Inorganic halide perovskite material with low thermal conductivity and preparation method and application thereof

Abstract

The invention discloses an inorganic halide perovskite material with low thermal conductivity and a preparation method and application thereof. The molecular formula of the inorganic halide perovskite material with low thermal conductivity is Rb4Sb2Br12; the inorganic halide perovskite material with low thermal conductivity is a quadruple perovskite material and belongs to an I41 / a space group of a tetragonal system; the inorganic halide perovskite material with low thermal conductivity is composed of a SbBr6 < 3-> octahedral framework, Rb atoms occupy cavities among octahedrons, and Sb is in a mixed valence state of + 3 and + 5; the Rb4Sb2Br12 perovskite single crystal prepared by the method is complex in structure, pollution-free, low in price and simple to prepare, has intrinsic low thermal conductivity, and can grow into large blocks; the intrinsic thermal conductivity of the Rb4Sb2Br12 single crystal at normal temperature can reach 0.24 Wm <-1 > K <-1 >, and the intrinsic thermal conductivity of the Rb4Sb2Br12 single crystal at 150 DEG C can reach 0.21 Wm <-1 > K <-1 >, so that the Rb4Sb2Br12 single crystal is a very promising low-thermal-conductivity material.

Description

Technical Field

[0001] The present invention belongs to the technical field of inorganic halide perovskite materials, and in particular relates to an inorganic halide perovskite material with low thermal conductivity, a preparation method thereof and an application thereof. Background Art

[0002] Thermal conductivity represents the heat conduction capacity of a material. Materials with intrinsic low thermal conductivity are widely used in the fields of thermal protection of high-speed aircraft, protection of electronic components on the surface of printed circuit boards, guidance of heat flow on the surface of thermal solar cells, thermal shielding of components on the surface of artificial skin, collection of waste heat by thermoelectric materials and thermoelectric conversion. Therefore, it is urgent to produce and prepare materials with low thermal conductivity, which is of great significance for the research of low thermal conductivity materials in thermoelectric materials and thermal insulation materials. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes an inorganic halide perovskite material with low thermal conductivity and a preparation method and application thereof. 4 Sb 2 Br 12 Perovskite single crystal has a complex structure, is pollution-free, inexpensive, easy to prepare, has intrinsically low thermal conductivity, and can grow into large blocks; at room temperature, Rb 4 Sb 2 Br 12 The intrinsic thermal conductivity of a single crystal can reach 0.24 W m - 1 K -1 , the intrinsic thermal conductivity can reach 0.21Wm at 150℃ -1 K -1 , is a very promising low thermal conductivity material.

[0004] The present invention adopts the following technical solutions:

[0005] An inorganic halide perovskite material with low thermal conductivity, wherein the molecular formula of the inorganic halide perovskite material with low thermal conductivity is Rb 4 Sb 2 Br 12 The inorganic halide perovskite material with low thermal conductivity is a quadruple perovskite material, which belongs to the tetragonal system, I4 1 / a space group; the inorganic halide perovskite material with low thermal conductivity is composed of SbBr 6 3- The octahedral framework is composed of Rb atoms occupying the cavities between the octahedra, among which Sb is in a mixed valence state of +3 and +5.

[0006] Preferably, the unit cell parameters of the inorganic halide perovskite material with low thermal conductivity are: α=β=γ=90°.

[0007] Preferably, at room temperature, Rb 4 Sb 2 Br 12 The intrinsic thermal conductivity of a single crystal is 0.24 W m -1 K -1 , the intrinsic thermal conductivity at 150°C is 0.21Wm -1 K -1 .

[0008] A method for preparing an inorganic halide perovskite material with low thermal conductivity, wherein the bulk single crystal growth method specifically comprises the following steps:

[0009] S1. Weigh RbBr powder and Sb in a stoichiometric ratio of 4:1:4. 2 O 3 Powder and KBrO 3 Powder, put into the reaction kettle, add 40ml concentrated HBr solution and mix well;

[0010] S2, placing the reactor into an oven for hydrothermal reaction;

[0011] S3, the black crystals obtained by the hydrothermal reaction are filtered and placed in a vacuum oven for drying to obtain large black single crystals, that is, Rb 4 Sb 2 Br 12 Single crystal.

[0012] Preferably, the RbBr powder and Sb 2 O 3 Powder and KBrO 3 The purity of the powder is ≥99.99%.

[0013] Preferably, the specific process of the hydrothermal reaction in step S2 is: heating from room temperature to 150°C in 0.5h, keeping at 150°C for 12h, cooling to 80°C after 3h, and finally cooling to 30°C within 48h.

[0014] Preferably, the drying condition in step S3 is: drying at 60° C. for 720 min.

[0015] Preferably, in step S3, Rb 4 Sb 2 Br 12 The diameter of the single crystal is greater than 6 mm.

[0016] An application of an inorganic halide perovskite material with low thermal conductivity, wherein the inorganic halide perovskite material with low thermal conductivity is used as a thermoelectric material or a heat insulation material.

[0017] After adopting the above technical solution, the present invention has the following advantages compared with the background technology:

[0018] First, according to the method provided by the present invention, an inorganic halide perovskite material with low thermal conductivity is prepared, which has the following advantages:

[0019] (1) The single crystals prepared by the present invention have a size of centimeters and are uniform in size and shape, with high product purity and good crystal dispersibility.

[0020] (2) The present invention uses Sb 2 O 3 The powder is used as a single antimony source, which reduces the cost of synthesis. The solvothermal method is used to prepare single crystals, which requires low temperature and a relatively simple preparation process. It consumes less energy than traditional solid-state reactions and is easier to achieve.

[0021] (3) Rb was tested by laser flash method 4 Sb 2 Br 12 The intrinsic thermal conductivity of a single crystal is 0.24 Wm at room temperature. -1 K -1 Low thermal conductivity, the intrinsic thermal conductivity is 0.21Wm at 150℃ -1 K -1， This indicates that this material has intrinsically low thermal conductivity and has the potential to become an excellent thermoelectric material or thermal insulation material.

[0022] (4) Rb grown by the present invention 4 Sb 2 Br 12 XRD test of perovskite single crystal shows that Rb 4 Sb 2 Br 12 The single crystal XRD diffraction peaks are consistent with the simulation results, and there are no impurity peaks, indicating that the single crystal material grown by the present invention is Rb 4 Sb 2 Br 12 Perovskite.

[0023] (5) Rb grown by the present invention 4 Sb 2 Br 12 The TGA test of the perovskite single crystal shows that the Rb 4 Sb 2 Br 12 Single crystals can be used at temperatures up to 200°C.

[0024] Second, the method for preparing the inorganic halide perovskite material with low thermal conductivity provided by the present invention has the following advantages:

[0025] Reduce costs: This method uses RbBr powder, Sb2 O 3 Powder and KBrO 3 Powder and HBr solution are used as initial raw materials, and single crystals are synthesized by solvothermal method, which has low cost and low energy consumption.

[0026] Optimized temperature control: Using an oven to perform multiple cooling and warming treatments from 150°C to room temperature, these steps provide ideal temperature conditions to help promote more uniform and efficient crystal growth.

[0027] Improved single crystal growth environment: The combination of PTFE lining and stainless steel shell provides a stable and well-controlled environment for single crystal growth, reducing the interference of impurities and the formation of crystal defects.

[0028] Improved applicability: This method is not only suitable for laboratory-scale production, but also has the potential to be expanded to larger-scale production due to its simplicity and controllability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Rb synthesized in Example 1 of the present invention 4 Sb 2 Br 12 Molecular structure of single crystals;

[0030] Figure 2 The bulk Rb synthesized in Example 1 of the present invention 4 Sb 2 Br 12 Physical picture of single crystal;

[0031] Figure 3 The bulk Rb synthesized in Example 1 of the present invention 4 Sb 2 Br 12 XRD pattern of single crystal;

[0032] Figure 4 Rb synthesized in Example 1 of the present invention 4 Sb 2 Br 12 Intrinsic thermal conductivity diagram of single crystal materials;

[0033] Figure 5 Rb synthesized in Example 1 of the present invention 4 Sb 2 Br 12 Raman spectrum of single crystal material;

[0034] Figure 6 Rb synthesized in Example 1 of the present invention 4 Sb 2 Br 12 Thermogravimetric curve of single crystal material. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] See also Figures 1 to 6 .

[0037] An inorganic halide perovskite material with low thermal conductivity, wherein the molecular formula of the inorganic halide perovskite material with low thermal conductivity is Rb 4 Sb 2 Br 12 The inorganic halide perovskite material with low thermal conductivity is a quadruple perovskite material, which belongs to the tetragonal system, I4 1 / a space group; the inorganic halide perovskite material with low thermal conductivity is composed of SbBr 6 3- The octahedral framework is composed of Rb atoms occupying the cavities between the octahedrons, wherein Sb is in a mixed valence state of +3 and +5; the unit cell parameters of the inorganic halide perovskite material with low thermal conductivity are: α=β=γ=90°.

[0038] Example 1

[0039] Rb in an inorganic halide perovskite material with low thermal conductivity 4 Sb 2 Br 12 The growth of bulk single crystals of perovskite includes the following steps:

[0040] S1. Weighing: Weigh RbBr powder (3.9689 g, 24 mmol), Sb 2 O 3 Powder (1.7492 g, 6 mmol), KBrO 3 Powder (4.0080 g, 24 mmol), and add 40 mL of HBr into a 100 mL Teflon-lined stainless steel reactor using a pipette;

[0041] S2. Hydrothermal reaction: The reactor containing the mixture in step S1 is placed in an oven, and the temperature is raised from room temperature to 150°C in 0.5 h, and kept at 150°C for 12 h, and then cooled to 80°C after 3 h, and finally cooled to 30°C within 48 hours to obtain Rb 4 Sb 2 Br 12 Single crystal;

[0042] S3, filtration and drying: The solution in the reaction kettle in step S2 is filtered to obtain precipitated black crystals, and the black crystals are dried in a vacuum oven at 60° C. for 720 min, i.e., Rb 4 Sb 2 Br 12 Single crystal material.

[0043] Performance Test:

[0044] (1) The bulk Rb prepared in Example 1 was 4 Sb 2 Br 12 The single crystal was polished and then analyzed by X-ray diffraction. The X-ray diffraction peaks of the prepared samples were consistent with those of Rb 4 Sb 2 Br 12 The calculation results are completely consistent with Figure 3 shown.

[0045] (2) The bulk Rb prepared in Example 1 was 4 Sb 2 Br 12 The single crystal was cut and polished into a 6*6mm, 1mm thick square piece. The thermal diffusion coefficient D of the square piece was tested using the LFA467 laser flash thermal conductivity instrument produced by NETZSCH in Germany. The total thermal conductivity was measured by κ tot =C p Dρ is calculated, density ρ is obtained by Archimedes drainage method, specific heat C p It is calculated by the Dulong-Petit formula. The relationship between the total thermal conductivity and temperature is as follows: Figure 4 As shown, with the increase of temperature, Rb 4 Sb 2 Br 12 The thermal conductivity of the single crystal increases from 0.24 Wm at room temperature to -1 K -1 Reduced to 0.21W m at 150°C -1 K -1 , which is a material with extremely low thermal conductivity.

[0046] (3) The bulk Rb prepared in Example 1 was 4 Sb 2 Br 12 The single crystal was ground into powder, and the material prepared in Example 1 was tested using a DXR2Xi instrument from Thermo Electron of the United States, and the Raman spectrum was obtained as follows: Figure 5 As shown. In the Raman spectrum of this material, 200 cm -1 With 215cm -1 There are two obvious peaks in the displacement. Analysis of the spectrum shows that the Raman spectrum is located at 150cm -1 ~300cm -1The two obvious peaks between the two are the peaks of Sb-Br bonds, and there is no peak of Rb atom bonding, which confirms that the material structure is composed of SbBr 6 3- Composing the framework, Rb atoms occupy the cavities between the octahedra.

[0047] (4) The bulk Rb obtained in Example 1 was 4 Sb 2 Br 12 Grind the single crystal into powder, take 5-10 mg and put it into Al 2 O 3 In the crucible, a blank Al 2 O 3 Crucible as reference, in N 2 In the atmosphere, the STA449-F5 instrument of the German Netzsch Instrument Manufacturing Company was used to -1 The material prepared in Example 1 was subjected to a thermogravimetric analysis test at a heating rate of Figure 6 According to the thermogravimetric analysis test, Rb 4 Sb 2 Br 12 Obvious weight loss phenomenon began to appear at 210℃, indicating that the material began to decompose at 210℃.

[0048] The single crystal prepared by the present invention has a size of centimeters, and is uniform in size and shape, has high product purity, and has good crystal dispersibility. 2 O 3 The powder is used as a single antimony source, which reduces the cost of synthesis. The solvent thermal method is used to prepare single crystals, which requires low temperature and simple preparation process. It consumes less energy than traditional solid-state reactions and is easier to achieve. The laser scattering method was used to test Rb 4 Sb 2 Br 12 The thermal conductivity of a single crystal, its Rb 4 Sb 2 Br 12 The thermal conductivity of a single crystal is 0.24 Wm -1 K -1 , indicating that this synthetic material has extremely low thermal conductivity; therefore, the inorganic halide perovskite material with low thermal conductivity prepared by the present invention can be used as a thermoelectric material or thermal insulation material and applied in the fields of optoelectronics, energy and other advanced materials.

[0049] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An inorganic halide perovskite material with low thermal conductivity, characterized in that: The inorganic halide perovskite material with low thermal conductivity has a molecular formula of Rb4Sb2Br 12 The inorganic halide perovskite material with low thermal conductivity is a quadruple perovskite material, belonging to the tetragonal system and the I41 / a space group; the inorganic halide perovskite material with low thermal conductivity is composed of SbBr6 3- The octahedral framework consists of Rb atoms occupying the cavities between the octahedra, among which Sb is in a mixed valence state of +3 and +5.

2. An inorganic halide perovskite material with low thermal conductivity as claimed in claim 1, characterized in that: The unit cell parameters of the inorganic halide perovskite material with low thermal conductivity are: α=β=γ=90°.

3. The inorganic halide perovskite material with low thermal conductivity according to claim 1, characterized in that: Rb4Sb2Br at room temperature 12 The intrinsic thermal conductivity of a single crystal is 0.24 W m -1 K -1 , the intrinsic thermal conductivity at 150°C is 0.21Wm -1 K -1 .

4. A method for preparing an inorganic halide perovskite material with low thermal conductivity as claimed in any one of claims 1 to 3, characterized in that: The bulk single crystal growth method specifically comprises the following steps: S1. Weigh RbBr powder, Sb2O3 powder and KBrO3 powder according to the stoichiometric ratio of 4:1:4, put them into a reactor, and then add 40 ml of concentrated HBr solution to mix evenly; S2, placing the reactor into an oven for hydrothermal reaction; S3, the black crystals obtained by the hydrothermal reaction are filtered and placed in a vacuum oven for drying to obtain large black single crystals, that is, Rb4Sb2Br 12 Single crystal.

5. The method for preparing an inorganic halide perovskite material with low thermal conductivity according to claim 4, characterized in that: The purity of the RbBr powder, Sb2O3 powder and KBrO3 powder in step S1 is ≥99.99%.

6. The method for preparing an inorganic halide perovskite material with low thermal conductivity according to claim 4, characterized in that: The specific process of the hydrothermal reaction in step S2 is: heating from room temperature to 150°C in 0.5h, keeping at 150°C for 12h, cooling to 80°C after 3h, and finally cooling to 30°C within 48h.

7. The method for preparing an inorganic halide perovskite material with low thermal conductivity according to claim 4, characterized in that: The drying conditions in step S3 are: drying at 60° C. for 720 min.

8. The method for preparing an inorganic halide perovskite material with low thermal conductivity according to claim 4, characterized in that: In step S3, Rb4Sb2Br 12 The diameter of the single crystal is greater than 6 mm.

9. An application of the inorganic halide perovskite material with low thermal conductivity as claimed in any one of claims 1 to 3, characterized in that: The inorganic halide perovskite material with low thermal conductivity is used as a thermoelectric material or a thermal insulation material.

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