Sn < 2 + >-activated full-inorganic bromide near-infrared luminescent material as well as preparation method and application thereof

Abstract

The invention discloses a Sn < 2 + > activated full-inorganic bromide near-infrared luminescent material as well as a preparation method and application thereof. The Sn < 2 + > activated full-inorganic bromide near-infrared luminescent material has a structural formula of Cs7Cd3 (1-x) Br13-y: SnxIy, wherein 0.01 < = x < = 0.05, and 0 < = y < = 0.07; the preparation method comprises the following steps: dissolving a Cs precursor, a Cd precursor and a Sn precursor in a mixed solution of hydrobromic acid and hydroiodic acid, and carrying out hydrothermal reaction for 10-12h at 160-185 DEG C. The inorganic near-infrared luminescent material is obtained by taking Sn < 2 + > as an activator, has a wide visible light coverage range, can be excited by light in a wavelength range of 250-420 nm to emit near-infrared light with a peak wavelength in a range of 450-1050 nm, can meet the application of multiple scenes, and has wide application prospects. The method is suitable for the fields of night vision, NIR-LED, nondestructive testing, medical science and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of near-infrared luminescent materials, and specifically relates to a Sn 2+ Activated all-inorganic bromide near-infrared luminescent material, preparation method and application thereof. Background Art

[0002] Broadband near-infrared light sources have unique advantages, such as strong penetrability, low dispersion and absorption, allowing them to penetrate tissue more deeply; near-infrared light has a thermal effect and can resonate with most molecules, converting light energy into molecular internal energy (heat energy); near-infrared spectroscopy is a non-destructive analytical technique that can quickly and accurately detect and analyze the composition, structure, and properties of materials through the absorption, reflection, and transmission properties of near-infrared light. These characteristics make near-infrared luminescent materials have broad application potential in biomedicine, food testing, safety, sensing, agricultural production and other fields. In addition, near-infrared light is compatible with existing silicon-based photodetectors, which facilitates the establishment of portable spectral analysis systems for rapid detection.

[0003] At present, most of the mainstream near-infrared luminescent materials are based on Cr 3+ Doped matrix achieves near-infrared luminescence because they have a wide light absorption interval, unique energy levels, and broadband emission controlled in a weak crystal field. However, this type of phosphor luminescent material has the disadvantages of high raw material cost and high sintering temperature, and Cr 3+ It is easy to generate high-valent Cr ions (such as Cr 6+ );Cr 6+ It is carcinogenic and may cause irritation, sensitivity and allergic dermatitis in contact with the skin, and may cause certain damage to the respiratory and digestive systems. 6+ It is difficult to degrade in the environment, is persistent, and may cause long-term harm to the ecosystem. Reference: Nasirzadeh, N; Mohammadian, Y; Dehgan, G, Health Risk Assessment of Occupational Exposure to Hexavalent Chromium in Iranian Workplaces: a Meta-analysis Study. Biological Trace Element Research 2022, 200(4), 1551-1560.

[0004] Metal halides with perovskite structures and their derivatives have attracted considerable attention as a new generation of luminescent materials due to their exceptional optoelectronic properties. These materials are widely used in solar cells, light-emitting diodes, and photodetectors due to their excellent light absorption properties, efficient carrier transport, and convenient solution preparation methods. However, the luminescence properties of perovskite materials in the near-infrared spectral region are relatively poorly studied, which limits their application in infrared light-emitting devices. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a Sn 2+ The invention relates to an activated all-inorganic bromide near-infrared luminescent material and a preparation method thereof. The preparation method is simple and is conducive to industrial production.

[0006] The present invention also provides the Sn 2+ Application of activated all-inorganic bromide near-infrared luminescent materials as see-through materials.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A Sn 2+ Activated all-inorganic bromide near-infrared luminescent material, the Sn 2+ The structural formula of the activated all-inorganic bromide near-infrared luminescent material is: Cs7Cd 3(1-x) Br 13-y :Sn x I y ; Among them, 0.01≤x≤0.05, 0≤y≤0.07.

[0009] The Sn 2+ The activated all-inorganic bromide near-infrared luminescent material can be excited by light in the wavelength range of 250 to 420 nm to emit near-infrared light with a peak wavelength in the range of 450 to 1050 nm.

[0010] The present invention also provides the Sn 2+ The invention relates to a preparation method of an activated all-inorganic bromide near-infrared luminescent material, comprising the following steps: dissolving a Cs precursor, a Cd precursor, and a Sn precursor in a mixed solution of hydrobromic acid and hydroiodic acid, performing a hydrothermal reaction at 160-185°C for 10-12 hours, cooling, washing, and drying the mixture to obtain Sn. 2+ Activated all-inorganic bromide near-infrared luminescent materials.

[0011] The molar ratio of the Cs precursor, the Cd precursor and the Sn precursor is 7:3(1-x):x, 0.01≤x≤0.05.

[0012] The mixed solution of hydrobromic acid and hydroiodic acid is a mixed solution composed of hydrobromic acid and hydroiodic acid in a molar ratio of 13-y:y, where 0≤y≤0.07.

[0013] The Cd precursor is one or more of Cd bromide, Cd carbonate, Cd oxalate, and Cd acetate.

[0014] The Sn precursor is Sn bromide.

[0015] The Cs precursor is one or more of Cs bromide and Cs carbonate.

[0016] Furthermore, the Cd precursor is preferably cadmium acetate; the Sn precursor is preferably tin bromide; and the Cs precursor is preferably cesium bromide.

[0017] The present invention also provides the Sn 2+ Application of activated all-inorganic bromide near-infrared luminescent materials as see-through materials.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The Sn provided by the present invention 2+ The activated all-inorganic bromide near-infrared luminescent material has a new chemical composition and its emission peak exceeds 700nm. 2+ As activator, Sn 2+ The self-trapped exciton (STE) emission introduced by doping achieves broadband near-infrared luminescence by adjusting the electron-phonon coupling strength. It covers a wide range of visible light and can be excited by light in the wavelength range of 250 to 420 nm to emit near-infrared light with a peak wavelength in the range of 450 to 1050 nm.

[0020] It can meet the application needs of a wide range of scenarios and is suitable for night vision, NIR-LED, non-destructive testing, and medical fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Sn prepared in Examples 1-4 2+ X-ray diffraction patterns of activated all-inorganic bromide near-infrared luminescent materials;

[0022] Figure 2 Sn obtained in Example 1 2+ Element distribution mapping image of activated all-inorganic bromide near-infrared luminescent materials;

[0023] Figure 3 Sn obtained in Example 1 2+ Excitation and emission spectra of activated all-inorganic bromide near-infrared luminescent materials;

[0024] Figure 4 Sn obtained in Example 1-4 2+ Emission spectrum curve of activated all-inorganic bromide near-infrared luminescent material;

[0025] Figure 5 PVC medicine bottle (a) under natural light and the Sn in Example 1 2+ A PVC pharmaceutical bottle photographed in dark conditions using a near-infrared camera under illumination of an activated all-inorganic bromide near-infrared luminescent material (b). DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the embodiments.

[0027] The Cd(CH3COO)2·2H2O, SnBr2, and CsBr used in each embodiment and comparative example were all analytically pure; the mass concentration of the hydrobromic acid used was 48%, and the mass concentration of the hydroiodic acid was 57%; all of the above raw materials were commercially available.

[0028] Example 1

[0029] The molar amounts of Cd(CH3COO)2·2H2O, SnBr2, and CsBr were 1 mmol, 0.0067 mmol, and 2.097 mmol, respectively. The raw materials Cd(CH3COO)2·2H2O, SnBr2, and CsBr were mixed with 2.79 mL of HBr and 0.21 mL of HI, added to a reactor, heated at 180°C for 12 h, and naturally cooled to room temperature; the obtained crystals were washed three times with anhydrous ethanol solution; finally, the sample was placed in a vacuum environment at 65°C and dried for 12 h to obtain Sn 2+ The activated all-inorganic bromide near-infrared luminescent material is denoted as B1.

[0030] Example 2

[0031] The method described in Example 1 was followed, except that the amounts of HBr and HI were changed to 2.82 mL and 0.18 mL, respectively, to obtain Sn 2+ The activated all-inorganic bromide near-infrared luminescent material is denoted as B2.

[0032] Example 3

[0033] The method described in Example 1 was followed, except that the amounts of HBr and HI were changed to 2.85 mL and 0.15 mL, respectively, to obtain Sn 2+ The activated all-inorganic bromide near-infrared luminescent material is denoted as B3.

[0034] Example 4

[0035] The method described in Example 1 was followed, except that the amounts of HBr and HI were changed to 3 mL and 0 mL, respectively, to obtain Sn 2+ The activated all-inorganic bromide near-infrared luminescent material is denoted as B4.

[0036] Test Example 1

[0037] The Sn prepared in Examples 1-4 was characterized by X-ray diffraction. 2+ The activated all-inorganic bromide near-infrared luminescent material was analyzed, and the results were as follows Figure 1 shown.

[0038] Depend on Figure 1 It can be seen that the Sn prepared in Example 1 2+ The X-ray diffraction pattern of the activated all-inorganic bromide near-infrared luminescent material has the same diffraction peaks as the space group I4-mcm and the chemical composition Cs7Cd3Br 13 The results were consistent with the standard spectrum (PDF#97-007-2153), confirming the reliability of the hydrothermal method for synthesizing the target material.

[0039] Test Example 2

[0040] Figure 2 The Sn prepared in Example 4 2+ Element distribution mapping image of activated all-inorganic bromide near-infrared luminescent materials, by Figure 2 It can be seen that each element is evenly mixed in the crystal structure.

[0041] Test Example 3

[0042] The Sn prepared in Examples 1-4 was analyzed by fluorescence spectrometer. 2+ The activated all-inorganic bromide near-infrared luminescent material was analyzed, and the results were as follows Figure 3 shown.

[0043] Depend on Figure 3 It can be seen that the Sn prepared in Example 1 2+ The activated all-inorganic bromide near-infrared luminescent material has an emission peak at 740nm under 288nm excitation, which can show long-wavelength near-infrared luminescence characteristics. 2+ The activated all-inorganic bromide near-infrared luminescent material can be excited by ultraviolet light to emit near-infrared light, and can convert ultraviolet light into near-infrared light.

[0044] Figure 4 The Sn prepared in Examples 1-4 2+ The emission spectrum of the activated all-inorganic bromide near-infrared luminescent material under 334 nm excitation is given by Figure 4 It can be seen that the Sn prepared in Examples 1-42+ The maximum emission peak of the activated all-inorganic bromide near-infrared luminescent material remained unchanged, appearing at 760 nm. However, the luminescence intensity of the luminescent material prepared in Example 1 was significantly enhanced compared to the luminescent materials in Examples 2, 3, and 4. This indicates that the luminescence intensity of the material can be adjusted by optimizing the amount of hydrobromic acid added.

[0045] Application Example 1

[0046] Sn obtained in Example 1 2+ The results of the activated all-inorganic bromide near-infrared luminescent materials in terms of penetration ability are as follows Figure 5 shown.

[0047] The method is as follows: Organic AB glue is mixed with the luminescent material prepared in Example 1 at a mass ratio of 2:1 and stirred for 10 minutes. The mixture is then evenly applied to a 10W UV lamp with a wavelength of 420nm. The mixture is then dried at 60°C for 12 hours to solidify, thereby producing a UV lamp coated with the luminescent material prepared in Example 1. A dark test is performed: The prepared UV lamp is powered on and illuminated on a PVC pharmaceutical bottle, and a night vision image is captured using a near-infrared camera.

[0048] Figure 5 a shows a PVC medicine bottle under natural light. Figure 5 b is Sn prepared in Example 1 2+ The PVC medicine bottle photographed by a near-infrared camera under the illumination of the activated all-inorganic bromide near-infrared luminescent material light source can clearly observe the empty and filled parts in the PVC medicine bottle, showing the Sn obtained in Example 1 2+ Applications and penetration capabilities of activated all-inorganic bromide near-infrared luminescent materials.

[0049] The above reference embodiment is a Sn 2+ The detailed description of the activated all-inorganic bromide near-infrared luminescent material, its preparation method and application is illustrative rather than restrictive. Several embodiments can be listed according to the limited scope. Therefore, changes and modifications without departing from the overall concept of the present invention should fall within the scope of protection of the present invention.

Claims

1. A Sn 2+ An activated all-inorganic bromide near-infrared luminescent material, characterized in that: The Sn 2+ The structural formula of the activated all-inorganic bromide near-infrared luminescent material is: Cs7Cd 3(1-x) Br 13-y :Sn x I y ; Among them, 0.01≤x≤0.05, 0≤y≤0.

07.

2. Sn according to claim 1 2+ An activated all-inorganic bromide near-infrared luminescent material, characterized in that: The Sn 2+ The activated all-inorganic bromide near-infrared luminescent material can be excited by light in the wavelength range of 250 to 420 nm to emit near-infrared light with a peak wavelength in the range of 450 to 1050 nm.

3. Sn according to claim 1 or 2 2+ The method for preparing an activated all-inorganic bromide near-infrared luminescent material is characterized in that: The preparation method comprises the following steps: dissolving a Cs precursor, a Cd precursor, and a Sn precursor in a mixed solution of hydrobromic acid and hydroiodic acid, performing a hydrothermal reaction at 160-185° C. for 10-12 hours, cooling, washing, and drying to obtain Sn. 2+ Activated all-inorganic bromide near-infrared luminescent materials.

4. The preparation method according to claim 3, characterized in that The molar ratio of the Cs precursor, the Cd precursor and the Sn precursor is 7:3-3x:x, 0.01≤x≤0.

05.

5. The preparation method according to claim 3, characterized in that The mixed solution of hydrobromic acid and hydroiodic acid is a mixed solution composed of hydrobromic acid and hydroiodic acid in a molar ratio of 13-y:y, where 0≤y≤0.

07.

6. The preparation method according to claim 3, characterized in that The Cd precursor is one or more of Cd bromide, Cd carbonate, Cd oxalate, and Cd acetate.

7. The preparation method according to claim 3, characterized in that The Sn precursor is Sn bromide.

8. The preparation method according to claim 3, characterized in that The Cs precursor is one or more of Cs bromide and Cs carbonate.

9. The preparation method according to claim 3, characterized in that The Cd precursor is cadmium acetate; The Sn precursor is tin bromide; the Cs precursor is cesium bromide.

10. Sn according to claim 1 or 2 2+ Application of activated all-inorganic bromide near-infrared luminescent materials as see-through materials.

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