Preparation method of low-melting-point gallium-based metal cubic micro-nanoparticles

Abstract

The application relates to the technical field of non-noble metal micro-nanoparticle preparation and morphology control, in particular to a preparation method of low-melting-point gallium-based metal cubic morphology micro-nanoparticles. The method comprises the following steps: ultrasonic dispersion of single-layer graphene oxide or its derivative in water to obtain a single-layer graphene oxide or its derivative aqueous solution; adding molten low-melting-point gallium-based metal into the first solution to obtain a mixture; the temperature of the mixture is above the melting point of the low-melting-point gallium-based metal, and the first solution is a solution for removing or inhibiting oxidation of the gallium-based metal material; mixing the single-layer graphene oxide or its derivative aqueous solution with the mixture, and performing ultrasonic treatment in the cooling process to obtain a suspension containing gallium-based metal micro-nanoparticles with cubic morphology. The method is simple and easy to implement, can obtain gallium-based metal micro-nanoparticles with cubic morphology, and can serve as an experimental platform for studying the characteristics and micro characteristics of gallium-based metal substances.

Description

Technical Field

[0001] This invention relates to the field of non-noble metal micro / nanoparticle preparation and morphology control technology, specifically to a method for preparing low-melting-point gallium-based cubic micro / nanoparticles. Background Technology

[0002] Metallic micro- and nanomaterials, due to their unique physical, chemical, and optical properties, have been widely applied in numerous fields such as catalysis, energy, and biomedicine. Considering the scarcity and high cost of noble metal micro- and nanomaterials, the exploration and development of non-noble metal micro- and nanomaterials have gradually attracted more attention. Furthermore, research on non-noble metal micro- and nanomaterials has also promoted a deeper understanding of the inherent material properties of non-noble metals.

[0003] The morphology of metallic micro / nanoparticles has a significant impact on their properties, and developing effective methods for controlling particle morphology has become an important direction in the research of non-noble metal micro / nanoparticles. Currently, research on the morphology control of non-noble metal micro / nanoparticles mainly focuses on high-melting-point metals such as copper, iron, and aluminum, but research on the morphology control of low-melting-point non-noble metal micro / nanoparticles, represented by gallium-based metal materials, is still in its early stages. Furthermore, our understanding of the physical properties and functions of gallium-based metal materials is still insufficient, including gallium dimers, the short-range ordered layering phenomenon on the gallium surface, and the solid-state transition of gallium. Therefore, developing gallium-based metal micro / nanoparticles with specific morphologies will have a significant promoting effect and research value on the study of the material and microscopic properties of gallium-based metal materials themselves.

[0004] However, the inherent properties of gallium-based metals limit the use of conventional manipulation methods in the morphology control of their micro / nanoparticles. Due to the low melting point of gallium-based metals, the upper temperature limit of the fabrication process is imposed when preparing micro / nanoparticles with specific morphologies. Furthermore, the relatively reactive metallic nature of gallium-based metals makes it difficult for weaker reducing agents to reduce them from precursor salts, thus limiting the use of bottom-up fabrication methods. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a method for preparing low-melting-point gallium-based cubic micro / nanoparticles.

[0006] The method for preparing low-melting-point gallium-based cubic micro / nanoparticles provided by this invention includes the following steps:

[0007] A single-layer graphene oxide or its derivatives are ultrasonically dispersed in water to obtain an aqueous solution of single-layer graphene oxide or its derivatives.

[0008] Molten low-melting-point gallium-based metal is added to a first solution to obtain a mixture; the temperature of the mixture is above the melting point of the low-melting-point gallium-based metal, and the first solution is a solution used to remove or inhibit the oxidation of gallium-based metal materials;

[0009] An aqueous solution of the monolayer graphene oxide or its derivatives is mixed with the mixture, and ultrasonic treatment is performed during the cooling process to obtain a suspension containing cubic gallium-based metal micro / nanoparticles.

[0010] The preparation method provided by this invention is simple and easy to implement, and can better obtain cubic gallium-based metal micro-nanoparticles. These cubic gallium-based metal micro-nanoparticles can be used as an experimental platform for studying the properties and microstructure of gallium-based metal materials.

[0011] Furthermore, this invention has discovered that a combination of a specific solidification process and an ultrasonic process is beneficial for forming more regular cubic metal crystals, and also beneficial for preparing micro- and nano-sized particles. Combining the two processes under specific conditions provides a more reliable guarantee for preparing cubic gallium-based metal nanoparticles.

[0012] Preferably, the low-melting-point gallium-based metal is gallium or an alloy of gallium, wherein the gallium alloy is an alloy of gallium with one or more of indium, tin, and zinc. The melting point of the low-melting-point gallium-based metal in this invention is preferably below 330°C.

[0013] Preferably, the mass concentration of graphene oxide or its derivatives in the aqueous solution is 0.1–2.0 mg / mL, more preferably 0.8–1.2 mg / mL, such as 1.1 mg / mL, 1 mg / mL, or 0.9 mg / mL. In this invention, adding a specific concentration of graphene oxide aqueous solution can effectively encapsulate the particles, further solving the problem of particle dispersion stability, with a concentration of 1 mg / mL being more optimal.

[0014] Preferably, the first solution is an aqueous solution of an acid or base or an organic solution, preferably a hydrochloric acid solution or an aqueous solution of sodium hydroxide.

[0015] Preferably, the pH of the first solution is less than 3 or greater than 11.5, and more preferably pH = 0 or 14.

[0016] Further preferably, the volume ratio of the low-melting-point gallium-based metal to the first solution is 1:10 to 50, more preferably 1:15 to 30, and even more preferably 1:20 to 25.

[0017] Further preferably, the volume ratio of the aqueous solution of the monolayer graphene oxide or its derivative to the low-melting-point gallium-based metal is 1:10 to 50, preferably 1:20 to 30.

[0018] Further preferably, the temperature of the mixture is maintained above 30°C, preferably 30–60°C, and more preferably 45–55°C.

[0019] Preferably, the suspension is washed using low-temperature centrifugation or dialysis to remove excess graphene oxide or its derivatives and residual solutes in the first solution. The present invention preferably uses dialysis to remove the solutes in the first solution and low-melting-point gallium-based metal ions from the suspension.

[0020] Further preferably, the mixture is subjected to ultrasonic treatment during the cooling process, so that the low-melting-point gallium-based metal material in the mixture is transformed into micro-nano particles.

[0021] In a further preferred embodiment, the ultrasonic treatment method during the cooling process involves simultaneous and synchronous cooling and ultrasonic treatment.

[0022] Further preferably, the cooling process is a cooling method in which a low-temperature refrigerant is used to flush the wall surface.

[0023] Further preferably, the cryogenic fluid is cooling water or a cooling organic working fluid.

[0024] Further preferably, the temperature of the cryogenic liquid is 0–20°C, and more preferably 9–11°C.

[0025] Further preferably, during the cooling process, intermittent ultrasound is used, with an optimal working time of 80–120 ms, an interval of 0.5–1.5 s, and a total ultrasound duration of 0.8–1.2 min. In this embodiment of the invention, the optimal processing parameters are: processing with an ultrasonic disruptor, using intermittent ultrasound, with an optimal working time of 100 ms, an interval of 1 s, and a total ultrasound duration of 1 min; simultaneously, cooling water at 10°C is used to rinse the outer wall of the beaker to cool the mixture.

[0026] The beneficial effects of this invention are at least as follows: Current methods for controlling the morphology of metal micro / nanoparticles are mainly based on bottom-up reduction methods, using reducing agents to reduce metal precursor salts into elemental metal particles, which often require a high-temperature environment. However, for low-melting-point gallium-based metal materials, neither reduction methods nor high-temperature environments are suitable for preparing gallium-based metal micro / nanoparticles with specific morphologies. This invention proposes for the first time a method combining ultrasonic treatment and solidification to prepare cubic gallium-based metal micro / nanoparticles. The experimental apparatus and reagents used in the preparation method of this invention are readily available and easy to operate. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart illustrating the preparation method of low-melting-point gallium-based cubic micro / nanoparticles provided by this invention;

[0029] Figure 2 A schematic diagram of the preparation apparatus for the preparation method of low-melting-point gallium-based metal cubic micro / nanoparticles provided by the present invention.

[0030] Figure 3 Electron microscopy images of low-melting-point gallium-based cubic micro / nanoparticles provided in embodiments of the present invention;

[0031] Figure 4 Electron microscopy images of low-melting-point gallium-based cubic micro / nanoparticles (without graphene oxide) provided by this invention. Detailed Implementation

[0032] To clearly illustrate the content of this invention, the invention will be described in detail below with reference to embodiments, comparative examples, and accompanying drawings. The following embodiments and comparative examples are used to illustrate the invention, but are not intended to limit the scope of the invention. To make the objectives, technical solutions, and advantages of the invention clearer, the invention will be further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0033] This invention provides a method for preparing low-melting-point gallium-based cubic micro / nanoparticles, such as... Figure 1 As shown, the steps include:

[0034] Monolayer graphene oxide or its derivatives are uniformly dispersed in deionized water, and the graphene oxide or its derivatives are fully dispersed by ultrasonication.

[0035] Low-melting-point gallium-based metal materials are heated above their melting point while maintaining a liquid flow state.

[0036] Molten gallium-based metal material is added to a specific solution, and the mixture is kept at a temperature higher than the melting point of the gallium-based metal; wherein, the specific solution is an aqueous solution or organic solution that can remove or inhibit the oxidation of the gallium-based metal material;

[0037] An aqueous solution of graphene oxide or its derivatives is added to the above mixture and mixed thoroughly.

[0038] During the cooling process, the mixture was ultrasonically treated to prepare a suspension containing cubic gallium-based metal micro / nanoparticles.

[0039] Excess graphene oxide or its derivatives, as well as residual solutes in specific solutions, are washed away from the suspension using methods such as low-temperature centrifugation or dialysis.

[0040] The present invention will be described in detail below through embodiments. In the following embodiments of the present invention, the liquid metal used is pure gallium, the solution is hydrochloric acid solution, and a single layer of graphene oxide is added. The process method employs simultaneous ultrasonic and cooling treatment.

[0041] Example 1

[0042] This embodiment relates to a method for preparing low-melting-point gallium-based cubic micro / nanoparticles, comprising the following steps:

[0043] 1) Dissolve monolayer graphene oxide in deionized water and use ultrasound to disperse it evenly to prepare a graphene oxide solution with a concentration of 1 mg / mL.

[0044] 2) Heat pure gallium to a molten state, use a pipette to draw 1.0 mL of pure gallium liquid into a beaker, and add 20 mL of 1.0 mol / L hydrochloric acid solution (pH 0).

[0045] 3) Add the graphene oxide solution to a beaker (the volume ratio of graphene oxide solution to pure gallium liquid is 1:20), and heat the beaker in a 50°C water bath.

[0046] 4) The above mixture was processed using an ultrasonic disruptor. The ultrasonic treatment was intermittent, with a working time of 100 ms followed by a 1 s interval, for a total ultrasonic duration of 1 minute. Simultaneously, the mixture was cooled by rinsing the outer wall of the beaker with cooling water at 10°C. The experimental setup is as follows: Figure 2 As shown, a suspension containing pure gallium micro / nanoparticles encapsulated in reduced graphene with a cubic morphology was obtained.

[0047] 5) Hydrochloric acid and gallium ions were removed from the suspension using dialysis. The suspension was then dropped onto a suitable substrate for observation. Electron micrographs of cubic pure gallium micro / nanoparticles are shown below. Figure 3 As shown.

[0048] Comparative Example 1

[0049] This comparative example involves setting graphene oxide as a blank, and the specific operation steps are as follows:

[0050] 1) Heat pure gallium to a molten state, use a pipette to draw 1.0 mL of pure gallium liquid into a beaker, and add 20 mL of 1.0 mol / L hydrochloric acid solution (pH 0).

[0051] 2) Heat the beaker in a 50°C water bath;

[0052] 4) The above mixture was processed using an ultrasonic disruptor. The ultrasonic treatment was intermittent, with a working time of 100 ms followed by a 1 s interval, for a total ultrasonic duration of 1 minute. Simultaneously, the mixture was cooled by rinsing the outer wall of the beaker with cooling water at 10°C. The experimental setup was the same as in Example 1. Figure 2 As shown, a suspension containing cubic morphology pure gallium micro / nanoparticles was obtained.

[0053] 5) Using dialysis, hydrochloric acid and gallium ions were removed from the suspension. The suspension was then dropped onto a suitable substrate for observation. Electron micrographs of cubic pure gallium micro / nanoparticles are shown below. Figure 4 As shown.

[0054] The cubic-shaped reduced graphene-encapsulated pure gallium micro / nanoparticles obtained in Example 1 have a more standard cubic structure. While the pure gallium micro / nanoparticles obtained in Comparative Example 1 also have a generally cubic structure, their morphology often exhibits certain defects. Therefore, adding graphene oxide during the preparation process helps to obtain gallium-based metal micro / nanoparticles with a more complete cubic structure.

[0055] Example 2

[0056] The same scheme as in Example 1 was adopted, except that the hydrochloric acid solution in step 2) was replaced with a sodium hydroxide solution with a concentration of 1.0 mol / L (pH of the solution was 14), while other process conditions remained unchanged.

[0057] Example 3

[0058] The same scheme as in Example 1 is adopted, except that the pure gallium metal in step 2) is replaced with a eutectic gallium-indium alloy with a volume of 1 mL, while other process conditions remain unchanged.

[0059] Comparative Example 2

[0060] The same scheme as in Example 1 is adopted, except that the process of simultaneous ultrasonic and cooling in step 4) is changed to ultrasonic treatment alone, while other process conditions remain unchanged.

[0061] By comparing Examples 2, 3, and Comparative Example 2, the results show that cubic gallium-based metal nanoparticles can be prepared using both acidic and alkaline solutions within the scope of this invention. Cubic nanoparticles can also be prepared using pure gallium and gallium-indium alloys as raw materials. However, cubic gallium-based metal nanoparticles cannot be prepared using only ultrasonic processing.

[0062] This invention provides a method for preparing low-melting-point gallium-based metal cubic micro / nanoparticles. By combining ultrasonic treatment with solidification, cubic gallium-based metal micro / nanoparticles are prepared. The addition of graphene oxide during the preparation process helps to maintain the cubic morphology of the gallium-based metal micro / nanoparticles.

[0063] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing low-melting-point gallium-based cubic micro / nanoparticles, characterized in that, include: Monolayer graphene oxide was ultrasonically dispersed in water to obtain an aqueous solution of monolayer graphene oxide. Molten low-melting-point gallium-based metal is added to a first solution to obtain a mixture; the temperature of the mixture is above the melting point of the low-melting-point gallium-based metal, and the first solution is a solution used to remove or inhibit the oxidation of gallium-based metal materials; The aqueous solution of the monolayer graphene oxide was mixed with the mixture, and ultrasonic treatment was performed during the cooling process to obtain a suspension containing cubic gallium-based metal micro-nano particles. The ultrasonic treatment method used in the cooling process involves simultaneous cooling and ultrasonic treatment.

2. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 1, characterized in that, The low-melting-point gallium-based metal is gallium or an alloy of gallium, and the gallium alloy is an alloy of gallium with one or more of indium, tin, and zinc.

3. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 1, characterized in that, The mass concentration of graphene oxide in the single-layer graphene oxide aqueous solution is 0.1~2.0 mg / mL.

4. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 1, characterized in that, The first solution is an aqueous solution of an acid or base or an organic solution; And / or, the pH of the first solution is less than 3 or greater than 11.

5.

5. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 4, characterized in that, The volume ratio of the low-melting-point gallium-based metal to the first solution is 1:10~50.

6. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 2 or 3, characterized in that, The volume ratio of the monolayer graphene oxide aqueous solution to the low-melting-point gallium-based metal is 1:10~50.

7. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 1, 4, or 5, characterized in that, The temperature of the mixture is maintained above 30 °C.

8. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 1, characterized in that, It also includes washing the suspension using low-temperature centrifugation or dialysis methods.

9. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 8, characterized in that, Wash away excess graphene oxide and residual solutes from the first solution in the suspension.

10. The method for preparing low-melting-point gallium-based cubic micro / nanoparticles according to claim 1, characterized in that, The cooling process is a method of cooling the wall surface by flushing it with low-temperature refrigerant; And / or, the cryogenic fluid is cooling water or a cooling organic working fluid; And / or, the temperature of the cryogenic liquid is 0~20 ℃.

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