Antimony quantum dots with different morphologies and their ion exchange preparation methods and applications

Abstract

This invention belongs to the field of luminescent nanocrystal materials technology, specifically to antimony compound quantum dots of different morphologies and their ion exchange preparation methods and applications. This invention uses hexahedral Cu... 3‑x Sb nanocrystals, tetrahedral Cu 3‑x Sb nanocrystals or spherical Cu 3‑x Using Sb nanocrystals as a template, and with the precursor soluble In 3+ Salt, soluble Ga 3+ Salt or soluble Al 3+ Salt undergoes ion exchange reaction to obtain antimony compound quantum dots with different morphologies. The preparation method of antimony compound quantum dots with different morphologies of the present invention suppresses the Kirkendall effect and regulates the ion exchange balance to achieve the synergy of dissolution-intercalation balance, ligand effect and temperature effect, so as to obtain high-quality antimony compound (XSb, X=In, Ga, Al) quantum dots and overcome the technical defects of the preparation of antimony compound quantum dots with different morphologies in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of luminescent nanocrystal materials technology, specifically antimony quantum dots with different morphologies and their ion exchange preparation methods and applications. Background Technology

[0002] Quantum dots (QDs) are inorganic semiconductor nanocrystals with a diameter of less than 10 nm. When their particle size is smaller than or close to the exciton Bohr radius, a quantum size effect occurs; that is, as the size of the quantum dots gradually decreases, their spectrum exhibits a blue shift. The smaller the size, the more significant the blue shift. Therefore, by controlling the size of the quantum dots, their band gap width can be easily adjusted, thereby controlling the color of the emitted light. Semiconductor quantum dots possess excellent optical properties such as broadband absorption, narrowband emission, large absorption cross-section, and tunable luminescence.

[0003] III-V group semiconductor quantum dots are considered an ideal alternative to traditional cadmium- and lead-containing II-VI group quantum dots due to their excellent optoelectronic properties and environmental friendliness. InP quantum dots, as a representative of III-V group semiconductors, have already achieved commercial applications in the display field. However, the emission wavelength of InP quantum dots mainly covers the visible light region (450nm~700nm). For light-emitting applications in the near-infrared (NIR) region (700nm~1700nm), it is necessary to find III-V group semiconductor materials with smaller band gaps.

[0004] Antimonide semiconductor materials, such as InSb, GaSb, and AlSb, possess extremely narrow band gaps (the bulk band gap of InSb is approximately 0.17 eV, corresponding to a wavelength of 7.3 μm), making them ideal choices for preparing mid-infrared quantum dot materials. Among them, InSb quantum dots have attracted much attention due to their potential applications in optical communication, night vision, thermal imaging, and bioimaging. InSb has a very large exciton Bohr radius (approximately 65 nm) and a strong quantum confinement effect, which allows it to exhibit significant quantum size effects even at larger sizes, enabling wide-range luminescence modulation from near-infrared to mid-infrared.

[0005] Currently, the direct synthesis of antimonybide (XSb, X=In, Ga, Al) quantum dots faces many challenges, specifically: 1) The X-Sb bond is highly covalent and has low reactivity, requiring harsh high-temperature conditions for direct synthesis, making nucleation and growth difficult under mild conditions; 2) The reactivity of antimony precursors is difficult to control, easily leading to difficulties in separating nucleation and growth, and uneven size and morphology distribution; 3) Direct synthesis usually yields spherical quantum dots, lacking controllable preparation of anisotropic morphologies such as hexahedrons and tetrahedrons, which limits their potential in applications such as polarized luminescence and directional assembly due to the lack of morphological diversity; 4) The surface of antimonybide (XSb, X=In, Ga, Al) quantum dots is prone to defect states, leading to nonradiative recombination, low luminescence quantum yield, and poor stability.

[0006] Ion exchange technology provides an important alternative route for the preparation of group III-V quantum dots. This technology utilizes the high surface reactivity and low solid-state ion diffusion barrier of cations in nanocrystals to replace the host cations in the template nanocrystals with externally introduced guest cations, achieving a transformation from one material to another. Ion exchange technology has advantages such as mild reaction conditions, controllable product morphology, and the ability to prepare crystal phases and morphologies that are difficult to obtain through direct synthesis.

[0007] Cu 3-x Sb (copper-antimony compound) is an important template material with a hexagonal crystal structure, and various morphologies such as hexahedron, tetrahedron, and spheres can be obtained by controlling the synthesis conditions. Cu 3-x Cu in Sb + Ions have high ionic mobility and are easily attracted by other trivalent cations (such as In). 3+ Exchange is an ideal template for preparing antimony compound quantum dots.

[0008] However, existing methods for preparing XSb via ion exchange suffer from the problem of difficulty in controlling equilibrium, specifically: Cu + With X 3+(X = In, Ga, Al) exhibit differences in valence state (+1 vs +3) and ionic radius. Heterovalent ion exchange involves charge compensation and vacancy formation. Imbalanced ion exchange can easily lead to the Kirkendall effect, resulting in lattice defects and vacancies during the exchange process, causing internal voids or cracks and affecting the morphology and optical properties of the product. Furthermore, the dissolution-intercalation equilibrium during ion exchange determines whether exchange can occur and the theoretical maximum concentration of vacancies. The ligand effect, by altering ion activity and interfacial state, determines whether the exchange proceeds uniformly or generates a significant vacancy flow. The temperature effect determines whether the system can overcome the potential barrier to achieve an equilibrium structure or be kinetically locked in a defect-rich metastable state. In summary, current methods for preparing XSb via ion exchange cannot achieve a synergistic effect of dissolution-intercalation equilibrium, ligand effects, and temperature effects. Summary of the Invention

[0009] To address the shortcomings of the existing technologies, this invention provides antimony compound quantum dots with different morphologies, their ion-exchange preparation methods, and applications. This invention uses hexahedral Cu... 3-x Sb nanocrystals, tetrahedral Cu 3-x Sb nanocrystals or spherical Cu 3-x Using Sb nanocrystals as a template, and with the precursor soluble In 3+ Salt, soluble Ga 3+ Salt or soluble Al 3+ Salt undergoes ion exchange reaction to obtain antimony compound quantum dots with different morphologies. The method of this invention suppresses the Kirkendall effect and regulates the ion exchange balance to achieve the synergy of dissolution-intercalation balance, ligand effect, and temperature effect, thereby obtaining high-quality antimony compound (XSb, X=In, Ga, Al) quantum dots and overcoming the technical defects of existing technologies in the preparation of antimony compound quantum dots with different morphologies.

[0010] Based on the above technical objectives, the present invention adopts the following technical solution: This invention protects a method for preparing antimony compound quantum dots with different morphologies by ion exchange, comprising the following steps: The morphology of antimonybide quantum dots is hexahedral, tetrahedral, or spherical. The antimonybide quantum dots are XSb quantum dots, where X is In, Ga, or Al.

[0011] With soluble In 3+ Salt, soluble Ga 3+ Salt or soluble Al 3+ Salt is a precursor.

[0012] Hexahedral antimonide quantum dots are prepared according to the following steps: the precursor is mixed with the first ligand, and in an oxygen-free environment, the mixture is heated to 180℃~220℃. Temperatures outside this range will leave template residue and induce the Kirkendall effect. Hexahedral Cu is then implanted. 3-x The Sb nanocrystals were dispersed in toluene and then subjected to ion exchange reaction for 45 min to 75 min. Reactions outside this time range would result in size inhomogeneity, yielding hexahedral XSb quantum dots. The first ligand consisted of trioctylphosphine and oleylamine, with the volume fraction of trioctylphosphine in the first ligand being 0.05% to 0.15%.

[0013] Tetrahedral antimonide quantum dots are prepared according to the following steps: The precursor and the second ligand are mixed, and the mixture is heated to 200℃~240℃ in an oxygen-free environment. Temperatures outside this range will result in the coexistence of zincblende and wurtzite. Tetrahedral Cu is then implanted. 3- x The Sb nanocrystals were dispersed in toluene and then subjected to ion exchange reaction for 30 to 60 minutes. If the reaction time was not within this range, agglomeration and core-shell structure would easily form, resulting in tetrahedral XSb quantum dots. The second ligand was composed of trioctylphosphine and oleylamine, with the volume fraction of trioctylphosphine in the second ligand being 0.15% to 0.35%.

[0014] Spherical antimonide quantum dots are prepared according to the following steps: the precursor is mixed with the third ligand, and the mixture is heated to 230℃~270℃ in an oxygen-free environment. Temperatures outside this range will lead to size inhomogeneity and agglomeration. Spherical Cu is then implanted. 3-x The Sb nanocrystals were dispersed in toluene and then subjected to ion exchange reaction for 20 to 50 minutes. Outside of this time range, residual template and increased surface defects were observed, resulting in spherical XSb quantum dots. The third ligand consisted of trioctylphosphine and oleylamine, with the volume fraction of trioctylphosphine in the third ligand being 0.35% to 0.60%.

[0015] Preferably, the amount of precursor material, the volume of the first ligand, and the hexahedral Cu 3-x The molar ratio of Sb nanocrystals is 0.5 mmol to 2.0 mmol: 5 mL to 15 mL: 0.05 mmol to 0.3 mmol.

[0016] Preferably, the amount of precursor material, the volume of the first ligand, and the tetrahedral Cu 3-x The molar ratio of Sb nanocrystals is 0.5 mmol to 2.0 mmol: 4 mL to 12 mL: 0.05 mmol to 0.3 mmol.

[0017] Preferably, the amount of precursor substance, the volume of the first ligand, and the spherical Cu... 3-xThe molar ratio of Sb nanocrystals is 0.5 mmol to 2.0 mmol: 3 mL to 10 mL: 0.05 mmol to 0.3 mmol.

[0018] Preferably, hexahedral Cu 3-x Sb nanocrystals were prepared according to the following steps: using copper carboxylates as the copper source, triphenylantimony, trioctylantimony, or antimony halide as the antimony source, trioctylphosphine as the ligand, 1-octadecene as the non-coordinating solvent, and hexadecylamine as the morphology directing agent. Hexadecylamine enhances anisotropy and can guide the formation of specific morphologies. The reaction was carried out at 280°C~320°C to obtain Cu nanosheets or hexahedral nanocrystals. 3-x Sb nanocrystals; wherein the mass ratio of trioctylphosphine to 1-octadecene is 1:2~10; and the mass ratio of copper source, antimony source to ligand is 1:0.2~1:5~20.

[0019] Preferably, tetrahedral Cu 3-x Sb nanocrystals were prepared according to the following steps: using copper halides as the copper source, triphenylantimony, trioctylantimony, or antimony halide as the antimony source, trioctylphosphine as the ligand, 1-octadecene as the non-coordinating solvent, and hexadecylamine as the morphology directing agent. Hexadecylamine enhances anisotropy and can guide the formation of specific morphologies. The reaction was carried out at 200°C~250°C to obtain Cu nanocrystals with tetrahedral morphology. 3-x Sb nanocrystals; wherein the mass ratio of trioctylphosphine to 1-octadecene is 1:1~5; and the mass ratio of copper source, antimony source to ligand is 1:0.5~1:10~30.

[0020] Preferably, spherical Cu 3-x Sb nanocrystals were prepared according to the following steps: using copper nitrate or sulfate as the copper source, triphenylantimony, trioctylantimony, or antimony halide as the antimony source, trioctylphosphine as the ligand, 1-octadecene as the non-coordinating solvent, and hexadecylamine as the morphology directing agent. Hexadecylamine enhances anisotropy and can guide the formation of specific morphologies. The reaction was carried out at 240°C~280°C to obtain spherical Cu nanocrystals. 3-x Sb nanocrystals; wherein the mass ratio of trioctylphosphine to 1-octadecene is 1:0.5~3; and the mass ratio of copper source, antimony source to ligand is 1:0.3~1:8~25.

[0021] This invention also protects antimonide quantum dots with different morphologies, which are prepared using the above-described method.

[0022] This invention also protects the application of antimonybide quantum dots with different morphologies in the preparation of luminescent materials.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention aims to provide a method for preparing antimony bromide (XSb, X = In, Ga, Al) quantum dots of different morphologies via ion exchange, solving the following technical problems: 1. This invention solves the problem of uncontrollable defects in the ion exchange process by optimizing the ligand composition (the ratio of trioctylphosphine to oleylamine), the reaction temperature (within the range of 180°C to 270°C, with temperature control based on different morphologies), and the precursor ratio (In). 3+ Ga 3+ Al 3+ The concentration of ligands in ion exchange regulates the ion exchange equilibrium, i.e., through coordination competition (ligands and two metal ions (X...)). 3+ and Cu + Coordination between X and X) 3+ The embedding rate and Cu + The dissolution rate achieves dynamic matching.

[0024] This invention regulates X in the precursor 3+ An excess of this energy compensates for the vacancy formation energy and breaks down the energy barrier for vacancy filling.

[0025] This invention optimizes the reaction temperature and, through synergistic control of ligand composition and precursor ratio, enables Cu... + Dissolution rate and X 3+ The embedding rate reaches dynamic matching during the reaction process, thereby effectively suppressing the Kirkendall effect and obtaining high-quality antimony (XSb, X=In, Ga, Al) quantum dots.

[0026] The technical solution of the present invention will be compared with the prior art below, as detailed below. 2. This invention solves the problems of harsh reaction conditions and uniform morphology in the direct synthesis of antimony compound (XSb, X = In, Ga, Al) quantum dots, by utilizing Cu 3-x Antimony compound (XSb, X = In, Ga, Al) quantum dots were prepared by using Sb as a template through a mild ion exchange reaction.

[0027] 3. This invention solves the problem of poor morphological controllability of antimony compound (XSb, X = In, Ga, Al) quantum dots by controlling the Cu... 3-x The morphology (hexahedral, tetrahedral, spherical) and ion exchange conditions of Sb templates are precisely controlled to achieve precise control over the morphology of antimonybide quantum dots.

[0028] 4. This invention establishes a method for obtaining Cu 3-x The ion exchange mechanism model from Sb to antimonide (XSb, X = In, Ga, Al) provides theoretical guidance for the preparation of other antimonide quantum dots.

[0029] 5. The XSb prepared by the method of this invention has the following advantages: 1) Morphological diversity: For the first time, the controllable preparation of antimonide (XSb, X=In, Ga, Al) quantum dots with various morphologies such as hexahedron, tetrahedron and spherical has been achieved, breaking through the limitation of direct synthesis of single morphology.

[0030] 2) Mild reaction conditions: The ion exchange reaction temperature (180°C~270°C) is significantly lower than the temperature required for direct synthesis of antimony (XSb, X=In, Ga, Al) quantum dots (>350°C), which reduces energy consumption and equipment requirements.

[0031] 3) Size and morphology are controllable: by adjusting Cu 3-x The size and morphology of the Sb template, as well as the ion exchange conditions, can precisely control the size (5nm~50nm) and morphology of antimony compound (XSb, X=In, Ga, Al) quantum dots.

[0032] 4) Tunable Crystal Phase: By selecting different ion exchange conditions, antimonybide (XSb, X=In, Ga, Al) quantum dots with zincblende (tetrahedral morphology in Example 2) or wurtzite (hexahedral morphology in Example 1 and spherical morphology in Example 3) structures can be obtained. Compared with the zincblende structure, wurtzite antimonybide (XSb, X=In, Ga, Al) quantum dots have stronger spontaneous polarization and piezoelectric polarization effects, which can effectively promote the separation of photogenerated carriers; their band structure is more tunable due to the difference in crystal field splitting and spin-orbit coupling; at the same time, the lower effective electron mass gives them higher carrier mobility.

[0033] 5) Tunable near-infrared emission: The emission wavelength of antimony compound (XSb, X=In, Ga, Al) quantum dots covers the range of 1000nm~3000nm. The emission wavelength can be adjusted by size to achieve emission in the near-infrared I region (NIR-I, 700nm~900nm) (spherical morphology of Example 3), the near-infrared II region (NIR-II, 900nm~1700nm) (tetrahedral morphology of Example 2) and the mid-infrared (MIR,>1700nm) (hexahedral morphology of Example 1).

[0034] 6. The antimony quantum dots of the present invention can also significantly reduce surface defects and improve the luminescence quantum yield through optimized surface treatment and shell coating. Attached Figure Description

[0035] Figure 1 The Cu with hexahedral morphology in Example 1 3-x Transmission electron microscopy image of the Sb template.

[0036] Figure 2The tetrahedral Cu in Example 2 3-x Transmission electron microscopy image of the Sb template.

[0037] Figure 3 The spherical Cu in Example 3 3-x Transmission electron microscopy image of the Sb template.

[0038] Figure 4 This is a transmission electron microscope (TEM) image of the hexahedral InSb quantum dots in Example 1.

[0039] Figure 5 This is a transmission electron microscope (TEM) image of the tetrahedral InSb quantum dots in Example 2.

[0040] Figure 6 This is a transmission electron microscope (TEM) image of the spherical InSb quantum dots in Example 3.

[0041] Figure 7 The image shows the XRD pattern of the tetrahedral InSb quantum dots in Example 2.

[0042] Figure 8 The image shows the fluorescence absorption spectrum of the spherical InSb quantum dots in Example 3. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0044] This invention provides a method for preparing antimony bromide (XSb, X = In, Ga, Al) quantum dots of different morphologies by ion exchange, comprising the following steps: Step 1: Cu 3-x The synthesis of Sb-templated nanocrystals involved controlling the copper source, antimony source, ligand type and ratio, and reaction temperature parameters to synthesize Cu nanocrystals with specific morphologies. 3-x Sb nanocrystals.

[0045] hexahedral Cu 3-x Sb: Use copper carboxylates (such as copper acetate, copper stearate) as the copper source, such as triphenylantimony, trioctylantimony, or antimony halides (SbCl3, SbBr). 3、 Using SbI3 as the antimony source, trioctylphosphine (TOP) as the ligand, 1-octadecene (ODE) as the non-coordinating solvent, and hexadecylamine (HDA) as the morphology directing agent, the reaction is carried out at 280°C~320°C to obtain hexagonal nanosheets or hexahedral nanocrystals.

[0046] Tetrahedral Cu 3-x Sb: Use copper halides (such as copper chloride, copper bromide) as the copper source, such as triphenylantimony, trioctylantimony, or antimony halides (SbCl3, SbBr). 3、 Using SbI3 as the antimony source, trioctylphosphine (TOP) as the ligand, 1-octadecene (ODE) as the non-coordinating solvent, and hexadecylamine (HDA) as the morphology directing agent, rapid nucleation was achieved at 200°C~250°C, promoting anisotropic growth and yielding a tetrahedral morphology.

[0047] Spherical Cu 3-x Sb: Uses copper nitrates or sulfates as the copper source, such as triphenylantimony, trioctylantimony, or antimony halides (SbCl3, SbBr). 3、 Using SbI3 as the antimony source, trioctylphosphine (TOP) as the ligand, 1-octadecene (ODE) as the non-coordinating solvent, and hexadecylamine (HDA) as the morphology guiding agent, the reaction was carried out at 240°C~280°C, and spherical nanocrystals were obtained by isotropic growth.

[0048] Step 2: Cu + To X 3+ The ion exchange reaction will synthesize Cu 3-x Sb nanocrystals dispersed in In 3+ Precursor, Ga 3+ Precursor or Al 3+ In the precursor reaction system, an ion exchange reaction is carried out to prepare XSb quantum dots: In 3+ Precursors: indium iodide (InI3), indium bromide (InBr3), indium chloride (InCl3), indium nitrate, indium acetate, concentration 0.5 mmol~2.0 mmol.

[0049] Ga 3+ Precursors: gallium iodide (GaI3), gallium bromide (GaBr3), gallium chloride (GaCl3), gallium nitrate, gallium acetate, concentration 0.5 mmol~2.0 mmol.

[0050] Al 3+ Precursors: aluminum iodide (AlI3), aluminum bromide (AlBr3), aluminum chloride (AlCl3), aluminum nitrate, aluminum acetate, concentration 0.5mmol~2.0mmol.

[0051] Ligand system: a mixture of TOP and OAm ligands, controlling ion exchange balance by regulating TOP (TOP volume fraction).

[0052] Low TOP (0.05%~0.15%): Slow ion exchange maintains the template morphology and yields complete antimony compound (XSb, X=In, Ga, Al) nanocrystals with hexahedral morphology.

[0053] Medium TOP (0.15%~0.35%): Balanced ion exchange, suitable for most morphologies, with tetrahedral morphology.

[0054] High TOP (0.35%~0.60%): Rapid ion exchange may produce internal voids or cracks, resulting in a spherical morphology.

[0055] The reaction temperature for ion exchange is 180°C to 270°C. The higher the temperature, the faster the ion exchange rate. The temperature should be adjusted according to the morphology and size requirements.

[0056] The reaction time for ion exchange reaction is 20 min to 75 min, which can be adjusted according to the morphology and size requirements.

[0057] The precursor, trioctylphosphine, and oleylamine were mixed, degassed under vacuum, and then heated to 180℃~220℃ before being injected into hexahedral Cu. 3-x A toluene dispersion of Sb nanocrystals was reacted for 45-75 minutes to obtain hexahedral XSb quantum dots.

[0058] The precursor, trioctylphosphine, and oleylamine were mixed, degassed under vacuum, and then heated to 200℃~240℃ before being injected into tetrahedral Cu. 3-x A toluene dispersion of Sb nanocrystals was reacted for 30-60 minutes to obtain tetrahedral XSb quantum dots.

[0059] The precursor, trioctylphosphine, and oleylamine were mixed, degassed under vacuum, and then heated to 230℃~270℃ before being injected into spherical Cu. 3- x A toluene dispersion of Sb nanocrystals was reacted for another 20 to 50 minutes to obtain spherical InSb quantum dots.

[0060] Step 3: Surface passivation or shell coating: Surface treatment and shell growth are performed on the antimony bromide (XSb, X = In, Ga, Al) quantum dots obtained by ion exchange. Surface cleaning: Use NOBF4 or HF to remove surface Cu residue and oxides.

[0061] Shell coating: Growing InP, ZnSe, ZnS or GaSb shells improves luminescence efficiency and stability.

[0062] Mechanism of morphological inheritance: Cu 3-xThe morphology of the Sb template can be partially or completely transferred to the antimonide (XSb, X = In, Ga, Al) products during ion exchange.

[0063] hexahedral Cu 3-x Sb → hexahedral / disc-shaped antimonide (XSb, X = In, Ga, Al) (preserving hexagonal symmetry).

[0064] Tetrahedral Cu 3-x Sb → tetrahedral / pyramidal antimonide (XSb, X = In, Ga, Al) (preserving anisotropy).

[0065] Spherical Cu 3-x Sb → Spherical antimonide (XSb, X = In, Ga, Al) (isotropic).

[0066] By adjusting the ion exchange conditions, it is also possible to introduce changes in the internal structure (such as core-shell structure or hollow structure) while maintaining the overall morphology.

[0067] The technical solution of the present invention will be further studied using the following embodiments, as detailed below: Example 1 An ion exchange method for preparing antimony bide quantum dots with different morphologies, wherein the antimony bide quantum dots have a hexahedral morphology, includes the following steps: S1, hexahedral Cu 3-x Synthesis of Sb template: Copper acetate (Cu(Ac)2, 0.5 mmol, 90 mg), hexadecylamine (HDA, 1.0 g), trioctylphosphine (TOP, 1.6 mL), and 1-octadecene (ODE, 10 mL) were added to a three-necked flask. The mixture was degassed under vacuum at 120°C for 30 min, then heated to 300°C. Under argon protection, a 1 mL solution of triphenylantimony (0.25 mmol, 88 mg) in ODE was rapidly injected. After reacting for 10 min, the mixture was cooled to room temperature, precipitated with toluene and ethanol, centrifuged (4000 rpm, 10 min), and dispersed in toluene to obtain hexahedral Cu. 3-x Sb nanosheets.

[0068] S2. Preparation of hexahedral InSb quantum dots (low TOP conditions): Indium iodide (InI3, 1.0 mmol, 495 mg), trioctylphosphine (TOP, 0.5 mL), and oleylamine (OAm, 6.5 mL) were added to a three-necked flask and degassed under vacuum at 120°C for 30 min; then the temperature was raised to 200°C, and hexahedral Cu was injected. 3-x A 1 mL toluene dispersion of Sb nanocrystals (approximately 0.1 mmol Sb content) was reacted for 60 min, then cooled, and precipitated and washed with toluene and ethanol to obtain hexahedral InSb quantum dots, maintaining the hexagonal morphology of the template, as shown below. Figure 1 and Figure 4 As shown.

[0069] Example 2 An ion exchange method for preparing antimony bide quantum dots with different morphologies, wherein the antimony bide quantum dots have a tetrahedral morphology, includes the following steps: S1, tetrahedral Cu 3-x Synthesis of Sb template: Copper chloride (CuCl2, 0.5 mmol, 67 mg), hexadecylamine (HDA, 0.5 g), trioctylphosphine (TOP, 3.5 mL), and 1-octadecene (ODE, 7 mL) were added to a three-necked flask. The mixture was degassed under vacuum at 120°C for 30 min, then heated to 220°C. Under argon protection, a TOP solution of trioctylantimony (0.3 mmol) (1 mL) was rapidly injected. After reacting for 5 min, the mixture was cooled to room temperature, precipitated with toluene and ethanol, centrifuged (4000 rpm, 10 min), and dispersed in toluene to obtain tetrahedral Cu. 3-x Sb nanocrystals.

[0070] S2. Preparation of tetrahedral InSb quantum dots (medium TOP conditions): Indium iodide (InI3, 1.0 mmol, 495 mg), trioctylphosphine (TOP, 1.5 mL), and oleylamine (OAm, 5.5 mL) were added to a three-necked flask and degassed under vacuum at 120°C for 30 min; then the temperature was raised to 220°C, and tetrahedral Cu was injected. 3-x A 1 mL toluene dispersion of Sb nanocrystals (approximately 0.1 mmol Sb content) was reacted for 45 min, then cooled and washed. Precipitation and washing with toluene and ethanol yielded tetrahedral InSb quantum dots, maintaining the tetrahedral morphology of the template. Figure 2 and Figure 5 As shown. Figure 7 As shown, the tetrahedral InSb quantum dots are antimony quantum dots with a zincblende structure.

[0071] Example 3 An ion exchange method for preparing antimony bromide quantum dots with different morphologies, wherein the antimony bromide quantum dots are spherical, includes the following steps: S1, Spherical Cu 3-xSynthesis of Sb template: Copper nitrate (Cu(NO3)2, 0.5 mmol, 93 mg), hexadecylamine (HDA, 1.5 g), trioctylphosphine (TOP, 0.5 mL), and 1-octadecene (ODE, 10 mL) were added to a three-necked flask. The mixture was degassed under vacuum at 120°C for 30 min, then heated to 260°C. Under argon protection, a solution of triphenylantimony (0.25 mmol) in ODE (1 mL) was rapidly injected. After reacting for 15 min, the mixture was cooled to room temperature, precipitated with toluene and ethanol, centrifuged (4000 rpm, 10 min), and dispersed in toluene to obtain spherical Cu... 3-x Sb nanocrystals.

[0072] S2. Preparation of spherical InSb quantum dots (high TOP conditions): Indium chloride (InCl3, 1.0 mmol, 221 mg), trioctylphosphine (TOP, 3.5 mL), and oleylamine (OAm, 3.5 mL) were added together to a three-necked flask and degassed under vacuum at 120°C for 30 min; then the temperature was raised to 250°C, and spherical Cu... 3-x A 1 mL toluene dispersion of Sb nanocrystals (approximately 0.1 mmol Sb content) was reacted for 30 min, then cooled and washed. Precipitation and washing with toluene and ethanol yielded spherical InSb quantum dots, maintaining the spherical morphology of the template. Figure 3 and Figure 6 As shown. Figure 8 As shown, spherical InSb quantum dots achieve luminescence in the near-infrared I region (NIR-I, 700nm~900nm).

[0073] This invention can also realize the preparation of core-shell InSb / InP quantum dots. Specifically, to grow an InP shell on the surface of the InSb quantum dots in Examples 1 to 5, the InSb quantum dots are dispersed in an ODE solution containing In(Ac)3 and tris(dimethylamine)phosphorus, and the InP shell is grown by reacting at 280°C for 30 min to obtain an InSb / InP core-shell structure, thereby improving the luminescence efficiency.

[0074] This invention can also achieve surface passivation of InSb quantum dots. Specifically, the InSb quantum dots of Examples 1 to 5 are passivated by dispersing InSb quantum dots in a DMF solution (1M) of NOBF4 and reacting at room temperature for 30 min. The HF generated by the hydrolysis of NOBF4 removes the oxides and Cu residues on the surface of the InSb quantum dots, and the F⁻ ions passivate the surface, significantly improving the photoluminescence intensity.

[0075] Although specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes or modifications can be made to these embodiments without departing from the spirit and scope of the present invention, which is defined only by the appended claims.

Claims

1. A method for preparing antimony compound quantum dots with different morphologies by ion exchange, characterized in that, Includes the following steps: The precursor and ligand were mixed, heated to the ion exchange temperature in an oxygen-free environment, and then injected into Cu. 3-x Using Sb nanocrystalline templates, ion exchange reactions are then carried out to obtain antimonybide quantum dots with different morphologies; The ligand is composed of trioctylphosphine and oleylamine; The precursor is soluble In 3+ Salt, soluble Ga 3+ Salt or soluble Al 3+ Salt; When Cu 3-x The Sb nanocrystalline template is a hexahedral Cu. 3-x When Sb nanocrystals are used, the volume fraction of trioctylphosphine in the ligand is 0.05%~0.15%. The ion exchange reaction conditions are: reaction at 180℃~220℃ for 45min~75min. The amount of precursor, the volume of the ligand, and the hexahedral Cu... 3-x The molar ratio of Sb nanocrystals is 0.5 mmol~2.0 mmol: 5 mL~15 mL: 0.05 mmol~0.3 mmol; When Cu 3-x The Sb nanocrystalline template is a tetrahedral Cu. 3-x When Sb nanocrystals are used, the volume fraction of trioctylphosphine in the ligand is 0.15%~0.35%. The ion exchange reaction conditions are: reaction at 200℃~240℃ for 30min~60min. The amount of precursor, the volume of the ligand, and the tetrahedral Cu... 3-x The molar ratio of Sb nanocrystals is 0.5 mmol~2.0 mmol: 4 mL~12 mL: 0.05 mmol~0.3 mmol; When Cu 3-x The Sb nanocrystalline template is a spherical Cu. 3-x When Sb nanocrystals are used, the volume fraction of trioctylphosphine in the ligand is 0.35%~0.60%. The ion exchange reaction conditions are: reaction at 230℃~270℃ for 20min~50min. The amount of precursor, the volume of the ligand, and the tetrahedral Cu... 3-x The molar ratio of Sb nanocrystals is 0.5 mmol to 2.0 mmol: 3 mL to 10 mL: 0.05 mmol to 0.3 mmol.

2. The ion exchange preparation method for antimony compound quantum dots of different morphologies according to claim 1, characterized in that, hexahedral Cu 3-x Sb nanocrystals were prepared according to the following steps: using copper carboxylates as the copper source, triphenylantimony, trioctylantimony, or antimony halide as the antimony source, trioctylphosphine as the ligand, 1-octadecene as the non-coordinating solvent, and hexadecylamine as the morphology directing agent, the reaction was carried out at 280°C~320°C to obtain Cu nanosheets or hexahedral nanocrystals. 3-x Sb nanocrystals; The mass ratio of trioctylphosphine to 1-octadecene is 1:2~10; the mass ratio of copper source, antimony source to ligand is 1:0.2~1:5~20.

3. The ion exchange preparation method for antimony compound quantum dots of different morphologies according to claim 1, characterized in that, Tetrahedral Cu 3-x Sb nanocrystals were prepared according to the following steps: using copper halides as the copper source, triphenylantimony, trioctylantimony, or antimony halide as the antimony source, trioctylphosphine as the ligand, 1-octadecene as the non-coordinating solvent, and hexadecylamine as the morphology directing agent, the reaction was carried out at 200°C~250°C to obtain Cu nanocrystals with a tetrahedral morphology. 3-x Sb nanocrystals; The mass ratio of trioctylphosphine to 1-octadecene is 1:1~5; the mass ratio of copper source, antimony source to ligand is 1:0.5~1:10~30.

4. The ion exchange preparation method for antimony compound quantum dots of different morphologies according to claim 1, characterized in that, Spherical Cu 3-x Sb nanocrystals were prepared according to the following steps: using copper nitrate or sulfate as the copper source, triphenylantimony, trioctylantimony, or antimony halide as the antimony source, trioctylphosphine as the ligand, 1-octadecene as the non-coordinating solvent, and hexadecylamine as the morphology directing agent, the reaction was carried out at 240°C~280°C to obtain spherical Cu nanocrystals. 3-x Sb nanocrystals; The mass ratio of trioctylphosphine to 1-octadecene is 1:0.5~3; the mass ratio of copper source, antimony source to ligand is 1:0.3~1:8~25.

5. A type of antimony compound quantum dot with different morphologies, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 4.

6. The antimonybide quantum dots with different morphologies according to claim 5, characterized in that, The morphology of antimonybide quantum dots is hexahedral, tetrahedral, or spherical. The antimonybide quantum dots are XSb quantum dots, where X is In, Ga, or Al.

7. The antimonybide quantum dots with different morphologies according to claim 5, characterized in that, Surface passivation or shell coating can also be performed on antimony quantum dots with different morphologies.

8. The application of antimonybide quantum dots with different morphologies as described in claim 5 in the preparation of luminescent materials.

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