Preparation method of zinc-aluminum spinel and zinc-aluminum spinel with hollow structure

Abstract

The invention relates to a preparation method of zinc-aluminum spinel and zinc-aluminum spinel with a hollow structure. According to the preparation method, metal zinc powder and aluminum powder serve as raw materials, absolute ethyl alcohol is added, ultrasonic mixing is conducted, then suspension liquid is subjected to solid-liquid separation, roasting is conducted in the air atmosphere, and finally the zinc-aluminum spinel of the hollow structure is obtained. The preparation method is simple, efficient and easy to operate, and the obtained product is uniform in particle size, has a complete hollow structure and can adapt to various application scenes.

Description

Technical Field

[0001] This invention belongs to the field of zinc-aluminum spinel preparation technology, specifically relating to a zinc-aluminum spinel with a hollow structure and its preparation method. Background Technology

[0002] Zinc-aluminum spinel is a ternary inorganic compound with the chemical formula ZnAl₂O₄ and a spinel structure. In this structure, oxygen ions are cubically close-packed, while zinc and aluminum ions occupy different lattice positions. This lattice structure endows zinc-aluminum spinel with unique properties, such as excellent thermal stability, high mechanical strength and hardness, and strong resistance to acids and alkalis. This material can be used as a high-quality refractory and optical material, and it can also be applied in semiconductor and catalyst support applications.

[0003] Currently, the main methods for preparing zinc-aluminum spinel include solid-state methods, precipitation methods, co-precipitation methods, sol-gel methods, hydrothermal methods, and molten salt synthesis methods. These methods primarily use alumina and zinc oxide, or zinc salts and aluminum salts, as the main raw materials, attempting to reduce the dependence on heat treatment and thus obtain materials with higher specific surface area, smaller particle size, and higher chemical purity. However, this often overlooks the issue of particle morphology. When zinc-aluminum spinel particles possess unique morphologies or structures, they will have potential applications in a wider range of fields.

[0004] CN 105819849A discloses a zinc aluminate nanopowder and its preparation method. The method uses aluminum and zinc salts as raw materials, adds a morphology control agent and urea, reacts in a high-pressure reactor, and then performs low-temperature drying and high-temperature calcination to obtain zinc aluminate nanopowder with a fluffy sea urchin-like structure. Although CN 105819849A yields a product with a unique morphology, the synthesis process requires numerous reagents and is complex, which is not conducive to practical applications. Summary of the Invention

[0005] The problem the invention aims to solve

[0006] In view of the above situation, there is a need for a method that requires fewer reagents, is easy to operate, and can obtain zinc-aluminum spinel with unique morphology or structure.

[0007] Solution for solving the problem

[0008] In this invention, zinc-aluminum spinel with a unique hollow structure was obtained through a simple preparation method.

[0009] Specifically, the present invention provides a method for preparing zinc-aluminum spinel, which includes the following steps:

[0010] Step a: Add zinc powder and aluminum powder to anhydrous ethanol, sonicate at room temperature to obtain zinc-aluminum suspension, then filter or centrifuge the suspension and dry it to obtain zinc-aluminum mixed powder;

[0011] Step b: The zinc-aluminum mixed powder obtained in step a is calcined in air atmosphere to obtain zinc-aluminum spinel with a hollow structure.

[0012] According to the preparation method described above, in step a, both the zinc powder and the aluminum powder are spherical.

[0013] According to the preparation method described above, in step a, the particle size (D50) of the zinc powder and the aluminum powder is 10 nm to 10 μm, and the particle size (D50) of the zinc powder and the aluminum powder is the same or different, preferably the particle size (D50) of the zinc powder and the aluminum powder is the same.

[0014] According to the preparation method described above, in step a, the molar ratio of the zinc powder to the aluminum powder is 0.5:1.

[0015] According to the preparation method described above, in step a, the ultrasonic treatment time is 5 min to 15 min.

[0016] According to the preparation method described above, in step a, the drying temperature is 80-150℃ and the drying time is 8-15h.

[0017] According to the preparation method described above, in step b, the target calcination temperature is 800℃~1200℃, the heating rate is 0.5℃ / min~2℃ / min, and the holding time is 1.5~3h.

[0018] The present invention also provides a zinc-aluminum spinel prepared by the above-described preparation method, wherein the zinc-aluminum spinel has a hollow structure.

[0019] The effects of the invention

[0020] The preparation method of the present invention is simple and easy to operate, and the obtained zinc-aluminum spinel particles are uniform in size and have a complete hollow structure. Attached Figure Description

[0021] Figure 1 The image shows the X-ray diffraction (XRD) pattern of the zinc-aluminum spinel prepared in Example 1.

[0022] Figure 2 This is a particle size distribution diagram of the zinc-aluminum spinel prepared in Example 2.

[0023] Figure 3The specific surface area of ​​the zinc-aluminum spinel prepared in Example 2

[0024] Figure 4 The image shows the X-ray diffraction (XRD) pattern of the zinc-aluminum spinel prepared in Example 2.

[0025] Figure 5 This is a transmission electron microscope image of the zinc-aluminum spinel prepared in Example 2.

[0026] Figure 6 The image shows a transmission electron microscope image and elemental distribution diagram of the zinc-aluminum spinel prepared in Example 2.

[0027] Figure 7 Transmission electron microscope image of zinc-aluminum spinel prepared in Comparative Example 1. Detailed Implementation

[0028] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0029] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0030] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0031] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0032] In this manual, "room temperature" refers to the ambient temperature, which is usually "25℃±5℃".

[0033] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0034] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0035] The method for preparing zinc-aluminum spinel of the present invention uses spherical metallic zinc powder and aluminum powder as raw materials, and obtains zinc-aluminum spinel with a hollow structure through simple ultrasonic mixing and calcination.

[0036] Specifically, the method for preparing zinc-aluminum spinel of the present invention includes the following steps: step a of mixing raw materials and step b of calcining powder. Each step is described in detail below.

[0037] Step a

[0038] In step a, zinc powder and aluminum powder are added to anhydrous ethanol and ultrasonically treated at room temperature to obtain a zinc-aluminum suspension. The suspension is then filtered or centrifuged and dried to obtain a zinc-aluminum mixed powder.

[0039] In a preferred embodiment, both the zinc powder and aluminum powder used in this invention are spherical, which is to make it easier for the metal particles to undergo the Kirkendall effect with oxygen during subsequent oxidation.

[0040] The particle size (D50) of the zinc powder and aluminum powder used in this invention can each be 10 nm to 10 μm, for example, 20 nm, 50 nm, 100 nm, 500 nm, 800 nm, 1 μm, 3 μm, 5 μm, 8 μm, etc. In specific embodiments, the particle size (D50) of the zinc powder and aluminum powder can be the same or different, but it is preferred that the particle size (D50) of the zinc powder and aluminum powder is the same. This is because the same particle size can ensure the uniformity of the subsequent solid-phase reaction and can better control the particle size of the zinc-aluminum spinel obtained after the reaction.

[0041] In step a, the molar ratio of zinc powder to aluminum powder is a stoichiometric ratio, which is 0.5:1.

[0042] In this invention, anhydrous ethanol is used as the solvent for dispersing zinc and aluminum powders. Water cannot be used to prevent them from reacting with water. The amount of ethanol used is not particularly limited, as long as it is sufficient to disperse the zinc and aluminum powders. In specific embodiments, the amount of anhydrous ethanol can be 2 to 5 times the mass of the powders, for example, 2, 3, 4, or 5 times the mass. The mass of the powders here refers to the total mass of the zinc and aluminum powders.

[0043] In step a, the ultrasonic treatment time can be 5 min to 15 min, for example, 6 min, 8 min, 10 min, 12 min, etc.

[0044] In step a, the drying temperature can be 80-150℃, for example, 90℃, 100℃, 120℃, etc.; the drying time can be 8-15h, for example, 9h, 10h, 12h, etc.

[0045] Step a involves thoroughly and uniformly mixing zinc powder and aluminum powder, allowing them to react fully and produce zinc-aluminum spinel with a hollow structure.

[0046] Step b

[0047] In step b, the zinc-aluminum mixed powder obtained in step a is calcined in air atmosphere from room temperature to a target temperature to obtain zinc-aluminum spinel with a hollow structure.

[0048] In step b, the target calcination temperature can be 800℃ to 1200℃, for example, 900℃, 1000℃, 1100℃, etc. The heating rate can be 0.5℃ / min to 2℃ / min, for example, 0.8℃ / min, 1.0℃ / min, 1.2℃ / min, 1.5℃ / min, 1.8℃ / min, etc. The holding time can be 1.5 to 3 hours, for example, 1.8 hours, 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, etc.

[0049] Furthermore, this invention also provides zinc-aluminum spinel prepared by the above-described preparation method. The zinc-aluminum spinel of this invention has a hollow structure. The average particle size of the zinc-aluminum spinel of this invention can be 50–150 nm, preferably 80–120 nm, for example, 60 nm, 100 nm, 130 nm, etc. The zinc-aluminum spinel of this invention has a high specific surface area, and its BETN2 adsorption specific surface area can be 60–90 m² / s. 2 / g, for example, can be 65m 2 / g、70m 2 / g、75m 2 / g、80m 2 / g、85m 2 / g etc.

[0050] Example

[0051] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0052] Example 1

[0053] Weigh out 6.5380g of spherical zinc powder (D) according to a zinc-aluminum molar ratio of 0.5:1. 50 =1μm) and 5.3960g of spherical metallic aluminum powder (D 50 =1μm), add 35g of anhydrous ethanol, and sonicate at room temperature for 10min to obtain a zinc-aluminum suspension. Then filter or centrifuge the suspension, and finally dry it at 100℃ for 12h to obtain a zinc-aluminum mixed powder. Under air atmosphere, heat from room temperature to 1200℃ at a heating rate of 1℃ / min and hold at that temperature for 2h to finally obtain zinc-aluminum spinel with a hollow structure.

[0054] The above samples were subjected to phase analysis using X-ray diffraction (XRD, CuKα rays, λ = 0.1541 nm, model: D8-Advance A25, Brucker GmbH, Germany, operating voltage 35 kV, operating current 30 mA, scanning speed in step scan mode 6° / min, diffraction angle range 20°–90°). Figure 1 As shown, the phase of the sample is spinel.

[0055] Example 2

[0056] Weigh out 6.5380g of spherical zinc powder (D) according to a zinc-aluminum molar ratio of 0.5:1. 50 =50nm) and 5.3960g of spherical metallic aluminum powder (D 50 =50nm), add 35g of anhydrous ethanol, and sonicate at room temperature for 10min to obtain a zinc-aluminum suspension. Then filter or centrifuge the suspension, and finally dry it at 100℃ for 12h to obtain a zinc-aluminum mixed powder. Under air atmosphere, heat from room temperature to 1000℃ at a rate of 1℃ / min and hold for 2h to finally obtain zinc-aluminum spinel with a hollow structure, the particle size distribution of which is shown in the figure. Figure 2 As shown, the average particle size is approximately 117.60 nm, and its BET N2 adsorption specific surface area is approximately 70.91 m². 2 / g, such as Figure 3 As shown.

[0057] The above samples were subjected to phase analysis using X-ray diffraction (XRD), such as... Figure 4 As shown, the phase of the sample is spinel. The morphology of the sample was observed using a transmission electron microscope (TEM, model: JEM-2100F, NEC Corporation, point resolution 0.23 nm; lattice resolution 0.10 nm; EDS elemental analysis range: Be~U). Figure 5 The zinc-aluminum spinel exhibits a complete hollow structure. Compositional analysis of the above samples was performed using EDS spectroscopy with a TEM, as shown... Figure 6As shown, the distribution of zinc, aluminum, and oxygen elements in the hollow magnesium aluminum spinel particles can be clearly seen.

[0058] Example 3

[0059] Weigh out 6.5380g of spherical zinc powder (D) according to a zinc-aluminum molar ratio of 0.5:1. 50 =1μm) and 5.3960g of spherical metallic aluminum powder (D 50 =1μm), add 35g of anhydrous ethanol, and sonicate at room temperature for 10min to obtain a zinc-aluminum suspension. Then filter or centrifuge the suspension, and finally dry it at 100℃ for 12h to obtain a zinc-aluminum mixed powder. Under air atmosphere, heat from room temperature to 1200℃ at a heating rate of 0.5℃ / min and hold for 2h to finally obtain zinc-aluminum spinel with a hollow structure.

[0060] Comparative Example 1

[0061] Weigh out 6.08g of zinc oxide powder (D) according to a zinc-aluminum molar ratio of 0.5:1. 50 =1μm) and 7.65g alumina powder (D 50 =1μm), add 35g of anhydrous ethanol, and sonicate at room temperature for 10min to obtain a suspension. Then filter or centrifuge the suspension, and finally dry it at 100℃ for 12h to obtain a mixed powder. Under air atmosphere, heat from room temperature to 1200℃ at a heating rate of 0.5℃ / min and hold for 2h. However, it is impossible to obtain zinc aluminum spinel with a hollow structure, and its morphology is as follows. Figure 7 As shown.

[0062] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for the production of zinc-aluminum spinel, characterized in that, It comprises the following steps: Step a: adding metal zinc powder and metal aluminum powder into anhydrous ethanol, ultrasonic treatment at room temperature to obtain a zinc-aluminum suspension, then filtering or centrifuging the suspension and drying to obtain a zinc-aluminum mixed powder; Step b: calcining the zinc-aluminum mixed powder obtained in step a in an air atmosphere to obtain a zinc-aluminum spinel with a hollow structure.

2. The preparation method according to claim 1, wherein in step a, the metal zinc powder and the metal aluminum powder are both spherical.

3. The preparation method according to claim 1 or 2, wherein in step a, the particle size (D50) of the metal zinc powder and the metal aluminum powder is respectively 10 nm to 10 μm, and the particle size (D50) of the metal zinc powder and the metal aluminum powder is the same or different, preferably the particle size (D50) of the metal zinc powder and the metal aluminum powder is the same.

4. The preparation method according to any one of claims 1 to 3, wherein in step a, the molar ratio of the metal zinc powder to the metal aluminum powder is 0.5:

1.

5. The preparation method according to any one of claims 1 to 4, wherein in step a, the ultrasonic treatment time is 5 min to 15 min.

6. The preparation method according to any one of claims 1 to 5, wherein in step a, the drying temperature is 80 to 150 °C, and the drying time is 8 to 15 h.

7. The preparation method according to any one of claims 1 to 6, wherein in step b, the target calcination temperature is 800 °C to 1200 °C, the heating rate is 0.5 °C / min to 2 °C / min, and the holding time is 1.5 to 3 h.

8. A zinc-aluminum spinel produced by the method of any one of claims 1-7, wherein the zinc-aluminum spinel has a zinc content of 0.1-0.5 wt.%, a bulk density of 1.5-2.5 g / cm3, and a particle size of 0.1-10 μm. The zinc-aluminum spinel has a hollow structure.

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