Novel perovskite fluorescent material as well as synthesis method and application thereof

Abstract

The invention discloses a novel perovskite fluorescent material as well as a synthesis method and application thereof, and belongs to the technical field of luminescent materials. The color-changing material Cs4In1-xSbxCl7 (x = 0-0.1) is prepared through an anti-solvent method, and the material has the advantages of fast water response, methanol response, thermal response, good local stability, high repeated and reversible use degree and good multiple induced luminescence color-changing phenomenon. After water is added into an original sample, yellow light is changed into orange light, and the orange light is recovered to yellow light after moisture is removed; after methanol is added, yellow light is changed into green light, and after methanol is removed, yellow light is recovered; after heating, yellow light is changed into cyan light, and after cooling, yellow light is recovered. And the treatment of adding water, adding methanol and heating has a superposed color changing effect, so that the method can be well applied to an advanced anti-counterfeiting technology and is suitable for industrial production. In addition, according to the preparation method, raw materials are cheap and easy to obtain, high-temperature sintering is not needed, harmful waste is avoided, reaction conditions are mild, and the materials do not need to be further purified.

Description

Technical Field

[0001] The invention relates to a novel perovskite fluorescent material and a synthesis method and application thereof, belonging to the technical field of luminescent materials. Background Art

[0002] Perovskite has good photoluminescent properties and can be combined with anti-counterfeiting technology to produce and use anti-counterfeiting materials. For the new perovskite material hydroluminescent color-changing CsPbBr3 nanocrystal, there are problems such as toxicity, complex synthesis process, and expensive raw materials for other hydroluminescent color-changing materials. Current anti-counterfeiting materials require a new type of non-toxic perovskite material that can be easily synthesized and environmentally friendly, so as to achieve high-quality anti-counterfeiting materials with multiple anti-counterfeiting functions.

[0003] Anti-counterfeiting technology that changes color under a single substance is actually very common, and a single color change condition will limit the application of color change.

[0004] It is relatively rare for the same material to have different color changes after different treatments. Due to the different color change effects and different color changes after superimposed treatments, this flexible color change response provides huge advantages for the design of advanced anti-counterfeiting material products. Summary of the invention

[0005] In order to solve the problems existing in the existing perovskite luminescent materials, one of the purposes of the present invention is to provide a new type of perovskite fluorescent material, the structural formula of the new type of perovskite fluorescent material is: Cs4In 1-x Sb x Cl7, wherein x=0-1.

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

[0007] Preferably, the molar ratio of InCl3·4H2O, Sb2(Ac)3 and CsCl is 1-x:0.5x:4, wherein 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 units of mmol:mL.

[0009] The third object of the present invention is to provide an application of the novel perovskite fluorescent material in anti-counterfeiting or light storage.

[0010] A fourth object of the present invention is to provide a novel perovskite fluorescent material for use in methanol detection.

[0011] Principle of the present invention: Cs4In 1-x Sb x Cl7 (x = 0-1) fluorescent material reacts with water, and the fluorescent material spontaneously tends to Cs2In with slightly lower system energy 1-x Sb x Cl 5· H2O (x = 0-1), after the water is removed, it can be transformed back to the original Cs4In 1-x Sb x Cl7 (x = 0-0.1), due to the change of crystal structure, its luminescence performance has changed. 1-x Sb x Under the action of heating or methanol, the Cl7 (x = 0-1) fluorescent material can move to Cs3In with higher system energy. 1-x Sb x Cl6 (x = 0-1), cooling or removing methanol can turn back to the original Cs4In 1-x Sb x Cl7 (x = 0-1), due to the transformation of the crystal structure, its luminescence properties change.

[0012] Concentrated HCl promotes the ionization of solution ions and the progress of the reaction. On the other hand, concentrated HCl reacts with Sb2(Ac)3 to produce SbCl3 precursor. If concentrated HCl is lacking in the preparation process, Cs4In 1-x Sb x A new type of perovskite fluorescent material based on Cl7 (x=0-1).

[0013] Beneficial effects of the present invention

[0014] (1) The present invention prepares a new type of perovskite fluorescent material with high luminescence quantum yield by a simple anti-solvent method. 1-x Sb x Cl7 (x = 0-1), this structure is a new 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 proportion of elements, the phase of the structure will change, so Cs4In 1- x Sb xCl7 has a brand-new phase structure. This new phase structure enables the material to have faster water response, methanol response, temperature response, good stability, high repeated reversible use and good water-induced luminescence color change phenomenon. After adding water, the luminescence changes from yellow to orange, and after removing the water, it returns to yellow; after adding methanol, the luminescence changes from yellow to green, and after removing the methanol, it returns to yellow; after heating, the luminescence changes from yellow to cyan, and after cooling, it returns to yellow; the untreated sample, the sample after adding water and the sample after adding methanol will produce different luminescence changes with changes in temperature.

[0015] (2) The preparation method of the present invention has cheap and readily available raw materials, does not require high-temperature sintering, does not produce any hazardous waste, has mild reaction conditions, and does not require further purification of the material.

[0016] (3) Since the present invention has a photochromic effect caused by methanol treatment, it can be used for qualitative detection of methanol content in a solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the synthesis of the new perovskite fluorescent material of the present invention.

[0018] Figure 2 This is the single crystal XRD information of the new perovskite fluorescent material synthesized in Example 1 of the present invention.

[0019] Figure 3 XRD diagrams of the novel perovskite fluorescent materials synthesized in Examples 1 and 3 of the present invention.

[0020] Figure 4 This is a fluorescence emission diagram of the new perovskite fluorescent material synthesized in Example 1 and Example 3 of the present invention.

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

[0022] Figure 6 The new perovskite fluorescent material synthesized in Example 3 of the present invention is transformed into Cs2In after adding water 1- x Sb x Cl 5· XRD pattern of H2O(x=0).

[0023] Figure 7 The new perovskite fluorescent material synthesized in Example 3 of the present invention is transformed into Cs3In after adding methanol 1- x Sb x XRD pattern of Cl6·H2O (x=0).

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

[0025] Fig. 9 This is the XRD diagram of the sample recovery after adding water and then removing water, adding methanol and then removing methanol, and heating and then cooling the new perovskite fluorescent material synthesized in Example 3 of the present invention.

[0026] Fig.10 This is a graph showing the luminescence changes of the perovskite material prepared in comparative example 1 of the present invention under ultraviolet irradiation in response to water, methanol, temperature changes and other measures.

[0027] Fig.11 This is a graph showing the luminescence changes of the Sb-doped perovskite synthesized in Example 3 of the present invention under ultraviolet irradiation in response to temperature, the original sample, the removal of water after adding water, the removal of methanol after adding methanol, etc.

[0028] Fig.12 This is a graph of the luminescence quantum yield of the new perovskite fluorescent material synthesized in Example 3 of the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following embodiments are only 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 shall be subject to the claims.

[0030] Example 1

[0031] This embodiment provides a method for preparing a novel perovskite fluorescent material, comprising the following steps: 0.15 mmol of InCl 3·4 After H2O and 0.6mmol of CsCl were mixed and stirred, 2ml of concentrated HCl and 10ml of DMF and a solvent containing ethanol were added to perform an anti-solvent method to precipitate and obtain a new perovskite fluorescent material Cs4In1Cl7.

[0032] Example 2

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

[0034] Example 3

[0035] In this example, the same preparation method as in Example 1 and Example 2 was used to prepare Cs4In0.99 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, InCl 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 new perovskite fluorescent material Cs4In 1-x Sb x Specific steps for the synthesis of Cl7(x=0). Cs4In 1-x Sb x Cl7 (x = 0-1) is synthesized in the same manner.

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

[0040] Depend on Figure 3 It can be seen that the new perovskite fluorescent material Cs4In synthesized in Example 1 and Example 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 images of Cl7 are very good.

[0041] Depend on Figure 4 It can be seen that the new perovskite fluorescent material Cs4In synthesized in Example 1 and Example 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 curve has the same luminescence center.

[0042] Depend on Figure 5 It can be seen that the new perovskite fluorescent material Cs4In synthesized in Example 3 0.99 Sb 0.01 The emission fluorescence center of Cl7 changes significantly after adding water, methanol, or heating.

[0043] Depend on Figure 6 It can be seen that the new perovskite fluorescent material Cs4In synthesized in Example 3 0.99 Sb 0.01 Cl7 will transform into Cs2In after adding water 0.99 Sb 0.01 Cl 5， Explains the change of its luminescence from yellow to orange due to Cs4In 0.99 Sb 0.01 Cl7 phase transformation into Cs2In 0.99 Sb 0.01 Cl5.

[0044] Depend on Figure 7 It can be seen that the new perovskite fluorescent material Cs4In synthesized in Example 3 0.99 Sb 0.01 Cl7 will transform into Cs3In after adding methanol 0.99 Sb 0.01 Cl6 explains the change in luminescence from yellow to green due to Cs4In 0.99 Sb 0.01 Cl7 phase transformation into Cs3In 0.99 Sb 0.01 Cl6.

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

[0046] Depend on Fig. 9 It can be seen that the new perovskite fluorescent material Cs4In synthesized in Example 30.99 Sb 0.01 Cl7 samples can be recovered by removing water after adding water, removing methanol after adding methanol, and cooling after heating, which proves the recyclability of anti-counterfeiting materials.

[0047] Depend on Fig.10 It can be seen that the new perovskite fluorescent material Cs4In synthesized in Example 3 0.99 Sb 0.01 Cl7 will undergo obvious changes in luminescent color in response to water, methanol, temperature changes, and other measures.

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

[0049] Depend on Fig.12 It can be seen that the new 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] The present invention provides a method for preparing a perovskite fluorescent material, comprising the following steps: 3· 4H2O, 0.0015mmol Sb2(Ac)3 and 0.6mmol CsCl were mixed, 5ml concentrated HCl was added, stirred and dried to obtain a perovskite fluorescent material, the structural formula of which is: Cs2In 0.99 In 0.01 Cl 5· H2O. Comparative Example 1 cannot synthesize Cs4In 0.99 Sb 0.01 Cl7 material, but synthesized orange-emitting Cs2In 0.99 Sb 0.01 Cl 5· H2O material.

[0052] The material prepared in this comparative example changes color when heated under ultraviolet light and changes to cyan under ultraviolet light, but does not change color when water or methanol is added under ultraviolet light, because Cs2In 0.99 Sb 0.01 Cl 5· H2O can only be converted into Cs3In by heating 0.99 Sb 0.01Cl6. Adding water or methanol did not convert the material into other phases.

[0053] Comparative Example 2

[0054] The present invention provides a method for preparing a perovskite fluorescent material, comprising the following steps: 3· 4H2O, 0.0015mmol Sb2(Ac)3 and 0.6mmol CsCl were mixed, 10ml concentrated HCl was added, stirred and centrifuged 5 times with ethanol to obtain a perovskite fluorescent material with the structural formula: Cs3In 1-x Sb x Cl6 (x = 0-1). Comparative Example 2: Cs4In cannot be synthesized 0.99 Sb 0.01 Cl7 material, but synthesized cyan luminescent Cs3In 0.99 Sb 0.01 Cl6 material.

[0055] The material prepared in this comparative example changes color under ultraviolet light after adding water, and changes to orange light under ultraviolet light, but does not change color under ultraviolet light after heating or adding methanol, because Cs3In 0.99 Sb 0.01 Cl6 can only be converted to Cs2In by adding water 0.99 Sb 0.01 Cl 5· H2O. Heating or adding methanol does not convert this material to other phases.

[0056] Comparative Example 3

[0057] The present invention provides a method for preparing a perovskite fluorescent material, comprising the following steps: adding 0.1485 mmol of InCl 3· 4H2O, 0.0015mmol of Sb2(Ac)3 and 0.6mmol of CsCl were mixed, and 10ml of concentrated DMF was added and stirred to obtain a perovskite fluorescent material, whose structural formula is: Cs3In 0.99 Sb 0.01 Comparative Example 3: Cs4In cannot be synthesized 0.99 Sb 0.01 Cl7 material, but synthesized cyan luminescent Cs3In 0.99 Sb 0.01 Cl6 material.

[0058] The material prepared in this comparative example changes color under ultraviolet light after adding water, and changes to orange light under ultraviolet light, but does not change color under ultraviolet light after heating or adding methanol, because Cs3In 0.99 Sb0.01 Cl6 can only be converted to Cs2In by adding water 0.99 Sb 0.01 Cl 5· H2O. Heating or adding methanol does not convert this material to other phases.

[0059] Comparative Example 4

[0060] The present invention provides a method for preparing a perovskite fluorescent material, comprising the following steps: 3· 4H2O, 0.0015mmol Sb2(Ac)3 and 0.6mmol CsCl were mixed, ground at room temperature, sintered at 200℃ for 5 hours, and its structural formula after cooling was: Cs3In 0.99 Sb 0.01 Comparative Example 4: Cs4In cannot be synthesized 0.99 Sb 0.01 Cl7 material, but synthesized cyan luminescent Cs3In 0.99 Sb 0.01 Cl6 material.

[0061] The material prepared in this comparative example changes color under ultraviolet light after adding water, and changes to orange light under ultraviolet light, but does not change color under ultraviolet light after heating or adding methanol, because Cs3In 0.99 Sb 0.01 Cl6 can only be converted to Cs2In by adding water 0.99 Sb 0.01 Cl 5· H2O. Heating or adding methanol does not convert this material to other phases.

[0062] From all the embodiments and comparative examples, it can be seen that in the general perovskite synthesis, concentrated hydrochloric acid and dimethylformamide are each separated solutes and play the role of solvents, while in the present invention, concentrated hydrochloric acid and solutes are dispersed together in dimethylformamide and promote the ionization of the raw materials, thereby providing the necessary hydrogen ion and chloride ion conditions for the synthesis of this structure.

Claims

1. A new type of perovskite fluorescent material, characterized in that: Its structural formula is: Cs4In 1-x Sb x Cl7, wherein x=0-1.

2. The method for synthesizing the novel perovskite fluorescent material according to claim 1, characterized in that: The specific preparation method is as follows: InCl 3· After 4H2O, Sb2(Ac)3 and CsCl are mixed, concentrated hydrochloric acid and dimethylformamide are added, stirred, and then put into a solvent containing ethanol to perform anti-solvent method precipitation to obtain a new perovskite fluorescent material.

3. The method for synthesizing the novel perovskite fluorescent material according to claim 2, characterized in that: The InCl 3· The molar ratio of 4H2O, Sb2(Ac)3, and CsCl is 1-x:0.5x:4, where x=0-1.

4. The method for synthesizing the novel perovskite fluorescent material according to claim 2, characterized in that: 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, and the unit is mmol:mL.

5. Application of the novel perovskite fluorescent material according to claim 1 in anti-counterfeiting or light storage.

6. Application of the novel perovskite fluorescent material according to claim 1 in methanol detection.

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