Conductive zinc oxide powder and preparation method thereof

Abstract

The present application discloses a conductive zinc oxide powder and a preparation method thereof, which relates to the technical field of conductive powder materials, and comprises: configuring a zinc source, a doping element source and an oxide powder into a suspension; spray drying the suspension to obtain a precursor; and sintering the precursor to obtain a conductive zinc oxide powder. The present application improves the problem that the existing preparation method is not environmentally friendly, simplifies the preparation process, improves the preparation efficiency, and is conducive to large-scale production and commercialization.

Description

Technical Field

[0001] The present application relates to the field of conductive powder materials, and in particular to a conductive zinc oxide powder and a preparation method thereof. Background Art

[0002] With the rapid development of the electronics industry and the improvement of people's living standards, conductive powder materials, as a functional filler in the preparation process of plastics, coatings, fibers, ceramics, etc., can give them antistatic and electromagnetic shielding properties, and have attracted widespread attention. At present, the commonly used conductive powders are metal powders, carbon powders and oxide conductive powders. Among oxide conductive powders, common semiconductor materials include doped tin oxide, indium oxide, zinc oxide, etc. Among them, the band gap of zinc oxide is about 3.4eV. It is an intrinsic n-type semiconductor with the advantages of environmental friendliness, abundant raw materials, and low production cost. It is an excellent conductive powder material.

[0003] At present, researchers usually use hydrothermal method, sol-gel method, solid-phase sintering method, co-precipitation method, etc. to prepare powder materials. The hydrothermal method mainly adds a precipitant to the salt solution, and after high-temperature hydrothermal in an autoclave, the product is obtained after washing, filtering, and drying; the sol-gel method is to add a stabilizer to the solution, and the product is obtained after a long period of drying and grinding; the precipitation method is to add a precipitant to the prepared solution to generate a precipitate, and after a long period of stirring, mixing and drying, the target powder is obtained.

[0004] For example, a method for preparing light-colored doped nano-conductive zinc oxide powder comprises: preparing a zinc salt solution containing aluminum, gallium or tin, then adding the above solution into an alkaline solution such as ammonia water, urotropine or urea, and obtaining light-colored doped nano-conductive zinc oxide powder through a one-step hydrothermal treatment. Another example is a method for preparing conductive zinc oxide powder, wherein the corresponding zinc source, aluminum source and dispersant are put into a reactor, and water is used as a medium. Through the unique effects of ultrasound and microwaves, a gel-state precursor with uniform doping and stable properties is efficiently obtained, and then after calcination at a certain temperature, a conductive zinc oxide nano-powder doped with aluminum oxide is prepared.

[0005] With respect to the above-mentioned related technologies, the inventors believe that the following defects exist: in the existing technology for preparing conductive zinc oxide powder, in addition to metal soluble salts, non-conductive powders, precipitants or stabilizers and other reactants must be used during the preparation to obtain a conductive powder precursor, and often steps such as water washing, filtering, drying, crushing, grinding, and waste liquid treatment are required. The preparation process is relatively complicated, so the preparation efficiency is low, the cost is high, and it is not environmentally friendly, which is not conducive to large-scale production and commercialization. Summary of the invention

[0006] (I) Purpose of the invention

[0007] The purpose of the present application is to provide a conductive zinc oxide powder and a preparation method thereof, wherein a zinc source, a doping element source and an oxide powder are used as raw materials, and a conductive zinc oxide powder can be prepared through a spray drying and sintering process, so as to improve the problems of low preparation efficiency, high cost, poor environmental protection and unfavorable large-scale production and commercialization of the existing preparation method.

[0008] (II) Technical solution

[0009] In order to improve the above problems, according to one aspect of the present application, a method for preparing a conductive zinc oxide powder is provided, which comprises:

[0010] The zinc source, the doping element source and the oxide powder are configured into a suspension;

[0011] spray drying the suspension to obtain a precursor;

[0012] The precursor is sintered to obtain conductive zinc oxide powder.

[0013] Optionally, the molar content of the doping element source in the sum of the zinc source and the doping element source is 1%-10%.

[0014] Optionally, the zinc source is selected from soluble zinc salts.

[0015] Optionally, the zinc source is selected from at least one of zinc nitrate and zinc acetate.

[0016] Optionally, the doping element in the doping element source is selected from elements in the third or fourth main group, and the doping element source is selected from soluble salts of doping elements.

[0017] Optionally, the doping element source is selected from at least one of gallium chloride, gallium nitrate, gallium acetate, indium chloride, indium nitrate, indium acetate, tin chloride, tin nitrate, tin acetate, aluminum chloride, aluminum nitrate, and aluminum acetate.

[0018] Optionally, the spray drying has a spray rate of 1 mL / min-10 L / min, and a drying temperature of 100°C-280°C.

[0019] Optionally, sintering the precursor includes:

[0020] The precursor is heated to 800° C.-1200° C. at 5° C. / min-20° C. / min in an air atmosphere, and maintained at this temperature for 30 min-240 min.

[0021] Optionally, sintering the precursor further comprises:

[0022] The product obtained by the above process is kept in an inert atmosphere or a reducing atmosphere at a temperature range of 400° C. to 1000° C. for 30 min to 240 min.

[0023] According to another aspect of the present application, a conductive zinc oxide powder prepared by the above preparation method is provided.

[0024] (III) Beneficial effects

[0025] The above-mentioned technical scheme of the present application has the following beneficial technical effects: first, in the preparation process of the conductive zinc oxide powder, there is no need to add reactants such as precipitants, stabilizers or dispersants, and no waste liquid is generated in the preparation process, which is more environmentally friendly compared with the existing method for preparing conductive zinc oxide powder; secondly, since the preparation process of the conductive zinc oxide powder in the prior art is relatively complicated, it often requires steps such as water washing, filtering, drying, crushing, grinding and waste liquid treatment, while in the present application, only zinc source, doping element source, oxide powder and water are used as raw materials, and zinc oxide powder can be prepared through spray drying and sintering processes, which simplifies the preparation process, reduces costs, improves preparation efficiency, and is conducive to large-scale production and commercialization. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present application.

[0027] In the description of the present application, it should be noted that the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] The present application is described in detail below with reference to the embodiments:

[0029] As a specific embodiment of the present application, the present application provides a method for preparing a conductive zinc oxide powder, the preparation method comprising:

[0030] A zinc source and a doping element source are configured into a solution, wherein the molar content of the doping element source in the total of the zinc source and the doping element source is 1%-10%, and oxide powder is added into the solution to configure into a suspension;

[0031] The suspension is spray-dried to obtain a precursor;

[0032] Sintering the precursor to obtain conductive zinc oxide powder;

[0033] Specifically, a zinc source and a doping element source are configured into a solution, wherein the molar content of the doping element source in the total of the zinc source and the doping element source is 1%-10%, and oxide powder is added into the solution to configure into a suspension:

[0034] In some embodiments, the zinc source is selected from soluble zinc salts, the doping element in the doping element source is selected from elements in the third main group or the fourth main group, and further, the doping element source is selected from soluble salts of doping elements.

[0035] In an exemplary embodiment, the soluble zinc salt is at least one of zinc nitrate and zinc acetate, and the soluble salt of the doping element is at least one of gallium chloride, gallium nitrate, gallium acetate, indium chloride, indium nitrate, indium acetate, tin chloride, tin nitrate, tin acetate, aluminum chloride, aluminum nitrate, and aluminum acetate.

[0036] Specifically, the suspension is spray-dried to obtain a precursor:

[0037] In some embodiments, the spray drying rate is 1 mL / min-10 L / min, and the drying temperature is 100°C-280°C. During the spray drying process of the suspension, the water molecules on the surface of the oxide powder evaporate rapidly, and capillary forces are generated on the surface of the oxide powder, so that the zinc ions and the metal dopant ions are uniformly adsorbed on the surface of the oxide powder to obtain a conductive zinc oxide powder precursor. Due to the collision of the airflow generated by the spray drying equipment on the powder, the conductive zinc oxide powder prepared in the present application has a smaller particle size and a narrower particle size distribution.

[0038] Although spray drying is a traditional method for drying materials, this application not only utilizes the drying effect of spray drying technology on solvents, but more importantly, utilizes this process to achieve the coating of any oxide with a doped zinc oxide precursor, and any oxide can be zinc oxide, magnesium oxide, titanium oxide, gallium oxide, silicon oxide, etc. This application uses the capillary force generated by the evaporation process of water molecules on the surface of the oxide powder during the spray drying process to allow zinc ions and metal doping ions to fully contact the oxide powder and be uniformly adsorbed on the oxide surface. At the same time, spray drying also has the effect of refining droplets and enhancing powder fluidity, promoting the formation of a dense doped zinc oxide shell on the oxide surface, and laying the foundation for subsequent solid phase sintering to obtain oxide-doped zinc oxide core-shell nano-conductive powder.

[0039] Based on the spray drying technology mentioned above, the doped zinc oxide powder can be coated on the surface of any white oxide powder, and then a multifunctional composite powder can be constructed. That is, it is only necessary to select the core layer material according to the service conditions of the composite powder material, and use the core layer oxide material to reduce the density, improve the whiteness, enhance the radiation resistance and other functions, and then use the doped zinc oxide shell layer to play a conductive role to meet different application requirements. For example, the method of the present application can be used to prepare magnesium aluminate and aluminum-doped zinc oxide core-shell nanopowders, which have the characteristics of low density, antistatic, radiation resistance, high reflectivity, etc., and are suitable for use as thermal control coating fillers for satellites. On the one hand, this takes advantage of the conductivity of aluminum-doped zinc oxide, and on the other hand, it takes advantage of the fact that the density of magnesium aluminate is less than that of zinc oxide, and its ultraviolet light reflection ability and radiation resistance are stronger than those of zinc oxide.

[0040] Specifically, in sintering the precursor to obtain the conductive zinc oxide powder:

[0041] The sintering process consists of two stages.

[0042] The first stage is the air sintering process: the precursor is heated to 800-1200°C at 5-20°C / min in an air atmosphere and maintained for 30-240 minutes. During the air sintering process, impurity elements in the precursor, such as carbon, nitrogen, and hydrogen, can be removed, and a dense doped zinc oxide shell layer is formed on the surface of the oxide powder.

[0043] The second stage is a reducing atmosphere sintering process: the product obtained through the first stage air sintering process is kept in a reducing atmosphere at a temperature range of 400°C-1000°C for 30min-240min. During the sintering process in an inert atmosphere or a reducing atmosphere, metal impurities and excess oxygen elements in the doped zinc oxide shell can be removed, and the generation of excessive adsorbed oxygen can be avoided, thereby making the doped zinc oxide shell on the surface of the oxide powder denser.

[0044] After a large number of tests, it was found that white conductive zinc oxide powder cannot be prepared by sintering in air or reducing atmosphere alone. The main reason is that high-temperature air sintering is conducive to the bonding of oxygen and zinc, reducing deep-level defects such as impurities or oxygen vacancies, but it will inevitably introduce excessive interstitial oxygen or surface adsorbed oxygen into the zinc oxide lattice. As acceptors, they will capture carriers, causing the zinc oxide powder prepared by high-temperature air sintering to be non-conductive; if a one-step reducing atmosphere sintering is directly performed, it will cause excessive oxygen vacancies and other defects in zinc oxide. Although they can provide electrons as donors, they are easy to absorb visible light, reducing the whiteness of the zinc oxide powder, and the resulting conductive powder is usually gray-black.

[0045] The two-step sintering technology route is adopted, and the first step is high-temperature air sintering to remove impurities and form a doped zinc oxide shell. Further, low-temperature inert atmosphere or reducing atmosphere sintering is used to remove adsorbed oxygen and activate dopants, so that a high-whiteness conductive doped zinc oxide shell can be prepared. In summary, the solid-phase sintering technology used in this application is designed for oxide-doped zinc oxide precursor nanopowders. The two-step sintering technology route is not well known to those skilled in the art, but is invented through a lot of creative work of the applicant and is creative.

[0046] The following introduces a preferred embodiment of "a method for preparing conductive zinc oxide powder". The embodiment is only a better or preferred solution to achieve the purpose of this application, but does not constitute a limitation to the present invention.

[0047] Example 1

[0048] Weigh 546 g of zinc nitrate and 9.5 g of gallium nitrate, dissolve in 1 L of deionized water, and stir evenly at 1000 rpm with a stirrer. Weigh 60.45 g of zinc oxide powder, wherein the particle size of the zinc oxide powder is 1-3 μm, and stir evenly at 600 rpm with a stirrer to obtain a suspension.

[0049] The suspension was spray dried using a small laboratory spray dryer. During this process, the spray rate of the spray dryer was controlled to be 10 ml / min, and the drying temperature of the spray dryer was controlled to be 150° C., to obtain a conductive zinc oxide powder precursor.

[0050] The conductive zinc oxide powder precursor is placed in a tube furnace, first heated to 1000°C at 10°C / min and maintained for 120 min, then nitrogen is introduced into the tube furnace, and the product obtained by the above sintering process is maintained at 700°C for 120 min, and finally cooled to room temperature to obtain a conductive powder.

[0051] The obtained conductive zinc oxide powder has a whiteness of 85±1%, a resistivity of 0.35±0.2Ω·m, and an average particle size of 3-5μm.

[0052] Example 2

[0053] Weigh 546 g of zinc nitrate and 13.2 g of gallium chloride, dissolve in 1 L of deionized water, and stir evenly at 1000 rpm with a stirrer. Weigh 60.45 g of silicon oxide powder with a particle size of 1 μm into the zinc nitrate and gallium chloride solutions, and stir evenly at 600 rpm with a stirrer to obtain a suspension.

[0054] The suspension was spray dried using a small laboratory spray dryer. During this process, the spray rate of the spray dryer was controlled to be 10 ml / min, and the drying temperature of the spray dryer was controlled to be 180° C., to obtain a conductive zinc oxide powder precursor.

[0055] The conductive zinc oxide powder precursor is placed in a tube furnace, first heated to 1000°C at 8°C / min and maintained for 120 minutes, then nitrogen is introduced into the tube furnace, and the product obtained by the above sintering process is maintained at 800°C for 120 minutes, and finally cooled to room temperature to obtain a conductive zinc oxide powder.

[0056] The obtained conductive zinc oxide powder has a whiteness of 88±1%, a resistivity of 0.8±0.2Ω·m, and a particle size of 1-3μm.

[0057] Example 3

[0058] 10 kg of zinc acetate and 0.62 kg of gallium nitrate were weighed, dissolved in 40 L of deionized water, and stirred evenly at 800 rpm using a stirrer. 5 kg of zinc oxide powder was weighed and placed in the above zinc acetate and gallium nitrate solutions. The particle size of the zinc oxide powder was 1-3 μm. The mixture was stirred evenly at 400 rpm using a stirrer to obtain a suspension.

[0059] The suspension was spray dried using an industrial large-scale spray drying device. During this process, the spray rate of the spray drying was controlled to be 1 L / min, and the drying temperature of the spray drying was controlled to be 180° C., to obtain a conductive zinc oxide powder precursor.

[0060] The conductive zinc oxide powder precursor is placed in a tube furnace, first heated to 1000°C at 8°C / min and maintained for 120 minutes, then nitrogen is introduced into the tube furnace, and the product obtained through the above sintering process is maintained at 900°C for 120 minutes, and finally cooled to room temperature to obtain a conductive zinc oxide powder.

[0061] The obtained conductive zinc oxide powder has a whiteness of 81±1%, a resistivity of 0.7±0.2Ω·m, and a particle size of 1-3μm.

[0062] Example 4

[0063] Weigh 2.5 kg of zinc nitrate and 0.33 kg of gallium nitrate, dissolve in 24 L of deionized water, and stir evenly at 600 rpm with a stirrer. Weigh 3 kg of silicon oxide powder with a particle size of 1 μm and place it in the above zinc nitrate and gallium nitrate solutions, and stir evenly at 400 rpm with a stirrer to obtain a suspension.

[0064] The suspension was spray dried using an industrial large-scale spray drying device. During this process, the spray rate of the spray drying was controlled to be 0.5 L / min, and the drying temperature of the spray drying was controlled to be 210° C., to obtain a conductive zinc oxide powder precursor.

[0065] The conductive zinc oxide powder precursor is placed in a tube furnace, first heated to 900°C at 8°C / min and maintained for 120 minutes, then nitrogen is introduced into the tube furnace, and the product obtained by the above sintering process is maintained at 800°C for 120 minutes, and finally cooled to room temperature to obtain a conductive zinc oxide powder.

[0066] The obtained conductive zinc oxide powder has a whiteness of 83±1%, a resistivity of 0.9±0.2Ω·m, and a particle size of 1-3μm.

[0067] The present application also provides a conductive zinc oxide powder, which is prepared according to the aforementioned preparation method.

[0068] Comparative Example 1

[0069] Prepare 100ml of 0.1mol / L zinc nitrate solution; add 0.5wt% aluminum sulfate to the solution to form solution A; prepare 100ml of 0.1mol / L ammonia solution B; mix solution A and solution B evenly and stir for 0.5h; transfer the above solution to a stainless steel autoclave lined with polytetrafluoroethylene and perform hydrothermal reaction at 120 degrees Celsius for 6 hours. After the reaction, wash the precipitated product with deionized water three times and then dry it to obtain the target light-colored aluminum-doped nano zinc oxide conductive powder.

[0070] This preparation process requires adding an alkaline solution as a precipitant to the metal salt solution, and also requires a long period of high temperature and high pressure hydrothermal reaction process to obtain the powder. Compared with the examples of the present application, the preparation efficiency of comparative example 1 is low and waste liquid will be generated, which is not conducive to large-scale production and commercialization.

[0071] Comparative Example 2

[0072] Weigh 1kg of commercially available nano-zinc oxide, wash it three times with deionized water and ethanol respectively, and set aside. Weigh another 0.02kg of gallium chloride and dissolve it in 2L of deionized water. Under the stirring of an electric stirrer at a speed of 400rpm, add the washed commercially available nano-zinc oxide to the above gallium chloride solution while stirring to form a paste, continue stirring for 2 hours, put the above paste into a 120℃ oven for drying, and obtain a powder, then put the powder into a rotary tube furnace, and fill the rotary tube furnace with inert gas, set the rotary tube furnace heating program, first heat to 100℃, keep warm for 0.5h, then heat to 200℃, keep warm for 0.5h, then heat to 300℃, keep warm for 4h; after the insulation is completed, cool down, first cool down to 200℃, keep warm for 0.5h, then cool down to 100℃, keep warm for 0.5h, and finally cool down to room temperature to obtain nano-zinc oxide powder. The heating temperature of the water vapor generator connected to the rotary tube furnace was set to 60 °C, and the flow rate of the inert gas was 100 mL / min;

[0073] The volume resistivity and whiteness of the obtained nano zinc oxide powder were tested. The test method for the volume resistivity was as follows: the obtained nano zinc oxide powder was pressed into a cylinder with a diameter of 20 mm and a height of 5 mm under a pressure of 20 MPa, and the resistance of the cylinder was tested by a circuit. After calculation, the volume resistivity was obtained to be 800 Ω·m; the whiteness value was tested using a whiteness meter, and the test result was a whiteness value of 95.

[0074] Comparative Example 2 has the following differences from the present application, which are briefly described as follows:

[0075] In terms of raw materials, in Comparative Example 2, zinc oxide powder and soluble salt of doped ions are used as raw materials, water is used as solvent, and the three are mixed and stirred for a long time, and the surface corrosion and reaction of the zinc oxide powder by the dopant ions are used to form doped zinc oxide on its surface as a conductive shell. This method uses the core layer material as the reaction raw material, and requires that the core layer material must be zinc oxide to prepare the doped zinc oxide shell, which has limitations. In the present application, the applicant uses soluble zinc salt, soluble salt of doping elements, oxide powder and water as raw materials, and spray-dries them after mixing the four. During the spray drying process, the capillary force generated by the evaporation of water molecules on the oxide surface is used to adsorb zinc ions and dopant ions, and a doped zinc oxide precursor is formed on the oxide surface. Since the raw materials for forming the doped zinc oxide shell have been added to the mixed material, the restriction on the type of oxide material in Comparative Example 2 is broken, and any material such as zinc oxide, magnesium oxide, aluminum oxide, silicon oxide, etc. can be used, and it can be further used to achieve weight loss, radiation resistance, full spectrum reflection and other functions, which can expand the application field of zinc oxide conductive powder.

[0076] In terms of technical solutions, the two also have obvious differences. In comparative example 2, the reactants are dried in an oven and the precursor is converted into conductive zinc oxide powder by steam sintering. The present application adopts a spray drying and step-by-step sintering process, which are obviously different.

[0077] Specifically:

[0078] The temperature inside the oven is uneven. During the drying process, the moisture in the outer powder evaporates quickly, while the moisture in the inner powder evaporates slowly, resulting in serious agglomeration of the powder after drying and uneven electrical properties. In contrast, spray drying uses airflow pressure and centrifugal force to atomize water, and then evaporates it with the help of hot air. This principle determines that the powder prepared in this application has good fluidity and uniform particle size.

[0079] In Comparative Example 2, the conductive powder is prepared by sintering in a steam atmosphere, which will be disturbed and affected by the humidity of the external environment. For example, the performance of the conductive powder prepared in dry winter weather and hot and humid summer weather will be different. However, the present application adopts a two-step sintering method, and the gas concentration and pressure of the reducing atmosphere in the second step can be accurately controlled by an industrial flow meter. With the help of the thermal conduction of gas molecules, the conductive powder prepared in the present application has good consistency and batch stability.

[0080] To sum up, firstly, when the conductive zinc oxide powder is prepared by the method provided in the present application, there is no need to add reactants such as precipitants, stabilizers or dispersants, and no waste liquid is generated during the preparation process, which is more environmentally friendly than the existing method for preparing conductive zinc oxide powder; secondly, in the present application, only zinc source, doping element source, oxide powder and water are used as raw materials, and zinc oxide powder can be prepared through spray drying and sintering processes, which simplifies the preparation process, reduces the preparation cost, improves the preparation efficiency, and is conducive to large-scale production and commercialization.

[0081] It should be understood that the above specific embodiments of the present application are only used to illustrate or explain the principles of the present application, and do not constitute a limitation to the present application. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present application should be included in the protection scope of the present application. In addition, the claims attached to the present application are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for preparing conductive zinc oxide powder, wherein: include: A zinc source, a doping element source and an oxide powder are configured into a suspension, wherein the zinc source and the doping element source are configured into a solution, and the oxide powder is added into the solution to configure the suspension; the molar content of the doping element source in the total of the zinc source and the doping element source is 1%-10%; The suspension is spray-dried to obtain a precursor, wherein the precursor is a conductive zinc oxide powder precursor, the spray rate of the spray drying is 1 mL / min-10 L / min, and the drying temperature of the spray drying is 100° C.-280° C.; The precursor is sintered to obtain a conductive zinc oxide powder, wherein the conductive zinc oxide powder is an oxide powder with a doped zinc oxide shell layer formed on the surface; wherein the sintering is a two-step sintering, wherein the first step is to remove impurities by sintering in high-temperature air to form a doped zinc oxide shell layer on the surface of the oxide powder; and the second step is to sinter the product of the first step in a low-temperature inert atmosphere or a reducing atmosphere to remove adsorbed oxygen and activate dopants to prepare a doped zinc oxide shell layer on the surface of the oxide powder, wherein the doped zinc oxide shell layer obtained in the second step is conductive and denser than the doped zinc oxide shell layer obtained in the first step; Wherein, the zinc source is selected from soluble zinc salts.

2. The method for preparing conductive zinc oxide powder according to claim 1, wherein: The zinc source is selected from at least one of zinc nitrate and zinc acetate.

3. The method for preparing conductive zinc oxide powder according to claim 1, wherein: The doping element in the doping element source is selected from elements in the third or fourth main group, and the doping element source is selected from soluble salts of doping elements.

4. The method for preparing conductive zinc oxide powder according to claim 1, wherein: The doping element source is selected from at least one of gallium chloride, gallium nitrate, gallium acetate, indium chloride, indium nitrate, indium acetate, tin chloride, tin nitrate, tin acetate, aluminum chloride, aluminum nitrate, and aluminum acetate.

5. The method for preparing conductive zinc oxide powder according to claim 1, wherein: The sintering of the precursor comprises: The precursor is heated to 800° C.-1200° C. at 5° C. / min-20° C. / min in an air atmosphere, and maintained at this temperature for 30 min-240 min.

6. The method for preparing conductive zinc oxide powder according to claim 5, wherein: The sintering of the precursor further comprises: The product obtained by the above process is kept in an inert atmosphere or a reducing atmosphere at a temperature range of 400° C. to 1000° C. for 30 min to 240 min.