Ion-doped zero-dimensional Sn-based halide nano material and preparation method and application thereof

Abstract

The invention particularly relates to an ion-doped zero-dimensional Sn-based halide nano material as well as a preparation method and application thereof, and belongs to the technical field of nano luminescent materials. The method comprises the following steps: directly injecting a solution dissolved with a doped ionic compound into a preheated solution dissolved with an alkali metal compound and a Sn-based compound in an inert atmosphere for full reaction, and carrying out ice bath rapid cooling, centrifugation and washing to obtain the perovskite nanocrystalline ion doped zero-dimensional Sn-based halide nano material. According to the preparation method, the reaction raw materials are wide in source and easy to obtain, synthesis conditions are easy to control, high practical application value is achieved, and the prepared nanometer material is excellent in luminescence performance, high in practicability and wide in application prospect in the aspects of solid-state illumination, X-ray nanometer scintillators, up-conversion nanometer lasers, deep tissue biological imaging and the like.

Description

Technical Field

[0001] The present invention specifically relates to an ion-doped zero-dimensional Sn-based halide nanomaterial and a preparation method and application thereof, belonging to the technical field of nano-luminescent materials. Background Art

[0002] Near-infrared light, especially long-wavelength near-infrared light exceeding 1500 nm, has excellent penetration into biological tissue. Within this wavelength range, light absorption, scattering, and autofluorescence by biological tissue are greatly reduced, resulting in a deep penetration depth, which will facilitate in vivo imaging of biological tissue. In recent years, lead halide perovskite materials have attracted widespread attention in various fields due to their exceptional nonlinear optical properties, such as excellent five-photon absorption cross-sections and low-threshold upconversion stimulated emission. These materials exhibit multiphoton absorption and upconversion luminescence in the near-infrared region. However, the toxicity of lead and the instability of its lattice structure have greatly limited its application in in vivo imaging of biological tissue. Therefore, the development of non-lead halide perovskite nanomaterials with excellent nonlinear optical properties is of great research significance.

[0003] In this context, Sn-based metal halide perovskites, as an important non-lead halide perovskite material, are non-toxic, green, and environmentally friendly, showing potential as a replacement for lead halide perovskites and are expected to play a significant role in the field of biological tissue imaging. However, existing Sn-based metal halide perovskites are all micron-crystalline materials. Influenced by the micron-crystal size effect, existing Sn-based metal halide materials primarily emit light through single-photon absorption down-transfer, exhibiting the characteristics of excitation in the ultraviolet region (200-400 nm) and emission in the visible region (400-700 nm). Due to the extremely weak penetration of ultraviolet light into biological tissue, it can usually only act on the surface of biological tissue and has difficulty penetrating deeply into the tissue. This significantly limits the application of existing Sn-based metal halide perovskites and hinders their replacement for lead halide perovskites. Therefore, there is an urgent need to develop new Sn-based halide materials that can effectively absorb near-infrared light and have a wide absorption cross-section. Summary of the Invention

[0004] In response to existing problems, the present invention provides an ion-doped zero-dimensional Sn-based halide nanomaterial, a preparation method and application thereof; the material is a nanocrystalline material with good multi-photon absorption upconversion luminescence performance and a wide absorption cross-section in the near-infrared region, and is green, environmentally friendly, non-toxic, and has excellent thermal stability and storage stability. It has broad application prospects and is expected to replace lead halide perovskite materials.

[0005] The technical solutions of the present invention are as follows:

[0006] The present invention provides a method for preparing an ion-doped zero-dimensional Sn-based halide nanomaterial, comprising the following steps:

[0007] S1. Dissolve the doped ion compound sufficiently in a solvent to obtain solution A;

[0008] S2. Under the protection of an inert gas, dissolve an alkali metal compound and a tin-based compound sufficiently in a mixed solvent composed of oleic acid, oleylamine, and octadecene to obtain solution B;

[0009] S3. Continuously heat the solution B obtained in step S2 to 150-180 °C under the protection of an inert gas, and then inject the solution A obtained in step S1 into it at a constant temperature and react for 5-50 s; subsequently, cool the obtained reaction solution to room temperature, and after centrifugation and washing, obtain the ion-doped zero-dimensional Sn-based halide nanomaterial.

[0010] Further, the doped ion compound in step S1 is one of oxides, halides, or acetates of Cu + , Mn 2+ , Te 4+ or Se 4+ ; the solvent is one of acetic acid, hydrochloric acid, hydrobromic acid, and oxalic acid; the amount of the solvent is 1-10 times the total molar amount of the tin-based compound and the doped ion compound.

[0011] Further, the alkali metal compound in step S2 is one of carbonates, halides, or acetates of Na, K, Rb, or Cs; the tin-based compound is one of tin dioxide, tin tetrachloride, sodium stannate, tin acetate, and tin acetylacetonate; the volume ratio of oleic acid, oleylamine, and octadecene is (1-10):(1-10):(1-20).

[0012] Further, the tin-based compound is added in a molar ratio of (1-x):x to the doped ion compound, 0% < x < 100%, and the total molar amount of the added tin-based compound and the doped ion compound is in a ratio of 1:(0.5-3) to the molar amount of the alkali metal compound.

[0013] Further, after drying the obtained ion-doped zero-dimensional Sn-based halide nanomaterial, a nanomaterial solid powder can be obtained; the drying temperature is 40-100 °C, preferably 60-90 °C.

[0014] Further, by dispersing the obtained ion-doped zero-dimensional Sn-based halide nanomaterial in a non-polar organic solvent, a nanomaterial solution can be obtained; the non-polar organic solvent dispersant is selected from one or a combination of several of n-hexane, cyclohexane, chloroform, dichloromethane, or toluene, preferably cyclohexane and / or toluene.

[0015] The present invention also provides an ion-doped zero-dimensional Sn-based halide nanomaterial prepared by the above preparation method. The ion-doped zero-dimensional Sn-based halide nanomaterial is nanocrystalline particles with a particle size between 25.9 and 29.2 nm, and is represented by the chemical formula A2SnCl6:x M, where A is an alkali metal element, M is a doping ion, and x is the percentage of the molar number of the doping ion in the total molar number of Sn and the doping ion, 0% < x < 100%; wherein, the alkali metal element is one of Na, K, Rb, Cs; the doping ion is Cu + , Mn 2+ , Te 4+ , Se 4+ One of them.

[0016] The present invention provides an application method of the above ion-doped zero-dimensional Sn-based halide nanomaterial. Under the excitation of a laser with any wavelength within the range of 800 nm to 2600 nm, the ion-doped zero-dimensional Sn-based halide nanomaterial can emit up-conversion luminescence; this material has a wide absorption cross-section and excellent luminescence properties, and can be applied to solid-state lighting, X-ray nanoscintillators, up-conversion nanolasers, and deep tissue bioimaging, etc.

[0017] Different from the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention provides a new method for preparing ion-doped zero-dimensional Sn-based halide nanomaterials. By directly injecting a solution containing a doping ion compound into a preheated solution containing an alkali metal compound and a Sn-based compound under an inert atmosphere, the reduction of the doping ion is effectively avoided and the doping ion compound is promoted to fully react; the obtained reaction solution is rapidly cooled by ice bath, and after centrifugation and washing, a perovskite nanocrystal ion-doped zero-dimensional Sn-based halide nanomaterial with uniform size and good dispersibility is obtained; by controlling the type and amount of the doping ion, the present invention can prepare zero-dimensional Sn-based halide nanomaterials doped with different amounts of Cu + , Mn 2+ , Te 4+ , Se 4+ And other ion-doped zero-dimensional Sn-based halide nanomaterials; the reaction raw materials of this preparation method are widely available and easy to obtain, the synthesis conditions are easy to control, and it has high practical application value.

[0019] 2. Different from existing Sn-based halide perovskite materials, the ion-doped zero-dimensional Sn-based halide nanomaterials prepared by the present invention are nanocrystals with a particle size between 25.9 and 29.2 nm. Under the excitation of femtosecond pulsed lasers in the wide near-infrared band of 800 nm to 2600 nm, they achieve two-photon to seven-photon absorption upconversion luminescence, effectively expanding the response range of Sn-based halides to near-infrared light; the absorption cross-section of this material is comparable to that of lead halide perovskite nanomaterials and is superior to most traditional nonlinear optical materials. Its response characteristics to long-wavelength near-infrared light are of great value in many fields such as solid-state lighting, X-ray nanoscintillators, and upconversion nanolasers, especially in the in vivo imaging of biological tissues. Given the excellent penetrability of long-wavelength near-infrared light in biological tissues, it shows extremely outstanding application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is Te in Example 1 4+ Schematic diagram of the synthesis of doped Cs2SnCl6 nanomaterials and liquid phase luminescence photos of nanomaterials;

[0021] Figure 2 For different concentrations of Te in Example 1 4+ Doped Cs2SnCl6:xTe 4+ (x = 0%, 1%, 3%, 5%, 7%, 10%) X-ray powder diffraction patterns of nanomaterials;

[0022] Figure 3 is Te in Example 1 4+ Cs2SnCl6:xTe with doping concentrations of (a) 0%, (b) 1%, (c) 5%, (d) 7%, and (e) 10%. 4+ Transmission electron microscopy images of nanomaterials and their corresponding particle size distribution and high-resolution transmission electron microscopy images.

[0023] Figure 4 Cs2SnCl6:5%Te in Example 3 4+ X-ray photoelectron spectroscopy of nanomaterials;

[0024] Figure 5 Cs2SnCl6:5%Te in Example 3 4+ Raman spectra of nanomaterials;

[0025] Figure 6 Cs2SnCl6:5%Te in Example 3 4+ Excitation emission spectrum of nanomaterials; solid line: emission spectrum (excitation wavelength is 385nm); dotted line: excitation spectrum (emission wavelength is 575nm).

[0026] Figure 7Cs2SnCl6:5%Te in Example 3 4+ Thermogravimetric spectra of nanomaterials;

[0027] Figure 8 Cs2SnCl6:5%Te in Example 3 4+ Light stability of nanomaterials;

[0028] Figure 9 Cs2SnCl6:5%Te in Example 3 4+ X-ray powder diffraction spectrum of the nanomaterial after being placed in air for two years;

[0029] Figure 10 Cs2SnCl6:5%Te in Example 3 4+ A photo of the nanomaterial's morphology after two years in air;

[0030] Figure 11 Cs2SnCl6:5%Te in Example 3 4+ The luminescence intensity of the nanomaterial after being placed in air for two years;

[0031] Figure 12 Cs2SnCl6:5%Te in Example 3 4+ Upconversion emission spectra of nanomaterials under 800nm~2600nm wide-band femtosecond pulse laser excitation;

[0032] Figure 13 Cs2SnCl6:5%Te in Example 3 4+ The nonlinear slope of nanomaterials under femtosecond pulse laser excitation in a wide band of 800nm to 2600nm;

[0033] Figure 14 Cs2SnCl6:5%Te in Example 3 4+ Upconversion luminescence spectra of nanomaterials before and after threshold under 800nm and 1300nm femtosecond pulse laser excitation. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and preferred embodiments. The given embodiments are only for illustrating the present invention, rather than for limiting the scope of the present invention.

[0035] Unless otherwise specified, the materials, reagents, etc. used in the following examples can be obtained from commercial sources; the methods in the following examples are conventional methods unless otherwise specified.

[0036] The instruments and equipment used in the tests in the following examples are as follows:

[0037] The X-ray powder diffraction analysis of the product of the embodiment of the present invention was performed using an instrument model of MiniFlex600 manufactured by Rigaku, and the radiation wavelength of the copper target was λ=0.154187 nm.

[0038] The transmission electron microscope used for the product of the embodiment of the present invention is a TECNAI G2 F20 manufactured by FEI.

[0039] The X-ray photoelectron spectroscopy test of the product in the embodiment of the present invention is performed using an instrument model of ESCALAB 250Xi, manufactured by Thermo Fisher.

[0040] The Raman spectroscopy test of the product according to the embodiment of the present invention is performed using a micro-Ramanspectrometer manufactured by Horiba Scientific.

[0041] The thermal analysis test of the product of the embodiment of the present invention is performed using an instrument model STA449-F5 Jupiter manufactured by Netzsch.

[0042] The emission spectrum and fluorescence decay curve characterization of the product of the embodiment of the present invention were performed using an instrument model FLS980 manufactured by Edinburgh. The excitation light sources were xenon lamps and microsecond lamps, the excitation wavelength was 385 nm, and the monitoring wavelength was 575 nm.

[0043] The instrument model used for characterizing the multiphoton absorption upconversion emission spectrum and power dependence of the product of the embodiment of the present invention is Acton, the manufacturer is SpectraPro-2300, and the excitation light source is a femtosecond pulse laser.

[0044] Example 1

[0045] This embodiment provides a method for preparing an ion-doped zero-dimensional Sn-based halide nanomaterial, comprising the following steps:

[0046] S1. Weigh 0.004 mmol TeCl4 and mix with 200 μL hydrochloric acid at room temperature to obtain solution A.

[0047] S2. Under inert gas protection, 0.2 mmol Cs2CO3 and 0.396 mmol Sn(CH3COO)4 were mixed with 1 mL oleic acid, 1 mL oleylamine, and 14 mL octadecene in a 100 mL round-bottom flask. The mixture was slowly heated to 120°C under nitrogen atmosphere until completely dissolved. After keeping warm for one hour, solution B was obtained.

[0048] S3. The solution B obtained in step S2 is further heated to 160° C. under the protection of inert gas. After maintaining the temperature for 10 minutes, the solution A obtained in step S1 is immediately injected thereinto and reacted for 20 seconds. The resulting reaction solution is then cooled to room temperature in an ice bath, and the resulting reactant is centrifugally washed with cyclohexane and acetone to obtain the ion-doped zero-dimensional Sn-based halide nanomaterial.

[0049] The ion-doped zero-dimensional Sn-based halide nanomaterial obtained in this embodiment is a nanocrystal with a chemical formula of Cs2SnCl6:1%Te 4+ .

[0050] Example 2

[0051] This embodiment provides a method for preparing ion-doped zero-dimensional Sn-based halide nanomaterials, which differs from embodiment 1 in that:

[0052] In step S1, 0.012 mmol of TeCl4 was weighed and mixed with 200 μL of hydrochloric acid at room temperature to obtain solution A;

[0053] In step S2, under inert gas protection, 0.2 mmol Cs2CO3 and 0.388 mmol Sn(CH3COO)4 were mixed with 1 mL oleic acid, 1 mL oleylamine, and 14 mL octadecene in a 100 mL round-bottom flask and slowly heated to 120°C under a nitrogen atmosphere until completely dissolved. After keeping warm for one hour, solution B was obtained;

[0054] The remaining steps and drugs used are the same as those in Example 1 and will not be repeated here.

[0055] The ion-doped zero-dimensional Sn-based halide nanomaterial obtained in this embodiment is a nanocrystal with a chemical formula of Cs2SnCl6:3%Te 4+ .

[0056] Example 3

[0057] This embodiment provides a method for preparing ion-doped zero-dimensional Sn-based halide nanomaterials, which differs from embodiment 1 in that:

[0058] In step S1, 0.02 mmol TeCl4 was weighed and mixed with 200 μL hydrochloric acid at room temperature to obtain solution A;

[0059] In step S2, under inert gas protection, 0.2 mmol Cs2CO3 and 0.38 mmol Sn(CH3COO)4 were mixed with 1 mL oleic acid, 1 mL oleylamine, and 14 mL octadecene in a 100 mL round-bottom flask and slowly heated to 120°C under a nitrogen atmosphere until completely dissolved. After keeping warm for one hour, solution B was obtained;

[0060] The remaining steps and drugs used are the same as those in Example 1 and will not be repeated here.

[0061] The ion-doped zero-dimensional Sn-based halide nanomaterial obtained in this embodiment is a nanocrystal with a chemical formula of Cs2SnCl6:5%Te 4+ .

[0062] Example 4

[0063] This embodiment provides a method for preparing ion-doped zero-dimensional Sn-based halide nanomaterials, which differs from embodiment 1 in that:

[0064] In step S1, 0.028 mmol TeCl4 was weighed and mixed with 200 μL hydrochloric acid at room temperature to obtain solution A;

[0065] In step S2, under inert gas protection, 0.2 mmol Cs2CO3 and 0.372 mmol Sn(CH3COO)4 were mixed with 1 mL oleic acid, 1 mL oleylamine, and 14 mL octadecene in a 100 mL round-bottom flask and slowly heated to 120°C under a nitrogen atmosphere until completely dissolved. After keeping warm for one hour, solution B was obtained;

[0066] The remaining steps and drugs used are the same as those in Example 1 and will not be repeated here.

[0067] The ion-doped zero-dimensional Sn-based halide nanomaterial obtained in this embodiment is a nanocrystal with a chemical formula of Cs2SnCl6:7%Te 4+ .

[0068] Example 5

[0069] This embodiment provides a method for preparing ion-doped zero-dimensional Sn-based halide nanomaterials, which differs from embodiment 1 in that:

[0070] In step S1, 0.04 mmol TeCl4 was weighed and mixed with 200 μL hydrochloric acid at room temperature to obtain solution A;

[0071] In step S2, under inert gas protection, 0.2 mmol Cs2CO3 and 0.36 mmol Sn(CH3COO)4 were mixed with 1 mL oleic acid, 1 mL oleylamine, and 14 mL octadecene in a 100 mL round-bottom flask and slowly heated to 120°C under a nitrogen atmosphere until completely dissolved. After keeping warm for one hour, solution B was obtained;

[0072] The remaining steps and drugs used are the same as those in Example 1 and will not be repeated here.

[0073] The ion-doped zero-dimensional Sn-based halide nanomaterial obtained in this embodiment is a nanocrystal with a chemical formula of Cs2SnCl6:10%Te 4+.

[0074] Comparative Example 1

[0075] This comparative example provides a method for preparing Sn-based halide nanomaterials, which differs from Example 1 in that:

[0076] In step S1, TeCl4 was not added, and 200 μL of hydrochloric acid was used as solution A;

[0077] In step S2, under inert gas protection, 0.2 mmol Cs2CO3 and 0.4 mmol Sn(CH3COO)4 were mixed with 1 mL oleic acid, 1 mL oleylamine, and 14 mL octadecene in a 100 mL round-bottom flask and slowly heated to 120°C under a nitrogen atmosphere until completely dissolved. After keeping warm for one hour, solution B was obtained;

[0078] The remaining steps and drugs used are the same as those in Example 1 and will not be repeated here.

[0079] The chemical formula of the Sn-based halide nanomaterial obtained in this comparative example is Cs2SnCl6.

[0080] Example 6

[0081] This embodiment provides a method for preparing an ion-doped zero-dimensional Sn-based halide nanomaterial, comprising the following steps:

[0082] S1. Weigh 0.004 mmol TeCl4 and mix with 200 μL acetic acid at room temperature to obtain solution A.

[0083] S2. Under inert gas protection, 0.133 mmol Cs2CO3 and 0.396 mmol Sn(CH3COO)4 were mixed with 1 mL oleic acid, 1 mL oleylamine, and 20 mL octadecene in a 100 mL round-bottom flask. The mixture was slowly heated to 120°C in a nitrogen atmosphere until the mixture was completely dissolved. After keeping the mixture warm for one hour, solution B was obtained.

[0084] S3. The solution B obtained in step S2 is further heated to 150° C. under the protection of inert gas. After maintaining the temperature for 10 minutes, the solution A obtained in step S1 is immediately injected thereinto and reacted for 5 seconds. The resulting reaction solution is then cooled to room temperature in an ice bath, and the obtained reactant is centrifugally washed with cyclohexane and acetone to obtain the ion-doped zero-dimensional Sn-based halide nanomaterial.

[0085] The ion-doped zero-dimensional Sn-based halide nanomaterial obtained in this embodiment is a nanocrystal with a chemical formula of Cs2SnCl6:1%Te 4+ .

[0086] Example 7

[0087] This embodiment provides a method for preparing an ion-doped zero-dimensional Sn-based halide nanomaterial, comprising the following steps:

[0088] S1. Weigh 0.004 mmol TeCl4 and mix with 200 μL hydrobromic acid at room temperature to obtain solution A.

[0089] S2. Under inert gas protection, 0.8 mmol Cs2CO3 and 0.396 mmol Sn(CH3COO)4 were mixed with 10 mL oleic acid, 10 mL oleylamine, and 1 mL octadecene in a 100 mL round-bottom flask. The mixture was slowly heated to 120°C in a nitrogen atmosphere until completely dissolved. After keeping warm for one hour, solution B was obtained.

[0090] S3. The solution B obtained in step S2 is further heated to 180° C. under the protection of inert gas. After maintaining the temperature for 10 minutes, the solution A obtained in step S1 is immediately injected thereinto and reacted for 50 seconds. The resulting reaction solution is then cooled to room temperature in an ice bath, and the resulting reactant is centrifugally washed with cyclohexane and acetone to obtain the ion-doped zero-dimensional Sn-based halide nanomaterial.

[0091] The ion-doped zero-dimensional Sn-based halide nanomaterial obtained in this embodiment is a nanocrystal with a chemical formula of Cs2SnCl6:1%Te 4+ .

[0092] Performance Testing

[0093] Select different Te 4+ The doped Cs2SnCl6 sample was subjected to structural characterization and optical property testing and compared with the undoped sample of Comparative Example 1. The results are as follows:

[0094] Different Te in Examples 1 to 5 4+ The synthesis diagram of the doped Cs2SnCl6 sample and the liquid phase luminescence photos of the nanomaterials are shown in the figure. Figure 1 As shown;

[0095] like Figure 2 As shown, different Te 4+ Doping concentration Cs2SnCl6:xTe 4+ The XRD powder diffraction patterns of the nanomaterials show that the diffraction peaks of the obtained nanomaterials all correspond to the standard PDF cards of cubic phase Cs2SnCl6, indicating that the synthesized nanomaterials are all pure phases. 4+ With the increasing doping concentration, the diffraction peak of powder XRD shifts to a lower angle, indicating that the larger ionic radius of Te 4+ (0.097nm) replaced the smaller ionic radius of Sn 4+ (0.069nm) causes the lattice to expand.

[0096] like Figure 3 As shown, the transmission electron microscopy images and the corresponding particle size distribution as well as the high-resolution transmission electron microscopy images show that Cs2SnCl6:xTe 4+ The morphology of the nanomaterials is relatively uniform, with good dispersion and a particle size of about 25.9 to 29.2 nm. 4+ With the increase of doping concentration, the particle size shows an increasing trend, and the (220) crystal plane spacing increases from 0.338nm of undoped to 0.355nm.

[0097] like Figure 4 As shown, X-ray photoelectron spectroscopy shows that Cs2SnCl6:Te 4+ The nanomaterials contain Cs, Sn, Cl, and Te elements, and they are all in corresponding valence states.

[0098] like Figure 5 As shown, Raman spectroscopy reveals that Te 4+ [TeCl6] is present in doped nanomaterials 2- Octahedral vibration peak.

[0099] like Figure 6 As shown, under 385nm excitation, the nanomaterial has an emission peak at 575nm, and the measured down-transferred photoluminescence quantum yield of the nanomaterial is 51.3%, which is better than other ion-doped Sn-based halides with the same particle size.

[0100] like Figure 7 As shown in the figure, the thermogravimetric analysis spectrum shows that the initial mass of the nanomaterial remains unchanged at a temperature of 267°C, indicating that it has excellent thermal stability.

[0101] like Figure 8 As shown, after the prepared nanomaterial was continuously irradiated with 365nm ultraviolet light for three hours, it was observed that the fluorescence emission intensity of the nanomaterial hardly decayed, and the results showed that the nanomaterial had excellent anti-light stability.

[0102] like Figure 9 and Figure 10 As shown in the figure, the nanomaterial does not undergo phase change and its morphology hardly changes significantly after being placed under ambient conditions for two years, indicating that the nanomaterial has good air stability.

[0103] like Figure 11 As shown, after the nanomaterial was placed under ambient conditions for two years, its fluorescence emission intensity could still maintain 63.8% of the initial intensity, indicating that the sample has good photostability.

[0104] like Figure 12As shown, under the excitation of a wide-band femtosecond pulse laser from 800 nm to 2600 nm, all upconversion spectra of the nanomaterials exhibit broadband yellow light emission, which is consistent with the down-transferred fluorescence spectrum.

[0105] like Figure 13 As shown in the figure, the nonlinear slope of the nanomaterial under the excitation of femtosecond pulse laser in a wide band of 800nm to 2600nm increases from 2 to 7 with the increase of excitation wavelength, indicating that the nanomaterial has two-photon to seven-photon absorption effect.

[0106] like Figure 14 As shown, the upconversion luminescence spectra of the nanomaterial before and after the threshold under 800nm and 1300nm femtosecond pulse laser excitation verify that the nanomaterial has amplified spontaneous emission of two-photon and three-photon excitation.

[0107] It can be seen that the different Te 4+ The doped Cs2SnCl6 sample has good multi-photon absorption upconversion luminescence performance and a wide absorption cross-section. Under the excitation of femtosecond pulse laser in the wide near-infrared band of 800nm to 2600nm, it can achieve two-photon to seven-photon absorption upconversion luminescence. Its response characteristics to long-wavelength near-infrared light are of great value in many fields such as solid-state lighting, X-ray nanoscintillators, and upconversion nanolasers. Especially in the in vivo imaging of biological tissues, given the excellent penetration of long-wavelength near-infrared light into biological tissues, it shows extremely outstanding application potential.

[0108] In addition, in the preparation method of the ion-doped zero-dimensional Sn-based halide nanomaterial described in Examples 1 to 7 above, the doping amount and type of the doping ion of the zero-dimensional Sn-based halide nanomaterial can be regulated by changing the type and amount of the doping ion compound in step S1. The doping ion compound can be Cu + 、Mn 2+ 、Te 4+ or Se 4+any one of the oxides, halides or acetates of, and the solvent used may be any one of acetic acid, hydrochloric acid, hydrobromic acid and oxalic acid; at the same time, the alkali metal compound in step S2 of the present invention may be any one of the carbonates, halides or acetates of Na, K, Rb or Cs; by changing the alkali metal compound, the preparation of different Sn-based halides can be achieved; the tin-based compound used in step S2 may also be one of tin dioxide, tin tetrachloride, sodium stannate, tin acetate, and tin acetylacetonate; the preparation method of the present invention has a wide range of raw material sources and a wide range of applications. The above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For ordinary technicians in the field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to enumerate all the embodiments here. It is obvious that all the extensions of the technical solutions of the present invention are obvious.

Claims

1. A method for preparing ion-doped zero-dimensional Sn-based halide nanomaterials, characterized in that: It includes the following steps: S1, fully dissolving the doping ion compound in a solvent to obtain solution A; the doping ion compound is Cu + 、Mn 2 + 、Te 4+ or Se 4+ One of the oxides, halides or acetates of S2. Under the protection of inert gas, fully dissolve an alkali metal compound and a tin-based compound in a mixed solvent composed of oleic acid, oleylamine and octadecene to obtain solution B; S3. Continuously heat the solution B obtained in step S2 to 150 - 180 °C under the protection of inert gas, and then inject the solution A obtained in step S1 into it at a constant temperature and react for 5 - 50 s; subsequently, cool the obtained reaction solution to room temperature, and after centrifugation and washing, obtain the ion-doped zero-dimensional Sn-based halide nanomaterial.

2. The method for preparing the ion-doped zero-dimensional Sn-based halide nanomaterial according to claim 1, characterized in that: In step S1, the solvent is one of acetic acid, hydrochloric acid, hydrobromic acid and oxalic acid; the dosage of the solvent is 1 - 10 times the total molar amount of the tin-based compound and the doped ionic compound.

3. The method for preparing the ion-doped zero-dimensional Sn-based halide nanomaterial according to claim 1, characterized in that: In step S2, the alkali metal compound is one of carbonates, halides or acetates of Na, K, Rb or Cs.

4. The method for preparing the ion-doped zero-dimensional Sn-based halide nanomaterial according to claim 1, characterized in that: In step S2, the tin-based compound is one of tin dioxide, tin tetrachloride, sodium stannate, tin acetate, tin acetylacetonate.

5. The method for preparing the ion-doped zero-dimensional Sn-based halide nanomaterial according to claim 1, characterized in that: In the mixed solvent of step S2, the volume ratio of oleic acid, oleylamine and octadecene is (1 - 10):(1 - 10):(1 - 20).

6. The method for preparing the ion-doped zero-dimensional Sn-based halide nanomaterial according to claim 1, characterized in that: The tin-based compound is added in a molar ratio of (1 - x):x to the doped ionic compound, 0% < x < 100%, and the ratio of the total molar amount of the added tin-based compound and the doped ionic compound to the molar amount of the alkali metal compound is 1:(0.5 - 3).

7. An ion-doped zero-dimensional Sn-based halide nanomaterial, characterized in that: It is prepared by the preparation method of the ion-doped zero-dimensional Sn-based halide nanomaterial according to any one of claims 1 - 6.

8. The ion-doped zero-dimensional Sn-based halide nanomaterial according to claim 7, characterized in that: The ion-doped zero-dimensional Sn-based halide nanomaterial is nanocrystalline particles with a particle size between 25.9 - 29.2 nm, represented by the chemical formula A2SnCl6:xM, where A is an alkali metal element, M is a doped ion, and x is the percentage of the molar number of the doped ion in the total molar number of Sn and the doped ion, 0% < x < 100%; Wherein, the alkali metal element is one of Na, K, Rb, and Cs; the doping ion is Cu + 、Mn 2+ 、Te 4+ 、Se 4+ One of them.

9. Use of the ion-doped zero-dimensional Sn-based halide nanomaterial according to any one of claims 7 to 8, characterized in that: Under the excitation of laser with any wavelength within the range of 800 nm - 2600 nm, the ion-doped zero-dimensional Sn-based halide nanomaterial exhibits upconversion luminescence.

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