A method for determining the content of cesium in a full inorganic perovskite CsPbX3

Abstract

The present application relates to a kind of determination methods of cesium content in all-inorganic perovskite CsPbX3, belong to inorganic perovskite battery technical field.The test method includes ① with mixed acid digestion sample;② adding sulfuric acid precipitates lead matrix;③ adding rubidium salt and sensitizer improves the degree of atomization of cesium;④ atomic absorption spectrometry draws standard curve;⑤ the content of cesium element is determined.The present application mainly solves the problem of the determination of cesium content in inorganic perovskite CsPbX3, with good precision, high accuracy, wide concentration range, low analysis cost, the advantages such as simple and fast operation, effectively fill the blank of inorganic perovskite battery chemical analysis method.Can be used as the determination method of cesium content in inorganic perovskite CsPbX3.

Description

Technical Field

[0001] This invention belongs to the field of inorganic perovskite battery technology, and relates to a method for determining the cesium content in all-inorganic perovskite CsPbX3, and particularly to a method for determining the cesium content in inorganic perovskite CsPbX3 batteries. Background Technology

[0002] Perovskite materials are a class of compounds with a perovskite structure, typically exhibiting an ABX3 crystal structure, where the A-site is a larger cation, the B-site a smaller cation, and the X-site an anion. Perovskite materials have attracted considerable attention due to their applications in optoelectronics. Lead halide perovskite materials are particularly noteworthy in optoelectronic devices due to their superior optoelectronic properties, including long electron-hole carrier lifetimes, high light absorption coefficients, tunable band gaps and composition, and outstanding quantum yields. CsPbX3 perovskite is a direct wide-bandgap semiconductor, its crystal structure is highly temperature-sensitive, and its emission region is located in the blue-violet band. The A-site in CsPbX3 contains cesium, and its content significantly affects the defects at the A-site, thus crucially influencing the number of holes. Accurate determination of the cesium content in CsPbX3 is of great significance for the research and industrialization of inorganic perovskite materials; however, currently, there are no reports in publicly available patents, standards, or literature regarding the determination of cesium content in CsPbX3 materials.

[0003] GB / T 17413.3-2010 Chemical Analysis Methods for Lithium, Rubidium and Cesium Ores - Part 3: Determination of Cesium Content specifies a cesium content range of 10 μg / g to 1.0 × 10⁻⁶ μg / g. 4 The test method, with a concentration of μg / g, is applicable to lithium ore, rubidium ore, cesium ore, tantalum ore, niobium ore, and rare earth ores. However, both the content range and applicability of this test method do not meet the testing requirements for cesium content in CsPbX3 materials. Summary of the Invention

[0004] The purpose of this invention is to provide a method for determining the cesium content in inorganic perovskite CsPbX3 batteries. This method can accurately determine the cesium content in all-inorganic perovskite CsPbX3, solving the problem of cesium content determination in inorganic perovskite CsPbX3 and filling the gap in chemical analysis methods for inorganic perovskite batteries.

[0005] This invention provides a method for determining the cesium content in CsPbX3 inorganic perovskite solar cells, including steps such as sample weighing, acid dissolution and digestion, precipitation separation, deionization agent, working curve configuration, and measurement calculation.

[0006] A method for determining the cesium content in all-inorganic perovskite CsPbX3 includes the following steps:

[0007] (1) Accurately weigh the all-inorganic perovskite CsPbX3 sample, with a mass of m, and place it in a beaker.

[0008] (2) Add mixed acid, heat to digest the sample, and evaporate the solution to a certain volume;

[0009] (3) Slowly add sulfuric acid until no new white precipitate is added to the solution, then add a certain amount of sulfuric acid. Transfer all the precipitate and supernatant to a volumetric flask, dilute with water to a total volume of V, mix well, and filter dry with slow filter paper.

[0010] (4) Take a portion of the filtrate volume V1 into a volumetric flask, add the deionizing agent rubidium salt and sensitizer, then add a certain volume of sulfuric acid, dilute with water to volume V2, mix well, and obtain the sample solution.

[0011] (5) At a wavelength of 800-900 nm using an atomic absorption spectrophotometer, with an air-acetylene lean flame and water used for zeroing, measure the absorbance of the blank sample and the sample solution, and calculate the corresponding cesium content based on the working curve.

[0012] In step (1), the mass fraction of cesium in the all-inorganic perovskite CsPbX3 sample is between 2.00% and 30.00%. CsPbX3 includes CsPbCl3, CsPbBr3 and / or CsPbI3, etc., where X is Cl, Br and / or I.

[0013] In step (2), the mass-to-volume ratio of the sample to the digesting acid is (0.01–0.2 g):(10–20 mL), i.e., 0.01 g:20 mL to 0.2 g:10 mL, and the volume of mixed acid added to each 0.01–0.2 g sample is 10–20 mL; the mixed acid (digesting acid) is nitric acid, hydrogen peroxide, and water, with a volume ratio of 2:1:2 to 2:1:4; the nitric acid is concentrated nitric acid (preferably 68% by mass), the hydrogen peroxide has a mass fraction ≥30%, and the water used in the test method is grade II or above water conforming to GB / T 6682. The heating temperature is 180–250 °C. The volume ratio of the solution after heating and evaporation to the volume of the added mixed acid is (5–6):(10–20), i.e., 1:4 to 3:5.

[0014] In step (3), the concentration of sulfuric acid is such that the volume ratio of concentrated sulfuric acid (95%–98% by mass) to water is 1:(0–3). The volume ratio of the added sulfuric acid to the volume of the mixed acid is (2–5):(10–20), that is, 1:10 to 1:2.

[0015] In step (4), the added rubidium salt is a rubidium chloride or rubidium nitrate solution, and the concentration of the rubidium salt solution is 10-40 mg / mL.

[0016] The sensitizer is one or a combination of two or more of sodium dodecylbenzenesulfonate, 8-hydroxyquinoline, ethylenediaminetetraacetic acid, ammonium chloride, and ammonium sulfate, and its addition amount is 3% to 10% of the solution volume.

[0017] The volume ratio of sulfuric acid added after adding the rubidium salt deionizing agent and sensitizer to the volume of mixed acid added is (1-10):(10-20), i.e., 1:20 to 1:1. The sulfuric acid concentration is concentrated sulfuric acid (mass fraction 95-98%) with a volume ratio of water of 1:(0-3).

[0018] In the sample solution, the concentration of the rubidium salt is greater than 3000 mg / L, preferably 3000–6000 mg / L. After dilution with water, the volume ratio of the solution to the volume of the mixed acid is preferably 100:(10–20).

[0019] In step (5), the method for preparing the working curve includes the following steps:

[0020] 1) Accurately transfer 0.00 mL, 1.00 mL, 2.00 mL, 3.00 mL, 4.00 mL, 6.00 mL, and 8.00 mL of cesium standard solution into 100 mL volumetric flasks, add the rubidium salt solution (an antiionizing agent) and sensitizer, then add 1–10 mL of sulfuric acid. Dilute to the mark with water and mix well. The standard points of the standard curve may be increased or adjusted as needed.

[0021] 2) At a wavelength of 800-900 nm using an atomic absorption spectrophotometer, an air-acetylene lean flame was used, and the instrument was zeroed with water. The absorbance was measured, and a working curve was plotted with cesium concentration on the x-axis and absorbance on the y-axis.

[0022] In step 1), the concentration of the cesium standard solution is 100–1000 μg / mL.

[0023] The added rubidium salt is a rubidium chloride or rubidium nitrate solution, and the concentration of the rubidium salt solution is 10-40 mg / mL.

[0024] The sensitizer is one or a combination of two or more of sodium dodecylbenzenesulfonate, 8-hydroxyquinoline, ethylenediaminetetraacetic acid, ammonium chloride, and ammonium sulfate, and its addition amount is 3% to 10% of the solution volume.

[0025] The sulfuric acid is a mixed solution of concentrated sulfuric acid (mass fraction 95-98%) and water in a volume ratio of 1:(0-3).

[0026] The solution is diluted with water to 100 mL, and the concentration of the rubidium salt in the mixed solution is 3000–6000 mg / L. The water used in the test method is grade II or above water that meets the requirements of GB / T 6682.

[0027] In the aforementioned test method for determining the cesium content in CsPbX3 using atomic absorption spectrophotometry, the cesium content w in the sample is calculated using equation (1) based on the working curve.

[0028]

[0029] Wherein: ρ - the mass concentration of cesium in the sample solution obtained from the working curve, in micrograms per milliliter (μg / mL);

[0030] ρ0 - The mass concentration of cesium in the blank solution obtained from the working curve, in micrograms per milliliter (μg / mL);

[0031] V - Total volume of the test solution, in milliliters (mL);

[0032] V1 - Volume taken, in milliliters (mL);

[0033] V2 - Test volume, in milliliters (mL);

[0034] m - Mass of the sample, in grams (g).

[0035] The beneficial effects of this invention are as follows: This invention provides a method for determining the cesium content in CsPbX3 inorganic perovskite solar cells. This method is the first to achieve quantitative analysis of high-content cesium by dissolving CsPbX3 samples and increasing the sensitization of high-content cesium through atomization. It has the advantages of simple operation and high accuracy, filling a gap in this field. This method can well meet the requirements for determining the cesium content in CsPbX3. The samples applicable to this method include CsPbCl3, CsPbBr3, CsPbI3, and other CsPbX3 materials. Attached Figure Description

[0036] Figure 1 The working curve of Example 1;

[0037] Figure 2 This is the working curve for Example 2. Detailed Implementation

[0038] This invention provides a method for determining the cesium content in CsPbX3 inorganic perovskite solar cells. The invention will be further illustrated below with reference to specific examples.

[0039] The mass fraction of cesium in CsPbX3 is between 2.00% and 30.00%, and the water used in the test method is grade II or above water that meets the requirements of GB / T6682.

[0040] The present invention discloses a method for determining the cesium content in an inorganic perovskite solar cell CsPbX3, comprising the steps of sample weighing, acid dissolution and digestion, precipitation separation, deionization agent, working curve configuration, and measurement calculation.

[0041] 1) Accurately weigh the sample to a mass of m and place it in a beaker.

[0042] 2) The mass-to-volume ratio of sample to digesting acid is (0.01–0.2 g):(10–20 mL). Add the mixed acid and heat at 180–250 °C to digest until the solution volume is 5–6 mL. The mixed acid is nitric acid, hydrogen peroxide, and water, with a volume ratio of 2:1:(2–4).

[0043] 3) Slowly add 1:(0~3) sulfuric acid until no new white precipitate forms in the solution. Then add 2~5mL of sulfuric acid. Transfer all the precipitate and supernatant to a volumetric flask, dilute with water to a total volume of V, mix well, and filter dry with slow-speed filter paper.

[0044] 4) Take a portion of the filtrate volume V1 into a volumetric flask, add 10-15 mL of rubidium chloride or rubidium nitrate solution with a concentration of 10-40 mg / mL, add 3%-10% sensitizer, then add 1-10 mL of 1:(0-3) sulfuric acid, dilute with water to volume V2, and mix well.

[0045] 5) At a wavelength of 800–900 nm using an atomic absorption spectrophotometer, with an air-acetylene lean flame and water used for zeroing, measure the absorbance of the blank sample and the sample solution, and calculate the corresponding cesium amount based on the working curve.

[0046] The method for preparing the working curve includes the following steps:

[0047] 1) Accurately transfer 0.00 mL, 1.00 mL, 2.00 mL, 3.00 mL, 4.00 mL, 6.00 mL, and 8.00 mL of cesium standard solution into a series of 100 mL volumetric flasks. Add 10–15 mL of rubidium chloride or rubidium nitrate solution with a concentration of 10–40 mg / mL, add 3%–10% sensitizer, and then add 1–10 mL of 1:(0–3) sulfuric acid. Dilute with water to the mark and mix well.

[0048] 2) At a wavelength of 800-900 nm using an atomic absorption spectrophotometer, an air-acetylene lean flame was used, and the instrument was zeroed with water. The absorbance was measured, and a working curve was plotted with cesium concentration on the x-axis and absorbance on the y-axis.

[0049] The concentration of the cesium standard solution is 100–1000 μg / mL.

[0050] In the method of this invention, the sulfuric acid concentration used is such that the volume ratio of concentrated sulfuric acid to water is 1:(0-3). The rubidium salt is a rubidium chloride or rubidium nitrate solution. The concentration of the rubidium salt solution is 10-40 mg / mL. The amount of rubidium salt added should ensure that the concentration in the test solution is greater than 3000 mg / L.

[0051] The sensitizer is one or a combination of sodium dodecylbenzenesulfonate, 8-hydroxyquinoline, ethylenediaminetetraacetic acid, ammonium chloride, and ammonium sulfate, and its addition amount is 3% to 10% of the solution volume.

[0052] Calculation of analysis results

[0053] The cesium content is expressed as the cesium mass fraction w, and is calculated according to formula (1):

[0054]

[0055] Wherein: ρ—the mass concentration of cesium in the sample solution obtained from the working curve, in micrograms per milliliter (μg / mL);

[0056] ρ0—The mass concentration of cesium in the blank solution obtained from the working curve, in micrograms per milliliter (μg / mL);

[0057] V—Total volume of the test solution, in milliliters (mL);

[0058] V1 — Volume taken, in milliliters (mL);

[0059] V2—Test volume, in milliliters (mL);

[0060] m — the mass of the sample, in grams (g).

[0061] Example 1

[0062] Example 1 of this invention provides a method for determining the cesium content in CsPbCl3 of inorganic perovskite solar cells, using only reagents confirmed to be of analytical grade:

[0063] Digestion acid: The volume ratio of nitric acid (ρ = 1.42 g / mL), hydrogen peroxide (ρ = 1.10 g / mL), and water is 2:1:3;

[0064] Sulfuric acid (1+1) is a solution of concentrated sulfuric acid (ρ=1.84g / mL) and water in a volume ratio of 1:1;

[0065] The concentration of rubidium nitrate is 40 mg / mL;

[0066] Cesium standard solution: 100ug / mL.

[0067] (1) Accurately weigh 0.10g (accurate to 0.0001g) of sample, place it in a beaker, add 15mL of mixed acid, heat to digest the sample, and heat to evaporate to a volume of 5-6mL;

[0068] (2) Slowly add sulfuric acid until no new white precipitate forms in the solution, then add 2 mL of sulfuric acid. Transfer all the precipitate and supernatant to a volumetric flask, dilute with water to 100 mL, mix well, and filter dry with slow-speed filter paper.

[0069] (3) Take 10.00 mL of filtrate into a volumetric flask, add 8 mL of rubidium nitrate and 4 wt.% ethylenediaminetetraacetic acid and ammonium sulfate (the mass ratio of the two is 2:1), then add 2 mL of sulfuric acid, dilute with water to 100 mL, and mix well;

[0070] (4) At a wavelength of 852 nm, use an air-acetylene lean flame and zero the instrument with water to measure the absorbance of the blank sample and the sample solution. Calculate the corresponding amount of cesium based on the working curve.

[0071] The method for preparing the working curve includes the following steps:

[0072] 1) Accurately transfer 0.00 mL, 1.00 mL, 2.00 mL, 4.00 mL, 6.00 mL, and 8.00 mL of cesium standard solution into a series of 100 mL volumetric flasks. Add 10 mL of rubidium nitrate and 4 wt.% ethylenediaminetetraacetic acid and ammonium sulfate (mass ratio of the two is 2:1). Then add 2 mL of sulfuric acid, dilute with water to the mark, and mix well.

[0073] 2) At a wavelength of 852 nm using an atomic absorption spectrophotometer, an air-acetylene lean-burn flame was used, and the instrument was zeroed with water. The absorbance was measured, and a plot was created with cesium concentration on the x-axis and absorbance on the y-axis. Figure 1 The working curve shown.

[0074] Analysis results: The cesium content in the tested sample was calculated according to formula (1). The test was repeated 7 times using the same process, and the results are shown in Table 1.

[0075] Example 2

[0076] Example 2 of this invention provides a method for determining the cesium content in CsPbBr3 of inorganic perovskite solar cells, using only reagents confirmed to be of analytical grade:

[0077] Digestion acid: The volume ratio of nitric acid (ρ = 1.42 g / mL), hydrogen peroxide (ρ = 1.10 g / mL), and water is 2:1:2;

[0078] Sulfuric acid (1+2) is a solution of concentrated sulfuric acid (ρ=1.84g / mL) and water in a volume ratio of 1:2;

[0079] The concentration of rubidium chloride is 30 mg / mL;

[0080] Cesium standard solution: 1000 ug / mL.

[0081] (1) Accurately weigh 0.050 g (accurate to 0.0001 g) of sample, place it in a beaker, add 10 mL of mixed acid, heat to digest the sample, and heat to evaporate to a volume of 5-6 mL;

[0082] (2) Slowly add sulfuric acid until no new white precipitate forms in the solution, then add 3 mL of sulfuric acid. Transfer the precipitate and supernatant to a volumetric flask, dilute with water to 100 mL, mix well, and filter dry with slow-speed filter paper.

[0083] (3) Take 10.00 mL of filtrate into a volumetric flask, add 10 mL of rubidium chloride and 5 wt.% sodium dodecyl sulfate and 8-hydroxyquinoline (the mass ratio of the two is 1:3), then add 3 mL of sulfuric acid, dilute with water to 100 mL, and mix well;

[0084] (4) At a wavelength of 852 nm, use an air-acetylene lean flame and zero the instrument with water to measure the absorbance of the blank sample and the sample solution. Calculate the corresponding amount of cesium based on the working curve.

[0085] The method for preparing the working curve includes the following steps:

[0086] 1) Accurately transfer 0.00 mL, 1.00 mL, 2.00 mL, 4.00 mL, 6.00 mL, and 8.00 mL of cesium standard solution into a series of 100 mL volumetric flasks. Add 10 mL of rubidium chloride and 5 wt.% sodium dodecyl sulfate and 8-hydroxyquinoline (mass ratio of the two is 1:3). Then add 3 mL of sulfuric acid, dilute with water to the mark, and mix well.

[0087] 2) At a wavelength of 852 nm using an atomic absorption spectrophotometer, an air-acetylene lean-burn flame was used, and the instrument was zeroed with water. The absorbance was measured, and a plot was created with cesium concentration on the x-axis and absorbance on the y-axis. Figure 2 The working curve shown.

[0088] Analysis results: The cesium content in the tested sample was calculated according to formula (1). The test was repeated 7 times using the same process, and the results are shown in Table 1.

[0089] Table 1 Precision test results

[0090]

[0091] As shown in Table 1, the RSD of cesium content is 0.23% to 0.76%, indicating that the method has good precision and can meet the analytical requirements.

[0092] Spike recovery experiments were performed on the samples according to the method described in this paper, and the results are shown in Table 2.

[0093] Table 2 Results of Spiked Recovery Test

[0094] Cesium content in sample / mg Added cesium amount / mg Measured cesium content / mg Recovery rate / % 5.98 6 12.01 100.5 13.84 15 28.81 99.8

[0095] As shown in Table 2, the spiked recovery rate of cesium in inorganic perovskite solar cell CsPbX3 obtained by this experimental method is 99.8%–100.5%, which is highly accurate and meets the analytical requirements.

[0096] Comparative Examples 1-2

[0097] Comparative Example 1 used the same sample as Example 1, and Comparative Example 2 used the same sample as Example 2. The cesium content was determined by the method specified in GB / T17413.3-2010 "Chemical Analysis Methods for Lithium Ore, Rubidium Ore and Cesium Ore - Part 3: Cesium Content Determination". The results are shown in Table 3.

[0098] Table 3 Precision test results

[0099]

[0100] Comparing the results in Tables 1 and 3, it can be seen that the test results provided by this invention are accurate, while the precision and accuracy of the test method specified in GB / T 17413.3-2010 cannot meet the test requirements.

[0101] The testing method of this invention includes: ① digesting the sample with a mixed acid; ② adding sulfuric acid to precipitate the lead matrix; ③ adding rubidium salt and a sensitizer to improve the atomization degree of cesium; ④ plotting a standard curve by atomic absorption spectrometry; and ⑤ determining the cesium content. This invention mainly solves the problem of cesium content determination in inorganic perovskite CsPbX3, and has the advantages of good precision, high accuracy, wide applicable concentration range, low analytical cost, and simple and rapid operation, effectively filling the gap in chemical analysis methods for inorganic perovskite batteries. It can be used as a method for determining the cesium content in inorganic perovskite CsPbX3.

Claims

1. A method for determining the cesium content in an all-inorganic perovskite CsPbX3, comprising the following steps: (1) Accurately weigh the all-inorganic perovskite CsPbX3 sample, with a mass of m, and place it in a beaker. The mass fraction of cesium in the all-inorganic perovskite CsPbX3 sample is between 2.00% and 30.00%. (2) Add mixed acid, heat to digest the sample, and evaporate the solution to a certain volume; the mass-volume ratio of the sample to the digestion acid is 0.01g:20mL ~ 0.2g:10mL; the mixed acid is nitric acid, hydrogen peroxide and water, with a volume ratio of 2:1:2 to 2:1:4, the nitric acid is concentrated nitric acid, and the mass fraction of hydrogen peroxide is ≥30%; the heating temperature is 180~250℃; the volume ratio of the solution after heating and evaporation to the volume of the added mixed acid is 1:4 to 3:5; (3) Slowly add sulfuric acid until no new white precipitate is added to the solution, then add more sulfuric acid. Transfer all the precipitate and supernatant to a volumetric flask, dilute with water to a total volume of V, mix well, and filter dry with slow filter paper. The sulfuric acid is concentrated sulfuric acid with a volume ratio of 1:0 to 1:3 to water. The volume ratio of the added sulfuric acid to the volume of the mixed acid is 1:10 to 1:

2. (4) Take a portion of the filtrate volume V1 into a volumetric flask, add the rubidium salt deionizing agent and sensitizer, then add sulfuric acid, dilute with water to volume V2, mix well, and obtain the sample solution; the ratio of the volume of sulfuric acid added after adding the rubidium salt deionizing agent and sensitizer to the volume of the mixed acid is 1:20 to 1:

1. (5) At a wavelength of 800~900nm, use an air-acetylene lean flame and zero with water to measure the absorbance of the blank sample and the sample solution. Calculate the corresponding cesium content based on the working curve.

2. The method for determining the cesium content in the all-inorganic perovskite CsPbX3 according to claim 1, characterized in that: The added rubidium salt is a rubidium chloride or rubidium nitrate solution, and the concentration of the rubidium salt solution is 10~40 mg / mL; the sensitizer is one or more combinations of sodium dodecylbenzenesulfonate, 8-hydroxyquinoline, ethylenediaminetetraacetic acid, ammonium chloride and ammonium sulfate.

3. The method for determining the cesium content in the all-inorganic perovskite CsPbX3 according to claim 1, characterized in that: In the sample solution, the concentration of the rubidium salt is greater than 3000 mg / L.

4. The method for determining the cesium content in the all-inorganic perovskite CsPbX3 according to claim 1, characterized in that: The method for preparing the working curve includes the following steps: 1) Accurately transfer 0.00 mL, 1.00 mL, 2.00 mL, 3.00 mL, 4.00 mL, 6.00 mL, and 8.00 mL of cesium standard solution into 100 mL volumetric flasks, add the rubidium salt solution (an anti-ionization agent) and sensitizer, then add 1-10 mL of sulfuric acid. Dilute with water to the mark and mix well. The standard points of the standard curve may be increased or adjusted as needed. 2) At a wavelength of 800~900nm, use an air-acetylene lean flame and zero the instrument with water to measure the absorbance. Plot the working curve with cesium concentration on the x-axis and absorbance on the y-axis.

5. The method for determining the cesium content in the all-inorganic perovskite CsPbX3 according to claim 4, characterized in that: The concentration of the cesium standard solution is 100~1000 μg / mL.

6. The method for determining the cesium content in the all-inorganic perovskite CsPbX3 according to claim 1, characterized in that: The cesium content in the sample is calculated using equation (1) based on the working curve. w , Equation (1) in: ρ- The mass concentration of cesium in the sample solution was obtained from the working curve, in micrograms per milliliter. ρ 0 - The mass concentration of cesium in the blank solution can be found from the working curve, in micrograms per milliliter; V - Total volume of the test solution, in milliliters; V 1 - Take a portion of the volume, in milliliters; V 2- Test volume, in milliliters; m - The mass of the sample, in grams.

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