A solid spherical β-phase gallium oxide powder and its preparation method

Abstract

This invention discloses a solid spherical β-phase gallium oxide powder. Using gallium nitrate solution as raw material, sodium dodecyl sulfate is used as a surfactant in conjunction with ammonia to prepare a precursor gallium hydroxyl oxide. The solid spherical β-phase gallium oxide powder is then obtained through drying and calcination. The particle size of the solid spherical β-phase gallium oxide powder is 0.75-3.21 μm. This invention also discloses a method for preparing the above-mentioned solid spherical β-phase gallium oxide powder. The solid spherical β-phase gallium oxide powder and its preparation method of this invention use sodium dodecyl sulfate as a surfactant to prepare spherical gallium oxide powder. Spherical gallium oxide powder can be prepared through simple operation and with only one surfactant. It has the advantages of simple operation, good repeatability, and the prepared spherical gallium oxide powder has good crystallinity.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor material preparation technology, specifically, it relates to a solid spherical β-phase gallium oxide powder and its preparation method. Background Technology

[0002] Gallium oxide (GaO) is an ultrawide bandgap semiconductor material with a bandgap of approximately 4.8–4.9 eV, and it has broad application prospects in fields such as ultraviolet photodetectors and power electronic devices. Among these, the β-phase GaO is the most thermodynamically stable crystalline phase. The microstructure of the powder directly affects its processing performance and device behavior, with spherical morphology offering significant advantages: spherical particles exhibit excellent geometric symmetry, good flowability, and a low angle of repose, facilitating casting, dry pressing, and other molding processes; they also have high packing density and low porosity, enabling the production of highly dense ceramic bodies; solid structures offer high mechanical strength, are less prone to breakage, and exhibit good batch-to-batch consistency; and their smooth surfaces result in fewer contact points, good dispersibility, and low agglomeration tendency. However, current technologies lack systematic research on the controllable synthesis of specific GaO powder morphologies and its regulation mechanisms. The understanding of morphology evolution laws is insufficient, and there are significant gaps in the mechanisms for controlling the morphology of GaO powders, hindering the controllable preparation and application expansion of high-performance GaO powders.

[0003] The prior art CN 116332224 A discloses a spherical gallium oxide and its preparation process, but its specification does not provide any SEM or TEM images to confirm the spherical morphology of the prepared gallium oxide particles. Based on the technical content described in the document, those skilled in the art cannot confirm whether the preparation of a spherical morphology has been truly achieved.

[0004] The prior art CN 118145696 A provides a method for preparing spherical gallium oxide powder, but the morphology of the gallium oxide particles shown in the accompanying drawings tends to be prismatic or blocky, which is obviously contradictory to its claimed "spherical morphology". This indicates that the technical solution disclosed in this document has not solved the technical problem of preparing spherical morphology.

[0005] In addition, although existing patents such as CN117160436A, CN111439778 A, CN 111592033 A, and CN 120157172 A use different types of surfactants such as sodium dodecylbenzenesulfonate, the gallium oxide powder prepared is not spherical, but has other morphologies such as ellipsoid, rod, and needle.

[0006] Therefore, there is an urgent need to develop a simple and low-cost method for preparing spherical β-phase gallium oxide to fill the aforementioned gap. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a solid spherical β-phase gallium oxide powder and its preparation method.

[0008] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0009] A solid spherical β-phase gallium oxide powder is prepared by using gallium nitrate solution as raw material, sodium dodecyl sulfate as surfactant and ammonia water to prepare gallium hydroxyl oxide precursor, and then obtaining the solid spherical β-phase gallium oxide powder by drying and calcination. The particle size of the solid spherical β-phase gallium oxide powder is 0.75-3.21 μm.

[0010] Specifically, the precursor gallium hydroxyoxide grows into a spherical morphology under the action of the surfactant sodium dodecyl sulfate.

[0011] This invention also discloses a method for preparing solid spherical β-phase gallium oxide powder as described above, comprising the following steps:

[0012] Prepare gallium nitrate solution by dissolving metallic gallium in nitric acid to obtain gallium nitrate stock solution, and then add deionized water to the gallium nitrate stock solution to adjust the concentration to obtain gallium nitrate solution for later use.

[0013] To prepare a sodium dodecyl sulfate solution, dissolve sodium dodecyl sulfate in deionized water. Sodium dodecyl sulfate is an anionic surfactant that undergoes clustering in water to form a nearly spherical micelle structure, in which sulfate ester groups (-OSO3) are present. - It is located on the outer surface of the micelles.

[0014] The reaction state was controlled by heating a gallium nitrate solution and then gradually and continuously adding a small amount of ammonia water under stirring to adjust the pH value of the solution. The pH value was maintained and the reaction continued until the solution reached a metastable state. The metastable solution was conducive to explosive and uniform destabilization and nucleation during aging precipitation under the action of sodium dodecyl sulfate surfactant and ammonia water.

[0015] To prepare the precursor suspension, sodium dodecyl sulfate solution was added to a metastable solution and stirred until homogeneous. Then, sufficient ammonia was continuously added dropwise to adjust the pH to a weakly alkaline state, allowing for aging and precipitation. After the reaction was complete, the precursor suspension was obtained. When the sodium dodecyl sulfate solution was mixed with gallium nitrate solution, due to the -OSO3... - with Ga 3+ There is an electrostatic attraction between them, Ga 3+ Ga adsorbed on the outer surface of micelles, with the addition of sufficient ammonia, the Ga enriched on the outer surface of the micelles... 3+ Further attract OH - This process generates gallium hydroxyoxide precipitate. At the same time, the sulfonic acid groups of sodium dodecyl sulfate (SDS) preferentially adsorb onto specific crystal planes of gallium hydroxyoxide, inhibiting crystal growth in that direction and resulting in anisotropic growth.

[0016] Gallium oxide powder was prepared by solid-liquid separation of the precursor turbidity, drying the obtained solid and calcining it to finally obtain solid spherical β-phase gallium oxide powder.

[0017] Specifically, in the step of preparing the gallium nitrate solution, the concentration of gallium ions in the prepared gallium nitrate solution is 0.1-1.0 mol / L.

[0018] Specifically, in the step of preparing the sodium dodecyl sulfate solution, the concentration of sodium dodecyl sulfate in the sodium dodecyl sulfate solution is 0.00025-0.0025 mol / L.

[0019] Specifically, in the reaction state control step, the heating temperature of the gallium nitrate solution is 35-95℃, the ammonia droplet acceleration rate is 0.6-2 mL / min, the stirring rate is 400-800 r / min, the solution pH is controlled to 3-5, and the reaction time is 0.5-1h.

[0020] Specifically, in the step of preparing the precursor turbid solution, the stirring rate is 400-800 r / min, the ammonia water dropping rate is 20-60 mL / min, the solution pH is adjusted to 7-10, and the reaction time for aging precipitation is 3-5 h.

[0021] Specifically, in the step of preparing gallium oxide powder, solid-liquid separation is performed by vacuum filtration, and drying is performed by vacuum drying. After drying, calcination is carried out in an air atmosphere to obtain solid spherical β-phase gallium oxide powder.

[0022] Furthermore, the vacuum drying temperature is 50-120℃, and the drying time is 8-48 h; the calcination temperature is 800-1000℃, and the calcination time is 1.5-3 h.

[0023] Preferably, the precipitate in the precursor turbidity is the precursor gallium hydroxyl oxide.

[0024] The present invention has the following beneficial effects:

[0025] (1) Spherical gallium oxide powder is prepared by using sodium dodecyl sulfate as a surfactant. Spherical gallium oxide powder can be prepared by simple operation and one surfactant. It has the characteristics of simple operation and good repeatability, and the prepared spherical gallium oxide powder has good crystallinity.

[0026] (2) In metastable solutions, with SDS micelles as the core, Ga 3+ Seed templates are formed through self-assembly, inducing OH... - Along a specific direction with Ga 3+The crystal nuclei combine to form stable crystal nuclei; the crystal nuclei continue to grow, completing the crystallization and precipitation process of gallium hydroxyl oxide, and finally growing outward from the crystal nucleation center to form a spherical morphology. After high-temperature calcination, this morphology of gallium hydroxyl oxide powder finally forms a structurally stable spherical morphology of β-phase gallium oxide powder. Attached Figure Description

[0027] Figure 1 These are SEM images of the solid spherical β-phase gallium oxide powder obtained in Examples 1-5 (ae) of the present invention.

[0028] Figure 2 This is a particle size distribution diagram of the solid spherical β-phase gallium oxide powder obtained in Example 3 of the present invention.

[0029] Figure 3 The image shows the XRD pattern of the solid spherical β-phase gallium oxide powder obtained in Example 3 of this invention.

[0030] Figure 4 This is a SEM image of the product obtained in Comparative Example 1 of the present invention.

[0031] Figure 5 These are SEM images of the products obtained in Comparative Example 2 (left) and Comparative Example 3 (right) of this invention.

[0032] Figure 6 This is a SEM image of the product obtained in Comparative Example 4 of the present invention.

[0033] Figure 7 This is a SEM image of the product obtained in Comparative Example 5 of the present invention. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the embodiments.

[0035] Example 1:

[0036] A method for preparing solid spherical β-phase gallium oxide powder according to Embodiment 1 of the present invention includes the following steps:

[0037] To prepare a gallium nitrate solution, weigh 1.40 g of metallic gallium, add 8.2 mL of nitric acid, and heat at 80°C for 3-5 h to dissolve it. Once the metallic gallium is completely dissolved, a gallium nitrate stock solution is obtained. Then, deionized water is added to the gallium nitrate stock solution to make the concentration of gallium ions in the gallium nitrate solution 1.0 mol / L for later use.

[0038] To prepare a sodium dodecyl sulfate solution, dissolve sodium dodecyl sulfate in deionized water to obtain a sodium dodecyl sulfate solution with a concentration of 0.0025 mol / L.

[0039] To control the reaction state, the gallium nitrate solution was heated to 35°C, and then a small amount of ammonia was continuously added dropwise at a rate of 2 mL / min under stirring at 800 r / min. The pH of the solution was adjusted to 3, and the reaction was continued for 0.5 h until the solution reached a metastable state.

[0040] Prepare the precursor turbidity by adding sodium dodecyl sulfate solution to the metastable solution and stirring at a rate of 800 r / min until homogeneous. Then, continuously add sufficient ammonia water at a dropping rate of 60 mL / min to adjust the pH of the solution to 7 and allow it to age and precipitate. Maintain the reaction at 35°C for 5 h. After the reaction is complete, the precursor turbidity is obtained.

[0041] Gallium oxide powder was prepared by solid-liquid separation of the precursor turbidity using vacuum filtration. The resulting solid was dried in a vacuum environment at a drying temperature of 60°C for 8 h, followed by calcination in air at a temperature of 900°C for 3 h, finally obtaining solid spherical β-phase gallium oxide powder. Its SEM image is shown below. Figure 1 As shown in (a).

[0042] Example 2:

[0043] A method for preparing solid spherical β-phase gallium oxide powder according to Embodiment 2 of the present invention includes the following steps:

[0044] To prepare a gallium nitrate solution, weigh 1.40 g of metallic gallium, add 8.2 mL of nitric acid, and heat at 80°C for 3-5 h to dissolve it. Once the metallic gallium is completely dissolved, a gallium nitrate stock solution is obtained. Then, deionized water is added to the gallium nitrate stock solution to make the concentration of gallium ions in the gallium nitrate solution 0.5 mol / L for later use.

[0045] Prepare a sodium dodecyl sulfate solution by dissolving sodium dodecyl sulfate in deionized water to obtain a sodium dodecyl sulfate solution with a concentration of 0.0010 mol / L.

[0046] To control the reaction state, the gallium nitrate solution was heated to 55°C, and then a small amount of ammonia was continuously added dropwise at a rate of 1.5 mL / min under stirring at 800 r / min. The pH of the solution was adjusted to 4, and the reaction was continued for 0.5 h until the solution reached a metastable state.

[0047] Prepare the precursor turbidity by adding sodium dodecyl sulfate solution to the metastable solution and stirring at a rate of 800 r / min until homogeneous. Then, continuously add sufficient ammonia water at a dropping rate of 60 mL / min to adjust the pH of the solution to 7 and carry out aging precipitation. Maintain the reaction at 55℃ for 4 h. After the reaction is completed, the precursor turbidity is obtained.

[0048] Gallium oxide powder was prepared by solid-liquid separation of the precursor turbidity using vacuum filtration. The resulting solid was dried in a vacuum environment at a drying temperature of 60°C for 8 h, followed by calcination in air at a temperature of 900°C for 3 h, finally obtaining solid spherical β-phase gallium oxide powder. Its SEM image is shown below. Figure 1 As shown in (b).

[0049] Example 3:

[0050] A method for preparing solid spherical β-phase gallium oxide powder according to Embodiment 3 of the present invention includes the following steps:

[0051] To prepare a gallium nitrate solution, weigh 1.40 g of metallic gallium, add 8.2 mL of nitric acid, and heat at 80°C for 3-5 h to dissolve it. Once the metallic gallium is completely dissolved, obtain the gallium nitrate stock solution. Then, add deionized water to the gallium nitrate stock solution to make the concentration of gallium ions in the gallium nitrate solution 0.2 mol / L for later use.

[0052] To prepare a sodium dodecyl sulfate solution, dissolve sodium dodecyl sulfate in deionized water to obtain a sodium dodecyl sulfate solution with a concentration of 0.00075 mol / L.

[0053] To control the reaction state, the gallium nitrate solution was heated to 75°C, and then a small amount of ammonia was continuously added dropwise at a rate of 1 mL / min under stirring at 600 r / min. The pH of the solution was adjusted to 4, and the reaction was continued for 1 h until the solution reached a metastable state.

[0054] Prepare the precursor turbidity by adding sodium dodecyl sulfate solution to the metastable solution and stirring at a rate of 600 r / min until homogeneous. Then, continuously add sufficient ammonia water at a dropping rate of 40 mL / min to adjust the pH of the solution to 8 and carry out aging precipitation. Maintain the reaction at 75℃ for 4 h. After the reaction is completed, the precursor turbidity is obtained.

[0055] Gallium oxide powder was prepared by solid-liquid separation of the precursor turbidity using vacuum filtration. The resulting solid was dried in a vacuum environment at a drying temperature of 60°C for 8 h, followed by calcination in air at a temperature of 900°C for 3 h, finally obtaining solid spherical β-phase gallium oxide powder. Its SEM image is shown below. Figure 1 As shown in (c). The particle size distribution of the solid spherical β-phase gallium oxide powder obtained in this embodiment is as follows. Figure 2 As shown in the figure, the particle size range is 0.75-3.21 μm. Figure 3 The image shows the XRD pattern of the solid spherical β-phase gallium oxide powder obtained in this embodiment.

[0056] Example 4:

[0057] A method for preparing solid spherical β-phase gallium oxide powder according to Embodiment 4 of the present invention includes the following steps:

[0058] To prepare a gallium nitrate solution, weigh 1.40 g of metallic gallium, add 8.2 mL of nitric acid, and heat at 80°C for 3-5 h to dissolve it. Once the metallic gallium is completely dissolved, a gallium nitrate stock solution is obtained. Then, deionized water is added to the gallium nitrate stock solution to make the concentration of gallium ions in the gallium nitrate solution 0.1 mol / L for later use.

[0059] Prepare a sodium dodecyl sulfate solution by dissolving sodium dodecyl sulfate in deionized water to obtain a sodium dodecyl sulfate solution with a concentration of 0.0005 mol / L.

[0060] To control the reaction conditions, the gallium nitrate solution was heated to 95°C, and then a small amount of ammonia was continuously added dropwise at a rate of 0.6 mL / min under stirring at 400 r / min. The pH of the solution was adjusted to 5, and the reaction was continued for 1 h until the solution reached a metastable state.

[0061] Prepare the precursor turbidity by adding sodium dodecyl sulfate solution to the metastable solution and stirring at a rate of 400 r / min until homogeneous. Then, continuously add sufficient ammonia water at a dropping rate of 20 mL / min to adjust the pH of the solution to 9 and carry out aging precipitation. Maintain the reaction at 95℃ for 3 h. After the reaction is completed, the precursor turbidity is obtained.

[0062] Gallium oxide powder was prepared by solid-liquid separation of the precursor turbidity using vacuum filtration. The resulting solid was dried in a vacuum environment at a drying temperature of 60°C for 8 h, followed by calcination in air at a temperature of 900°C for 3 h, finally obtaining solid spherical β-phase gallium oxide powder. Its SEM image is shown below. Figure 1 As shown in (d).

[0063] Example 5:

[0064] A method for preparing solid spherical β-phase gallium oxide powder according to Embodiment 5 of the present invention includes the following steps:

[0065] To prepare a gallium nitrate solution, weigh 0.7 g of metallic gallium, add 4 mL of nitric acid, and heat at 80°C for 3-5 h to dissolve it. Once the metallic gallium is completely dissolved, a gallium nitrate stock solution is obtained. Then, deionized water is added to the gallium nitrate stock solution to make the concentration of gallium ions in the gallium nitrate solution 0.2 mol / L for later use.

[0066] To prepare a sodium dodecyl sulfate solution, dissolve sodium dodecyl sulfate in deionized water to obtain a sodium dodecyl sulfate solution with a concentration of 0.00025 mol / L.

[0067] To control the reaction state, the gallium nitrate solution was heated to 80°C, and then a small amount of ammonia was continuously added dropwise at a rate of 1 mL / min under stirring at 500 r / min. The pH of the solution was adjusted to 4, and the reaction was continued for 0.5 h until the solution reached a metastable state.

[0068] Prepare the precursor turbidity by adding sodium dodecyl sulfate solution to the metastable solution and stirring at a rate of 500 r / min until homogeneous. Then, continuously add sufficient ammonia water at a dropping rate of 50 mL / min to adjust the pH of the solution to 9 and carry out aging precipitation. Maintain the reaction at 80℃ for 3 h. After the reaction is completed, the precursor turbidity is obtained.

[0069] Gallium oxide powder was prepared by solid-liquid separation of the precursor turbidity using vacuum filtration. The resulting solid was dried in a vacuum environment at a drying temperature of 60°C for 8 h, followed by calcination in air at a temperature of 900°C for 3 h, finally obtaining solid spherical β-phase gallium oxide powder. Its SEM image is shown below. Figure 1 As shown in (e).

[0070] Comparative Example 1:

[0071] Comparative Example 1 is essentially the same as Example 3, except that sodium dodecyl sulfate solution is not added for regulation in the step of preparing the precursor turbidity. The resulting SEM image of the gallium oxide powder is shown below. Figure 4 As shown. From Figure 4 As can be seen, the morphology of the obtained gallium oxide powder is rod-shaped without the addition of sodium dodecyl sulfate solution for regulation, which proves that the use of sodium dodecyl sulfate solution for regulation is an important step in generating spherical morphology.

[0072] Comparative Example 2:

[0073] Comparative Example 2 is essentially the same as Example 3, except that the sodium dodecyl sulfate solution concentration is 0.00001 mol / L, resulting in a SEM image of the prepared gallium oxide powder as shown below. Figure 5 As shown on the left.

[0074] Comparative Example 3:

[0075] Comparative Example 3 is essentially the same as Example 3, except that the sodium dodecyl sulfate solution concentration is 0.005 mol / L, resulting in a SEM image of the prepared gallium oxide powder as shown below. Figure 5 As shown on the right.

[0076] from Figure 5 As can be seen, when the concentration of the sodium dodecyl sulfate solution exceeds the range given in this application, the generated gallium oxide powder will not be able to form a spherical morphology. That is, the concentration range of the sodium dodecyl sulfate solution is also an important factor controlling the formation of spherical morphology.

[0077] Comparative Example 4:

[0078] Comparative Example 3 is essentially the same as Example 3, except that sodium dodecyl sulfate solution is replaced with sodium dodecylbenzenesulfonate solution (SDBS) at the same concentration. The resulting SEM image of the gallium oxide powder is shown below. Figure 6 As shown. From Figure 6 Based on this, it can be determined that gallium oxide powder generated by using sodium dodecylbenzenesulfonate instead of sodium dodecyl sulfate as a surfactant cannot have a spherical morphology.

[0079] Comparative Example 5:

[0080] Comparative Example 3 is essentially the same as Example 3, except that the sodium dodecyl sulfate solution is replaced with hexadecyltrimethylammonium bromide solution (CTAB), with the concentration remaining the same. The SEM image of the resulting gallium oxide powder is shown below. Figure 7 As shown. From Figure 7 Based on this, it can be determined that gallium oxide powder generated by using hexadecyltrimethylammonium bromide instead of sodium dodecyl sulfate as a surfactant cannot have a spherical morphology.

[0081] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A solid spherical β-phase gallium oxide powder, characterized in that: Gallium nitrate solution was used as raw material, sodium dodecyl sulfate was used as surfactant and ammonia was used to prepare the precursor gallium hydroxyl oxide, and then the solid spherical β-phase gallium oxide powder was obtained by drying and calcination. The particle size of the solid spherical β-phase gallium oxide powder was 0.75-3.21 μm.

2. The solid spherical β-phase gallium oxide powder according to claim 1, characterized in that: The precursor gallium hydroxyoxide grows into a spherical morphology under the action of the surfactant sodium dodecyl sulfate.

3. A method for preparing solid spherical β-phase gallium oxide powder as described in claim 1 or 2, characterized in that, Includes the following steps: Prepare gallium nitrate solution by dissolving metallic gallium in nitric acid to obtain gallium nitrate stock solution, and then add deionized water to the gallium nitrate stock solution to adjust the concentration to obtain gallium nitrate solution for later use. To prepare a sodium dodecyl sulfate solution, dissolve sodium dodecyl sulfate in deionized water. To regulate the reaction state, a gallium nitrate solution was heated, and then a small amount of ammonia was gradually and continuously added dropwise under stirring to adjust the pH value of the solution. The pH value was maintained and the reaction continued until the solution reached a metastable state. To prepare the precursor suspension, sodium dodecyl sulfate solution was added to the metastable solution and stirred until homogeneous. Then, sufficient ammonia water was continuously added dropwise to adjust the pH of the solution to be weakly alkaline. The solution was then aged and precipitated. After the reaction was completed, the precursor suspension was obtained. Gallium oxide powder was prepared by solid-liquid separation of the precursor turbidity, drying the obtained solid and calcining it to finally obtain solid spherical β-phase gallium oxide powder.

4. The method for preparing solid spherical β-phase gallium oxide powder according to claim 3, characterized in that: In the step of preparing the gallium nitrate solution, the concentration of gallium ions in the prepared gallium nitrate solution is 0.1-1.0 mol / L.

5. The method for preparing solid spherical β-phase gallium oxide powder according to claim 3, characterized in that: In the step of preparing the sodium dodecyl sulfate solution, the concentration of sodium dodecyl sulfate in the sodium dodecyl sulfate solution is 0.00025-0.0025 mol / L.

6. The method for preparing solid spherical β-phase gallium oxide powder according to claim 3, characterized in that: In the reaction state control step, the heating temperature of the gallium nitrate solution is 35-95℃, the ammonia droplet acceleration rate is 0.6-2 mL / min, the stirring rate is 400-800 r / min, the solution pH is controlled to 3-5, and the reaction time is 0.5-1 h.

7. The method for preparing solid spherical β-phase gallium oxide powder according to claim 3, characterized in that: In the step of preparing the precursor turbidity, the stirring rate is 400-800 r / min, the ammonia water dropping rate is 20-60 mL / min, the solution pH is adjusted to 7-10, and the reaction time for aging precipitation is 3-5 h.

8. The method for preparing solid spherical β-phase gallium oxide powder according to any one of claims 3-7, characterized in that: In the step of preparing gallium oxide powder, solid-liquid separation is performed by vacuum filtration, and drying is performed by vacuum drying. After drying, calcination is carried out in an air atmosphere to obtain solid spherical β-phase gallium oxide powder.

9. The method for preparing solid spherical β-phase gallium oxide powder according to claim 8, characterized in that: The vacuum drying temperature is 50-120℃, and the drying time is 8-48 h; the calcination temperature is 800-1000℃, and the calcination time is 1.5-3 h.

10. The method for preparing solid spherical β-phase gallium oxide powder according to any one of claims 3-7, characterized in that: The precipitate in the precursor turbidity is the precursor gallium hydroxyl oxide.

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