Bismuth ion doped Cs2-xRbxZr1-yHfyCl6 halogen perovskite photochromic material and preparation method thereof

Abstract

The invention belongs to the technical field of perovskite microcrystal powder materials, and particularly discloses a bismuth ion doped Cs2-xRbxZr1-yHfyCl6 halogen perovskite photochromic material and a preparation method thereof, the chemical formula of the bismuth ion doped Cs2-xRbxZr1-yHfyCl6 halogen perovskite photochromic material is Cs2-xRbxZr1-yHfyCl6: nBi < 3 + >, x is more than or equal to 0 and less than 2, y is more than or equal to 0 and less than 1, and n is more than 0 and less than 1. The perovskite microcrystal powder with photochromic performance is prepared through a coprecipitation method, the perovskite microcrystal powder material with uniform chemical components is directly obtained through a chemical reaction in a solution, and the method has the potential of batch production.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite microcrystalline powder materials, and particularly relates to a bismuth ion-doped Cs 2- x Rb x Zr 1-y Hf y Cl 6 halide perovskite photochromic material and a preparation method thereof. Background Art

[0002] With the continuous development of science and technology, people's research on luminescent materials has also been continuously deepened, and photochromic materials have gradually come into people's view. Photochromism refers to a phenomenon in which the color of a material itself undergoes reversible changes under certain light stimuli. Based on this optical characteristic, photochromic materials are widely used in optical glass, optical switches, information storage, anti-counterfeiting encryption, etc. Photochromism can occur in organic, inorganic, and hybrid materials. In the past, people's research on the photochromic effect mainly focused on organic compounds. However, due to problems such as poor stability, poor anti-fatigue performance, and high synthesis difficulty, organic compounds are severely restricted in daily use. Compared with the other two, inorganic materials are more suitable for commercial use.

[0003] There are mainly three explanations for the photochromic mechanism of inorganic materials: one is that a phase change occurs after the material is photoexcited; the second is that defects capture electrons or holes under the influence of an external field, resulting in the formation of color centers; the third is that the ionic valence state changes. In recent years, the research on inorganic photochromic materials has mainly focused on oxides, such as metal oxides (MoO 3 , WO 3 and V 2 O 5 ), ferroelectrics (K 0.5 Na 0.5 NbO 3 , Na 0.5 Bi 2.5 Nb 2 O 9 , Bi 4 Ti 3 O 12 ), rare earth-doped materials (Ca 2 SnO 4 :Eu 2+ , Sr 2 SnO 4 :Sm 3+ , BaMgSiO 4 :Eu 2+), while the research on halides is relatively lacking. Different from oxides that require high temperatures and strict synthesis conditions, halide perovskites have solution processability and natural advantages in synthesis. Moreover, halide perovskites have advantages such as adjustable band gaps and high defect tolerance, making them suitable as matrices to accommodate doped ions and adjust the relevant defect levels. Cs 2 ZrCl 6 is a zero-dimensional metal halide double perovskite. When the dimension decreases from three-dimensional to zero-dimensional, the orbital overlap decreases and the band gap increases, which can accommodate more doping energy levels. Regarding the research on doping modification of Cs 2 ZrCl 6 has developed to a certain extent. For example, doping Bi 3+ , Sb 3+ , Te 4+ and other ions can achieve the regulation of emission color and can be used to fabricate white light emitting diodes (WLEDs). Te 4+ co-doped with Er 3+ , Yb 3+ , Nd 3+ can achieve near-infrared emission. The doping of Lu 3 + can improve the light yield of the material and can be used for X-ray imaging. However, there is currently no report on the research of photochromism of Cs 2 ZrCl 6 . The existing technical problem is how to create a large number of defects in Cs 2 ZrCl 6 perovskite. Photochromism requires the material to undergo reversible electronic or structural changes under light irradiation, while the synthesis of Cs 2 ZrCl 6 usually pursues high crystallinity and low defect density to enhance the luminescence performance. For example, ionic liquid-assisted synthesis can passivate surface defects and improve stability, but this may inhibit the formation of dynamic defects or active sites required for photochromism. In addition, existing preparation methods (such as high-temperature thermal injection or high-pressure conditions) may not be conducive to the introduction of photosensitive components and the generation of defect states. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects existing in the prior art and provide a bismuth ion-doped Cs 2-x Rb x Zr 1-y Hf y Cl 6 halide perovskite photochromic material and its preparation method, which endows the material with photochromic properties by doping bismuth ions at the B site of the perovskite ABX 3 .

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A bismuth ion-doped Cs 2-x Rb x Zr 1-y Hf y Cl 6 halide perovskite photochromic material, with the chemical formula Cs 2- x Rb x Zr 1-y Hf y Cl 6 :nBi 3+ , where 0 ≤ x < 2, 0 ≤ y < 1, 0 < n < 1.

[0007] In a preferred embodiment of the present invention, the chemical formula is Cs 2-x Rb x ZrCl 6 :nBi 3+ (0 < x < 2, 0 < n < 1), Cs 2 Zr 1-y Hf y Cl 6 :nBi 3+ (0 < y < 1, 0 < n < 1), Cs 2-x Rb x Zr 1-y Hf y Cl 6 :nBi 3+ (0 < x < 2, 0 < y < 1, 0 < n < 1).

[0008] In a preferred embodiment of the present invention, the Cs 2-x Rb x Zr 1-y Hf y Cl 6 in the Cs source is at least one of inorganic salts of Cs, the Rb source is at least one of inorganic salts of Rb, and the Bi source is at least one of oxides or chlorides of Bi.

[0009] More preferably, the Cs 2-x Rb x Zr 1-y Hf y Cl 6 in the Cs source is at least one of CsCl or Cs 2 CO 3 in the Rb source is at least one of Rb 2 CO 3 or RbCl, and the Bi source is Bi 2 O3 or BiCl 3 at least one of

[0010] In a preferred embodiment of the present invention, the Cs 2-x Rb x Zr 1-y Hf y Cl 6 The Zr source among them is ZrCl 4 and the Hf source is HfCl 4 , and the Cl source is HCl.

[0011] A preparation method of a bismuth ion-doped Cs 2-x Rb x Zr 1-y Hf y Cl 6 halide perovskite photochromic material, characterized by comprising the following steps:

[0012] S1: Dissolve the precipitating agent Cs source and Rb source in concentrated hydrochloric acid in proportion to form solution A; dissolve the Zr source, Hf source and Bi source in concentrated hydrochloric acid in proportion to form solution B;

[0013] S2: Heat and stir the solution A and solution B obtained in step S1 respectively, and then slowly inject solution A into solution B under vigorous stirring for reaction;

[0014] S3: Centrifuge to extract the reaction product in step S2, wash, dry, and then grind it into microcrystals to obtain the bismuth ion-doped Cs 2-x Rb x Zr 1-y Hf y Cl 6 halide perovskite photochromic material.

[0015] In a preferred embodiment of the present invention, the concentration of the concentrated hydrochloric acid in step S1 is 8-12 mol / L.

[0016] In a preferred embodiment of the present invention, the temperature for heating and stirring in step S2 is 50-70 °C, and the stirring time is 20-50 min.

[0017] In a preferred embodiment of the present invention, the reaction temperature in step S2 is 60-80 °C, and the stirring speed is 400-700 rpm.

[0018] In a preferred embodiment of the present invention, the drying temperature in step S3 is 70-90 °C, and the drying time is 5-7 h.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. By introducing Bi 3+ ions, the present invention endows the material with photochromic properties, and its advantages are fast color change rate, relatively high color change degree, and high stability after color change.

[0021] 2. The present invention prepares perovskite microcrystalline powder with photochromic properties by the coprecipitation method. Through the chemical reaction in the solution, perovskite microcrystalline powder materials with uniform chemical composition are directly obtained, which has the potential for mass production. Description of the Drawings

[0022] Figure 1 XRD pattern of the material prepared in Example 1;

[0023] Figure 2 Diffuse reflection spectrum of the material prepared in Example 1;

[0024] Figure 3 XRD pattern of the material prepared in Example 2;

[0025] Figure 4 Diffuse reflection spectrum of the material prepared in Example 2;

[0026] Figure 5 XRD pattern of the material prepared in Example 3;

[0027] Figure 6 Diffuse reflection spectrum of the material prepared in Example 3;

[0028] Figure 7 XRD pattern of the material prepared in Example 4;

[0029] Figure 8 Diffuse reflection spectrum of the material prepared in Example 4;

[0030] Figure 9 XRD pattern of the material prepared in Example 5;

[0031] Figure 10 Diffuse reflection spectrum of the material prepared in Example 5;

[0032] Figure 11 XRD pattern of the material prepared in Example 6;

[0033] Figure 12 Diffuse reflection spectrum of the material prepared in Example 6;

[0034] Figure 13 XRD pattern of the material prepared in Example 7;

[0035] Figure 14Diffuse reflection spectrum of the material prepared in Example 7;

[0036] Figure 15 XRD pattern of the material prepared in Example 8;

[0037] Figure 16 Diffuse reflection spectrum of the material prepared in Example 8;

[0038] Figure 17 Comparison chart of XRD patterns of the materials prepared in Examples 1 - 8. Detailed implementation mode

[0039] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0040] Example 1

[0041] Cs 1.8 Rb 0.2 ZrCl 6 :0.02Bi 3+ A perovskite photochromic material is prepared by the following method:

[0042] S1. Dissolve 9.5 mmol of CsCl and 0.5 mmol of Rb 2 CO 3 in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form solution A; dissolve 5 mmol of ZrCl 4 powder and 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form solution B.

[0043] S2. Heat and stir solutions A and B at 60 °C for 30 min respectively, and then, under vigorous stirring, slowly inject solution A into solution B and continue to stir at 60 °C for 1 h for reaction.

[0044] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect and store it in a drying oven.

[0045] Example 2

[0046] Cs 0.2 Rb 1.8 ZrCl 6 :0.02Bi 3+ A perovskite photochromic material is prepared by the following method:

[0047] S1. Dissolve 0.5 mmol of CsCl and 9.5 mmol of Rb 2 CO 3 in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form solution A; dissolve 5 mmol of ZrCl 4 powder and 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form solution B.

[0048] S2. Heat and stir solution A and solution B at 60 °C for 30 min respectively. Then, under vigorous stirring, slowly pour solution A into solution B and continue stirring at 60 °C for 1 h for reaction.

[0049] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect them and store them in a drying oven.

[0050] Example 3

[0051] Cs 2 Zr 0.9 Hf 0.1 Cl 6 :0.02Bi 3+ Perovskite photochromic material is prepared by the following method:

[0052] S1. Dissolve 10 mmol of CsCl in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form solution A; dissolve 4.5 mmol of ZrCl 4 powder, 0.5 mmol of HfCl 4 , and 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form solution B.

[0053] S2. Heat and stir solution A and solution B at 60 °C for 30 min respectively. Then, under vigorous stirring, slowly pour solution A into solution B and continue stirring at 60 °C for 1 h for reaction.

[0054] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect them and store them in a drying oven.

[0055] Example 4

[0056] Cs 2 Zr 0.1 Hf 0.9 Cl 6: 0.02 Bi 3+ Perovskite photochromic material, prepared by the following method:

[0057] S1. Dissolve 10 mmol of CsCl in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form solution A; dissolve 0.5 mmol of ZrCl 4 powder and 4.5 mmol of HfCl 4 , 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form solution B.

[0058] S2. Heat and stir solution A and solution B at 60 °C for 30 min respectively. Then, under vigorous stirring, slowly pour solution A into solution B and continue to stir at 60 °C for 1 h for reaction.

[0059] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect and store it in a drying oven.

[0060] Example 5

[0061] Cs 1.8 Rb 0.2 Zr 0.9 Hf 0.1 Cl 6 : 0.02 Bi 3+ Perovskite photochromic material, prepared by the following method:

[0062] S1. Dissolve 9.5 mmol of CsCl and 0.5 mmol of Rb 2 CO 3 in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form solution A; dissolve 4.5 mmol of ZrCl 4 powder and 0.5 mmol of HfCl 4 , 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form solution B.

[0063] S2. Heat and stir solution A and solution B at 60 °C for 30 min respectively. Then, under vigorous stirring, slowly pour solution A into solution B and continue to stir at 60 °C for 1 h for reaction.

[0064] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect and store it in a drying oven.

[0065] Example 6

[0066] Cs 0.2 Rb 1.8 Zr 0.9 Hf 0.1 Cl 6 : 0.02Bi 3+ A perovskite photochromic material is prepared by the following method:

[0067] S1. Dissolve 0.5 mmol of CsCl and 9.5 mmol of Rb 2 CO 3 in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form solution A; dissolve 4.5 mmol of ZrCl 4 powder, 0.5 mmol of HfCl 4 , and 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form solution B.

[0068] S2. Heat and stir solution A and solution B at 60 °C for 30 min respectively, and then slowly inject solution A into solution B under vigorous stirring, and continue to stir at 60 °C for 1 h for reaction.

[0069] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution, and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect it, and store it in a drying oven.

[0070] Example 7

[0071] Cs 1.8 Rb 0.2 Zr 0.1 Hf 0.9 Cl 6 : 0.02Bi 3+ A perovskite photochromic material is prepared by the following method:

[0072] S1. Dissolve 9.5 mmol of CsCl and 0.5 mmol of Rb 2 CO 3 in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form solution A; dissolve 0.5 mmol of ZrCl 4 powder, 4.5 mmol of HfCl 4 , and 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form solution B.

[0073] S2. Heat and stir the A solution and the B solution at 60 °C for 30 min respectively. Then, under vigorous stirring, slowly inject the A solution into the B solution and continue to stir at 60 °C for 1 h for the reaction.

[0074] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect them and store them in a drying oven.

[0075] Example 8

[0076] Cs 0.2 Rb 1.8 Zr 0.1 Hf 0.9 Cl 6 : 0.02Bi 3+ A perovskite photochromic material is prepared by the following method:

[0077] S1. Dissolve 0.5 mmol of CsCl and 9.5 mmol of Rb 2 CO 3 in 12.5 mL of 12 mol / L concentrated hydrochloric acid to form an A solution; dissolve 0.5 mmol of ZrCl 4 powder and 4.5 mmol of HfCl 4 , 0.05 mmol of Bi 2 O 3 in 50 mL of 12 mol / L concentrated hydrochloric acid to form a B solution.

[0078] S2. Heat and stir the A solution and the B solution at 60 °C for 30 min respectively. Then, under vigorous stirring, slowly inject the A solution into the B solution and continue to stir at 60 °C for 1 h for the reaction.

[0079] S3. Extract the product from the solution by centrifugation, then wash it three times with methanol solution and dry it at 80 °C for 6 h. After drying, grind it into microcrystals using an agate mortar, collect them and store them in a drying oven.

[0080] The perovskite photochromic materials obtained in the above Examples 1 - 8 were subjected to diffuse reflection and XRD tests. The powder X-ray diffraction data were measured by a Rigaku SmartLab X-ray Diffractometer in Japan. Equipped with a Cu Ka (λ = 0.15405 nm) X-ray tube, the test was carried out at 40 kV and 30 mA. The scanning step was 0.02°, and the scanning speed of the ordinary sample was 10° / min. The diffuse reflection spectrum was measured by a Shimadzu UV-2550 ultraviolet-visible spectrophotometer in Japan in the spectral range of 200 - 800 nm.

[0081] Among them, the photochromic ability can be represented by the change value of diffuse reflection (ΔR):

[0082] ΔR = R 0 - R 1 (1)

[0083] R 0 and R 1 respectively represent the diffuse reflection values of the material before and after color change. Calculate ΔR in the visible light range using formula (1).

[0084] Figure 1 The XRD pattern shown represents that the material prepared in Example 1 matches well with the PDF#74 - 0505 - Cs 2 ZrCl 6 card, proving that the synthesized material is a pure phase, and the peak position has a slight right shift, indicating that an element with a smaller radius is doped, which is consistent with the doping characteristics of Rb.

[0085] Figure 2 The ultraviolet diffuse reflection spectrum of the material prepared in Example 1 is shown. By comparing the diffuse reflection intensities before and after irradiation with a 254 nm ultraviolet lamp, it is proved that the Cs 1.8 Rb 0.2 ZrCl 6 :0.02Bi 3+ prepared in Example 1 has a photochromic effect. By calculation using formula (1), it is obtained that Example 1 has the highest color change degree ΔR of 16.41% at 290 nm.

[0086] Figure 3 The XRD pattern shown represents that the material prepared in Example 2 (Cs 0.2 Rb 1.8 ZrCl 6 :0.02Bi 3+ ) matches well with the PDF#74 - 0504 - Rb 2 ZrCl 6 card. This indicates that the Cs 0.2 Rb 1.8 ZrCl 6 :0.02Bi 3+ compound material has been successfully synthesized.

[0087] Figure 4 The ultraviolet diffuse reflection spectrum of the material (Cs 0.2 Rb 1.8 ZrCl 6 :0.02Bi 3+ ) prepared in Example 2 is shown. By comparing the diffuse reflection intensities before and after irradiation with a 254 nm ultraviolet lamp, it is proved that Cs 0.2 Rb 1.8 ZrCl6 : 0.02 Bi 3+ has a photochromic effect. The actual Cs is calculated by formula (1) 0.2 Rb 1.8 ZrCl 6 : 0.02 Bi 3+ has the highest color change degree ΔR of 8.7% at 285 nm.

[0088] Figure 5 The XRD pattern shown represents the material (Cs 2 Zr 0.9 Hf 0.1 Cl 6 : 0.02 Bi 3+ ) prepared in Example 3 and the PDF#74 - 0505 - Cs 2 ZrCl 6 card and PDF#32 - 0233 - Cs 2 HfCl 6 cards match well, proving that the synthesized is a pure phase. The peak position has a small left shift compared to the main crystal phase, proving that elements with larger radii are doped, which is consistent with the doping characteristics of Hf.

[0089] Figure 6 For the material Cs 2 Zr 0.9 Hf 0.1 Cl 6 : 0.02 Bi 3+ prepared in Example 3, the UV - diffuse reflectance spectrum. By comparing the diffuse reflectance intensities before and after irradiation with a 254 nm UV lamp, it is proved that Cs 2 Zr 0.9 Hf 0.1 Cl 6 : 0.02 Bi 3+ has photochromic properties. The Cs 2 Zr 0.9 Hf 0.1 Cl 6 : 0.02 Bi 3+ has the highest color change degree ΔR of 11.42% at 550 nm.

[0090] Figure 7 The XRD pattern shown represents the material (Cs 2 Zr 0.1 Hf 0.9 Cl 6 : 0.02 Bi 3+ ) prepared in Example 4 and the PDF#74 - 0505 - Cs 2 ZrCl 6Card and PDF#32-0233-Cs 2 HfCl 6 The card matches well, proving that the synthesized product is a pure phase. The peak position has a small right shift compared to the main crystal phase, indicating the doping of an element with a smaller radius, which is consistent with the doping characteristics of Cs.

[0091] Figure 8 The material prepared in Example 4 (Cs 2 Zr 0.1 Hf 0.9 Cl 6 :0.02Bi 3+ ) UV diffuse reflectance spectrum. By comparing the diffuse reflectance intensities before and after irradiation with a 254 nm UV lamp, it is proved that Cs 2 Zr 0.1 Hf 0.9 Cl 6 :0.02Bi 3+ has a photochromic effect. By calculating with formula (1), it is obtained that Cs 2 Zr 0.1 Hf 0.9 Cl 6 :0.02Bi 3+ has the highest color change degree ΔR of 13.33% at 547 nm.

[0092] Figure 9 The XRD pattern shown represents the material prepared in Example 5 (Cs 1.8 Rb 0.2 Zr 0.9 Hf 0.1 Cl 6 :0.02Bi 3 + ) is similar to the PDF#74-0505-Cs 2 ZrCl 6 card. This proves that the synthesized material is a pure solid solution phase.

[0093] Figure 10 The UV diffuse reflectance spectrum of the material prepared in Example 5 (Cs 1.8 Rb 0.2 Zr 0.9 Hf 0.1 Cl 6 :0.02Bi 3+ ) By comparing the diffuse reflectance intensities before and after irradiation with a 254 nm UV lamp, it is proved that Cs 1.8 Rb 0.2 Zr 0.9 Hf 0.1 Cl 6 :0.02Bi 3+It has a photochromic effect. Cs is calculated through formula (1). 1.8 Rb 0.2 Zr 0.9 Hf 0.1 Cl 6 : 0.02Bi 3+ It has the highest color change degree ΔR of 15.42% at 554 nm.

[0094] Figure 11 The XRD pattern shown represents the material (Cs 0.2 Rb 1.8 Zr 0.9 Hf 0.1 Cl 6 : 0.02Bi 3 + ) prepared in Example 6 is similar to the PDF#74 - 0504 - Rb 2 ZrCl 6 card. This proves that the synthesized main crystal phase is a new solid solution phase of Cs 0.2 Rb 1.8 Zr 0.9 Hf 0.1 Cl 6 : 0.02Bi 3+ .

[0095] Figure 12 The UV - diffuse reflectance spectrum of the material (Cs 0.2 Rb 1.8 Zr 0.9 Hf 0.1 Cl 6 : 0.02Bi 3+ ) prepared in Example 6. By comparing the diffuse reflectance intensities before and after irradiation with a 254 - nm UV lamp, it is proved that Cs 0.2 Rb 1.8 Zr 0.9 Hf 0.1 Cl 6 : 0.02Bi 3+ has a photochromic effect. Cs is calculated through formula (1). 0.2 Rb 1.8 Zr 0.9 Hf 0.1 Cl 6 : 0.02Bi 3+ It has the highest color change degree ΔR of 17.77% at 337 nm.

[0096] Figure 13 The XRD pattern shown represents Cs prepared in Example 7 1.8 Rb 0.2 Zr 0.1 Hf0.9 Cl 6 : 0.02 Bi 3+ matches well with PDF#32 - 0233 - Cs 2 HfCl 6 The card matches well. This proves that Cs 1.8 Rb 0.2 Zr 0.1 Hf 0.9 Cl 6 : 0.02 Bi 3+ solid solution phase.

[0097] Figure 14 The material prepared for Example 7 (Cs 1.8 Rb 0.2 Zr 0.1 Hf 0.9 Cl 6 : 0.02 Bi 3+ )'s UV - diffuse reflectance spectrum. By comparing the change in diffuse reflectance intensity before and after irradiation with a 254 nm UV lamp, it is proved that Cs 1.8 Rb 0.2 Zr 0.1 Hf 0.9 Cl 6 : 0.02 Bi 3+ has photochromic properties. Calculated by formula (1), Cs 1.8 Rb 0.2 Zr 0.1 Hf 0.9 Cl 6 : 0.02 Bi 3+ has the highest color change degree ΔR of 16.88% at 286 nm.

[0098] Figure 15 The XRD pattern shown represents the material prepared for Example 8 (Cs 0.2 Rb 1.8 Zr 0.1 Hf 0.9 Cl 6 : 0.02 Bi 3 + ) matches similarly with PDF#21 - 1027 - Rb 2 HfCl 6 The card. This proves that the synthesized material is a new Cs 0.2 Rb 1.8 Zr 0.1 Hf 0.9 Cl 6 : 0.02 Bi 3+ solid solution phase.

[0099] Figure 16The UV diffuse reflectance spectrum of the material (Cs 0.2 Rb 1.8 Zr 0.1 Hf 0.9 Cl 6 :0.02Bi 3+ ) prepared in Example 8. By comparing the change in diffuse reflectance intensity before and after irradiation with a 254 nm UV lamp, it is proved that Cs 0.2 Rb 1.8 Zr 0.1 Hf 0.9 Cl 6 :0.02Bi 3+ has a photochromic effect. By calculating with formula (1), Cs 0.2 Rb 1.8 Zr 0.1 Hf 0.9 Cl 6 :0.02Bi 3+ has the highest color change degree ΔR of 9.44% at 531 nm.

[0100] Figure 17 Comparison diagram of XRD patterns of the materials prepared in Examples 1 - 8.

[0101] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bismuth ion doped Cs 2-x R x Zr 1-y Hf y Cl6 halogen perovskite photochromic material, characterized in that Its chemical formula is Cs 2-x R x Zr 1-y Hf y Cl6:nBi 3+ , where 0≤x<2,0≤y<1,0<n<1.

2. Bismuth ion doped Cs as described in claim 1 2-x R x Zr 1-y Hf y Cl6 halogen perovskite photochromic material, characterized in that Its chemical formula is Cs 2-x R x ZrCl6:nBi 3+ (0<x<2,0<n<1), Cs2Zr 1-y Hf y Cl6:nBi 3+ (0<y<1,0<n<1) or Cs 2-x R x Zr 1-y Hf y Cl6:nBi 3+ One of (0<x<2, 0<y<1, 0<n<1).

3. Bismuth ion doped Cs as claimed in claim 1 2-x R x Zr 1-y Hf y Cl6 halogen perovskite photochromic material, characterized in that The Cs 2-x R x Zr 1-y Hf y Cl6:nBi 3+ The Cs source is at least one of the inorganic salts of Cs, the Rb source is at least one of the inorganic salts of Rb, and the Bi source is at least one of the oxides or chlorides of Bi.

4. Bismuth ion doped Cs as described in claim 3 2-x R x Zr 1-y Hf y Cl6 halogen perovskite photochromic material, characterized in that The Cs 2-x R x Zr 1-y Hf y Cl6:nBi 3+ The Cs source is at least one of CsCl or Cs2CO3, the Rb source is at least one of Rb2CO3 or RbCl, and the Bi source is at least one of Bi2O3 or BiCl3.

5. Bismuth ion doped Cs as claimed in claim 1 2-x R x Zr 1-y Hf y Cl6 halogen perovskite photochromic material, characterized in that The Cs 2-x R x Zr 1-y Hf y Cl6:nBi 3+ The Zr source is ZrCl4, the Hf source is HfCl4, and the Cl source is HCl.

6. A bismuth ion-doped Cs as claimed in any one of claims 1 to 5 2-x R x Zr 1-y Hf y A method for preparing a Cl6 halogen perovskite photochromic material, characterized in that: The following steps are involved: S1: Dissolve the precipitant Cs source and Rb source in concentrated hydrochloric acid in proportion to form solution A; According to the proportion of Zr source, The Hf source and the Bi source are dissolved in concentrated hydrochloric acid to form a B solution; S2: heating and stirring the solution A and solution B obtained in step S1 respectively, and then slowly injecting the solution A into the solution B under vigorous stirring to react; S3: The reaction product in step S2 is extracted by centrifugation, washed, dried, and then ground into microcrystals to obtain bismuth ion-doped Cs 2-x R x Zr 1-y Hf y Cl6 halogen perovskite photochromic materials.

7. Bismuth ion doped Cs as claimed in claim 6 2-x R x Zr 1-y Hf y A method for preparing a Cl6 halogen perovskite photochromic material, characterized in that: The concentration of concentrated hydrochloric acid in step S1 is 8-12 mol / L.

8. Bismuth ion doped Cs as claimed in claim 6 2-x R x Zr 1-y Hf y A method for preparing a Cl6 halogen perovskite photochromic material, characterized in that: The heating and stirring temperature in step S2 is 50-70° C., and the stirring time is 20-50 min.

9. Bismuth ion doped Cs as claimed in claim 6 2-x R x Zr 1-y Hf y A method for preparing a Cl6 halogen perovskite photochromic material, characterized in that: The reaction temperature in step S2 is 60-80° C., and the stirring speed is 400-700 rpm.

10. Bismuth ion doped Cs as claimed in claim 6 2-x R x Zr 1-y Hf y A method for preparing a Cl6 halogen perovskite photochromic material, characterized in that: The drying temperature in step S3 is 70-90° C., and the drying time is 5-7 hours.

Images