Preparation method of high-conductivity ITO (Indium Tin Oxide) nano powder

Abstract

The invention discloses a preparation method of high-conductivity ITO (Indium Tin Oxide) nano powder, which comprises the following steps: preparing a precursor solution, namely mixing and dissolving metal indium powder, hydrochloric acid and deionized water to prepare an InCl3 solution with the volume ratio of hydrochloric acid to deionized water being 1: 1 and the concentration of the InCl3 solution being 25g / ml; the preparation method comprises the following steps: preparing a SnCl4 solution by using SnCl4. 5H2O and deionized water according to the mass ratio of In2O3 to SnO2 of 9: 1, and mixing the two solutions; the problems that in the prior art, chloride ions are not thoroughly removed, powder is prone to agglomeration, and the quality of the powder is prone to being affected are solved.

Description

Technical Field

[0001] The invention relates to the technical field of ITO powder preparation, and in particular to a method for preparing high-conductivity ITO nano powder. Background Art

[0002] Indium Tin Oxide (ITO) is an N-type semiconductor material. Its ITO film has good conductivity, visible light transmittance, high infrared light reflectivity and ultraviolet light absorption. It is widely used in electronic computers, energy, electronics, national defense and military, aerospace, nuclear industry and other fields. The key to obtaining high-quality ITO film is high-quality ITO powder and high-purity, ultra-high-density ITO target. The current methods for preparing ITO powder include: sol-gel method, hydrothermal method, co-precipitation method, reduced pressure-volatilization oxidation method, spray thermal decomposition method, etc. Among them, the co-precipitation method is to dissolve InCl3 and SnCl4 in a solution to form a solution containing indium ions and tin ions, and add an alkaline solution such as ammonia water to the solution to obtain a precipitate containing indium and tin, and then filter and calcine the precipitate to obtain ITO powder. This method has the characteristics of simple process, easy operation, controllable conditions, short synthesis cycle and low cost, and is easy to realize industrial production. However, this method still has defects such as poor chloride ion removal effect, easy agglomeration of powder, and easy impact on powder quality. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing highly conductive ITO nanopowder, so as to solve the problems in the prior art that chloride ions are not completely removed, powders are easily agglomerated, and powder quality is easily affected.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for preparing highly conductive ITO nanopowder, comprising the following steps:

[0005] Precursor solution preparation: InCl3 solution was prepared by mixing and dissolving metal indium powder, hydrochloric acid and deionized water, the volume ratio of hydrochloric acid to deionized water was 1:1, and the concentration of InCl3 solution was 25 g / ml; SnCl4·5H2O and deionized water were used to prepare SnCl4 solution according to the In2O3 / SnO2 mass ratio of 9:1, and the two solutions were mixed;

[0006] Add precipitant: place the mixed solution in a reactor, add ammonia water dropwise, set the reactor with ultrasonic equipment, the temperature in the reactor is 70-80°C, the pH value at the reaction end is 7-9, and the aging is 1-1.5h;

[0007] Precursor precipitate treatment: remove the supernatant from the aged product, add deionized water, and introduce ozone to react with the aged product, and then dry it to obtain an ITO precursor;

[0008] Powder preparation: Calcine the dried ITO precursor precipitate for 3-4 hours to obtain ITO nanopowder at a calcination temperature of 700-800°C.

[0009] As a preferred embodiment of the present technical solution, the purity of the metal indium powder is greater than 99.99%.

[0010] As a preferred embodiment of the present technical solution, the concentration of the hydrochloric acid is 30-40%.

[0011] As a preferred embodiment of the present technical solution, the concentration of the ammonia water is 20-30%.

[0012] As a preferred embodiment of the present technical solution, the drying temperature is 80-90°C and the drying time is 15-20h.

[0013] As a preferred embodiment of the present technical solution, the volume ratio of the aged material to deionized water is 1:(1-2).

[0014] As a preferred embodiment of the present technical solution, the concentration of ozone is 60-80%.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. Through the control of various preparation parameters, the powder obtained is spherical in morphology, with a narrow particle size distribution, and the particle size and specific surface area are better than the existing requirements.

[0017] 2. The use of ultrasound can improve the dispersibility of the precipitate when the precipitant is added.

[0018] 3. By using ozone oxidation technology, the removal effect of chlorine atoms is improved, which reduces the agglomeration of products, improves the quality of products, and reduces the preparation cost. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1

[0021] The method for preparing the highly conductive ITO nano powder of the present invention comprises the following steps:

[0022] Precursor solution preparation: InCl3 solution is prepared by mixing and dissolving metal indium powder, 30% hydrochloric acid and deionized water, the volume ratio of hydrochloric acid to deionized water is 1:1, the concentration of InCl3 solution is 25g / ml, and the purity of metal indium powder is greater than 99.99%; SnCl4·5H2O and deionized water are used to prepare SnCl4 solution according to the In2O3 / SnO2 mass ratio of 9:1, and the two solutions are mixed;

[0023] Adding precipitant: placing the mixed solution in a reactor, adding ammonia water dropwise, the concentration of ammonia water is 30%, the reactor is equipped with ultrasonic equipment, the temperature in the reactor is 80°C, the pH value of the reaction end point is 9, and aging is 1h;

[0024] Precursor precipitate treatment: remove the supernatant from the aged product, add deionized water, the volume ratio of the aged product to the deionized water is 1:1, and introduce ozone to react with the aged product, the concentration of ozone is 60%. After completion, dry at 80°C and for 15 hours. The ITO precursor is obtained;

[0025] Powder preparation: The dried ITO precursor precipitate was calcined for 4 hours to obtain ITO nanopowder at a calcination temperature of 800°C.

[0026] The powder particles in this example are between 30-35 nm and are evenly distributed, with a specific surface area of ​​32.36 m 2 / g, and the agglomeration coefficient is 1.54.

[0027] Example 2

[0028] The method for preparing the highly conductive ITO nano powder of the present invention comprises the following steps:

[0029] Precursor solution preparation: InCl3 solution is prepared by mixing and dissolving metal indium powder, 40% hydrochloric acid and deionized water, the volume ratio of hydrochloric acid to deionized water is 1:1, the concentration of InCl3 solution is 25g / ml, and the purity of metal indium powder is greater than 99.99%; SnCl4·5H2O and deionized water are used to prepare SnCl4 solution according to the In2O3 / SnO2 mass ratio of 9:1, and the two solutions are mixed;

[0030] Add precipitant: place the mixed solution in a reactor, add ammonia water dropwise, the concentration of ammonia water is 20%, the reactor is equipped with ultrasonic equipment, the temperature in the reactor is 70°C, the pH value of the reaction end point is 7, and the aging is 1.5h;

[0031] Precursor precipitate treatment: remove the supernatant from the aged product, add deionized water, the volume ratio of the aged product to the deionized water is 1:1, and introduce ozone to react with the aged product, the concentration of ozone is 80%. After completion, dry at 90°C and for 20 hours. The ITO precursor is obtained;

[0032] Powder preparation: The dried ITO precursor precipitate was calcined for 3 hours to obtain ITO nanopowder at a calcination temperature of 700°C.

[0033] The powder particles in this example are between 38-45 nm and have a specific surface area of ​​34.73 m 2 / g, and the agglomeration coefficient is 1.69.

[0034] Example 3

[0035] The method for preparing the highly conductive ITO nano powder of the present invention comprises the following steps:

[0036] Precursor solution preparation: InCl3 solution is prepared by mixing and dissolving metal indium powder, 35% hydrochloric acid and deionized water, the volume ratio of hydrochloric acid to deionized water is 1:1, the concentration of InCl3 solution is 25g / ml, and the purity of metal indium powder is greater than 99.99%; SnCl4·5H2O and deionized water are used to prepare SnCl4 solution according to the In2O3 / SnO2 mass ratio of 9:1, and the two solutions are mixed;

[0037] Add precipitant: place the mixed solution in a reactor, add ammonia water dropwise, the concentration of ammonia water is 25%, the reactor is equipped with ultrasonic equipment, the temperature in the reactor is 75°C, the pH value of the reaction end point is 8, and the aging is 1.5h;

[0038] Precursor precipitate treatment: remove the supernatant from the aged product, add deionized water, the volume ratio of the aged product to deionized water is 1:2, and introduce ozone to react with the aged product, the concentration of ozone is 70%. After completion, dry at 85°C and for 18 hours. The ITO precursor is obtained;

[0039] Powder preparation: The dried ITO precursor precipitate was calcined for 3.5 hours to obtain ITO nanopowder at a calcination temperature of 750°C.

[0040] The powder particles in this example are between 38-42 nm and have a specific surface area of ​​48.92 m 2 / g, and the agglomeration coefficient is 1.95.

[0041] Example 4

[0042] The method for preparing the highly conductive ITO nano powder of the present invention comprises the following steps:

[0043] Precursor solution preparation: InCl3 solution is prepared by mixing and dissolving metal indium powder, 40% hydrochloric acid and deionized water, the volume ratio of hydrochloric acid to deionized water is 1:1, the concentration of InCl3 solution is 25g / ml, and the purity of metal indium powder is greater than 99.99%; SnCl4·5H2O and deionized water are used to prepare SnCl4 solution according to the In2O3 / SnO2 mass ratio of 9:1, and the two solutions are mixed;

[0044] Adding precipitant: placing the mixed solution in a reactor, adding ammonia water dropwise, the concentration of ammonia water is 20%, the reactor is equipped with ultrasonic equipment, the temperature in the reactor is 75°C, the pH value of the reaction end point is 8, and aging is 1.3h;

[0045] Precursor precipitate treatment: remove the supernatant from the aged product, add deionized water, the volume ratio of the aged product to deionized water is 1:1.5, and introduce ozone to react with the aged product, the concentration of ozone is 80%. After completion, dry at 80°C and for 16 hours. The ITO precursor is obtained;

[0046] Powder preparation: The dried ITO precursor precipitate was calcined for 3 hours to obtain ITO nanopowder at a calcination temperature of 780°C.

[0047] The powder particles in this example are between 31-43 nm and have a specific surface area of ​​49.13 m 2 / g, and the agglomeration coefficient is 1.76.

[0048] Example 5

[0049] The method for preparing the highly conductive ITO nano powder of the present invention comprises the following steps:

[0050] Precursor solution preparation: InCl3 solution is prepared by mixing and dissolving metal indium powder, 38% hydrochloric acid and deionized water, the volume ratio of hydrochloric acid to deionized water is 1:1, the concentration of InCl3 solution is 25g / ml, and the purity of metal indium powder is greater than 99.99%; SnCl4·5H2O and deionized water are used to prepare SnCl4 solution according to the In2O3 / SnO2 mass ratio of 9:1, and the two solutions are mixed;

[0051] Add precipitant: place the mixed solution in a reactor, add ammonia water dropwise, the concentration of ammonia water is 27%, the reactor is equipped with ultrasonic equipment, the temperature in the reactor is 73°C, the pH value of the reaction end point is 8.5, and the aging is 1h;

[0052] Precursor precipitate treatment: remove the supernatant from the aged product, add deionized water, the volume ratio of the aged product to deionized water is 1:2, and introduce ozone to react with the aged product, the concentration of ozone is 80%. After completion, dry at 89°C and for 18 hours. The ITO precursor is obtained;

[0053] Powder preparation: The dried ITO precursor precipitate was calcined for 4 hours to obtain ITO nanopowder at a calcination temperature of 740°C.

[0054] The powder particles in this example are between 41-52 nm and have a specific surface area of ​​39.71 m 2 / g, and the agglomeration coefficient is 1.81.

[0055] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing highly conductive ITO nanopowder, characterized in that: The following steps are involved: Precursor solution preparation: InCl3 solution is prepared by mixing and dissolving metal indium powder, hydrochloric acid and deionized water, the volume ratio of hydrochloric acid to deionized water is 1:1, and the concentration of InCl3 solution is 25g / ml; SnCl4·5H2O and deionized water are used to prepare SnCl4 solution according to the In2O3 / SnO2 mass ratio of 9:1, and the two solutions are mixed; Add precipitant: Place the mixed solution in a reactor, add ammonia water dropwise, set the reactor with ultrasonic equipment, the temperature in the reactor is 70-80°C, the pH value at the reaction end is 7-9, and the aging is 1-1.5h; Precursor precipitate treatment: remove the supernatant from the aged product, add deionized water, and introduce ozone to react with the aged product, and then dry it to obtain an ITO precursor; Powder preparation: Calcine the dried ITO precursor precipitate for 3-4 hours to obtain ITO nanopowder at a calcination temperature of 700-800°C.

2. The preparation method according to claim 1, characterized in that: The purity of the metal indium powder is greater than 99.99%.

3. The preparation method according to claim 1, characterized in that: The concentration of the hydrochloric acid is 30-40%.

4. The preparation method according to claim 1, characterized in that: The concentration of the ammonia water is 20-30%.

5. The preparation method according to claim 1, characterized in that: The drying temperature is 80-90° C., and the drying time is 15-20 hours.

6. The preparation method according to claim 1, characterized in that: The volume ratio of the aged material to deionized water is 1:(1-2).

7. The preparation method according to claim 1, characterized in that: The concentration of the ozone is 60-80%.