Perovskite fluorescent material, synthesis method and application thereof

Abstract

The application discloses a novel perovskite fluorescent material and a synthesis method and application thereof, and belongs to the technical field of luminescent materials. 1‑ x Sb x Cl7(x=0-0.1), the material has fast water response, methanol response, heat response, local good stability, high repeatable use degree and good multiple induction luminescence color change phenomenon, and after adding water, yellow luminescence changes into orange luminescence, and after removing water, the yellow luminescence is restored; after adding methanol, yellow luminescence changes into green luminescence, and after removing methanol, the yellow luminescence is restored; after heating, yellow luminescence changes into cyan luminescence, and after cooling, the yellow luminescence is restored. And the water adding, methanol adding and heating treatment have superimposed color change effects, can be well applied to high-grade anti-counterfeiting technology, and are suitable for industrial production. In addition, the preparation method has the advantages of cheap and easily available raw materials, no high-temperature sintering, no harmful waste, mild reaction condition and no need of further purification of the material.

Description

Technical Field

[0001] This invention relates to a novel perovskite fluorescent material, its synthesis method, and its application, belonging to the field of luminescent material technology. Background Technology

[0002] Perovskites possess excellent photoluminescent properties, which can be combined with anti-counterfeiting technology for the production and use of anti-counterfeiting materials. However, novel perovskite materials, such as hydroluminescent CsPbBr3 nanocrystals, present challenges due to their toxicity, complex synthesis process, and the high cost of raw materials found in other hydroluminescent materials. Currently, there is a need for a novel, non-toxic perovskite material that is easy to synthesize, environmentally friendly, and capable of providing high-quality anti-counterfeiting materials with multiple layers of protection.

[0003] Color-changing anti-counterfeiting technology based on a single substance is already quite common, but a single color-changing condition limits its application.

[0004] It is relatively rare for the same material to exhibit different color-changing luminescence after different treatments. Due to the different color-changing effects, and the different color changes after superimposed treatments, this flexible color-changing response provides a huge advantage for the design of advanced anti-counterfeiting materials. Summary of the Invention

[0005] To address the problems existing in current perovskite luminescent materials, one objective of this invention is to provide a novel perovskite fluorescent material with the structural formula: Cs4In. 1-x Sb x Cl7, where x = 0 - 1.

[0006] The second objective of this invention is to provide a novel method for synthesizing perovskite fluorescent materials. The specific preparation method is as follows: InCl3·4H2O, Sb2(Ac)3, and CsCl are mixed, and then concentrated hydrochloric acid and dimethylformamide (DMF) are added to a solvent containing ethanol to react and precipitate the novel perovskite fluorescent material.

[0007] Preferably, the molar ratio of InCl3·4H2O, Sb2(Ac)3, and CsCl is 1-x:0.5x:4, where x = 0-1.

[0008] Preferably, the volume ratio of concentrated hydrochloric acid to dimethylformamide is 1:5; the molar volume ratio of CsCl to concentrated hydrochloric acid is 0.3:1, in mmol:mL.

[0009] A third objective of this invention is to provide an application of the novel perovskite fluorescent material in anti-counterfeiting or optical storage.

[0010] The fourth objective of this invention is to provide an application of a novel perovskite fluorescent material in methanol detection.

[0011] The principle of this invention: This invention, Cs4In 1-x Sb x When Cl7 (x = 0-1) fluorescent material reacts with water, the fluorescent material spontaneously tends towards the slightly lower energy Cs2In. 1-x Sb x Cl 5· H2O (x = 0-1), after the water is removed, can revert back to its original form Cs4In. 1-x Sb x Cl7 (x = 0-0.1) exhibits altered luminescence properties due to a change in its crystal structure. This invention relates to Cs4In. 1-x Sb x Cl7 (x = 0-1) fluorescent materials, under heating or the action of methanol, can convert to Cs3In with higher system energy. 1-x Sb x Cl6 (x = 0-1) can be converted back to its original form Cs4In by cooling or removing methanol. 1-x Sb x Cl7 (x = 0-1) undergoes a change in its luminescence properties due to a transformation in its crystal structure.

[0012] Concentrated HCl promotes the ionization of ions in the solution, thus accelerating the reaction process. On the other hand, concentrated HCl reacts with Sb₂(Ac)₃ to produce the SbCl₃ precursor. If concentrated HCl is lacking during the preparation process, Cs₄In cannot be synthesized. 1-x Sb x A novel perovskite fluorescent material with Cl7 (x = 0-1).

[0013] Beneficial effects of the present invention

[0014] (1) This invention prepares a novel perovskite fluorescent material with high luminescence quantum yield, Cs4In, via a simple antisolvent method for color-changing applications. 1-x Sb x Cl7 (x = 0-1), this structure is a novel chemical formula, different from the previous Cs. a In b Cl c (a = 1, 2, 3, b = 1, 2, c = 3, 6, 9, etc.), due to the change in the element ratio, the phase structure will change, hence Cs4In 1- x Sb xCl7 possesses a novel phase structure, which enables the material to exhibit rapid water, methanol, and temperature responses, good stability, high reversibility, and excellent hydroluminescence. Upon adding water, the emission changes from yellow to orange, and returns to yellow after removing water. Upon adding methanol, the emission changes from yellow to green, and returns to yellow after removing methanol. Upon heating, the emission changes from yellow to cyan, and returns to yellow after cooling. The untreated sample, the sample with added water, and the sample with added methanol exhibit different emission changes with temperature.

[0015] (2) The preparation method described in this invention uses inexpensive and readily available raw materials, does not require high-temperature sintering, produces no harmful waste, has mild reaction conditions, and does not require further purification of the materials.

[0016] (3) Because the present invention has the effect of photochromism caused by methanol treatment, it can be used for qualitative detection of methanol content in solution. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the synthesis of the novel perovskite fluorescent material of this invention.

[0018] Figure 2 The XRD information of the novel perovskite fluorescent material synthesized in Example 1 of this invention is shown in single-crystal XRD.

[0019] Figure 3 The images show the XRD patterns of the novel perovskite fluorescent materials synthesized in Examples 1 and 3 of this invention.

[0020] Figure 4 The images show the fluorescence emission patterns of the novel perovskite fluorescent materials synthesized in Examples 1 and 3 of this invention.

[0021] Figure 5 This is a comparison of the emission of the novel perovskite fluorescent material synthesized in Example 3 of the present invention under 350 nm excitation, with the emission after adding water, methanol, and heating.

[0022] Figure 6 The novel perovskite fluorescent material synthesized in Example 3 of this invention undergoes a phase transformation to Cs2In upon the addition of water. 1- x Sb x Cl 5· XRD pattern of H2O (x=0).

[0023] Figure 7 The novel perovskite fluorescent material synthesized in Example 3 of this invention undergoes a phase transformation to Cs3In upon addition of methanol. 1- x Sb x XRD pattern of Cl6·H2O (x=0).

[0024] Figure 8 The XRD pattern of the temperature-dependent phase transition of the novel perovskite fluorescent material synthesized in Example 3 of this invention.

[0025] Figure 9 The XRD pattern is the recovered sample of the novel perovskite fluorescent material synthesized in Example 3 of this invention after adding water and removing water, adding methanol and removing methanol, and heating and cooling.

[0026] Figure 10 The image shows the luminescence changes of the perovskite material prepared in Comparative Example 1 of this invention under ultraviolet irradiation in response to water, methanol, temperature changes, and other measures.

[0027] Figure 11 The images show the original sample of the Sb-doped perovskite synthesized in Example 3 of this invention, and the changes in luminescence under ultraviolet irradiation after adding water and removing water, adding methanol and removing methanol, and temperature response.

[0028] Figure 12 This is a luminescence quantum yield diagram of the novel perovskite fluorescent material synthesized in Example 3 of the present invention. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following embodiments are merely simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0030] Example 1

[0031] This embodiment provides a novel method for preparing perovskite fluorescent materials, comprising the following steps: adding 0.15 mmol of InCl... 3·4 After mixing and stirring H2O and 0.6 mmol of CsCl, 2 ml of concentrated HCl and 10 ml of DMF and a solvent containing ethanol were added to the solvent for antisolvent precipitation to obtain the novel perovskite fluorescent material Cs4In1Cl7.

[0032] Example 2

[0033] This embodiment provides a method for preparing a novel perovskite fluorescent material, comprising the following steps: mixing and stirring 0.075 mmol of Sb2(Ac)3 and 0.6 mmol of CsCl, then adding 2 ml of concentrated HCl and 10 ml of DMF, and a solvent containing ethanol, to perform anti-solvent precipitation to obtain the novel perovskite fluorescent material Cs4Sb1Cl7.

[0034] Example 3

[0035] In this embodiment, the same preparation method as in Examples 1 and 2 was used to prepare Cs4In.0.99 Sb 0.01 Cl7, Cs4In 0.97 Sb 0.03 Cl7, Cs4In 0.95 Sb 0.05 Cl7, Cs4In 0.93 Sb 0.07 Cl7, Cs4In 0.90 Sb 0.10 Cl7, in which Sb2(Ac)3, CsCl, and InCl are involved in the preparation of each material. 3·4 The amount of H2O used is shown in Table 1.

[0036] Table 1

[0037]

[0038] Depend on Figure 1 It can be seen that the synthesized novel perovskite fluorescent material Cs4In 1-x Sb x The specific steps for synthesizing Cl7 (x=0). Cs4In 1-x Sb x Cl7 (x = 0 - 1) is synthesized using the same method.

[0039] Depend on Figure 2 It can be seen that the structural information of the novel perovskite fluorescent material Cs4In1Cl7 synthesized in Example 1 was obtained by single-crystal XRD analysis.

[0040] Depend on Figure 3 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Examples 1 and 3... 1-x Sb x Cl7 (x=0-1) at specific concentrations Cs4InCl7, Cs4In 0.99 Sb 0.01 Cl7, Cs4In 0.97 Sb 0.03 Cl7, Cs4In 0.95 Sb 0.05 Cl7, Cs4In 0.93 Sb 0.07 Cl7, Cs4In 0.90 Sb 0.10 The XRD patterns of Cl7 all show excellent characteristics.

[0041] Depend on Figure 4 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Examples 1 and 3... 1-x Sb x Cl7 (x=0-1) at specific concentrations Cs4InCl7, Cs4In 0.99 Sb0.01 Cl7, Cs4In 0.97 Sb 0.03 Cl7, Cs4In 0.95 Sb 0.05 Cl7, Cs4In 0.93 Sb 0.07 Cl7, Cs4In 0.90 Sb 0.10 The Cl7 fluorescence curves have the same luminescence center.

[0042] Depend on Figure 5 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3... 0.99 Sb 0.01 The emission centers of Cl7 underwent significant changes after treatment with water, methanol, and heating.

[0043] Depend on Figure 6 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3... 0.99 Sb 0.01 Cl7 will transform into Cs2In upon addition of water. 0.99 Sb 0.01 Cl 5， The explanation for its light emission changing from yellow to orange is due to Cs4In 0.99 Sb 0.01 Cl7 phase transformation Cs2In 0.99 Sb 0.01 Cl5.

[0044] Depend on Figure 7 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3... 0.99 Sb 0.01 Cl7 will transform into Cs3In upon addition of methanol. 0.99 Sb 0.01 Cl6 explains the principle behind its luminescence changing from yellow to green due to Cs4In 0.99 Sb 0.01 Cl7 phase transformation Cs3In 0.99 Sb 0.01 Cl6.

[0045] Depend on Figure 8 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3... 0.99 Sb 0.01 Under temperature changes, Cl7 will transform into Cs3In. 0.99 Sb 0.01 Cl6.

[0046] Depend on Figure 9 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3...0.99 Sb 0.01 The fact that Cl7 could be recovered after adding water to remove water, adding methanol to remove methanol, and heating and then cooling proves the recyclability of the anti-counterfeiting material.

[0047] Depend on Figure 10 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3... 0.99 Sb 0.01 Cl7 will exhibit distinct changes in its luminescent color when reacting with water, methanol, or temperature changes.

[0048] Depend on Figure 11 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3... 0.99 Sb 0.01 The original Cl7 (A), the luminescence color changes after adding water to remove water (G), and the addition of methanol to remove methanol (E) show significantly different temperature responses.

[0049] Depend on Figure 12 It can be seen that the novel perovskite fluorescent material Cs4In synthesized in Example 3... 0.99 Sb 0.01 Cl7 has a very high photon yield.

[0050] Comparative Example 1

[0051] This invention provides a method for preparing perovskite fluorescent materials, comprising the following steps: adding 0.1485 mmol of InCl... 3· A perovskite fluorescent material was obtained by mixing 4H₂O, 0.0015 mmol of Sb₂(Ac)₃, and 0.6 mmol of CsCl, followed by adding 5 ml of concentrated HCl, stirring, and drying. The material's structural formula is: Cs₂In 0.99 In 0.01 Cl 5· H2O. Comparative Example 1 could not synthesize Cs4In. 0.99 Sb 0.01 Instead of using Cl7 material, they synthesized orange-luminescent Cs2In. 0.99 Sb 0.01 Cl 5· H2O material.

[0052] The material prepared in this comparative example undergoes a color change under ultraviolet light upon heating, turning bluish-green under ultraviolet light irradiation. However, the material does not change color under ultraviolet light after adding water or methanol because Cs2In 0.99 Sb 0.01 Cl 5· H2O can only be converted into Cs3In through heating. 0.99 Sb 0.01Cl6. Adding water or methanol cannot transform the material into other phases.

[0053] Comparative Example 2

[0054] This invention provides a method for preparing perovskite fluorescent materials, comprising the following steps: adding 0.1485 mmol of InCl... 3· A perovskite fluorescent material was obtained by mixing 4H₂O, 0.0015 mmol of Sb₂(Ac)₃, and 0.6 mmol of CsCl, followed by adding 10 mL of concentrated HCl and stirring. The mixture was then centrifuged five times with ethanol. The structural formula is: Cs₃In 1-x Sb x Cl6 (x = 0-1). Comparative Example 2 could not synthesize Cs4In. 0.99 Sb 0.01 Instead of Cl7 material, a cyan-luminescent Cs3In was synthesized. 0.99 Sb 0.01 Cl6 material.

[0055] The material prepared in this comparative example changes color under ultraviolet light after the addition of water, turning orange under ultraviolet light. However, the material does not change color under ultraviolet light after heating or adding methanol because Cs3In 0.99 Sb 0.01 Cl6 can only be converted into Cs2In through water treatment. 0.99 Sb 0.01 Cl 5· H2O. Heating or adding methanol cannot transform the material into other phases.

[0056] Comparative Example 3

[0057] This invention provides a method for preparing perovskite fluorescent materials, comprising the following steps: adding 0.1485 mmol of InCl... 3· A perovskite fluorescent material was obtained by mixing 4H₂O, 0.0015 mmol of Sb₂(Ac)₃, and 0.6 mmol of CsCl, followed by adding 10 ml of concentrated DMF and stirring. The material's structural formula is: Cs₃In 0.99 Sb 0.01 Cl6. Comparative Example 3 could not synthesize Cs4In. 0.99 Sb 0.01 Instead of Cl7 material, a cyan-luminescent Cs3In was synthesized. 0.99 Sb 0.01 Cl6 material.

[0058] The material prepared in this comparative example changes color under ultraviolet light after the addition of water, turning orange under ultraviolet light. However, the material does not change color under ultraviolet light after heating or adding methanol because Cs3In 0.99 Sb0.01 Cl6 can only be converted into Cs2In through water treatment. 0.99 Sb 0.01 Cl 5· H2O. Heating or adding methanol cannot transform the material into other phases.

[0059] Comparative Example 4

[0060] This invention provides a method for preparing perovskite fluorescent materials, comprising the following steps: adding 0.1485 mmol of InCl... 3· After mixing 4H2O, 0.0015 mmol of Sb2(Ac)3 and 0.6 mmol of CsCl, the mixture was ground at room temperature and sintered at 200℃ for 5 hours. The resulting structure after cooling was: Cs3In 0.99 Sb 0.01 Cl6. Comparative Example 4 could not synthesize Cs4In. 0.99 Sb 0.01 Instead of Cl7 material, a cyan-luminescent Cs3In was synthesized. 0.99 Sb 0.01 Cl6 material.

[0061] The material prepared in this comparative example changes color under ultraviolet light after the addition of water, turning orange under ultraviolet light. However, the material does not change color under ultraviolet light after heating or adding methanol because Cs3In 0.99 Sb 0.01 Cl6 can only be converted into Cs2In through water treatment. 0.99 Sb 0.01 Cl 5· H2O. Heating or adding methanol cannot transform the material into other phases.

[0062] As can be seen from all the examples and comparative examples, in general perovskite synthesis, concentrated hydrochloric acid and dimethylformamide are separate solutes that act as solvents. However, in this invention, concentrated hydrochloric acid and solute are dispersed together in dimethylformamide and promote the ionization of the raw materials, providing the necessary hydrogen and chloride ion conditions for the synthesis of this structure.

Claims

1. A method for synthesizing a perovskite fluorescent material, characterized in that: The structural formula of the perovskite fluorescent material is: Cs4In 1-x Sb x Cl7, where x = 0.01-0.1; the synthesis method of the perovskite fluorescent material is as follows: InCl... 3· After mixing 4H2O, Sb(Ac)3, and CsCl, concentrated hydrochloric acid and dimethylformamide were added and stirred. The mixture was then placed in a container filled with ethanol for anti-solvent precipitation to obtain perovskite fluorescent material. The volume ratio of concentrated hydrochloric acid to dimethylformamide is 1:5; the molar volume ratio of CsCl to concentrated hydrochloric acid is 0.3:1, with units of mmol:mL.

2. The perovskite fluorescent material prepared by the synthesis method according to claim 1, characterized in that: The structural formula of the perovskite fluorescent material is: Cs4In 1-x Sb x Cl7, where x = 0.01 - 0.

1.

3. The application of the perovskite fluorescent material according to claim 2 in anti-counterfeiting or optical storage.

4. The application of the perovskite fluorescent material according to claim 2 in methanol detection.

Images