A one-step method for preparing gallium nitrate and flaky silver powder

Abstract

The present invention relates to a one-step method for preparing gallium nitrate and flaky silver powder, belonging to the field of materials technology. The method comprises adding ultrasonically and surface-treated Ga to an AgNO3 solution according to a molar ratio, reacting at a preset temperature for 12 to 36 hours to obtain a suspension of Ga(NO3)3 and Ag; centrifuging to obtain liquid Ga(NO3)3 and solid Ag; evaporating and concentrating the Ga(NO3)3 solution at a preset temperature and vacuum drying to obtain solid Ga(NO3)3; and vacuum drying the solid Ag to obtain flaky silver powder. The method utilizes the reducing property of metallic Ga towards Ag, reacting Ga with the AgNO3 solution to directly obtain Ga(NO3)3 and flaky Ag. The method has the advantages of simple steps, short time, low energy consumption, no pollution, and high efficiency. The resulting gallium nitrate product has a high purity of up to 99.9%, and the resulting flaky silver powder has an average particle size of 5 to 10 μm.

Description

Technical Field

[0001] The invention relates to a one-step method for preparing gallium nitrate and flaky silver powder, belonging to the technical field of materials. Background Art

[0002] Gallium nitrate, a key raw material for the preparation of high-purity gallium oxide, is of great significance to the semiconductor industry. Furthermore, in the biomedical field, gallium nitrate and its derivatives, such as gallic acid, have demonstrated significant anti-tumor activity. Furthermore, in the energy sector, it is used as a conductive layer in solar panel electrodes, improving electrical conductivity and light absorption, reducing energy loss, and increasing conversion efficiency. Currently, there are diverse strategies for preparing gallium nitrate, which can be summarized into three main pathways: through the reaction of gallium oxide with strong acids and bases, the solvation reaction of gallium with water, and the interaction of sponge gallium with strong acids and bases. However, while these methods are effective for the synthesis of gallium nitrate, they face significant challenges. In particular, the lengthy process of dissolving gallium oxide with concentrated nitric acid (taking dozens of hours and performed under continuous heating and water replenishment) is not only inefficient and costly, but also associated with environmental issues such as nitric acid volatilization, posing a threat to the ecosystem.

[0003] As an important conductive material, silver flake powder has demonstrated widespread application value in the electronics and electrical industry, automotive industry, energy sector, medical devices, printing technology, and other fields. Currently, most silver flake powders are converted from spherical or granular silver powders through a complex ball milling process. This process not only requires inert gas protection to prevent oxidation, but also requires the use of lubricants and dispersants to finely control the particle size. It also involves multiple tedious steps such as grading, polishing, modification, and purification. This series of high-precision operations not only relies on high-end equipment, but also comes with extended production cycles, significantly increased energy consumption, and increased costs.

[0004] Therefore, the preparation of gallium nitrate and flaky silver powder is very difficult in the prior art. Summary of the Invention

[0005] To address the environmental pollution challenges posed by strong acids and bases in the traditional gallium nitrate preparation process, as well as the complex and lengthy preparation process for flaky silver powder, the present invention proposes a one-step method for preparing gallium nitrate and flaky silver powder. This method utilizes the reducing properties of metallic Ga on AgNO₃ to simultaneously generate high-purity Ga(NO₃)₃ and flaky Ag directly in the reaction between Ga and AgNO₃ solutions. Specifically, ultrasonically treated and surface-treated Ga is added to the AgNO₃ solution according to a molar ratio, and the mixture reacts at a preset temperature for 12 to 36 hours to produce a suspension of Ga(NO₃)₃ and Ag. This suspension is then centrifuged to produce liquid Ga(NO₃)₃ and solid Ag. The Ga(NO₃)₃ solution is evaporated and concentrated at a preset temperature and vacuum-dried to produce solid Ga(NO₃). The Ag solid is then vacuum-dried to produce flaky silver powder. This process not only simplifies the preparation steps and significantly shortens production time, but also significantly reduces energy consumption, achieving zero pollution emissions and demonstrating exceptionally high environmental benefits and production efficiency.

[0006] A one-step method for preparing gallium nitrate and flaky silver powder, the specific steps are as follows:

[0007] (1) ultrasonically dispersing metallic Ga in alcohol to obtain a metallic Ga particle suspension with a particle size of 0.1 to 10 μm, and then vacuum drying to volatilize excess alcohol to obtain metallic Ga particles;

[0008] (2) adding metallic Ga particles to the AgNO3 solution and stirring the reaction at a temperature of 20-60°C for 12-36 hours to obtain a suspension of Ga(NO3)3 and Ag;

[0009] (3) The suspension of Ga(NO3)3 and Ag is centrifuged to obtain Ga(NO3)3 liquid and Ag solid; the Ag solid is vacuum dried to obtain flaky silver powder;

[0010] (4) The Ga(NO3)3 solution is evaporated and concentrated at a temperature of 40-60°C and vacuum dried to obtain solid Ga(NO3)3.

[0011] The temperature of the ultrasonic dispersion in step (1) is 30-40° C. and the time is 0.5-2 h; the vacuum drying temperature is 30-70° C.

[0012] The alcohol in step (1) is one or more of methanol, ethanol, and isopropanol.

[0013] In the step (2), the concentration of the AgNO3 solution is 0.1-2 mol / L, and the molar ratio of metal Ga to AgNO3 is 1:(3-5).

[0014] Preferably, the vacuum drying temperature in step (3) is 30-100°C.

[0015] Preferably, the evaporation concentration in step (4) is atmospheric pressure concentration or reduced pressure concentration, and the vacuum drying temperature is 30-60°C.

[0016] The mechanism of the one-step method for preparing gallium nitrate and flaky silver powder is as follows: by utilizing the strong reducing property of metal gallium (Ga) to silver (Ag), by precisely controlling the reaction conditions, metal gallium (Ga) is chemically reacted with silver nitrate (AgNO3) solution, and gallium acts as a reducing agent to effectively reduce silver ions (Ag + ) is reduced to metallic silver (Ag), and at the same time it is oxidized to gallium ions (Ga 3+ ), and finally directly generate gallium nitrate (Ga(NO3)3) and pure metallic silver (Ag) precipitate.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention adopts a one-step reduction method to efficiently and directly prepare high-purity gallium nitrate (Ga(NO3)3) and high-quality flaky silver products. No other by-products are generated during the entire process, achieving a 100% conversion efficiency from raw materials to products, greatly improving production purity and economic benefits;

[0019] (2) The reaction conditions of the present invention are mild, and no corrosive substances such as strong acids and strong bases need to be introduced throughout the process, nor does it require a complex high-temperature and high-pressure environment. The experimental steps are simple and clear, and the operation is convenient. This not only reduces production risks, but also significantly reduces environmental pollution, while ensuring an extremely high conversion rate.

[0020] (3) The gallium nitrate product prepared by the present invention has a purity of up to 99.9%, which meets the stringent requirements of high-tech fields such as semiconductors, optoelectronics and medicine for high-quality raw materials. At the same time, the average particle size of the prepared flaky silver powder is between 5 and 10 μm, which perfectly meets the specific requirements of many high-tech products for material morphology and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a SEM image of the flaky silver powder prepared in Example 1;

[0022] Figure 2 is a SEM image of the flaky silver powder prepared in Example 2;

[0023] Figure 3 This is the SEM image of the flaky silver powder prepared in Example 3. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0025] Example 1: A one-step method for preparing gallium nitrate and flaky silver powder, the specific steps are as follows:

[0026] (1) 1 g of metallic Ga was added to ethanol and ultrasonically dispersed at 30°C for 2 h to obtain a metallic Ga particle suspension with a particle size of 0.5-2 μm. After standing for 30 min, the suspension was vacuum-dried at 40°C to evaporate excess ethanol to obtain metallic Ga particles;

[0027] (2) Metal Ga particles were added to a 2 mol / L AgNO3 solution, and the mixture was stirred at 30°C for 24 h to obtain a suspension of Ga(NO3)3 and Ag; the molar ratio of the metal Ga to AgNO3 was 1:3;

[0028] (3) The suspension of Ga(NO3)3 and Ag was centrifuged to obtain Ga(NO3)3 liquid and Ag solid; the Ag solid was vacuum dried at 60°C to obtain flaky silver powder;

[0029] (4) The Ga(NO3)3 solution was evaporated and concentrated at atmospheric pressure at 60°C, and vacuum dried at 40°C to obtain a solid Ga(NO3)3 product;

[0030] The SEM image of the flaky silver powder in this embodiment is shown in FIG. Figure 1 ,from Figure 1 It can be seen that flaky silver powder with uniform particle size distribution was successfully obtained, and the average particle size of the flaky silver powder was about 8 to 10 μm;

[0031] The solid-state Ga(NO3)3 product of this embodiment was tested by an inductively coupled plasma spectrometer (ICP), and the purity of the solid-state Ga(NO3)3 product was as high as 99.98%.

[0032] Example 2: A one-step method for preparing gallium nitrate and flaky silver powder, the specific steps are as follows:

[0033] (1) 0.5 g of metallic Ga was added to methanol and ultrasonically dispersed at 40°C for 1 h to obtain a metallic Ga particle suspension with a particle size of 0.3 to 5 μm. After standing for 30 min, the suspension was vacuum dried at 40°C to evaporate excess ethanol to obtain metallic Ga particles;

[0034] (2) Metal Ga particles were added to a 1.5 mol / L AgNO3 solution, and the mixture was stirred at 40°C for 24 h to obtain a suspension of Ga(NO3)3 and Ag; the molar ratio of the metal Ga to AgNO3 was 1:3.5;

[0035] (3) The suspension of Ga(NO3)3 and Ag was centrifuged to obtain Ga(NO3)3 liquid and Ag solid; the Ag solid was vacuum dried at 80°C to obtain flaky silver powder;

[0036] (4) The Ga(NO3)3 solution was concentrated by evaporation at atmospheric pressure at 50°C and vacuum dried at 40°C to obtain solid Ga(NO3)3;

[0037] The SEM image of the flaky silver powder in this embodiment is shown in FIG. Figure 2 ,from Figure 2 It can be seen that the particle size of the prepared flaky silver powder is basically the same, and the particle size of the flaky silver powder is 8-9 μm;

[0038] The solid-state Ga(NO3)3 product of this embodiment was tested by an inductively coupled plasma spectrometer (ICP), and the purity of the solid-state Ga(NO3)3 product was as high as 99.90%.

[0039] Example 3: A one-step method for preparing gallium nitrate and flaky silver powder, the specific steps are as follows:

[0040] (1) 1.0 g of metallic Ga was added to isopropanol and ultrasonically dispersed at 35°C for 1.5 h to obtain a metallic Ga particle suspension with a particle size of 1 to 3 μm. After standing for 30 min, the suspension was vacuum dried at 40°C to evaporate excess ethanol to obtain metallic Ga particles.

[0041] (2) Metal Ga particles were added to a 1.0 mol / L AgNO3 solution, and the mixture was stirred at 60°C for 24 h to obtain a suspension of Ga(NO3)3 and Ag; the molar ratio of the metal Ga to AgNO3 was 1:4;

[0042] (3) The suspension of Ga(NO3)3 and Ag was centrifuged to obtain Ga(NO3)3 liquid and Ag solid; the Ag solid was vacuum dried at 90°C to obtain flaky silver powder;

[0043] (4) The Ga(NO3)3 solution was evaporated and concentrated at normal pressure at 40°C, and then vacuum dried at 40°C to obtain solid Ga(NO3)3;

[0044] The SEM image of the flaky silver powder in this embodiment is shown in FIG. Figure 3 ,from Figure 3 It can be seen that the particle size of the prepared flaky silver powder is relatively uniform, and the particle size of the flaky silver powder is about 5 to 8 μm;

[0045] The inductively coupled plasma spectrometer (ICP) test of the solid-state Ga(NO3)3 product in this embodiment shows that the purity of the solid-state Ga(NO3)3 product is as high as 99.84%.

[0046] The above describes the specific embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. A one-step method for preparing gallium nitrate and flaky silver powder, characterized in that: The specific steps are as follows: (1) ultrasonically dispersing metallic Ga in alcohol to obtain a metallic Ga particle suspension with a particle size of 0.1 to 10 μm, and then vacuum drying to volatilize excess alcohol to obtain metallic Ga particles; (2) Metal Ga particles are added to the AgNO3 solution and reacted at a temperature of 20-60°C for 12-36 hours to obtain a suspension of Ga(NO3)3 and Ag; (3) The suspension of Ga(NO3)3 and Ag is centrifuged to obtain Ga(NO3)3 liquid and Ag solid; the Ag solid is vacuum dried to obtain flaky silver powder; (4) The Ga(NO3)3 solution is evaporated and concentrated at a temperature of 40-60°C and vacuum dried to obtain solid Ga(NO3)3.

2. The method for preparing gallium nitrate and flaky silver powder in one step according to claim 1, characterized in that: The temperature of ultrasonic dispersion in step (1) is 30-40° C. and the time is 0.5-2 h; the vacuum drying temperature is 30-70° C.

3. The method for preparing gallium nitrate and flaky silver powder in one step according to claim 1, characterized in that: In step (1), the alcohol is one or more of methanol, ethanol, and isopropanol.

4. The method for preparing gallium nitrate and flaky silver powder in one step according to claim 1, characterized in that: In step (2), the concentration of the AgNO3 solution is 0.1-2 mol / L, and the molar ratio of metal Ga to AgNO3 is 1:(3-5).

5. The method for preparing gallium nitrate and flaky silver powder in one step according to claim 1, characterized in that: The vacuum drying temperature in step (3) is 30-100°C.

6. The method for preparing gallium nitrate and flaky silver powder in one step according to claim 1, characterized in that: The evaporation concentration in step (4) is normal pressure concentration or reduced pressure concentration, and the vacuum drying temperature is 30-60°C.

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