A rare earth doped bismuth oxyhalide material, a preparation method and applications thereof

Abstract

This invention belongs to the field of rare earth luminescent materials technology, specifically relating to a rare earth-doped bismuth halide material, its preparation method, and its application; the chemical formula of the rare earth-doped bismuth halide material is BiOX:Er. 3+ Where X = Cl and I. The preparation method of the rare earth-doped bismuth halide material includes the following steps: S1, adding bismuth nitrate, erbium nitrate, polyvinylpyrrolidone and mannitol to distilled water and mixing evenly to obtain a mixture, thus obtaining an initial reaction solution; S2, adding a halide to the mixture and stirring to obtain an initial reaction solution; S3, transferring the initial reaction solution into a high-pressure reactor lined with polytetrafluoroethylene for hydrothermal reaction, and after the reaction solution is naturally cooled to room temperature, centrifuging, washing, and then drying in an oven, and placing the dried sample in a muffle furnace for heat treatment, and after heat treatment, naturally cooling to obtain the rare earth-doped bismuth halide material; the molar ratio of bismuth nitrate to erbium nitrate is 1:(0.1~0.25); rare earth Er 3+ The doping concentration is 0.5 mol% to 20 mol%.

Description

Technical Field

[0001] This invention belongs to the field of rare earth luminescent materials technology, specifically relating to a rare earth-doped bismuth halide material, its preparation method, and its application. Background Technology

[0002] Photon upconversion luminescence, also known as nonlinear anti-Stokes luminescence, has broad application prospects in photovoltaics, bioimaging and diagnostics, information storage and security, lasers, and 3D displays. In recent years, intelligent control of upconversion light color and its novel applications have attracted increasing attention. Among them, rare-earth-doped upconversion luminescent materials, due to their tunable emission color, background-free excitation, and good chemical stability, hold promise for applications in optical anti-counterfeiting and information storage.

[0003] Photochromism refers to the reversible transition between two different states in a material's absorption spectrum, where at least one of these states is a transformation reaction under light stimulation. Reversible control of photochromic behavior can be achieved by adjusting the two states with different absorption spectra and colors under light stimulation.

[0004] Compared to other upconversion fluorescence strategies regulated by external fields, upconversion emission modulation based on photochromic effects offers advantages such as good reversibility, high security, ease of operation, and real-time response, making it more suitable for applications such as optical storage and anti-counterfeiting. Therefore, combining multicolor upconversion luminescence with photochromism will be beneficial for advanced anti-counterfeiting applications and information storage. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a rare-earth-doped bismuth halide material, its preparation method, and its applications.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A rare earth-doped bismuth halide material, wherein the chemical formula of the rare earth-doped bismuth halide material is BiOX:Er 3+ , where X = Cl and I.

[0008] A method for preparing a rare earth-doped bismuth halide material, the method comprising the following steps:

[0009] S1. Add bismuth nitrate, erbium nitrate, polyvinylpyrrolidone and mannitol to distilled water and mix well to obtain a mixture, thus obtaining the initial reaction solution;

[0010] S2. Add the halide to the mixture and stir to obtain the initial reaction solution;

[0011] S3. The initial reaction solution is transferred into a high-pressure autoclave with polytetrafluoroethylene as the inner lining for hydrothermal reaction. After the reaction solution is naturally cooled to room temperature, it is centrifuged, washed, and then placed in an oven to dry. The dried sample is then placed in a muffle furnace for heat treatment. After the heat treatment is completed, it is naturally cooled to obtain rare earth doped bismuth halide material.

[0012] The molar ratio of bismuth nitrate to erbium nitrate is 1:(0.1–0.25); rare earth element Er 3+ The doping concentration is 0.5 mol% to 20 mol%.

[0013] Furthermore, the amount of polyvinylpyrrolidone added is 0-800 mg.

[0014] Furthermore, the amount of mannitol added is (0.6-0.8) g.

[0015] Furthermore, the halide is potassium chloride or potassium iodide; the amount of the halide added is (3-5) mmol.

[0016] Furthermore, in step S3, the hydrothermal reaction temperature is 160-180℃, and the reaction time is 3-4 hours.

[0017] Furthermore, in step S3, the washing process involves sequentially using deionized water and ethanol, with the washing cycle repeated at least three times.

[0018] Furthermore, in step S3, the heat treatment temperature is 550-600℃, and the heat treatment time is 1-2 hours.

[0019] The above-described application of a rare earth-doped bismuth halide material in the fields of information storage and optical anti-counterfeiting.

[0020] The beneficial effects of this invention are:

[0021] 1. The advantages of this invention are as follows: The material exhibits a significant photochromic effect, displaying photochromism under 391nm ultraviolet radiation and showing obvious fading upon contact with water. Simultaneously, the material possesses orthogonal upconversion luminescence characteristics, emitting green and red light under 980nm and 1532nm laser excitation, respectively. Based on the reversible photochromic effect, the orthogonal upconversion luminescence of this luminescent material achieves real-time dynamic reversible controllability.

[0022] 2. The preparation process adopted in this invention is simple, has a high yield, and can be mass-produced. The prepared luminescent material has excellent reversible photochromic properties and tunable orthogonal upconversion luminescence performance, and has important application prospects in fields such as optical switching, information storage, and optical anti-counterfeiting. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0024] Figure 1 BiOI:Er provided in the embodiments of the present invention 3+ and BiOCl:Er 3+ X-ray diffraction pattern of luminescent material.

[0025] Figure 2 BiOI:Er provided in the embodiments of the present invention 3+ and BiOCl:Er 3+ Scanning electron microscope image of the luminescent material.

[0026] Figure 3 BiOI:Er provided in the embodiments of the present invention 3+ Upconversion emission spectrum of the material under 980 / 1532nm laser irradiation.

[0027] Figure 4 BiOI:Er provided in the embodiments of the present invention 3+ Absorption spectra of the material after irradiation with 391nm ultraviolet light for different times.

[0028] Figure 5 BiOI:Er provided in the embodiments of the present invention 3+ Absorption spectra of the material after different water bleaching times.

[0029] Figure 6 BiOI:Er provided in the embodiments of the present invention 3+ The graph shows the change in upconversion luminescence intensity (λex = 980 nm) of the material over time under 391 nm ultraviolet irradiation and water bleaching.

[0030] Figure 7 BiOI:Er provided in the embodiments of the present invention 3+ The graph shows the change in upconversion luminescence intensity (λex = 1532 nm) of the material under 391 nm ultraviolet irradiation and water bleaching over time.

[0031] Figure 8 BiOI:Er provided in the embodiments of the present invention 3+ The application of materials in the fields of optical anti-counterfeiting and information storage is showcased. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1:

[0034] The fluorescent material provided in this embodiment, which combines photochromism and orthogonal upconversion luminescence, is BiOI:5%Er 3+ The specific preparation method is as follows:

[0035] S1. Add bismuth nitrate pentahydrate (930.9424 mg, 1.90 mmol), 1 mL of erbium nitrate solution (0.1 mol / L), mannitol (600 mg), and polyvinylpyrrolidone (100 mg) to deionized water (60 mL), stir vigorously for 10 minutes to obtain a mixture;

[0036] S2. Then, potassium iodide (360 mg, 3 mmol) was added to the above mixture, and the mixture was stirred for 1 hour to obtain the initial reaction solution.

[0037] S3. Transfer the initial reaction solution to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and seal it. Then heat at 160 °C for 3 hours. Finally, collect the product by centrifugation, wash it three times with deionized water and ethanol, and dry it in a vacuum oven for 10 hours. Place the final product in a sealed crucible and heat-treat it in a muffle furnace at 550 °C for 1 hour. After natural cooling, BiOI:5%Er can be obtained. 3+ Luminescent materials.

[0038] Example 2:

[0039] The fluorescent material provided in this embodiment, which combines photochromism and orthogonal upconversion luminescence, is BiOCl:5%Er 3+ The specific preparation method is as follows:

[0040] S1. Add bismuth nitrate pentahydrate (930.9424 mg, 1.90 mmol), 1 mL of erbium nitrate solution (0.1 mol / L), mannitol (600 mg), and polyvinylpyrrolidone (100 mg) to deionized water (60 mL), stir vigorously for 10 minutes to obtain a mixture;

[0041] S2. Then, potassium chloride (360 mg, 3 mmol) was added to the above mixture, and the mixture was stirred for 1 hour to obtain the initial reaction solution.

[0042] S3. Transfer the mixture to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and seal it. Then heat at 160 °C for 3 hours. Finally, collect the product by centrifugation, wash it three times with deionized water and ethanol, and dry it in a vacuum oven for 10 hours. Place the final product in a sealed crucible and heat-treat it in a muffle furnace at 550 °C for 1 hour. After natural cooling, BiOCl:5%Er is obtained. 3+ Luminescent materials.

[0043] Example 3:

[0044] The BiOI:Er material provided in this embodiment combines photochromism and orthogonal upconversion luminescence. 3+ The specific preparation method for the agarose composite membrane is as follows:

[0045] 2 mL containing 0.15 g BiOI:Er 3+ A homogeneous solution was obtained by uniformly mixing the powder aqueous solution with 2 mL of glycerol. Subsequently, 6 mL of agarose aqueous solution (33.33 mg / mL) was slowly added to the above mixture. After stirring at 80 °C for 15 min, the mixture was poured into a glass mold and cured for a period of time to obtain a composite film for subsequent application demonstration.

[0046] Example 4:

[0047] The BiOCl:Er material provided in this embodiment combines photochromism and orthogonal upconversion luminescence. 3+ The specific preparation method for the agarose composite membrane is as follows:

[0048] 2 mL containing 0.15 g BiOCl:Er 3+ A homogeneous solution was obtained by uniformly mixing the powder aqueous solution with 2 mL of glycerol. Subsequently, 6 mL of agarose aqueous solution (33.33 mg / mL) was slowly added to the above mixture. After stirring at 80 °C for 15 min, the mixture was poured into a glass mold and cured for a period of time to obtain a composite film for subsequent application demonstration.

[0049] Comparative Example 1

[0050] Compared with Example 1, Comparative Example 1 did not add erbium nitrate solution to the raw materials, but the other raw materials and preparation methods were the same as in Example 1, and bismuth halogen oxide material was prepared.

[0051] The prepared bismuth halide material was tested for upconversion luminescence performance using a fluorescence spectrometer, and no fluorescence effect was found; however, photochromic effects were observed when it was irradiated with ultraviolet light.

[0052] Comparative Example 2

[0053] Compared with Example 1, Comparative Example 2 did not add PVP and mannitol to its raw materials, but the other raw materials and preparation methods were the same as in Example 1, and erbium ion-doped bismuth halide material was prepared.

[0054] The luminescence properties of the prepared erbium-doped bismuth halide material were detected by fluorescence spectroscopy, and upconversion luminescence was found. However, no photochromic effect was observed when the material was irradiated with ultraviolet light.

[0055] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A rare earth-doped bismuth halide material, characterized in that, The rare earth-doped bismuth halide material has the chemical formula BiOX:Er 3+ Where X = Cl or I; The preparation method of the rare earth-doped bismuth halide material includes the following steps: S1. Add bismuth nitrate, erbium nitrate, polyvinylpyrrolidone and mannitol to distilled water and mix well to obtain a mixture, thus obtaining the initial reaction solution; S2. Add the halide to the mixture and stir to obtain the initial reaction solution; S3. The initial reaction solution is transferred into a high-pressure autoclave with polytetrafluoroethylene as the inner lining for hydrothermal reaction. After the reaction solution is naturally cooled to room temperature, it is centrifuged, washed, and then placed in an oven to dry. The dried sample is then placed in a muffle furnace for heat treatment. After the heat treatment is completed, it is naturally cooled to obtain rare earth doped bismuth halide material. The molar ratio of bismuth nitrate to erbium nitrate is 1:(0.1–0.25); rare earth element Er 3+ The doping concentration is 0.5 mol% to 20 mol%. In step S3, the heat treatment temperature is 550-600℃ and the heat treatment time is 1-2 hours. The rare earth-doped bismuth halide material exhibits photochromism under 391nm ultraviolet radiation and shows obvious fading when exposed to water. At the same time, the rare earth-doped bismuth halide material has orthogonal upconversion luminescence characteristics and exhibits green and red light emission under 980nm and 1532nm laser excitation, respectively.

2. The rare earth-doped bismuth halide material according to claim 1, characterized in that, The amount of polyvinylpyrrolidone added is 100-800 mg.

3. The rare earth-doped bismuth halide material according to claim 1, characterized in that, The amount of mannitol added is 0.6 to 0.8 g.

4. The rare earth-doped bismuth halide material according to claim 1, characterized in that, The halide is potassium chloride or potassium iodide; the amount of halide added is 3-5 mmol.

5. The rare earth-doped bismuth halide material according to claim 1, characterized in that, In step S3, the hydrothermal reaction temperature is 160-180℃ and the reaction time is 3-4 hours.

6. The rare earth-doped bismuth halide material according to claim 1, characterized in that, In step S3, the washing process involves sequentially washing with deionized water and ethanol, with a minimum of three washing cycles.

7. The application of the rare earth-doped bismuth halide material as described in claim 1 in the fields of information storage and optical anti-counterfeiting.

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