A method for preparing zinc-based organometallic halide long afterglow material single crystal and powder
By preparing zinc-based organometal halide single crystals and powders, the problems of high energy consumption and oxygen quenching in all-inorganic and all-organic long afterglow materials have been solved, achieving low-cost and stable long afterglow performance, and expanding their applications in fire safety, encryption and anti-counterfeiting, and bioimaging.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CAPITAL NORMAL UNIVERSITY
- Filing Date
- 2022-11-16
- Publication Date
- 2026-05-19
AI Technical Summary
Existing all-inorganic long afterglow materials have high energy consumption and poor processability, while all-organic long afterglow materials are susceptible to oxygen quenching, which limits their large-scale industrial application and is also costly.
A method for preparing zinc-based organometal halide materials was adopted, which involved ultrasonic cleaning, heating and stirring, and precipitation treatment to prepare zinc-based organometal halide single crystals and powders. The materials exhibited long afterglow performance under low-power excitation.
The prepared zinc-based organometal halide materials can be excited by low-power white light at room temperature to produce ultra-long afterglow, exhibiting good stability and low cost, and are suitable for fields such as fire safety, encryption and anti-counterfeiting, and bioimaging.
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Figure CN115874288B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of synthesis and application of luminescent materials, specifically to a zinc-based organometal halide long afterglow material and its preparation method and application in single crystal and powder form. Background Technology
[0002] Long-afterglow luminescence refers to the phenomenon where materials can continuously emit light for an extended period after being excited by light. In recent decades, a series of all-inorganic and all-organic long-afterglow materials have been developed for applications in various industries, including fire safety, emergency lighting, encryption and anti-counterfeiting, and bioimaging. However, the preparation of all-inorganic long-afterglow materials requires high energy consumption, has poor processability, and necessitates expensive rare earth elements, limiting their practical applications. All-organic long-afterglow materials typically suffer from the fatal drawback of triplet quenching caused by oxygen, which hinders their large-scale industrial production. Therefore, designing and synthesizing long-lasting, high-efficiency long-afterglow materials with simple structures, low cost, and air stability remains essential.
[0003] Organometal halides are a novel type of optoelectronic material that is self-assembled at the molecular level from metal halides and organic cations. Due to the multi-selectivity of their organic cations and metals, the resulting differences in optoelectronic properties have already demonstrated excellent performance in the field of optoelectronic devices. Summary of the Invention
[0004] Therefore, one object of the present invention is to provide a method for preparing single crystals and powders of zinc-based organometal halide long afterglow materials, as well as related applications.
[0005] The method for preparing zinc-based organometal halide single crystals includes the following steps:
[0006] 1) Pretreatment of 10 mL glass sample vials and PTFE magnetic ingots: Clean with an ultrasonic bath (ultrapure water, dimethylformamide, ethanol, ultrapure water) for 15 minutes sequentially. After cleaning, dry the sample vials and magnetic ingots at 80°C for 30 minutes.
[0007] 2) Preparation of zinc halide hydrohalic acid solution: Add 0.5 mmol to 7 mmol of zinc halide to a sample vial, followed by 2 mL to 6 mL of hydrohalic acid. Stir at room temperature for 10 minutes to obtain a clear solution. The zinc halide includes, but is not limited to, one or more of zinc chloride and zinc bromide, with the preferred amount of zinc halide being 3 mmol. The hydrohalic acid includes, but is not limited to, one or more of hydrochloric acid and hydrobromic acid, with the preferred amount being 4 mL. The concentration of hydrochloric acid is 36%-38%, and the concentration of hydrobromic acid is 48%.
[0008] 3) Preparation of the organic ligand solution: Add 0.15 mmol to 1 mmol of 4-phenylbenzylamine to a new sample vial and add 1 mL to 4 mL of ethanol, or methanol, or isopropanol, or acetone, and stir for 10 minutes. The amount of 4-phenylbenzylamine is preferably 0.3 mmol. The solvent is preferably ethanol, and the amount of ethanol is preferably 4 mL.
[0009] 4) Keep stirring the solution in step 2) and slowly add the organic ligand solution prepared in step 3) to the solution in step 2). After the addition is complete, a white precipitate will form and the mixture will be stirred and reacted for 20 minutes.
[0010] 5) Place the mixed solution from step 4) on a heated stirring table and heat and stir to 200°C to 250°C until the precipitate is completely dissolved. The preferred heating temperature is 200°C.
[0011] 6) Place the hot, clear solution from step 5) in a quiet environment to cool naturally to room temperature for 2 hours.
[0012] 7) Filter the crystals precipitated by cooling in step 6), wash them three times with dichloromethane, and then place them in an oven at 60°C for 1 hour to obtain the final zinc-based organometallic halide single crystals.
[0013] The method for preparing the zinc-based organometal halide powder includes the following steps:
[0014] 1) Preparation of zinc halide precursor solution: Add 0.5 mmol to 7 mmol of zinc halide to a 10 mL centrifuge tube, add 1 mL to 4 mL of ethanol, methanol, isopropanol, or acetone, and simultaneously add 100 μL to 1000 μL of hydrohalic acid. Shake for 5 minutes until the zinc halide is completely dissolved. The zinc halide includes, but is not limited to, one or more of zinc chloride and zinc bromide, and the amount of zinc halide is preferably 3 mmol. The solvent is preferably ethanol, and the amount of ethanol is preferably 2 mL. The hydrohalic acid includes, but is not limited to, one or more of hydrochloric acid and hydrobromic acid, and the amount of hydrohalic acid is preferably 200 μL. The concentration of hydrochloric acid is 36%-38%, and the concentration of hydrobromic acid is 48%.
[0015] 2) Preparation of the organic ligand solution: Add 0.15 mmol to 1 mmol of 4-phenylbenzylamine to a new centrifuge tube and add 1 mL to 4 mL of ethanol, or methanol, or isopropanol, or acetone, and shake for 5 minutes. The amount of 4-phenylbenzylamine is preferably 0.3 mmol. The solvent is preferably ethanol, and the amount of ethanol is preferably 2 mL.
[0016] 3) Slowly add the zinc halide precursor solution prepared in step 1) to the organic ligand solution in step 2). After the addition is complete, shake vigorously for 5 minutes to produce a white precipitate, then continue shaking for another 5 minutes.
[0017] 4) After centrifuging the mixed solution from step 3), discard the supernatant to obtain a crude precipitate of zinc-based organometallic halides.
[0018] 5) Wash the crude precipitate obtained in step 4) repeatedly with dichloromethane, shake, centrifuge and discard the supernatant, and then place it in an oven at 60°C for 6 hours to obtain the final zinc-based organometallic halide powder.
[0019] Beneficial effects
[0020] The zinc-based organometal halide material of this invention exhibits excellent long-afterglow luminescence properties. The preparation method is simple, non-toxic, uses inexpensive raw materials, and possesses good stability. The synthesized material can be excited by low-power white light at room temperature, producing light with a duration of 40 seconds. ～ The ultra-long afterglow emission of 120 seconds, with afterglow performance significantly dependent on the selected raw materials, excitation time, and excitation power, has broad application prospects in fields such as fire safety, encryption and anti-counterfeiting, and bioimaging. Attached Figure Description
[0021] Figure 1 Figure 1 shows the single-crystal structure of the zinc-based organometal halide long afterglow material of the present invention; Figure (a) is Example 3 and Figure (b) is Example 4.
[0022] Figure 2 The images show the X-ray diffraction pattern and single-crystal simulated X-ray diffraction pattern of the chlorine-containing zinc-based organometal halide powder obtained in Example 1.
[0023] Figure 3 The images show the X-ray diffraction pattern and single-crystal simulated X-ray diffraction pattern of the bromine-containing zinc-based organometal halide powder obtained in Example 2.
[0024] Figure 4 The emission spectrum is that of the zinc-based organometal halide single crystal of the chlorine component obtained in step 7) of Example 3.
[0025] Figure 5 The emission spectrum is shown for the zinc-based organometal halide single crystal of the bromine component obtained in Example 4.
[0026] Figure 6 The lifetime decay curves at 568 nm are obtained at different excitation times in Comparative Example 1.
[0027] Figure 7 The lifetime decay curves at 577nm were obtained at different excitation times in Comparative Example 2.
[0028] Figure 8 The lifetime decay curves at 568 nm are obtained under different excitation powers in Comparative Example 3.
[0029] Figure 9 To compare the lifetime decay curves obtained at 577nm under different excitation powers in Example 4.
[0030] Figure 10 This is an example of the application of zinc-based organometal halide long afterglow materials in Example 2; Figure (a) is an example of fire safety application, and Figure (b) is an example of encryption and anti-counterfeiting application. Detailed Implementation
[0031] The present invention will now be described in detail. Before proceeding with the description, it should be understood that the terminology used in this specification and the appended claims should not be construed as limited to its general or dictionary meaning, but rather should be interpreted according to the meaning and concept corresponding to the technical aspects of the invention, based on the principle that the inventors are allowed to appropriately define the terms for the best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the invention. It should be understood that other equivalents or modifications can be obtained from it without departing from the spirit and scope of the invention.
[0032] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather should be interpreted based on the principle of allowing the inventors to appropriately define the terminology for the best interpretation, and based on its meaning and concept corresponding to the technical level of the invention. Therefore, the description herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the invention; thus, it should be understood that other equivalent implementations and modifications can be made without departing from the spirit and scope of the invention. Unless otherwise stated, the reagents and instruments used in the following examples are commercially available products.
[0033] The specific experimental procedures are as follows: Preparation methods for zinc-based organometallic halide single crystals and powders. The obtained samples were characterized using the following techniques: single-crystal X-ray diffraction and powder X-ray diffraction. Emission spectra and lifetime decay curves of the samples were obtained using an Edinburgh FLS1000 transient fluorescence spectrometer.
[0034] Example 1: Preparation of chlorine-based zinc-based organometallic halide powder
[0035] 1) Preparation of zinc chloride precursor solution: Add 3 mmol of zinc chloride to a 10 mL centrifuge tube, add 2 mL of ethanol, and simultaneously add 200 μL of hydrochloric acid. Shake for 5 minutes until the zinc chloride is completely dissolved. The concentration of hydrochloric acid is 36%-38%.
[0036] 2) Preparation of organic ligand solution: Add 0.3 mmol of 4-phenylbenzylamine to a new centrifuge tube and add 2 mL of ethanol, shake for 5 minutes.
[0037] 3) Slowly add the zinc chloride precursor solution prepared in step 1) to the organic ligand solution in step 2). After the addition is complete, shake vigorously for 5 minutes to produce a white precipitate, then continue shaking for another 5 minutes.
[0038] 4) After centrifuging the mixed solution from step 3), discard the supernatant to obtain a crude precipitate of the chlorine-containing zinc-based organometallic halide.
[0039] 5) The crude precipitate obtained in step 4) was washed repeatedly with dichloromethane, shaken, centrifuged and the supernatant was discarded. Then it was placed in an oven at 60°C for 6 hours to obtain the final chlorine component zinc-based organometallic halide powder, which was labeled as PZC-P.
[0040] Figure 2 The image shows the X-ray diffraction pattern of the zinc-based organometal halide powder PZC obtained in step 5) of Example 1. It can be seen that the synthesized PZC-P exhibits periodic diffraction peaks, and the X-ray diffraction peak positions correspond to those of the simulated single-crystal X-ray diffraction peaks. The diffraction peak near 5.6° corresponds to the (020) crystal plane, and the diffraction peak near 11.4° corresponds to the (100) crystal plane, exhibiting a distinct layered structure.
[0041] Example 2: Preparation of bromine-containing zinc-based organometallic halide powder
[0042] The synthesis process and raw material amounts in this embodiment are basically the same as in Example 1. The difference is that the raw materials zinc chloride and hydrochloric acid in Example 1 are replaced with zinc bromide and hydrobromic acid, respectively, and the concentration of hydrobromic acid is 48%. In addition, unlike Example 1, the powder product obtained in this embodiment is labeled as PZB-P.
[0043] Figure 3 The image shows the X-ray diffraction pattern of the bromine-containing zinc-based organometal halide powder PZB-P obtained in Example 2. It can be seen that the synthesized PZB-P also exhibits periodic diffraction peaks, and its X-ray diffraction peak positions correspond one-to-one with those of the simulated single-crystal X-ray diffraction peak positions. Furthermore, the diffraction peak near 5.6° corresponds to the (020) crystal plane, and the diffraction peak near 11.2° corresponds to the (100) crystal plane, exhibiting a distinct layered structure.
[0044] Figure 10Examples of practical applications of the zinc-based organometallic halide powder obtained in Example 2 are provided, with Figure (a) illustrating its application in fire safety and Figure (b) illustrating its application in anti-counterfeiting encryption. Figure (a) shows that the fire emergency escape lettering "EXIT" made from the powder sample obtained in Example 2 can be excited by low-power LED white light generated by electronic products such as mobile phones. Even after 30 seconds, the sample continues to emit orange-yellow light, and the lettering "EXIT" remains clearly visible. Figure (b) shows the information encryption process of a flower-shaped pattern (left) made from the powder sample obtained in Example 2 and a flower-shaped pattern (right) made from commercially available green phosphor under ultraviolet light excitation. Under bright field conditions, the two white flowers observed represent the first layer of "induced" information; under ultraviolet light irradiation, the resulting orange-yellow flower and green flower represent the second layer of "induced" information; the true information is the single flower that continuously emits orange-yellow light after ultraviolet excitation is stopped. The above application examples demonstrate that this zinc-based organometal halide long afterglow material has broad application prospects in fields such as fire safety, emergency lighting, and anti-counterfeiting encryption.
[0045] Example 3: Preparation of single crystals of chlorine-based zinc organometal halide
[0046] 1) Pretreatment of 10 ml glass sample vials and PTFE magnets: Clean them sequentially with an ultrasonic bath (ultrapure water, dimethylformamide, ethanol, ultrapure water) for 15 minutes. After cleaning, dry the sample vials and magnets at 80°C for 30 minutes for later use.
[0047] 2) Preparation of zinc chloride hydrochloric acid solution: Add 3 mmol of zinc chloride to a sample vial, followed by 4 mL of hydrochloric acid. Stir at room temperature for 10 minutes to obtain a clear solution. The concentration of hydrochloric acid is 36%-38%.
[0048] 3) Preparation of organic ligand solution: Add 0.3 mmol of 4-phenylbenzylamine to a new sample vial and add 4 mL of ethanol, stir for 10 minutes.
[0049] 4) Keep stirring the solution in step 2) and slowly add the organic ligand solution prepared in step 3) to the solution in step 2). After the addition is complete, a white precipitate will form and the mixture will be stirred and reacted for 20 minutes.
[0050] 5) Place the mixed solution from step 4) on a heated stirring table and heat and stir to 230°C until the precipitate is completely dissolved.
[0051] 6) Place the hot, clear solution from step 5) in a quiet environment and allow it to cool naturally to room temperature for 2 hours.
[0052] 7) The crystals precipitated in step 6) were filtered and washed three times with dichloromethane. Then, they were placed in an oven at 60°C for 1 hour to obtain the final single crystal of chlorine-based zinc organometallic halide, which was labeled as PZC-S.
[0053] 8) The emission spectrum and lifetime decay of single-crystal PZC-S were tested using an Edinburgh FLS1000 transient fluorescence spectrometer.
[0054] Figure 4 The emission spectrum of the zinc-based organometallic halide single crystal with chlorine component obtained in step 7) of Example 3 is shown. PZC-S exhibits a broad emission range of 425–800 nm, with the main peak located at 568 nm, displaying a yellowish light.
[0055] Example 4: Preparation of single crystals of bromine-containing zinc-based organometal halide
[0056] The synthesis process and raw material amounts in this embodiment are basically the same as in Example 3. The difference is that the raw materials zinc chloride and hydrochloric acid in Example 3 are replaced with zinc bromide and hydrobromic acid, respectively, in this embodiment, and the concentration of hydrobromic acid is 48%. In addition, unlike Example 3, the single crystal product obtained in this embodiment is labeled as PZB-S.
[0057] Figure 5 The emission spectrum of the zinc-based organometallic halide single crystal of the bromine component obtained in Example 4 is shown. PZB-S exhibits a broad emission spectrum of 450–800 nm, with two emission peaks at 577 nm and 614 nm. The main peak is located at 577 nm and appears as an orange-yellow light.
[0058] Comparative Example 1: Lifetime decay curves of zinc-based organometallic halides with chlorine components at different excitation times
[0059] The synthesis process of this comparative embodiment is basically the same as that of embodiment 3. The difference is that the lifetime decay test in this comparative embodiment should be specified as using a xenon lamp to excite the lifetime decay curves at 568nm corresponding to 1s, 5s and 10s respectively under a constant light power of 400 nanowatts.
[0060] Figure 6 The lifetime decay curves of PZC-S at the main peak of 568 nm are shown after excitation for 1 s, 5 s, and 10 s at a constant optical power of 400 nanowatts. It can be seen that when the excitation time is 1 s, the afterglow time of PZC-S reaches 70 s; when the excitation time is 5 s, the afterglow time reaches 90 s; and when the excitation time is 10 s, the afterglow time reaches 110 s.
[0061] Comparative Example 2: Lifetime decay curves of bromine-based zinc organometallic halides at different excitation times
[0062] The synthesis process of this comparative embodiment is basically the same as that of embodiment 4. The difference is that the lifetime decay test in this comparative embodiment should be specified as using a xenon lamp to excite the lifetime decay curves at 577nm for 1s, 5s and 10s respectively under a constant light power of 400 nanowatts.
[0063] Figure 7 The lifetime decay curves of PZB-S at the main peak of 577 nm are shown after excitation for 1 s, 5 s, and 10 s at a constant optical power of 400 nanowatts. It can be seen that when the excitation time is 1 s, the afterglow time of PZB-S reaches 100 s; when the excitation time is 5 s, the afterglow time reaches 110 s; and when the excitation time is 10 s, the afterglow time reaches 120 s.
[0064] Comparative Example 3: Lifetime decay curves of zinc-based organometallic halides with chlorine components under different excitation powers
[0065] The synthesis process of this comparative embodiment is basically the same as that of embodiment 3. The difference is that the lifetime decay test in this comparative embodiment should be specified as the lifetime decay curves at 568 nm corresponding to excitation power of 150 nanowatts, 300 nanowatts and 500 nanowatts under a constant excitation time of 1 second using a xenon lamp.
[0066] Figure 8 The lifetime decay curves of PZC-S at the main peak of 568 nm are shown under a constant excitation time of 1 s, using excitation powers of 150 nm, 300 nm, and 500 nm. It can be seen that when the excitation power is 150 nm, the afterglow time of PZC-S reaches 40 s; when the excitation power is 300 nm, the afterglow time reaches 50 s; and when the excitation power is 500 nm, the afterglow time reaches 80 s.
[0067] Comparative Example 4: Lifetime decay curves of bromine-based zinc organometallic halides under different excitation powers
[0068] The synthesis process of this comparative embodiment is basically the same as that of embodiment 4. The difference is that the lifetime decay test in this comparative embodiment should be specified as the lifetime decay curves at 577nm corresponding to excitation power of 150 nanowatts, 300 nanowatts and 500 nanowatts respectively, using a xenon lamp with a constant excitation time of 1s.
[0069] Figure 9The lifetime decay curves of PZB-S at the main peak of 577 nm are shown under a constant excitation time of 1 s, using excitation powers of 150 nm, 300 nm, and 500 nm. It can be seen that when the excitation power is 150 nm, the afterglow time of PZB-S reaches 50 s; when the excitation power is 300 nm, the afterglow time reaches 70 s; and when the excitation power is 500 nm, the afterglow time reaches 110 s.
Claims
1. A method for preparing zinc-based organometal halide single crystals, the method comprising the following steps: 1) Pretreatment of 10 ml glass sample vials and PTFE magnets: Clean them sequentially with an ultrasonic bath for 15 minutes each. After cleaning, dry the sample vials and magnets in an environment of 80°C for 30 minutes for later use. The ultrasonic bath consists of ultrapure water, dimethylformamide, ethanol, and ultrapure water. 2) Preparation of zinc halide hydrohalic acid solution: Add 0.5 mmol to 7 mmol of zinc halide to a sample vial, followed by 2 mL to 6 mL of hydrohalic acid. Stir at room temperature for 10 minutes to obtain a clear solution. The zinc halide includes, but is not limited to, one or more of zinc chloride and zinc bromide; the hydrohalic acid includes, but is not limited to, one or two of hydrochloric acid and hydrobromic acid, wherein the concentration of hydrochloric acid is 36%-38% and the concentration of hydrobromic acid is 48%; the amount of zinc halide is 3 mmol; the amount of hydrohalic acid is 4 mL. 3) Preparation of organic ligand solution: Add 0.15 mmol to 1 mmol of 4-phenylbenzylamine to a new sample vial and add 1 mL to 4 mL of ethanol, methanol, isopropanol, or acetone. Stir for 10 minutes. 4) While keeping the solution in step 2) stirred, slowly add the organic ligand solution prepared in step 3) to the solution in step 2). After the addition is complete, a white precipitate will form. Stir the reaction for 20 minutes. 5) Place the mixed solution from step 4) on a heated stirring table and heat and stir to 200°C until the precipitate is completely dissolved. 6) Place the hot, clear solution from step 5) in a quiet environment to cool naturally to room temperature for 2 hours. 7) The crystal precipitated in step 6) is filtered and washed three times with dichloromethane. Then it is placed in an oven at 60°C for 1 hour to obtain the final zinc-based organometal halide single crystal. The single crystal produces a long afterglow emission lasting 40 to 120 seconds after being excited by low-power white light at room temperature.
2. The preparation method according to claim 1, characterized in that, In step 3) above, the amount of 4-phenylbenzylamine is 0.3 mmol; the solvent is ethanol, and the amount of ethanol is 4 mL.