Precious metal nano-particles with different sizes prepared based on pH regulation and control liquid phase laser irradiation technology and preparation method of precious metal nano-particles

Abstract

The invention belongs to the technical field of material preparation, and particularly relates to precious metal nanoparticles with different sizes prepared based on a pH regulation and control liquid phase laser irradiation technology and a preparation method of the precious metal nanoparticles. On the basis of pH regulation and control, a liquid phase laser irradiation technology is adopted, and precious metal nano-particles with different sizes and the particle sizes smaller than 10 nm are obtained; the related precious metals comprise Ru, and also comprise Pt, Au, Ag and Pd, the method is suitable for various precious metals, and controllable preparation of nanoparticles with different sizes is realized by adjusting laser irradiation parameters, reaction time and pH environment. According to the method, the problem that the precious metal nano-particles with the particle sizes smaller than 10 nm and different sizes are difficult to prepare quickly and controllably in a large scale is solved, a brand new universal strategy is provided for preparation of the precious metal nano-particles with the particle sizes smaller than 10 nm, and further development of the precious metal materials in the fields of photoelectricity, energy storage and catalysis is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of material preparation, and particularly relates to a method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid-phase laser irradiation technology. Background Art

[0002] Nanomaterials, as new functional materials with characteristic sizes ranging from 1nm to 100nm, exhibit an exponential increase in the proportion of surface atoms as particle size decreases. When the particle size drops below 10nm, the surface state density reaches over 40% of that of the bulk material. This unique surface electronic structure enables nanomaterials to exhibit significant quantum size effects, surface effects, and quantum confinement effects, resulting in unique optoelectronic and electromagnetic properties that differ from those of macroscopic materials. Based on these properties, nanomaterials have demonstrated significant application value in fields such as biosensing, targeted drug delivery, photocatalysis, and energy storage.

[0003] As an important branch of nanotechnology, precious metal nanomaterials mainly include transition metal systems such as ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), palladium (Pd), iridium (Ir), and rhodium (Rh). Ruthenium-based nanomaterials, in particular, have attracted much attention due to their outstanding physical and chemical properties: their high melting point (2334°C) and strong corrosion resistance give them a stability advantage in high-temperature catalytic systems; their 4d orbital electronic structure gives them special charge transport properties; and their moderate work function (4.71eV) is conducive to interfacial charge regulation. However, existing synthesis processes have significant technical bottlenecks in particle size control: traditional hydrothermal methods are prone to particle size polydispersity, chemical reduction methods have difficulty breaking the 5nm lower limit, and vapor deposition methods face complex equipment dependence issues. This particle size control problem seriously restricts the application and expansion of ruthenium-based nanomaterials in precision fields such as quantum dot devices and single-atom catalysis. Summary of the Invention

[0004] In response to the deficiencies in the above-mentioned prior art, the present invention provides a method for preparing precious metal nanoparticles of different sizes based on pH-controlled liquid-phase laser irradiation technology and a preparation method thereof. The present invention first adjusts the pH and then adopts liquid-phase laser irradiation technology to provide a method for preparing precious metal nanoparticles of different sizes with a simple, controllable, rapid and universal process, overcoming the technical defects of the existing preparation methods; in addition, precious metal nanoparticles of different sizes with precisely controllable particle size, excellent monodispersity, purity, particle size <10nm, and uniform particle size are obtained, and the particle size can even reach 1nm~3nm, especially involving the preparation of Ru nanoparticles.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: The reactant of the present invention is a precious metal precursor, which is placed in a solvent with a pH of 7.5 to 14, and the target product is obtained by liquid-phase laser irradiation technology. Compared with the existing technology, the present invention provides a new preparation method for Ru nanoparticles for the first time, that is, by adjusting the pH and then performing liquid-phase laser irradiation to prepare Ru nanoparticles with a particle size of less than 10 nm. As far as pH control is concerned, the advantages are: simple and flexible operation: it can be regulated by directly adding alkali solution, which is easy to achieve rapid regulation; low cost and environmental friendliness: the alkali solution used is cheap and widely available, which can greatly reduce the preparation cost, and the subsequent treatment is simple and has little impact on the environment; strong compatibility: it can synergize with other control means (such as temperature, reaction time) for further optimization. As far as liquid-phase laser irradiation is concerned, no new impurities are introduced during the preparation process, so the precious metal nanoparticle product obtained is pure; in addition, the particle size distribution of the precious metal nanoparticles is uniform, which is mainly due to the laser melting treatment and surface adsorption of ions (after mixing with alkali solution, OH - It is adsorbed on the surface of noble metal nanoparticles, inhibiting the agglomeration of noble metal nanoparticles, maintaining a small size, further limiting the particle size and enhancing the catalytic activity), solving the problem of particle agglomeration.

[0006] The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid-phase laser irradiation technology comprises the following steps: The blocky noble metal precursor is mixed with a solvent having a pH value of 7.5 to 14 to obtain a noble metal precursor solution.

[0007] The solvent with a pH of 7.5 to 14 is composed of a non-alcoholic polar solvent and an alkaline solution, and the alkaline solution is selected from a 1 mol / L NaOH solution or a KOH solution. The noble metal reacts slowly or even does not react in the non-alcoholic solvent.

[0008] Wherein, the noble metal precursor includes Ru.

[0009] The precious metal precursor solution is irradiated using liquid-phase laser irradiation technology. The irradiation treatment instantly generates high temperature, melting the precious metal precursor. The precious metal in the high-temperature molten state condenses into nano-scale ultrafine particles in a solvent with a pH of 7.5 to 14. The surface charge of the alkaline solution enhances the electrostatic repulsion between the nano-scale ultrafine particles, inhibiting agglomeration to obtain a precious metal colloidal solution. The solvent in the precious metal colloidal solution is separated to obtain precious metal nanoparticles of different sizes.

[0010] Preferably, the volume ratio of the non-alcoholic polar solvent to the alkali solution is 5×10 2 :7~30.

[0011] Preferably, the non-alcoholic polar solvent is selected from acetone, N,N'-dimethylformamide, dimethyl sulfoxide, dioxane or ethylene glycol dimethyl ether.

[0012] Preferably, the non-alcoholic polar solvent is selected from dioxane.

[0013] Preferably, the noble metal precursor further includes Pt, Au, Ag or Pd.

[0014] Preferably, the liquid-phase laser irradiation technology has the following conditions: an emission wavelength of 1064 nm, a laser irradiation range of 1.3 cm, a laser irradiation energy of 0.5 J to 1.0 J, and laser irradiation at 5°C for 1 to 10 minutes. Different temperatures and laser irradiation energies can affect the preparation of noble metal nanoparticles, and these conditions were screened and obtained in this application.

[0015] Preferably, the method for separating the solvent from the noble metal colloidal solution is a reduced pressure distillation method.

[0016] The present invention also protects the preparation of noble metal nanoparticles of different sizes based on pH-controlled liquid-phase laser irradiation technology, which are prepared by the above-mentioned preparation method.

[0017] Preferably, the particle size of the noble metal nanoparticles is less than 10 nm.

[0018] Preferably, the particle size of the noble metal nanoparticles is 1 nm to 3 nm. Compared with the prior art, where the particle size of the noble metal nanoparticles ranges from 4 nm to 24 nm, the present invention achieves the goal of regulating the particle size of the noble metal nanoparticles to 1 nm to 3 nm by adjusting the pH.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The surface of noble metal nanoparticles usually carries an electric charge. pH regulates the electrostatic repulsion between noble metal nanoparticles by affecting the surface charge density. Under alkaline conditions, OH - Negatively charged, the higher surface charge enhances the electrostatic repulsion between the precious metal nanoparticles, inhibits agglomeration, and is conducive to the formation of small-sized metal nanoparticles with good dispersibility; based on this, the present invention first adjusts the pH, and then adopts liquid-phase laser irradiation technology to prepare precious metal nanoparticles. The principle of using liquid-phase laser irradiation technology to prepare precious metal nanoparticles is: 1064nm wavelength laser has the characteristics of high energy and strong heat generation. Under the large laser irradiation energy of 0.5J~1.0J, the high temperature generated instantly melts the surface of the precious metal precursor. The precious metal in the high-temperature molten state quickly condenses into nano-scale ultrafine particles in the solvent. The surface charge of the alkali solution enhances the electrostatic repulsion between the nano-scale ultrafine particles, inhibits agglomeration, and makes the obtained precious metal nanoparticles have a particle size of less than 10nm. In particular, a preparation method of Ru nanoparticles with a particle size of less than 10nm is provided, and the method is also generally applicable to other common precious metal materials.

[0020] The present invention utilizes pH control and liquid-phase laser irradiation technology to produce precious metal nanoparticles of varying sizes with a particle size less than 10 nm. The precious metals involved include Ru, Pt, Au, Ag, and Pd, and are applicable to a variety of precious metals. By adjusting laser irradiation parameters, reaction time, and pH conditions, the controlled preparation of nanoparticles of varying sizes is achieved. This invention addresses the difficulty in rapidly, controllably, and scalably preparing precious metal nanoparticles of varying sizes with a particle size less than 10 nm. It provides a new, universal strategy for the preparation of precious metal nanomaterials with a particle size less than 10 nm, helping to further advance the development of precious metal materials in the fields of optoelectronics, energy storage, and catalysis.

[0021] 2. Under the action of 1064nm wavelength pulsed laser irradiation, the present invention quickly and controllably prepares a series of size-controllable precious metal nanoparticle colloidal solutions, covering most precious metals, and the solvent types are expanded to non-alcohol polar solvents, which has the universal applicability of the preparation method.

[0022] 3. The noble metal nanoparticles obtained by the preparation method of the present invention undergo laser treatment during the preparation process, causing changes in the surface state of the noble metal and constructing small-sized noble metal nanoparticles. The small-sized noble metal nanoparticles have better photoelectric, catalytic and energy storage properties.

[0023] 4. The solvent in the colloidal solution prepared by the present invention is separated by rotary evaporation. The entire preparation process is highly pure and free of ligands. After the obtained powder is dispersed in the solvent, it still maintains a small size and is evenly distributed. This method is suitable for the large-scale preparation of precious metal nanoparticles. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 (a) is an optical photograph of the Ru precursor solution of Example 1, Figure 1 (b) is an optical photograph of the Ru particle colloidal solution of Example 1.

[0025] Figure 2 (a) is a transmission electron microscope image of Ru nanoparticles in Example 1. Figure 2 (b) is a statistical diagram of the particle size of Ru nanoparticles in Example 1.

[0026] Figure 3 Schematic diagram of the preparation of noble metal nanoparticles based on pH-controlled liquid-phase laser irradiation technology.

[0027] Figure 4 (a) is a transmission electron microscope image of the Au nanoparticles of Example 2. Figure 4 (b) is a statistical diagram of the particle size of Au nanoparticles in Example 2.

[0028] Figure 5(a) is a transmission electron microscope image of the Ag nanoparticles of Example 3. Figure 5 (b) is a statistical diagram of the particle size of the Ag nanoparticles in Example 3.

[0029] Figure 6 This is an optical photograph of the Au particle colloidal solution of Example 2.

[0030] Figure 7 This is an optical photograph of the Ag particle colloidal solution of Example 3.

[0031] Figure 8 (a) is a transmission electron microscope image of Ru nanoparticles in comparative example 1. Figure 8 (b) is a statistical diagram of the particle size of Ru nanoparticles in Comparative Example 1.

[0032] Figure 9 (a) is a transmission electron microscope image of Au nanoparticles in comparative example 2. Figure 9 (b) is a statistical diagram of the particle size of Au nanoparticles in Comparative Example 2.

[0033] Figure 10 (a) is a transmission electron microscope image of the Ag nanoparticles of Comparative Example 3. Figure 10 (b) is a statistical diagram of the particle size of Ag nanoparticles in Comparative Example 3.

[0034] Figure 11 (a) is a transmission electron microscope image of Ru nanoparticles in Example 4. Figure 11 (b) is a statistical diagram of the particle size of Ru nanoparticles in Example 4.

[0035] Figure 12 (a) is a transmission electron microscope image of Ru nanoparticles in Example 5. Figure 12 (b) is a statistical diagram of the particle size of Ru nanoparticles in Example 5. DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0037] The core technology of this invention is to first adjust the pH, then obtain a colloidal solution of precious metal nanoparticles through liquid-phase laser irradiation technology, and then obtain precious metal nanoparticles of different sizes through rotary evaporation technology. The present invention uses liquid-phase laser irradiation technology to prepare different precious metal nanoparticles in a solvent system with a pH of 7.5 to 14. The precious metals involved include Ru, Pt, Au, Ag, and Pd. It is also applicable to a variety of precious metals. By adjusting the laser irradiation parameters, reaction time, and solvent type, the precious metal nanoparticles can be prepared in a controllable manner. At the same time, due to its unique advantage of rapid preparation, it can also achieve large-scale preparation of precious metal nanoparticles.

[0038] The present invention provides a new universal strategy for the preparation of precious metal nanoparticles. The obtained precious metal nanomaterials are pure and have controllable particle size, which will help promote the further development of precious metal nanomaterials in the fields of optoelectronics, energy storage and catalysis.

[0039] The technical solution of the present invention is further explained below using examples and comparative examples, as shown below: Example 1 The method for preparing Ru nanoparticles based on pH-controlled liquid-phase laser irradiation technology comprises the following steps: S1. Place bulk Ru metal in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle.

[0040] S2. Continue to add 150 μL of 1 mol / L NaOH solution into the sample bottle and mix well to obtain a Ru precursor solution.

[0041] S3. At 5 °C, the Ru precursor solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.9 J to obtain a light yellow Ru particle colloidal solution.

[0042] S4. The Ru particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain a Ru nanoparticle powder sample.

[0043] Example 2 The method for preparing Au nanoparticles based on pH-controlled liquid-phase laser irradiation technology comprises the following steps: S1. Place the Au metal block in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle.

[0044] S2. Continue to add 150 μL of 1 mol / L NaOH solution into the sample bottle and mix well to obtain an Au precursor solution.

[0045] S3. At 5°C, the Au precursor solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.5 J to obtain a light pink Au particle colloidal solution.

[0046] S4. The Au particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain an Au nanoparticle powder sample.

[0047] Example 3 The method for preparing Ag nanoparticles based on pH-controlled liquid-phase laser irradiation technology comprises the following steps: S1. Place bulk Ag metal in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle.

[0048] S2. Continue to add 150 μL of 1 mol / L NaOH solution into the sample bottle and mix well to obtain an Ag precursor solution.

[0049] S3. At 5 °C, the Ag precursor solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.7 J to obtain a light yellow Ag particle colloidal solution.

[0050] S4. The Ag particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain an Ag nanoparticle powder sample.

[0051] Example 4 The method for preparing Ru nanoparticles based on pH-controlled liquid-phase laser irradiation technology is the same as the preparation steps in Example 1, except that the volume of the NaOH solution is replaced from 150 μL to 70 μL. The method includes the following steps: S1. Place bulk Ru metal in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle.

[0052] S2. Continue to add 70 μL of 1 mol / L NaOH solution into the sample bottle and mix well to obtain a Ru precursor solution.

[0053] S3. At 5 °C, the Ru precursor solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.9 J to obtain a light yellow Ru particle colloidal solution.

[0054] S4. The Ru particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain a Ru nanoparticle powder sample.

[0055] Example 5 The method for preparing Ru nanoparticles based on pH-controlled liquid-phase laser irradiation technology is the same as the preparation steps in Example 1, except that the volume of the NaOH solution is replaced from 150 μL to 300 μL. The method includes the following steps: S1. Place bulk Ru metal in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle.

[0056] S2. Continue to add 300 μL of 1 mol / L NaOH solution into the sample bottle and mix well to obtain a Ru precursor solution.

[0057] S3. At 5 °C, the Ru precursor solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.9 J to obtain a light yellow Ru particle colloidal solution.

[0058] S4. The Ru particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain a Ru nanoparticle powder sample.

[0059] Example 6 The method for preparing Ru nanoparticles based on pH-controlled liquid-phase laser irradiation technology comprises the following steps: S1. Place bulk Ru metal in a sample bottle, measure 3 mL of dioxane and add it to the sample bottle.

[0060] S2. Continue to add 150 μL of 1 mol / L NaOH solution into the sample bottle and mix well to obtain a Ru precursor solution.

[0061] S3. At 5 °C, the Ru precursor solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 1 min with a laser energy of 1.0 J to obtain a light yellow Ru particle colloidal solution.

[0062] S4. The Ru particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain a Ru nanoparticle powder sample.

[0063] Example 7 The method for preparing Ru nanoparticles based on pH-controlled liquid-phase laser irradiation technology comprises the following steps: S1. Place bulk Ru metal in a sample bottle, measure 3 mL of dioxane and add it to the sample bottle.

[0064] S2. Continue to add 150 μL of 1 mol / L NaOH solution into the sample bottle and mix well to obtain a Ru precursor solution.

[0065] S3. At 5 °C, the Ru precursor solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 10 min with a laser energy of 0.5 J to obtain a light yellow Ru particle colloidal solution.

[0066] S4. The Ru particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain a Ru nanoparticle powder sample.

[0067] Comparative Example 1 The method for preparing Ru nanoparticles using liquid phase laser irradiation technology is the same as the preparation steps in Example 1, except that no NaOH solution is added, and includes the following steps: S1. Place bulk Ru metal in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle to obtain a mixed solution.

[0068] S2. At 5°C, the mixed solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.9 J to obtain a light yellow Ru particle colloidal solution.

[0069] S3. The Ru particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain a Ru nanoparticle powder sample.

[0070] The results show that under these conditions, the laser reacts violently to the Ru precious metal material, which can easily cause safety hazards. At the same time, the particles agglomerate and increase in size, making it impossible to obtain small-sized Ru nanoparticles with better performance.

[0071] Comparative Example 2 The method for preparing Au nanoparticles using liquid phase laser irradiation technology is the same as the preparation steps in Example 2, except that no NaOH solution is added, and includes the following steps: S1. Place bulk Au metal in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle to obtain a mixed solution.

[0072] S2. At 5°C, the mixed solution was irradiated with a Nd:YAG pulsed laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.5 J to obtain a light pink Au particle colloidal solution.

[0073] S3. The Au particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain an Au nanoparticle powder sample.

[0074] At this energy density, the laser cannot completely process the Au precious metal material, and the particle size increases significantly, indicating that the preparation of small-sized Au nanoparticles cannot be achieved under this condition.

[0075] Comparative Example 3 The method for preparing Ag nanoparticles using liquid phase laser irradiation technology is the same as the preparation steps of Example 3, except that no NaOH solution is added, and includes the following steps: S1. Place bulk Ag metal in a sample bottle, measure 5 mL of dioxane and add it to the sample bottle to obtain a mixed solution.

[0076] S2. At 5°C, the mixed solution was irradiated with a Nd:YAG pulse laser (emission wavelength of 1064 nm, pulse frequency of 10 Hz, pulse width of 8 ns, spot size of 13 mm) for 5 min with a laser energy of 0.7 J to obtain a light yellow Ag particle colloidal solution.

[0077] S3. The Ag particle colloidal solution is purified by a rapid rotary evaporation method, and then vacuum dried to obtain an Ag nanoparticle powder sample.

[0078] At this energy density, the Ag precious metal material cannot be completely processed by laser, and the particle size increases significantly, indicating that the preparation of small-sized Ag nanoparticles cannot be achieved under this condition.

[0079] Examples 1 to 7 of the present invention all produced small-sized precious metal nanoparticles with a particle size of less than 10 nm. The preparation principle diagram is shown in FIG. Figure 3 The following uses the noble metal nanoparticles of Examples 1 to 5 and Comparative Examples 1 to 3 as examples to verify the technical effects, as shown below: Figure 1 (a) is an optical photograph of the Ru precursor solution that has not been irradiated by laser in Example 1. Figure 1 (b) is an optical photograph of the Ru particle colloidal solution in Example 1. In comparison, the solution before laser irradiation is clear and transparent. After laser treatment, the Ru particle colloidal solution turns yellow and is evenly dispersed without precipitation, indicating that Ru nanoparticles are generated under the action of the laser.

[0080] Depend on Figure 2 (a) The TEM image shows that the Ru nanoparticles prepared in Example 1 are spherical. Figure 2 From the particle size statistics of Ru nanoparticles (b), it can be seen that the size of the obtained Ru nanoparticles is about 1.19 nm, and the particle size distribution is uniform, and no agglomeration is found.

[0081] Depend on Figure 4 (a) The transmission electron microscopy image shows that the Au nanoparticles prepared in Example 2 are spherical; Figure 4 From the particle size statistics of Au nanoparticles in (b), it can be seen that the size of the obtained Au nanoparticles is about 2.38 nm, and the particle size distribution is uniform, and no agglomeration is found.

[0082] Depend on Figure 5 (a) The transmission electron microscopy image shows that the Ag nanoparticles prepared in Example 3 are spherical; Figure 5 From the particle size statistics of Ag nanoparticles (b), it can be seen that the size of the obtained Ag nanoparticles is about 1.20 nm, and the particle size distribution is uniform, and no agglomeration is found.

[0083] Figure 6 and Figure 7 These are optical photographs of the Au particle colloidal solution of Example 2 and the Ag particle colloidal solution of Example 3. After laser treatment, the Au particle colloidal solution turns light pink, and the Ag particle colloidal solution turns light yellow, and is evenly dispersed without precipitation, indicating that noble metal nanoparticles are produced under the action of the laser.

[0084] Depend on Figure 8 From the transmission electron microscope image (a), we can see that the Ru nanoparticles prepared in Comparative Example 1 are spherical. Figure 8 From the particle size statistics of Ru nanoparticles (b), it can be seen that the size of the obtained Ru nanoparticles is about 23.98 nm. Compared with the Ru nanoparticles in Example 1, the particle size is significantly larger, and the particle size distribution is uneven, and agglomeration occurs.

[0085] Depend on Figure 9 From the transmission electron microscope image (a), it can be seen that the Au nanoparticles prepared in Comparative Example 2 are spherical; Figure 9 From the particle size statistics of Au nanoparticles in (b), it can be seen that the size of the obtained Au nanoparticles is about 4.54 nm. Compared with the Au nanoparticles in Example 2, the particle size is significantly larger, and the particle size distribution is uneven, and agglomeration occurs.

[0086] Depend on Figure 10 From the transmission electron microscope image (a), we can see that the Ag nanoparticles prepared in Comparative Example 3 are spherical. Figure 10From the particle size statistics of the Ag nanoparticles in (b), it can be seen that the size of the obtained Ag nanoparticles is about 6.53 nm. Compared with the Ag nanoparticles in Example 3, the particle size is significantly larger, and the particle size distribution is uneven, and agglomeration occurs.

[0087] The following study uses the Ru nanoparticles of Examples 1, 4, and 5 as examples. Under the condition that 70 μL, 150 μL, and 300 μL of a 1 mol / L sodium hydroxide solution were added to 5 mL of dioxane, respectively, Ru was acted on by a laser pulse method. The TEM and particle size distribution diagrams obtained were: the statistical average particle size of 70 μL was 1.49 nm, the statistical average particle size of 150 μL was 1.19 nm, and the statistical average particle size of 300 μL was 6.57 nm. Small-sized Ru nanoparticles with a particle size of less than 10 nm were obtained.

[0088] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and variations. The above-mentioned embodiments are only preferred embodiments for fully illustrating the present invention, and their scope of protection is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art on the basis of the present invention are all within the scope of protection of the present invention, and the scope of protection of the present invention shall be subject to the claims.

Claims

1. A method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid-phase laser irradiation technology, characterized in that: The steps include: Mixing a noble metal precursor in a solvent having a pH of 7.5 to 14 to obtain a noble metal precursor solution; Wherein, the noble metal precursor includes Ru; The precious metal precursor solution is irradiated using liquid-phase laser irradiation technology. The irradiation treatment instantly generates high temperature, melting the precious metal precursor. The precious metal in the high-temperature molten state condenses into nano-scale ultrafine particles in a solvent with a pH of 7.5 to 14. The surface charge of the alkaline solution enhances the electrostatic repulsion between the nano-scale ultrafine particles, inhibiting agglomeration to obtain a precious metal colloidal solution. The solvent in the precious metal colloidal solution is separated to obtain precious metal nanoparticles of different sizes.

2. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid phase laser irradiation technology according to claim 1, characterized in that: in, The solvent with a pH of 7.5 to 14 is composed of non-alcoholic polar solvents and alkali solutions.

3. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid phase laser irradiation technology according to claim 2, characterized in that: The non-alcoholic polar solvent is selected from acetone, N,N'-dimethylformamide, dimethyl sulfoxide, dioxane or ethylene glycol dimethyl ether.

4. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid phase laser irradiation technology according to claim 3, characterized in that: The non-alcoholic polar solvent is selected from dioxane.

5. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid phase laser irradiation technology according to claim 1, characterized in that: Precious metal precursors also include Pt, Au, Ag or Pd.

6. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid phase laser irradiation technology according to claim 1, characterized in that: The conditions of liquid phase laser irradiation technology are: emission wavelength of 1064nm, laser irradiation range of 1.3cm, laser irradiation energy of 0.5J~1.0J, and laser irradiation at 5℃ for 1min~10min.

7. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid phase laser irradiation technology according to claim 1, characterized in that: The method for separating the solvent in the noble metal colloidal solution is the reduced pressure distillation method.

8. A method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid phase laser irradiation technology, characterized in that: Prepared by the preparation method according to any one of claims 1 to 7.

9. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid-phase laser irradiation technology according to claim 8, characterized in that: The particle size of the noble metal nanoparticles is less than 10 nm.

10. The method for preparing noble metal nanoparticles of different sizes based on pH-controlled liquid-phase laser irradiation technology according to claim 9, characterized in that: The particle size of precious metal nanoparticles is 1nm~3nm.

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