washing, finally obtain tin indium oxide nano particle powder.

2. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 1 is characterized in that, in the step 1), the used mineral acid of dissolution of metals indium is one or more mixed solutions of concentrated nitric acid, the vitriol oil, concentrated hydrochloric acid.

3. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 1 is characterized in that, in the step 1), the metal-salt of the indium of preparation initial soln is InCl ₃, In (NO ₃) ₃Perhaps In ₂(SO ₄) ₃

4. according to claim 1, the Low Temperature Solid-Phase preparation method of 2 or 3 described tin indium oxide nano particle powders, it is characterized in that, in the step 1), the In of the initial soln that configures ³⁺Concentration is 0.01-1mol/L.

5. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 1 is characterized in that step 2) in, the metal-salt of described tin is SnCl ₄, Sn (NO ₃) ₄Perhaps Sn (SO ₄) ₂

6. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 1 is characterized in that, in the step 3), the water-soluble inorganic salt that add in mixed solution A are NaCl, KCl, Na ₂SO ₄And K ₂SO ₄One or more mixing.

7. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 6 is characterized in that, the mol ratio that adds water-soluble inorganic salt and In3+ in mixed solution A is 5～100.

8. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 1 is characterized in that, in the step 5, reaction system is carried out drying treatment under 80～90 ℃ condition.

9. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 1 is characterized in that, in the step 6), the calcining temperature of calcined mixed powder is 300～500 ℃, and calcination time is 2～6 hours.

10. the Low Temperature Solid-Phase preparation method of tin indium oxide nano particle powder according to claim 1 is characterized in that, in the step 6), carries out drying treatment behind the removal inorganic salt under 80～90 ℃ condition.

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