CN106564937A - Preparation method of antimony-doped nanometer tin oxide (ATO) powder - Google Patents

Abstract

The invention relates to a preparation method of antimony-doped nanometer tin oxide (ATO) powder, especially to a preparation method of antimony-doped nanometer tin oxide (ATO) powder applicable to the field of nano-electric contact. According to present sol-gel preparation technology of ATO nanopowder, organic matter, alcohol, etc. are mainly used as reaction mediums, thus leading to large use amount of ethanol and high cost of raw materials. Optimization design of stable process and sintering process of a sol formula system in the synthesis process of ATO powder by a water-based sol-gel method is the technical key point in the invention. Then, by regulating technological factors including nSn/nSb mol ratio (mol ratio of Sn to Sb), reaction temperature, sintering temperature, etc., average size of the ATO nanopowder is within the range of 52 nm, and the powder has good dispersity. As Sb ions have been mixed into SnO2 crystal lattice and exist in the form of a solid solution, stable batch preparation of the ATO powder is realized. The prepared ATO powder will be used as a second reinforcing phase to be applied in the field of silver-based electric contact materials.

Description

A kind of preparation method of antimony-doped nano tin oxide (ATO) powder

technical field

The invention relates to the preparation of doped nano powder, in particular to a preparation method of antimony-doped nano tin oxide (ATO) powder applied in the field of nano electric contact.

Background technique

As an n-type semiconductor material with a wide band gap (Eg=3.8eV), tin dioxide can greatly improve its optical, electrical and gas-sensing properties by doping a certain amount of elements and synthesizing nanoparticles of a certain size. performance. Antimony-doped tin dioxide (ATO), as a new type of multifunctional transparent conductive material, is widely used in AgSnO ₂ electrical contact materials, electrical appliances and other fields because of its excellent characteristics such as good conductivity, weather resistance, stability and light color transparency. It has broad application prospects and development potential. A large number of studies have shown that the conductive properties of ATO powder are directly related to the particle size, microscopic morphology and other factors of the powder. At present, the methods for preparing antimony-doped tin dioxide mainly include chemical co-precipitation method, hydrothermal method and sol-gel method. The particle size analysis of ATO powder synthesized by co-precipitation method by Tao Liang et al. from Huazhong University of Science and Technology showed that the particle size of the powder showed a downward trend when the pH value of the solution increased from 1 to 5. HJJeon et al. synthesized nanoscale ATO powders by hydrothermal method using alcohol and 1,4-butanediol as solvents, and found that when the sintering temperature increased from 400°C to 1000°C, the average particle size of the powders was in the range of 5-50nm , where the average particle size of the fired powder at 800°C is 10-15nm, and the average particle size of the ATO powder fluctuates in the range of 5nm-30nm as the molar ratio of Sb increases. For details, see [Materials Letters, 2005, 59:1801-1810]. Zhong et al. synthesized spherical ATO powder by the sol-gel method using alcohol as organic solvent and metal salt as raw material, and found that the effect of sintering temperature on the average particle size of the powder was more significant than that of sintering time. For details, see [Particuology, 2012.10 :365-370]. In general, during the chemical co-precipitation synthesis process, ATO powder is prone to particle agglomeration and different particle sizes, while the sol-gel method can realize the mixing and doping of reactants at the molecular level and the synthesis temperature is low. Therefore, it is an ideal preparation method for ATO powder.

However, most of the sol-gel methods currently use ethanol as the reaction solvent, and there are few studies on water as the reaction solvent. In view of the fact that the latter can not only greatly reduce the amount of ethanol used and the cost of raw materials in the preparation of ATO powder by the conventional sol-gel method, but also significantly reduce the pressure on environmental protection and the complexity of tooling during the industrial mass production of the powder, so this method has comparative advantages. With great market application potential, it will also become a research hotspot in the field of powder green synthesis. The invention adopts a water-based sol-gel method to synthesize the ATO powder by regulating _nSn / _nSb molar ratio (the molar ratio of Sn and Sb), reaction temperature, sintering temperature and the like.

Contents of the invention

The technical problem to be solved by the present invention is to provide a preparation method of antimony-doped nano-tin oxide (ATO) nano-powder. The product prepared by the method can be used to improve the wettability between _SnO2 and Ag and the electrical properties of the electrical contact material, and the reaction synthesis conditions are simple and the cost is low.

The present invention is achieved through the following technical solutions:

A preparation method of antimony-doped nano-tin oxide powder, said preparation method comprising the steps of:

(1) Preparation of precursor solution A: the colorless transparent solution obtained after adding raw materials citric acid, ethylenediaminetetraacetic acid, and ammonia into water and mixing uniformly is precursor solution A; the citric acid: ethylenediaminetetraacetic acid : The substance molar ratio of ammonia is 2-5:1:0.5; the total substance concentration of raw materials in the precursor solution A is 0.03-0.6mol/L;

(2) Preparation of precursor solution B: add antimony trichloride and tin tetrachloride pentahydrate into water with a molar ratio of 1:6.67-20 and mix them uniformly to obtain a colorless and transparent solution that is precursor solution B ; The total substance concentration of the raw materials in the precursor solution B is 0.2-1.5mol/L;

(3) Preparation of antimony-doped nano-tin oxide powder: add precursor solution B dropwise to precursor solution A to form a uniform transparent solution, then add ammonia water to adjust the pH value to 7-9 to form a sol; after aging treatment A wet gel is formed, followed by drying, grinding, sieving, and sintering in sequence to finally obtain antimony-doped nano-tin oxide powder. The volume ratio of the precursor solution A to the precursor solution B is 1:1-3.

The ammonia described in step (1) of the present invention is recommended to be added in the form of ammonia water.

Further, the water in step (1) and step (2) is preferably deionized water.

Further, the mass concentration of ammonia water described in step (1) is 25% to 28%, preferably the mass concentration of ammonia water is 28%.

Still further, the aging time described in step (3) is 12～24h;

Furthermore, the drying temperature in step (3) is 80°C-100°C.

It is generally recommended that the sieve used in the sieving process in step (3) be 100-200 mesh.

Specifically, the sintering temperature in step (3) is 700-900°C, and the sintering time is 3h-6h.

Compared with prior art, the beneficial effect of the present invention is:

(1) The sol-gel process using water-based instead of alcohol-based can greatly reduce the amount of industrial alcohol used, and the process is more green and environmentally friendly.

(2) The sol-gel process can realize the doping of antimony ions and tin ions at the molecular level, and realize the homogeneous synthesis of ATO powder. The invention has mild reaction temperature, simple process equipment and easy realization of batch synthesis.

(3) The sintering temperature of the Ni-doped SnO ₂ powder prepared by the present invention is 700-900° C., and the reaction time is 3-6 hours. The high sintering temperature in the traditional preparation method is eliminated, the reaction cycle is shortened, and energy consumption is saved.

Description of drawings

Fig. 1 is the TEM picture of the ATO nanopowder of embodiment 1.

Fig. 2 (a), (b) are the photoelectron spectroscopy (XPS) figure of the ATO nanopowder of embodiment 1.

detailed description

The present invention is further described below in conjunction with specific embodiment, but protection scope of the present invention is not limited thereto:

Example 1

(1) Preparation of precursor solution A

According to the molar ratio of citric acid (C ₆ H ₈ O ₇ ), ethylenediaminetetraacetic acid (EDTA) and ammonia water with a mass concentration of 28% at a molar ratio of 2:1:0.5, 0.329 g of citric acid was weighed correspondingly using an electronic balance. , 0.250g of ethylenediaminetetraacetic acid and 0.053g of ammonia water, the solvent is 100mL of deionized water; a certain amount of solute is added to the solvent, stirred with a magnetic force until completely dissolved, and then pipetted into a volumetric flask with a glass rod to constant volume , to prepare a colorless and transparent solution with a concentration of 0.03 mol/L, that is, precursor solution A.

(2) Preparation of precursor solution B

Weigh antimony trichloride 0.217g and tin tetrachloride pentahydrate 6.678g respectively according to antimony trichloride and tin tetrachloride pentahydrate with a molar ratio of 1:20, add them to 100mL deionized water, and stir until completely dissolved, then pipetted into a volumetric flask to constant volume, and prepared into a colorless and transparent solution with a total concentration of 0.2 mol/L, namely precursor solution B.

(3) Preparation of ATO nanopowder

Using a pear-shaped separating funnel, 30 mL of precursor solution B was added dropwise into 10 mL of precursor solution A to form a uniform and transparent solution. After magnetically stirring evenly, slowly add ammonia solution with a mass concentration of 28% dropwise, adjust the pH of the solution to 7, and form a sol. After 24 hours of aging treatment, the sol forms a wet gel and is dried at 80°C; the powder obtained from the drying is ground and passed through a 200-mesh sieve. After grinding and sieving, the dried powder was sintered at 700°C for 6 hours to finally obtain ATO nanopowder.

Example 2

(1) Preparation of precursor solution A

According to citric acid (C ₆ H ₈ O ₇ ) with a molar ratio of 3.5:1:0.5, ethylenediaminetetraacetic acid (EDTA) and ammonia water with a mass concentration of 25%, respectively weigh 4.034 g of citric acid and ethylene diamine Add 1.753g of amine tetraacetic acid and 0.420g of ammonia water, add the above weighed solute into 100mL of deionized water solvent, stir it with magnetic force until it is completely dissolved, then transfer it to a volumetric flask with a glass rod to constant volume, and prepare the concentration It is a colorless and transparent solution of 0.3mol/L, that is, precursor solution A.

(2) Preparation of precursor solution B

Weigh 2.974g of antimony trichloride and 30.489g of tin tetrachloride pentahydrate respectively according to antimony trichloride and tin tetrachloride pentahydrate at a molar ratio of 1:6.67, add them to 100mL deionized water, and stir until completely Dissolved, then pipetted into a volumetric flask to constant volume, and prepared into a colorless and transparent solution with a total concentration of 1 mol/L, that is, precursor solution B.

(3) Preparation of ATO nanopowder

Using a pear-shaped separating funnel, 20 mL of precursor solution B was added dropwise into 10 mL of precursor solution A to form a uniform and transparent solution. After magnetically stirring evenly, slowly add ammonia solution with a mass concentration of 28% dropwise, adjust the pH of the solution to 9, and form a sol. After 20 hours of aging treatment, the sol forms a wet gel and is dried at 90°C; the dried powder is ground and passed through a 100-mesh sieve. After grinding and sieving, the dried powder was sintered at 900°C for 3 hours to finally obtain ATO nano-powder.

Example 3

(1) Preparation of precursor solution A

According to the molar ratio of citric acid (C ₆ H ₈ O ₇ ), ethylenediaminetetraacetic acid (EDTA) and ammonia water with a mass concentration of 26% in a molar ratio of 5:1:0.5, 8.867g of citric acid was weighed correspondingly using an electronic balance , 2.697g of ethylenediaminetetraacetic acid and 0.621g of ammonia water, the solvent is 100mL of deionized water; add a certain amount of solute to the solvent, stir it with magnetic force until it is completely dissolved, and then transfer it to a volumetric flask with a glass rod to constant volume , to prepare a colorless and transparent solution with a concentration of 0.6 mol/L, that is, precursor solution A.

(2) Preparation of precursor solution B

Weigh 2.444g of antimony trichloride and 48.834g of tin tetrachloride pentahydrate respectively according to antimony trichloride and tin tetrachloride pentahydrate at a molar ratio of 1:13, add them to 100mL deionized water, and stir until completely Dissolved, then pipetted into a volumetric flask to constant volume, and prepared into a colorless and transparent solution with a total concentration of 1.5 mol/L, namely precursor solution B.

(3) Preparation of ATO nanopowder

Using a pear-shaped separating funnel, 10 mL of precursor solution B was added dropwise into 10 mL of precursor solution A to form a uniform and transparent solution. After magnetically stirring evenly, slowly add ammonia solution with a concentration of 28% dropwise, adjust the pH of the solution to 8, and form a sol. After 12 hours of aging treatment, the sol forms a wet gel, and is dried at 100°C; the dried powder is ground and passed through a 150-mesh sieve. After grinding and sieving, the dried powder was sintered at 850°C for 5 hours to obtain ATO nano powder.

After testing, the average size of the ATO nanopowder obtained in Examples 1-3 is in the range of 52nm. The TEM photo of Example 1 is shown in Figure 1. The powder has good dispersibility, and Sb ions have been successfully incorporated into the _SnO2 crystal. The solid solution is formed by the lattice, and the Sn and Sb elements in the powder exist in the form of Sn ⁴⁺ , Sb ⁵⁺ and Sb ³⁺ respectively, and the content of Sb ³⁺ is relatively high. The XPS diagram of Example 1 is shown in Figure 2.

Claims (8)

1. a kind of stibium doped nanometer tin oxide raw powder's production technology, it is characterised in that described preparation method includes following step Suddenly：

(1) preparation of precursor solution first：Raw material citric acid, ethylenediamine tetra-acetic acid, ammonia are added to the water after being well mixed and are obtained Colourless transparent solution be precursor solution first；The citric acid：Ethylenediamine tetra-acetic acid：The amount ratio of the material of ammonia is 2～5： 1：0.5；The amount concentration of the total material of raw material is 0.03～0.6mol/L in the precursor solution first；

(2) preparation of precursor solution second：It is 1 by the amount ratio of material：6.67～20 trichloride antimony and stannic chloride pentahydrate add Enter the colourless transparent solution obtained after being well mixed in water and be precursor solution second；Raw material is total in the precursor solution second Substance withdrawl syndrome is 0.2～1.5mol/L；

(3) preparation of stibium doped nanometer tin oxide powder：Precursor solution second is added dropwise in precursor solution first, forms uniform Add ammoniacal liquor to adjust pH value to 7～9 after clear solution, form colloidal sol；Wet gel is formed after aged process, is dried successively Do, grind, sieving, sintering operation, it is final to obtain stibium doped nanometer tin oxide powder；The precursor solution first is molten with presoma The volumetric usage ratio of liquid second is 1：1～3.

2. stibium doped nanometer tin oxide raw powder's production technology as claimed in claim 1, it is characterised in that：Institute in step (1) State ammonia to add in the form of ammoniacal liquor.

3. stibium doped nanometer tin oxide raw powder's production technology as claimed in claim 1, it is characterised in that：Step (1) and step Suddenly the water in (2) is deionized water.

4. stibium doped nanometer tin oxide raw powder's production technology as claimed in claim 2, it is characterised in that：Institute in step (1) The mass concentration of the ammoniacal liquor stated is 25%～28%.

5. stibium doped nanometer tin oxide raw powder's production technology as claimed in claim 1, it is characterised in that：Institute in step (3) Digestion time is stated for 12～24h.

6. stibium doped nanometer tin oxide raw powder's production technology as claimed in claim 1, it is characterised in that：Institute in step (3) Drying temperature is stated for 80 DEG C～100 DEG C.

7. stibium doped nanometer tin oxide raw powder's production technology as claimed in claim 1, it is characterised in that：Institute in step (3) It is 100 mesh～200 mesh to state sieve used in the process of sieving.

8. stibium doped nanometer tin oxide raw powder's production technology as claimed in claim 1, it is characterised in that：Institute in step (3) It is 700～900 DEG C to state sintering temperature, sintering time 3h～6h.