CN1410354A

CN1410354A - Synthesis method of nano zinc oxide powder

Info

Publication number: CN1410354A
Application number: CN 02153787
Authority: CN
Inventors: 林元华; 南策文; 邓元
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2002-12-06
Filing date: 2002-12-06
Publication date: 2003-04-16
Anticipated expiration: 2022-12-06
Also published as: CN1152825C

Abstract

A process for synthesizing the nano-class ZnO powder includes such steps as mixing the sulfate, nitrate, or chloride of zinc with NaOH or KOH, reaction, filtering, washing and drying. Its advantages are simple operation, short period, low energy consumption and little pollution.

Description

Synthesis method of nano ZnO powder

Technical Field

The invention belongs to the technology of ceramic material preparation, and particularly relates to a method for synthesizing nano ZnO powder of an inorganic non-metallic functional ceramic material.

Background

Nano ZnO is a novel multifunctional fine inorganic product with a particle size of 1-100 nm, also known as ultra-fine ZnO. Due to the fine particle size and the large specific surface area, the nano ZnO generates a surface effect, a small size effect, a quantum tunneling effect and the like which are not possessed by the block body of the nano ZnO. Therefore, the nano ZnO has incomparable performance and application in the aspects of magnetic, optical, electric and sensitive components and parts and the like compared with common ZnO products. At present, the synthesis method of nano ZnO has beenA plurality of patents appear continuously. The more common preparation methods are a liquid phase method and a gas phase oxidation method. The liquid phase method is a precursor for directly precipitating ZnO, such as ZnCO₃、Zn(OH)₂、Zn₅(CO₃)₂(OH)₆And roasting the obtained precursor at a certain temperature to synthesize the nano ZnO. The zinc ingot is directly heated, melted and gasified, and proper reaction conditions are controlled; the gas phase oxidation method refers to the synthesis of nano ZnO powder by gas phase oxidation or the gas phase decomposition of Zn by plasma₅(CO₃)₂(OH)₆Synthesizing nanometer ZnO powder from the precursor. Chinese patent CN1296041 discloses a preparation method of nano zinc oxide. The method comprises the steps of firstly preparing zinc oxide seed crystals, then adding the obtained seed crystals into a zinc-containing solution, carrying out heterogeneous nucleation to prepare a precursor, and then carrying out heat treatment on the precursor, thereby obtaining the nano zinc oxide powder. Chen Dynasty, etc. invented a method for preparing zinc oxide nano powder with particle size range of 10-100 nm by using zinc salt solution and sodium hydroxide as main raw materials to prepare zinc hydroxide colloidal precipitate and carrying out hydrothermal or solvothermal reaction. Patent CN1083538 discloses a process and equipment for producing ultra-fine and ultra-pure active zinc oxide by plasma method. Improves the wet production process of zinc oxide, replaces a muffle furnace or a rotary kiln with a plasma generator, completes roasting, pyrolysis, crushing and refining of the basic zinc carbonate in the generator at one time, and realizes continuous production and process. Although the process can obtain nano ZnO particles with uniform particle size distribution, the energy consumption is larger. Grandma et al disclose a new method for preparing nano zinc oxide. The technical key is as follows: with Zn (NO)₃)₂The method comprises the steps of taking urea as a raw material, taking the urea as a uniform precipitator, carrying out hydrolysis on the urea at 122-126 ℃, carrying out reaction for 2-4 h, carrying out reaction on the urea at a reactant ratio (the amount of urea substance/the amount of zinc nitrate substance) of 2: 1-4: 1, and precipitating Zn (OH) in the synthesized intermediate₂In thatCalcining for 2.5-3.5 h at 450-500 ℃. CN1296041 provides a method for preparing nano zinc oxide, firstly preparing zinc oxide seed crystal, then adding the obtained seed crystal into zinc-containing solution to carry out heterogeneous nucleation to prepare precursor, and then preparing the precursorAnd (4) carrying out body heat treatment to obtain the nano zinc oxide powder. Although these methods synthesize superfine nano ZnO powder, they all have the disadvantages of large energy consumption, further roasting treatment and long production period. Moreover, the pollution to the environment is limited to a certain extent.

Disclosure of Invention

The invention aims to provide a method for synthesizing nano ZnO powder, which adopts solid zinc salt, NaOH or KOH solid alkali as raw materials. Weighing the above materials according to a certain component ratio, rapidly stirring for a periodof time by using an electric stirrer, adding a proper amount of distilled water, and washing until the materials are washed by BaCl containing 3%₂、AgNO₃No corresponding SO can be detected in the solution₄ ^2-、Cl^-Drying at a certain temperature to synthesize the nano-scale ZnO powder material; the synthesis process comprises the following steps:

① weighing analytically pure Zn salt powder and NaOH or KOH according to the molar ratio of 1: 2.0-1: 5.0, putting solid strong base into a container, adding Zn salt, rapidly stirring and mixing for 10-40 min to complete the reaction.

② A proper amount of water is added to the above reaction mixture, and the mixture is diluted and further stirred for about 3 to 10 min.

③ the precipitate is filtered and washed with water.

④ placing the sample in a drying oven, drying at 30-60 ℃, and obtaining the powder which is the nano ZnO.

The solid zinc salt comprises a sulfate, nitrate or chloride salt

The method has the beneficial effects that the nano ZnO powder is synthesized by adopting a mechanochemical method, compared with some conventional synthesis methods, the process can synthesize the nano ZnO powder in one step, and the primary particle size of the nano ZnO powder is calculated to be about 20-80 nm. The method has the advantages of simple process, easy control of parameters, no need of post-treatment, shortened production period, low energy consumption, no pollution to the environment, capability of recycling byproducts, realization of resource recycling and the like, easy industrial production and ideal green synthesis process.

Drawings

FIG. 1 is an XRD spectrum of ZnO powder of example 1.

FIG. 2 is an XRD spectrum of ZnO powder of example 2.

FIG. 3 is a microscopic morphology picture of the ZnO powder of example 2

Detailed Description

The invention relates to a method for synthesizing nano-scale ZnO powder. The raw materials adopt solid zinc sulfate, nitrate or chloride salt and NaOH or KOH solid alkali. Weighing the above materials according to a certain component ratio, rapidly stirring for a period of time by using an electric stirrer, adding a proper amount of distilled water, and washing until the materials are washed by BaCl containing 3%₂、AgNO₃No corresponding SO can be detected in the solution₄ ^2-、Cl^-And drying at a certain temperature to synthesize the nano-scale ZnO powder material. The synthesis process comprises the following steps:

③ the precipitate is filtered and washed with water.

The filtrate obtained in the preparation process is neutralized by acid, evaporated and dried to obtain a byproduct for recovery.

The process involves the following chemical reaction (with ZnSO)₄.7H₂O and NaOH for example):

(1)

(2)

(3)

the invention is further illustrated by the following illustrative examples:

example 1:

separately weighing and analyzing pure ZnSO according to the molar ratio of 1: 2₄.7H₂O28.74 g and sodium hydroxide 8g, and sample preparation was carried out in the same manner as in the above-mentioned steps (1) to (4). Rapidly stirring the mixture for 30min, diluting with distilled water, stirring for 4min, filtering, and washing until 3% BaCl is used₂No SO can be detected in the solution₄ ^2-. Then dried at 50 ℃. The dried sample was subjected to X-ray diffraction analysis, as shown in FIG. 1, and the crystal phase thereof was substantially zinc oxide, and the primary particle size thereof was calculated to be about 20 to 80 nm.

Example 2:

28.74g of analytically pure zinc sulfate and 10g of sodium hydroxide are weighed respectively according to the molar ratio of 1: 2.5, and samples are prepared according to the steps (1) - (4). Rapidly stirring the mixture for 25min, diluting with distilled water, stirring for 6min, filtering, and washingWashing until 3% BaCl is used₂No SO can be detected in the solution₄ ^2-. Then dried at 60 ℃. The dried sample was subjected to X-ray diffraction analysis and the product was essentially all zinc oxide, as shown in figure 2. The particle size of the sample is about 30-90 nm when observed under a transmission electron microscope, andthe picture of the microstructure is shown in figure 3.

Example 3:

13.64g of analytically pure zinc chloride and 22.4g of potassium hydroxide are weighed respectively according to the molar ratio of 1: 4.0, and samples are prepared according to the steps (1) to (4). Rapidly stirring the mixture for 35min, diluting with distilled water, stirring for 8min, filtering, and washing until 3% AgNO is used₃No Cl was detected in the solution^-. Then drying at 60 deg.C, making X-ray diffraction analysis on the dried sample, and the product is basically zinc oxide. And observing under a transmission electron microscope, wherein the particle size of the sample is about 30-90 nm.

Example 4:

analytically pure Zn (NO) is weighed according to the molar ratio of 1: 2.5 respectively₃)₂.6H₂O29.75 g and sodium hydroxide 10.0g, and the samples were prepared in the above-mentioned steps (1) to (4). Rapidly stirring the mixture for 20min, diluting with distilled water, stirring for 5min, filtering, and washing. Then dried at 60 ℃ and the dried sample was subjected to X-ray diffraction analysis, and the product was substantially zinc oxide similarly to example 2. And observing under a transmission electron microscope, wherein the particle size of the sample is about 20-70 nm.

Therefore, the nano ZnO powder can be obtained by a mechanochemical method by adopting solid-phase zinc salt and solid NaOH or KOH and controlling certain conditions.

Claims

1. A method for synthesizing nano ZnO powder is characterized in that: weighing solid zinc salt, NaOH or KOH solid alkali according to a certain component ratio, quickly stirring for a period of time by using an electric stirrer, adding a proper amount of distilled water, and washing until the mixture is washed by BaCl containing 3%₂、AgNO₃No corresponding SO can be detected in the solution₄ ^2-、Cl^-And drying at a certain temperature to synthesize the nano-scale ZnO powder material, wherein the synthesis process comprises the following steps:

① weighing analytically pure Zn salt powder and NaOH or KOH according to the molar ratio of 1: 2.0-1: 5.0, putting solid strong base into a container, adding Zn salt, rapidly stirring and mixing for 10-40 min to complete the reaction;

② adding appropriate amount of water into the above reactant, diluting, and further stirring for about 3-10 min;

③ filtering and washing the precipitate;

2. The method for synthesizing nano ZnO powder according to claim 1, which is characterized in that: the solid zinc salt comprises a sulfate, nitrate or chloride salt.