Preparation method of gallium oxide nanosheet and electrode sheet

Abstract

The present application relates to the technical field of gallium oxide, and particularly relates to a preparation method of gallium oxide nanosheet and an electrode sheet. The preparation method of the gallium oxide nanosheet comprises the following steps: A, placing tris(dimethylformamide) gallium and a solvent in a high-temperature and high-pressure reaction kettle, and cooling to room temperature after reaction to obtain a white solution; B, centrifuging the white solution obtained in the step A to collect white precipitates, and dispersing the white precipitates in a polar solvent to obtain a dispersion liquid of nanoscale gallium oxide. The electrode sheet is coated with a mixture of gallium oxide nanoparticles, acetylene black and polyvinylidene fluoride (PVDF) at a weight ratio of 8:1:1 on a carbon cloth. The preparation method is one-step synthesis, does not need to add other reactants in the middle, and can be carried out at low temperature in a closed container, so that operability, safety and preparation cost are greatly reduced. The electrode sheet has good conductivity, and a battery prepared by using the electrode sheet has excellent electrical performance.

Description

Technical Field

[0001] The present invention relates to the technical field of gallium oxide, and in particular to a preparation method of a gallium oxide nanosheet and an electrode sheet. Background Art

[0002] Gallium oxide (Ga2O3) nanomaterials have enormous application potential in areas such as UV-transparent electrodes, high-temperature gas sensors, solar-blind UV detectors, and power devices. Compared to products made from silicon carbide and gallium nitride, power devices made from Ga2O3 are more heat-resistant, more efficient, less expensive, and have a wider range of applications. As a fourth-generation semiconductor material, it has attracted widespread international attention and has begun industrialization. Therefore, achieving high-quality Ga2O3 nanomaterials with controllable morphology and size is crucial.

[0003] In recent years, extensive research has been conducted on the synthesis and properties of various Ga2O3 nanostructures, such as nanowires, nanorods, nanobelts, and nanowalls. Invention patent CN111439778A discloses a method for preparing nanoscale gallium oxide. Gallium nitrate is mixed with a surfactant and then precipitated using a precipitant. The mixture is then centrifuged and calcined at 600-900°C to produce nanoscale gallium oxide with an average particle size of 700-1000 nm. However, this method uses high calcination temperatures, resulting in agglomeration of the resulting microscopic particles, reducing product uniformity.

[0004] Invention patent CN116282134A discloses a method for preparing nano-sized gallium oxide by calcining gallium oxyhydroxide. The gallium oxyhydroxide precursor is pretreated with an inorganic salt solution and then calcined at high temperature to prepare a nano-sized β-Ga2O3 powder material.

[0005] Invention patent CN103086420B discloses a nano-gallium oxide and its applications. The product is prepared by heating a solution of gallium nitrate hydrate in a water bath and then calcining it at high temperature. The resulting gallium oxide is a nanocrystal with regular fan-shaped and needle-shaped morphologies, with a longitudinal length of 100 nm and a β-Ga2O3 crystal phase. In summary, the synthesis of gallium oxide generally requires high synthesis temperatures and some unconventional precursors. Furthermore, there are few reports on 2D materials based on Ga2O3 prepared at low temperatures by solution methods. Summary of the Invention

[0006] Based on this, the present invention aims to provide a method for preparing gallium oxide nanosheets. This method utilizes a single synthesis process, requiring no intermediate addition of reactants, and can be performed in a closed container at low temperatures, significantly reducing operability, safety, and production costs. The product can be separated by centrifugation, eliminating the need for purification, subsequent calcination, or grinding, and can subsequently be directly applied as anode material in batteries or in catalysis. Another object of the present invention is to provide an electrode sheet with excellent conductivity, enabling batteries prepared using this electrode sheet to exhibit superior electrical performance.

[0007] A method for preparing gallium oxide nanosheets comprises the following steps: A, placing tris(diformamide)gallium and a solvent in a high-temperature and high-pressure reactor, and cooling to room temperature after the reaction to obtain a white solution;

[0008] B. The white solution obtained in step A is centrifuged to obtain a white precipitate, and the white precipitate is dispersed in a polar solvent to obtain a dispersion of nano-gallium oxide.

[0009] In step A, the solvent is one or more of n-hexane, n-octane, isooctanoic acid, ethylene glycol, glycerol, n-octanol, or isooctyl alcohol. The reaction temperature is 80-300 degrees Celsius, and the reaction time is 2-24 hours.

[0010] In step B, the dispersing solvent is one or more of ethanol, isopropanol, acetone, and acetonitrile.

[0011] In this reaction, high temperature and pressure cause gallium tris(dimethylamide) to dissociate into gallium ions and dimethylamine molecules. The gallium ions then react with the minimal amount of oxygen in the solvent to form gallium oxide. Because the oxygen content is low, the resulting gallium oxide particles are smaller in size.

[0012] Preferably, in step A, the solvent is a mixture of n-hexane and n-octanol in a volume ratio of 1:(1.5-3).

[0013] Preferably, in step A, the solvent is a mixture of n-hexane and n-octanol in a volume ratio of 1:2.

[0014] An electrode sheet is obtained by coating a mixture of gallium oxide nanoparticles, acetylene black and polyvinylidene fluoride (PVDF) in a weight ratio of 8:1:1 on carbon cloth.

[0015] In order to better understand and implement the present invention, the present invention is described in detail below in conjunction with specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The XRD patterns of Ga2O3 obtained in Example 1 and Example 2 are shown;

[0017] Figure 2TEM spectrum of Ga2O3 obtained in Example 1;

[0018] Figure 3 The electron diffraction pattern of Ga2O3 obtained in Example 2 and the corresponding high-resolution micrograph;

[0019] Figure 4 is the UV-visible absorption spectrum of the Ga2O3 dispersion obtained in Example 2;

[0020] Figure 5 The battery performance test diagram of Example 6 and the comparative example. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] Example 1

[0023] Dissolve 0.05 g of tris(dimethylamide)gallium(III) ([Ga(NMe2)3]2) in 10 ml of n-hexane, place in a high-temperature and high-pressure reactor, heat to 220 degrees and maintain for 2 hours. After the reaction is completed, cool to room temperature. Centrifuge the resulting white suspension at 2000 rpm to obtain a white precipitate, which is then dispersed in 10 ml of acetonitrile.

[0024] Example 2

[0025] 0.05 g of tris(dimethylamide)gallium(III) ([Ga(NMe2)3]2) was dissolved in 10 ml of a mixture of n-hexane and n-octanol, wherein the mass ratio of n-hexane to n-octanol was 1:2. The mixture was placed in a high-temperature and high-pressure reactor, heated to 220 degrees and maintained for 24 hours. After the reaction was completed, it was cooled to room temperature. The resulting white suspension was centrifuged at 2000 rpm to obtain a white precipitate, which was dispersed in 10 ml of acetonitrile.

[0026] Example 3

[0027] Dissolve 0.05 g of tris(dimethylamide)gallium(III) ([Ga(NMe2)3]2) in 10 ml of n-hexane, place in a high-temperature and high-pressure reactor, heat to 300 degrees and maintain for 10 hours. After the reaction is completed, cool to room temperature. Centrifuge the resulting white suspension at 2000 rpm to obtain a white precipitate, which is then dispersed in 10 ml of acetonitrile.

[0028] Example 4

[0029] 0.05 g of tris(dimethylamide)gallium(III) ([Ga(NMe2)3]2) was dissolved in 10 ml of a mixture of n-hexane and n-octanol, wherein the mass ratio of n-hexane to n-octanol was 1:3. The mixture was placed in a high-temperature and high-pressure reactor, heated to 250 degrees and maintained for 15 hours. After the reaction was completed, it was cooled to room temperature. The resulting white suspension was centrifuged at 2000 rpm to obtain a white precipitate, which was dispersed in 10 ml of acetonitrile.

[0030] Example 5

[0031] 0.05 g of tris(dimethylamide)gallium(III) ([Ga(NMe2)3]2) was dissolved in 10 ml of a mixture of n-hexane and n-octanol, wherein the mass ratio of n-hexane to n-octanol was 1:1.5. The mixture was placed in a high-temperature and high-pressure reactor, heated to 250 degrees and maintained for 15 hours. After the reaction was completed, it was cooled to room temperature. The resulting white suspension was centrifuged at 2000 rpm to obtain a white precipitate, which was dispersed in 10 ml of acetonitrile.

[0032] Example 6

[0033] The dispersion obtained in Example 1 was mixed with acetylene black and polyvinylidene fluoride (PVDF) in a weight ratio of 8:1:1 and then coated on a carbon cloth with an initial density of 15.5 mg / cm 2 , Ga2O3 loading 4-8mg / cm 2 An electrode sheet 1 is obtained.

[0034] Comparative Example 1

[0035] Co3O4 was mixed with acetylene black and polyvinylidene fluoride (PVDF) in a weight ratio of 8:1:1 and then coated on carbon cloth with an initial density of 15.5 mg / cm 2 , Ga2O3 loading 4-8mg / cm 2 An electrode sheet 2 is obtained.

[0036] The electrical properties of the electrode sheet 1 obtained in Example 6 and the electrode sheet 2 obtained in Comparative Example 1 were tested.

[0037] The cell was assembled in the order of working electrode-membrane-lithium disk-nickel foam.

[0038] The electrolyte is a mixture of 1,3-dioxane and 1,2-dimethoxyethane in a volume ratio of 1:1, lithium bis(trifluoromethylsulfonyl)imide is 1 mol / L, and LiNO3 is 1 wt%. Microporous polypropylene is used as the membrane material.

[0039] During the test, the half-cell will be tested in the voltage range of 0.01 to 3V using a multi-channel battery test system.

[0040] from Figure 1 It can be seen that pure Ga2O3 nanoparticles can be prepared using the method disclosed in this application.

[0041] from Figure 2 It can be seen that the Ga2O3 particles prepared using the method disclosed in this application have uniform particle size and good dispersion.

[0042] from Figure 5 It can be seen that the performance of the battery made using the electrode sheet of Example 6 is better than that of Comparative Example 1.

[0043] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, and the present invention is intended to encompass such modifications and variations.

Claims

1. A method for preparing a dispersion of gallium oxide nanosheets, characterized in that: The method comprises the following steps: A. placing tris(dimethylamide)gallium ([Ga(NMe2)3]2) and a solvent in a high-temperature and high-pressure reactor to react at a reaction temperature of 80-300 degrees Celsius for 2-24 hours; cooling to room temperature after the reaction to obtain a white solution; B. centrifuging the white solution obtained in step A to obtain a white precipitate, dispersing the white precipitate in a polar solvent to obtain a dispersion of gallium oxide nanosheets; in step A, the solvent is one or more of n-hexane, n-octane, ethylene glycol, glycerol, n-octanol or isooctyl alcohol.

2. The method for preparing a dispersion of gallium oxide nanosheets according to claim 1, wherein: In step B, the dispersing solvent is one or more of ethanol, isopropanol, acetone, and acetonitrile.

3. The method for preparing a dispersion of gallium oxide nanosheets according to claim 2, wherein: In step A, the solvent is a mixture of n-hexane and n-octanol in a volume ratio of 1:(1.5-3).

4. The method for preparing a dispersion of gallium oxide nanosheets according to claim 3, wherein: In step A, the solvent is a mixture of n-hexane and n-octanol in a volume ratio of 1:

2.

5. An electrode sheet, characterized in that: The carbon cloth is coated with a mixture of a dispersion of the gallium oxide nanosheets according to any one of claims 1 to 4, acetylene black and polyvinylidene fluoride (PVDF) in a weight ratio of 8:1:1.

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