阅读说明：本技术 竹节状纳米氧化铟锡粉体的制备方法 (Preparation method of bamboo-shaped nano indium tin oxide powder ) 是由 岳都元 栾奕 贾志忠 于 2021-09-26 设计创作，主要内容包括：本发明涉及纳米氧化铟锡粉体技术领域,尤其涉及一种竹节状纳米氧化铟锡粉体的制备方法,包括如下步骤：(1)采用碱性爆发成核控制剂一次性加入铟和锡化合物水溶液,使其爆发成核；(2)采用弱碱性沉淀剂滴定步骤(1)所述成核后的铟和锡化合物水溶液,使晶核成长,得到铟锡氧化物前驱体；(3)将所述铟锡氧化物前驱体洗涤,干燥；(4)干燥后的所述氧化铟锡前驱体在不同反应条件下分别得到竹节状黄绿色氧化铟锡粉体和竹节状蓝色氧化铟锡粉体。本发明的有益效果是：竹节状纳米氧化铟锡粉体具有更加优良的导电性能,合成工艺简单,反应周期短,适合工业化生产。(The invention relates to the technical field of nano indium tin oxide powder, in particular to a preparation method of bamboo-shaped nano indium tin oxide powder, which comprises the following steps: (1) adding an indium and tin compound aqueous solution at one time by adopting an alkaline explosive nucleation control agent to ensure that the indium and tin compound aqueous solution explodes and nucleates; (2) titrating the nucleated indium and tin compound aqueous solution obtained in the step (1) by using a weakly alkaline precipitator to grow crystal nuclei to obtain an indium tin oxide precursor; (3) washing and drying the indium tin oxide precursor; (4) and respectively obtaining bamboo-shaped yellow-green indium tin oxide powder and bamboo-shaped blue indium tin oxide powder from the dried indium tin oxide precursor under different reaction conditions. The invention has the beneficial effects that: the bamboo-shaped nano indium tin oxide powder has more excellent conductive performance, simple synthesis process and short reaction period, and is suitable for industrial production.)

1. A preparation method of bamboo-shaped nano indium tin oxide powder is characterized by comprising the following steps:

(1) adding an indium and tin compound aqueous solution at one time by adopting an alkaline explosive nucleation control agent to ensure that the indium and tin compound aqueous solution explodes and nucleates;

(2) titrating the nucleated indium and tin compound aqueous solution obtained in the step (1) by using a weakly alkaline precipitator to grow crystal nuclei to obtain an indium tin oxide precursor;

(3) washing and drying the indium tin oxide precursor;

(4) the dried indium tin oxide precursor respectively obtains bamboo-shaped yellow-green indium tin oxide powder and bamboo-shaped blue indium tin oxide powder under different reaction conditions:

adding the dried indium tin oxide precursor into an enamel tray, and reacting at 750-800 ℃ for 1-2 hours to obtain bamboo-shaped yellow-green indium tin oxide powder with complete crystal form;

or: and adding the dried indium tin oxide precursor into a stainless steel closed container, and reacting for 4-5 hours at the temperature of 720 plus 750 ℃ to obtain bamboo-shaped blue indium tin oxide powder with complete crystal form.

2. The method for preparing bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (1), the alkaline burst nucleation controlling agent is one or a mixture of two or more of hydrazine hydrate, ammonium acetate and ammonium citrate.

3. The method for preparing bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (1), the amount of the alkaline explosion nucleation controlling agent added into the aqueous solution of indium and tin compounds at one time is controlled to be pH 2.7-3.0.

4. The preparation method of the bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (1), the stirring speed is 30-40r/min when the alkaline burst nucleation control agent is added at one time.

5. The method for preparing bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (2), the precipitant is one or a mixture of two or more of ammonia water, ammonium carbonate and ammonium bicarbonate, and the precipitant is diluted 1:1 with water.

6. The preparation method of the bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (2), the titration speed of the precipitant is 1:60-100 of the mass ratio of the dropwise addition amount per minute to the indium tin compound aqueous solution.

7. The method for preparing bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (2), when the precipitant is titrated, the stirring speed of the indium tin compound aqueous solution is 5-10 r/min.

8. The method for preparing bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (2), when the precipitant is titrated, the titration end point PH is 7.0-7.5.

9. The method for preparing the bamboo-shaped nano indium tin oxide powder according to claim 1, wherein in the step (3), the indium tin oxide precursor is washed until no chloride ion is detected by silver nitrate, washed by absolute ethyl alcohol and dried.

Technical Field

The invention relates to the technical field of nano indium tin oxide powder, in particular to a preparation method of bamboo-shaped nano indium tin oxide powder.

Background

The yellow-green indium tin oxide is used as a transparent conductive material with excellent performance, so that the yellow-green indium tin oxide can be widely applied to the fields of electronic displays, transparent electrodes, cold rays, cold light sheets, antistatic property and the like. In these fields, the main performance affecting the use of the ITO powder is the conductivity of the ITO powder, and the technical index directly affecting the conductivity is the crystal structure of the ITO powder. The prepared indium tin oxide powder with high conductivity is beneficial to the expanded application of the indium tin oxide powder in the field of conductivity.

The blue ITO has the characteristics of high transparency and infrared obstruction, and the performance enables the blue ITO to be widely applied to the fields of transparent heat insulation, infrared sensing and infrared stealth.

CN 108002427a discloses a method for preparing indium tin oxide nano powder, which uses ethanol and acetylacetone as solvent, and has the disadvantages of high production cost and strong pollution. CN106882835A discloses a preparation method of indium tin oxide composite powder, wherein the indium tin oxide prepared by the method is in a spherical aggregate shape. CN103318949A discloses a low-temperature solid-phase preparation method of indium tin oxide nano-particle powder, wherein the nano-particles prepared by the method are spherical, and the conversion of indium tin oxide precursors is incomplete and the conductivity is poor by low-temperature calcination.

One method is to directly carry out heat treatment on indium tin oxide precursor powder at 400-600 ℃ in a reducing atmosphere, so that the hydroxide is thermally decomposed into oxide in the reducing atmosphere (such as hydrogen, ethanol, ammonia gas and the like), and a large number of oxygen vacancies are generated on the surface of crystal grains, so that strong absorption occurs at the blue light wavelength in the visible light range, and the blue powder is formed. The other preparation method is a solvothermal method, the used solvent comprises various monohydric alcohols and polyhydric alcohols, and the crystal form transformation is realized at high temperature and high pressure to obtain the blue indium tin oxide powder. CN103771499A discloses a preparation method of blue nano indium tin oxide, and the method adopts a two-stage preparation process of firstly high-temperature calcination and then high-temperature high-pressure hydrothermal reaction, so that the process is complicated and the preparation cost is high.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: overcomes the defects in the prior art, and provides a preparation method of bamboo-shaped nano indium tin oxide powder with simple process, short preparation period, cost saving and better conductivity and infrared absorptivity.

The technical scheme for solving the technical problems is as follows:

a preparation method of bamboo-shaped nano indium tin oxide powder comprises the following steps:

(1) adding an indium and tin compound aqueous solution at one time by adopting an alkaline explosive nucleation control agent to ensure that the indium and tin compound aqueous solution explodes and nucleates;

(2) titrating the nucleated indium and tin compound aqueous solution obtained in the step (1) by using a weakly alkaline precipitator to grow crystal nuclei to obtain an indium tin oxide precursor;

(3) washing and drying the indium tin oxide precursor;

(4) the dried indium tin oxide precursor respectively obtains bamboo-shaped yellow-green indium tin oxide powder and bamboo-shaped blue indium tin oxide powder under different reaction conditions:

adding the dried indium tin oxide precursor into an enamel tray, and reacting at 750-800 ℃ for 1-2 hours to obtain bamboo-shaped yellow-green indium tin oxide powder with complete crystal form;

or: and adding the dried indium tin oxide precursor into a stainless steel closed container, and reacting for 4-5 hours at the temperature of 720 plus 750 ℃ to obtain bamboo-shaped blue indium tin oxide powder with complete crystal form.

Further, in the step (1), the alkaline burst nucleation control agent is one or a mixture of two or more of hydrazine hydrate, ammonium acetate and ammonium citrate.

Further, in the step (1), the amount of the alkaline burst nucleation controller added at one time to the aqueous solution of the indium and tin compound is controlled to have a pH of 2.7 to 3.0.

Further, in the step (1), the stirring speed is 30-40r/min when the alkaline burst nucleation control agent is added at one time.

Further, in the step (2), the weakly alkaline precipitant is one or a mixture of two or more of ammonia water, ammonium carbonate and ammonium bicarbonate, and the weakly alkaline precipitant is diluted 1:1 with water.

Further, in the step (2), the titration speed of the precipitant is that the mass ratio of the dropwise adding amount per minute to the indium tin compound aqueous solution is 1: 60-100.

Further, in the step (2), when the precipitant is titrated, the stirring speed of the indium tin compound aqueous solution is 5-10 r/min.

Further, in the step (2), when the precipitant is titrated, the titration end point pH is 7.0-7.5.

Further, in the step (3), the indium tin oxide precursor is washed until no chloride ions are detected by silver nitrate, washed by absolute ethyl alcohol and dried.

The invention has the beneficial effects that:

1. the bamboo-like nano indium tin oxide powder is prepared by adopting a crystal growth mode of explosive nucleation and slow growth, and has lower contact resistance compared with spherical nano indium tin oxide, small transmission resistance and higher transmission speed of electrons between the bamboo-like nano indium tin oxide powder, so that the conductivity of the bamboo-like nano indium tin oxide powder is improved, and the bamboo-like nano indium tin oxide powder has better conductivity compared with the publicly reported spherical indium tin oxide powder.

2. The blue indium tin oxide powder is mainly applied to the absorption function of the blue indium tin oxide powder on infrared rays, and the same mechanism is adopted, so that the transfer resistance of electron transition and transmission among bamboo-shaped indium tin oxide is obviously lower than the transfer resistance among spherical powder, and the absorption rate of the blue indium tin oxide on the infrared rays is improved.

3. According to the method for preparing the blue indium tin oxide powder, the dried indium tin oxide precursor is added into a stainless steel closed container, and gas generated by decomposition of the raw material at high temperature is skillfully utilized as a pressure source, so that the gas source is saved, and the cost is reduced.

4. According to the invention, a crystal form control template and a crystal form control agent are not used, the growth mode of the crystal form is directly controlled by using a feeding mode, and the prepared yellow-green powder has small nano-particle size and good conductivity; the prepared blue indium tin oxide powder not only has a bamboo-like shape, but also changes the traditional two-stage process route that indium tin oxide precursor is calcined at high temperature to obtain yellow-green powder, and then the yellow-green powder is converted into blue powder under high temperature and high pressure, and creates a process route that the indium tin oxide precursor is directly converted into the blue powder.

5. The synthesis process is simple, the reaction period is short, and the method is suitable for industrial production.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 XRD pattern of the yellow-green nano indium tin oxide of example 1 of the present invention;

FIG. 2 is a transmission electron microscope image of the yellow-green nano ITO of example 1 of the present invention;

FIG. 3 XRD pattern of blue nano indium tin oxide of example 1 of the present invention;

FIG. 4 is a transmission electron micrograph of blue nano ITO of example 1 of the present invention;

FIG. 5 XRD pattern of the greenish yellow nano-ITO of example 2 of the present invention;

FIG. 6 is a transmission electron microscope image of the yellow-green nano ITO of example 2 of the present invention;

FIG. 7 XRD pattern of blue nano indium tin oxide of example 2 of the present invention;

FIG. 8 is a transmission electron micrograph of blue nano ITO in example 2 of the present invention;

FIG. 9 XRD pattern of the greenish yellow nano-ITO of example 3 of the present invention;

FIG. 10 is a transmission electron microscope image of the yellow-green nano ITO of example 3 of the present invention;

FIG. 11 XRD pattern of blue nano indium tin oxide of example 3 of the present invention;

FIG. 12 is a transmission electron micrograph of blue nano ITO according to example 3 of the present invention;

FIG. 13 is a scanning electron micrograph of the yellow-green nano-ITO of comparative example 1 of the present invention;

FIG. 14 is a scanning electron micrograph of blue nano-ITO of comparative example 1 of the present invention;

FIG. 15 is a scanning electron micrograph of the yellow-green nano-ITO of comparative example 2 of the present invention;

FIG. 16 is a scanning electron microscope image of the blue nano indium tin oxide of comparative example 2 of the present invention.

Detailed Description

The principles and features of this invention are described below in conjunction with examples which are set forth to illustrate, but are not to be construed to limit the scope of the invention.

Example 1

30g of hydrazine hydrate is accurately weighed and quickly added into 300g of mixed aqueous solution of tin tetrachloride and indium trichloride at one time, the pH value of the aqueous solution is controlled to be 2.7, and the stirring speed is 40 r/min. Ammonium bicarbonate and water are diluted by 1:1, and the solution is titrated into the solution at the speed of 5ml/min, meanwhile, the stirring speed is adjusted to 10r/min, and the titration is stopped when the PH value reaches 7.1, so that the indium tin oxide precursor is obtained. Washing the precursor with water until no chloride ion is detected, washing with ethanol, filtering, and drying. The dried precursor is divided into two parts A and B. Putting the A part into an enamel tray, and reacting at 750 ℃ for 2 hours to obtain bamboo-shaped yellow-green indium tin oxide powder with complete crystal forms, wherein an XRD (X-ray diffraction) diagram is shown in figure 1, and a transmission electron microscope diagram is shown in figure 2; adding the B part into a stainless steel closed container, raising the temperature to 720 ℃, and reacting for 5 hours to obtain bamboo-shaped blue indium tin oxide powder with complete crystal forms, wherein an XRD (X-ray diffraction) pattern is shown in figure 3, and a Transmission Electron Microscope (TEM) pattern is shown in figure 4.

Example 2

38g of ammonium acetate is accurately weighed and rapidly added into 300g of mixed aqueous solution of stannic chloride and indium trichloride at one time, the pH of the aqueous solution is controlled to be 3.0, and the stirring speed is 30 r/min. And (3) diluting ammonia water and water at a ratio of 1:1, titrating into the solution at a speed of 3ml/min, adjusting the stirring speed to 50r/min, and stopping titrating until the pH value reaches 7.5 to obtain the indium tin oxide precursor. Washing the precursor with water until no chloride ion is detected, washing with ethanol, filtering, and drying. The dried precursor is divided into two parts A and B. Putting the A part into an enamel tray, and reacting for 1 hour at 800 ℃ to obtain bamboo-shaped yellow-green indium tin oxide powder with complete crystal form, wherein an XRD (X-ray diffraction) diagram is shown in figure 5, and a transmission electron microscope diagram is shown in figure 6; adding the B part into a stainless steel closed container, raising the temperature to 750 ℃, and reacting for 4 hours to obtain bamboo-shaped blue indium tin oxide powder with complete crystal forms, wherein an XRD (X-ray diffraction) pattern is shown in figure 7, and a Transmission Electron Microscope (TEM) pattern is shown in figure 8.

Example 3

34g of ammonium citrate is accurately weighed and rapidly added into 300g of mixed aqueous solution of tin tetrachloride and indium trichloride at one time, the pH value of the aqueous solution is controlled to be 2.8, and the stirring speed is 35 r/min. And (3) diluting ammonia water and water at a ratio of 1:1, titrating the solution into the solution at a speed of 6ml/min, adjusting the stirring speed to 7r/min, and stopping titrating until the pH value reaches 7.3 to obtain the indium tin oxide precursor. Washing the precursor with water until no chloride ion is detected, washing with ethanol, filtering, and drying. The dried precursor is divided into two parts A and B. Putting the A part into an enamel tray, and reacting at 780 ℃ for 1.5 hours to obtain bamboo-shaped yellow-green indium tin oxide powder with complete crystal forms, wherein an XRD (X-ray diffraction) diagram is shown in figure 9, and a transmission electron microscope diagram is shown in figure 10; adding the B part into a stainless steel closed container, raising the temperature to 740 ℃, and reacting for 4.5 hours to obtain bamboo-shaped blue indium tin oxide powder with complete crystal forms, wherein an XRD (X-ray diffraction) diagram is shown in figure 11, and a transmission electron microscope diagram is shown in figure 12.

In order to illustrate the importance of explosive nucleation and slow growth on the appearance of the bamboo-shaped nano indium tin oxide, a comparative example 1 and a comparative example 2 are specially designed, wherein the explosive nucleation process is omitted in the comparative example 1, and the reaction is directly titrated to the end point of the reaction; comparative example 2 the reaction was directly endcapped by means of explosive nucleation to compare the effect of different conditions on the final morphology.

Comparative example 1

Ammonium bicarbonate and water are diluted by 1:1, and the mixture is titrated into 300g of mixed aqueous solution of tin tetrachloride and indium trichloride at the speed of 5ml/min, the stirring speed is adjusted to 10r/min, and the titration is stopped when the PH value reaches 7.1, so that the indium tin oxide precursor is obtained. Washing the precursor with water until no chloride ion is detected, washing with ethanol, filtering, and drying. The dried precursor is divided into two parts A and B. Putting the A part into an enamel tray, reacting for 2 hours at 750 ℃ to obtain bamboo-shaped yellow-green indium tin oxide powder with complete crystal forms, and scanning an electron microscope picture as shown in figure 13; adding the B part into a stainless steel closed container, raising the temperature to 720 ℃, and reacting for 5 hours to obtain bamboo-shaped blue indium tin oxide powder with complete crystal forms, wherein a scanning electron microscope picture is shown as figure 14.

Comparative example 2

100g of hydrazine hydrate is weighed and quickly added into 300g of mixed aqueous solution of stannic chloride and indium trichloride, the final PH of the aqueous solution is controlled to be 7.1, and the stirring speed is 40r/min, so that the indium tin oxide precursor is obtained. Washing the precursor with water until no chloride ion is detected, washing with ethanol, filtering, and drying. The dried precursor is divided into two parts A and B. Putting the A part into an enamel tray, reacting for 2 hours at 750 ℃ to obtain bamboo-shaped yellow-green indium tin oxide powder with complete crystal forms, and scanning an electron microscope picture as shown in figure 15; and adding the B part into a stainless steel closed container, raising the temperature to 720 ℃, and reacting for 5 hours to obtain bamboo-shaped blue indium tin oxide powder with complete crystal forms, wherein a scanning electron microscope picture is shown as figure 16.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.