Silver chalcogenide-iron carbide hetero-nanostructure, and preparation method and application thereof

Abstract

This invention discloses a controllable preparation method for core-shell structured silver sulfide-iron carbide heterostructures using a seed-growth chemical liquid-phase method. Silver sulfide quantum dots, an organometallic compound of iron, and ammonium bromide salt are dissolved in a high-boiling-point organic solvent and subjected to a high-temperature carbonization reaction. The core-shell structured silver sulfide-iron carbide heterostructure is then precipitated via a polar organic liquid. This material exhibits ferromagnetism with a high maximum magnetic saturation intensity. Simultaneously, these heterostructured nanoparticles exhibit excellent near-infrared II luminescence properties. This invention prepares high-quality silver sulfide-iron carbide heterostructured nanoparticles using silver sulfide quantum dots, an organometallic compound of iron as a precursor, and an ammonium chloride salt. Water-soluble silver sulfide-iron carbide heterostructured nanoparticles are obtained through water-soluble modification with distearate phosphatidylethanolamine-polyethylene glycol. These nanoparticles have potential applications in optics, biomedicine, environmental science, materials science, catalysis, energy, and magnetic storage. The preparation method is simple and easy to implement, suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of materials technology and relates to the preparation of silver chalcogenide-iron carbide heterostructures. In particular, it relates to an ammonium halide-assisted chemical liquid-phase synthesis method, which has universal applicability to the preparation of silver chalcogenide-iron carbide heterostructures. Background Technology

[0002] Heterogeneous nanostructures have broad application prospects in fields such as optics, biomedicine, environmental science, materials, catalysis, energy, and magnetic storage due to their excellent properties such as multifunctionality, tunability, and stability.

[0003] Specifically, among all multi-component nanomaterials, heterogeneous nanostructures include core-shell structures, dimers (dumbbell-shaped, bifacial), and polymers. The advantages of heterogeneous nanostructures are mainly reflected in the following five aspects: (1) Multifunctionality. Heterogeneous nanostructures are composed of a core and a shell made of different materials. Therefore, the combination of different properties of different materials leads to some new properties of heterogeneous materials, thereby expanding their applications in electronics, optics, magnetism, and catalysis; (2) Effective cost reduction. Generally speaking, compared with pure metal nanoparticles, heterogeneous nanostructures can reduce the proportion of noble metals or transition metals. For example, by coating a thin layer of it on an inexpensive carrier, the use of noble metals can be significantly reduced; (3) Controllability. By changing the size, shape, morphology, and composition of heterogeneous nanostructures, as well as their thickness and shape, the properties of nanostructures can be easily and significantly adjusted; (4) Improved stability and dispersibility. It can prevent the aggregation, sintering, or influence of other reagents on nanoparticles; (5) Improved biocompatibility. From the perspective of practical biological applications, biocompatibility is an important issue. The biocompatibility of heterogeneous nanostructures can be improved by encapsulating highly biocompatible chemical components.

[0004] Silver chalcogenide quantum dots exhibit superior fluorescence in the near-infrared region. Furthermore, the excellent magnetic and photothermal properties of iron carbide magnetic nanostructures have attracted increasing attention. The preparation of silver chalcogenide-iron carbide heterostructures holds great promise for applications. Currently, achieving precise control of heterostructures at the nanoscale remains a significant challenge. Therefore, developing simple and cost-effective methods for preparing heterostructure nanostructures is of great importance in both science and engineering. Summary of the Invention

[0005] The present invention aims to provide a method for preparing silver chalcogenide-iron carbide heterostructure nanostructures. Monodisperse silver sulfide-iron carbide heterostructure nanoparticles are prepared (core thickness 5-15 nm, shell thickness 1-10 nm). On the one hand, these heterostructure nanoparticles exhibit intrinsic ferromagnetism. On the other hand, they also exhibit good near-infrared II fluorescence luminescence properties, with an excitation wavelength of 808 nm, an emission wavelength of 1071 nm, and a fluorescence lifetime of 218.16 nanoseconds. Therefore, these heterostructure nanoparticles have significant potential application value in the construction of nanoprobes based on magnetic resonance imaging and near-infrared II fluorescence imaging.

[0006] The silver chalcogenide-iron carbide heterostructure in this invention is formed by the reaction of silver chalcogenide quantum dots and iron organometallic compounds in a high-boiling-point organic solvent. Halogen ions play a very important role in the phase regulation of iron carbide. Finally, high-quality silver chalcogenide-iron carbide heterostructure is obtained by cleaning with an organic solvent.

[0007] The method for preparing silver chalcogenide-iron carbide heterostructures provided by this invention includes the following steps:

[0008] 1) Preparation of silver sulfide quantum dots;

[0009] 2) Grow iron carbide nanoshells on the prepared silver sulfide quantum dots to obtain silver sulfide-iron carbide heterogeneous nanoparticles.

[0010] 3) Preparation of water-soluble silver sulfide-iron carbide heterogeneous nanoparticles.

[0011] Step 1) Select silver precursors such as silver diethyldithiocarbamate or silver acetate, and dissolve them in a high-boiling organic solvent such as 1-dodecyl mercaptan or 1-hexadecyl mercaptan, for example, 1-dodecyl mercaptan.

[0012] Step 1) The dissolution process is usually carried out under a high-temperature protective atmosphere, with a temperature of 180-220 degrees Celsius, for example 210 degrees Celsius, for 0.5-3 hours, for example 1 hour, and the atmosphere is high-purity argon or high-purity nitrogen, for example argon.

[0013] Step 2) The prepared silver sulfide quantum dots and the organometallic compound of iron are sequentially added to a high-boiling-point mixed organic solvent, oleylamine / 1-octadecene or 1-octadecamine / 1-octadecene, for example, oleylamine / 1-octadecene. Then, ammonium halide salts are added, including ammonium chloride, hexadecyltrimethylammonium chloride, ammonium bromide, and hexadecyltrimethylammonium bromide, for example, ammonium bromide;

[0014] Step 2) Continue stirring the mixture at room temperature (e.g., 25°C) for 10-30 minutes (e.g., 10 minutes). The reaction is typically carried out under a high-temperature protective atmosphere (280-360°C, e.g., 300°C) for 1-3 hours (e.g., 1 hour), using high-purity argon or high-purity nitrogen (e.g., high-purity argon). Precipitation usually occurs at room temperature, and the washing organic solvent is ethanol or acetone (e.g., ethanol).

[0015] Step 3) Water-soluble silver sulfide-iron carbide heterogeneous nanoparticles were synthesized using distearate phosphatidylethanolamine-polyethylene glycol via an oil-in-water microemulsion method. The microemulsion method was performed using an ultrasonic disruptor.

[0016] The present invention further provides magnetic testing of the above-mentioned silver sulfide-iron carbide heterostructure nanoparticles. In addition, it provides fluorescence luminescence performance testing of the silver sulfide-iron carbide heterostructure nanoparticles, further clarifying their potential applications in the biomedical field. Attached Figure Description

[0017] Figure 1 Transmission electron microscope image of the silver sulfide quantum dots prepared in Example 1.

[0018] Figure 2 The image shows a transmission electron microscope image of the silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 1.

[0019] Figure 3 The image shows the X-ray diffraction pattern of the silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 1.

[0020] Figure 4 Transmission electron microscope image of the water-soluble silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 1.

[0021] Figure 5 The curve showing the relationship between magnetic susceptibility and temperature for the silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 1.

[0022] Figure 6 The magnetic susceptibility versus temperature curve of the water-soluble silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 1.

[0023] Figure 7 The fluorescence spectrum of the silver sulfide-iron carbide heterostructure nanoparticles prepared in Example 1.

[0024] Figure 8 The fluorescence spectrum of the water-soluble silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 1.

[0025] Figure 9Fluorescence lifetime analysis of water-soluble silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 1.

[0026] Figure 10 The image shows a transmission electron microscope image of the silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 2.

[0027] Figure 11 This is a transmission electron microscope image of the silver sulfide-iron carbide heterogeneous nanoparticles prepared in Example 3. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] Example 1

[0030] (1) Preparation of silver sulfide quantum dots;

[0031] 25.6 mg of silver diethyldithiocarbamate was dissolved in 10 g of 1-dodecyl mercaptan. The system was heated to 210 °C and held at this temperature for 1 hour under a high-purity argon atmosphere. After cooling to room temperature, 60 mL of anhydrous ethanol was added, and the mixture was centrifuged at 8000 rpm for 3 minutes to obtain silver sulfide quantum dots. The prepared silver sulfide quantum dots were dispersed in n-hexane for later use.

[0032] (2) Preparation of silver sulfide-iron carbide heterogeneous nanoparticles;

[0033] Silver sulfide-iron carbide heterostructure nanoparticles were synthesized using a simple seed growth method. 1 mL of silver sulfide quantum dots (10 mg / mL) and 9.8 mg of ammonium bromide were added to a mixed organic solvent system of 200 μL oleylamine and 20 mL octadecene. The system was heated to 120 °C and held for 30 min under an argon atmosphere. The temperature was then further increased to 80 °C, and 0.4 mL of iron carbonyl was rapidly injected and held for 10 min. After 10 min, the reaction system was further heated, reaching 300 °C and held for 30 min. The system was then cooled to room temperature, and 60 mL of anhydrous ethanol was added. The mixture was centrifuged at 8000 rpm for 3 min to obtain monodisperse silver sulfide-iron carbide heterostructure nanoparticles.

[0034] (3) Preparation of water-soluble silver sulfide-iron carbide heterogeneous nanoparticles.

[0035] 250 mg of distearate phosphatidylethanolamine-polyethylene glycol (molecular weight 4000) was dispersed in 12 mL of deionized water. Silver sulfide-iron carbide heterostructure nanoparticles were dispersed in 3 mL of dichloromethane solution at a concentration of 10 mg / mL. The two solutions were homogenized and then treated with an ultrasonic homogenizer for 10 minutes (ultrasonic mode: 5 minutes sonication, 5 minutes pause, ultrasonic power: 2000 W / h) to obtain an emulsion. This emulsion was then treated with a rotary evaporator at 25°C for 2 hours to obtain water-soluble silver sulfide-iron carbide heterostructure nanoparticles.

[0036] like Figure 1 As shown, transmission electron microscopy images characterize the size and morphology of silver sulfide quantum dots.

[0037] like Figure 2 As shown, transmission electron microscopy images characterize the size and morphology of silver sulfide-iron carbide heterostructure nanoparticles.

[0038] like Figure 3 As shown, the position and intensity of the diffraction peaks revealed by X-ray diffraction analysis are well matched with the standard cards of silver sulfide quantum dots (JCPDS 04-0072) and silver sulfide-iron carbide heterogeneous nanoparticles (JCPDS 36-1249), indicating that the material prepared by the above method is a homogeneous FeSe material.

[0039] like Figure 4 As shown, transmission electron microscopy images demonstrate the size and morphology of the water-soluble silver sulfide-iron carbide heterogeneous nanoparticles.

[0040] like Figure 5 As shown, the magnetization curves at room temperature (298 K) confirm the ferromagnetism of the silver sulfide-iron carbide hetero nanoparticles, with a maximum magnetic saturation intensity of 116.97 emu g. -1 .

[0041] like Figure 6 As shown, the magnetization curves at room temperature (298 K) confirm the ferromagnetism of the water-soluble silver sulfide-iron carbide hetero nanoparticles, with a maximum magnetic saturation intensity of 50.12 emu g. -1 .

[0042] like Figure 7 As shown, fluorescence spectroscopy at room temperature (298K) confirmed the luminescence properties of the silver sulfide-iron carbide heterostructure nanoparticles, with an excitation wavelength of 808 nm and an emission wavelength of 1068 nm.

[0043] like Figure 8 As shown, fluorescence spectroscopy at room temperature (298K) confirmed the luminescence properties of the silver sulfide-iron carbide heterostructure nanoparticles, with an excitation wavelength of 808 nm and an emission wavelength of 1071 nm.

[0044] like Figure 9 As shown, fluorescence lifetime characterization demonstrated the luminescence properties of the water-soluble silver sulfide-iron carbide heterostructure nanoparticles, with a fluorescence lifetime of 218.16 nanoseconds.

[0045] Example 2

[0046] Silver sulfide-iron carbide heterogeneous nanoparticles were synthesized using a simple seed growth method. 1 mL of silver sulfide quantum dots (10 mg / mL) and 36.5 mg of cetyltrimethylammonium bromide were added to a mixed organic solvent system of 200 μL oleylamine and 20 mL octadecene. The system was heated to 120 °C and held for 30 min under an argon atmosphere. The temperature was then further increased to 80 °C, and 0.4 mL of iron carbonyl was rapidly injected and held for 10 min. After 10 min, the reaction system was further heated, reaching 300 °C and held for 30 min. The system was then cooled to room temperature, and 60 mL of anhydrous ethanol was added. The mixture was centrifuged at 8000 rpm for 3 min to obtain monodisperse silver sulfide-iron carbide heterogeneous nanoparticles.

[0047] like Figure 10 As shown, the transmission electron microscope images reveal its size and morphology.

[0048] Example 3

[0049] Silver sulfide-iron carbide heterostructure nanoparticles were synthesized using a simple seed growth method. 1 mL of silver sulfide quantum dots (10 mg / mL) and 9.8 mg of ammonium bromide were added to a mixed organic solvent system of 200 μL oleylamine and 20 mL octadecene. The system was heated to 120 °C and held for 30 min under an argon atmosphere. The temperature was then further increased to 80 °C, and 1.412 g of ferric acetylacetone was rapidly injected and held for 10 min. After 10 min, the reaction system was further heated, reaching 320 °C and held for 30 min. The system was then cooled to room temperature, and 60 mL of anhydrous ethanol was added. The mixture was centrifuged at 8000 rpm for 3 min to obtain monodisperse silver sulfide-iron carbide heterostructure nanoparticles.

[0050] like Figure 11 As shown, the transmission electron microscope images reveal its size and morphology.

[0051] Example 4

[0052] Silver sulfide-iron carbide heterogeneous nanoparticles were synthesized using a simple seed growth method. 1 mL of silver sulfide quantum dots (10 mg / mL) and 36.5 mg of cetyltrimethylammonium bromide were added to a mixed organic solvent system of 200 μL oleylamine and 20 mL octadecene. The system was heated to 120 °C and held for 30 min under an argon atmosphere. The temperature was then further increased to 80 °C, and 0.4 mL of iron carbonyl was rapidly injected and held for 10 min. After 10 min, the reaction system was further heated, reaching 320 °C and held for 30 min. The system was then cooled to room temperature, and 60 mL of anhydrous ethanol was added. The mixture was centrifuged at 8000 rpm for 3 min to obtain monodisperse silver sulfide-iron carbide heterogeneous nanoparticles.

Claims

1. A method for preparing silver chalcogenide-iron carbide heterostructure nanoparticles, comprising the following steps: (1) Preparation of silver sulfide quantum dots: Select silver precursors such as silver diethyldithiocarbamate or silver acetate, and dissolve them in organic solvents such as 1-dodecyl mercaptan or 1-hexadecyl mercaptan. The dissolution process is carried out under a protective atmosphere at a temperature of 180-220 degrees Celsius for 0.5-3 hours. The atmosphere is high-purity argon or high-purity nitrogen. (2) An iron carbide nanoshell is grown on the prepared silver sulfide quantum dots to obtain silver chalcogenide-iron carbide heterogeneous nanoparticles. Specifically, the prepared silver sulfide quantum dots and iron organometallic compounds are added sequentially to a high-boiling-point mixed organic solvent oleamine / 1-octadecene or 1-octadecamine / 1-octadecene, and then an ammonium halide salt is added. The ammonium halide salt is one of ammonium chloride, hexadecyltrimethylammonium chloride, ammonium bromide and hexadecyltrimethylammonium bromide. The mixture is stirred at room temperature for 10-30 minutes, and then reacted at 280-360 degrees Celsius for 1-3 hours in a high-purity argon or high-purity nitrogen atmosphere. Then precipitation is carried out at room temperature, and the precipitate is washed with ethanol or acetone. The iron organometallic compound is one of acetylacetone iron, stearate iron and carbonyl iron.

2. A method for preparing water-soluble silver chalcogenide-iron carbide heterostructure nanoparticles, comprising the following steps: (1) Preparation of silver sulfide quantum dots: Select silver precursors such as silver diethyldithiocarbamate or silver acetate, and dissolve them in organic solvents such as 1-dodecyl mercaptan or 1-hexadecyl mercaptan. The dissolution process is carried out under a protective atmosphere at a temperature of 180-220 degrees Celsius for 0.5-3 hours. The atmosphere is high-purity argon or high-purity nitrogen. (2) An iron carbide nanoshell is grown on the prepared silver sulfide quantum dots to obtain silver chalcogenide-iron carbide heterogeneous nanoparticles. Specifically, the prepared silver sulfide quantum dots and iron organometallic compounds are added sequentially to a high-boiling-point mixed organic solvent oleamine / 1-octadecene or 1-octadecamine / 1-octadecene, and then an ammonium halide salt is added. The ammonium halide salt is one of ammonium chloride, hexadecyltrimethylammonium chloride, ammonium bromide and hexadecyltrimethylammonium bromide. The mixture is stirred at room temperature for 10-30 minutes, and then reacted at 280-360 degrees Celsius for 1-3 hours in a high-purity argon or high-purity nitrogen atmosphere. Then precipitation is carried out at room temperature, and the precipitate is washed with ethanol or acetone. The iron organometallic compound is one of acetylacetone iron, stearate iron and carbonyl iron. (3) Water-soluble silver chalcogenide-iron carbide hetero nanoparticles were synthesized by using distearate phosphatidylethanolamine-polyethylene glycol via an oil-in-water microemulsion method, and the microemulsion method was carried out by an ultrasonic disruptor.

3. The silver chalcogenide-iron carbide heterostructure nanoparticles obtained by the preparation method of silver chalcogenide-iron carbide heterostructure nanoparticles according to claim 1 are characterized in that... The nanoparticles have a core-shell structure, with a core size of 5-15 nanometers and a shell thickness of 1-10 nanometers.

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