阅读说明：本技术 钙钛矿化合物的制备方法 (Process for producing perovskite compound ) 是由 甄崇礼 廖洁娴 周理龙 于 2020-12-23 设计创作，主要内容包括：本发明属于纳米材料制备技术领域,具体涉及一种钙钛矿化合物的制备方法。将钙钛矿化合物的前驱体溶于溶剂中,混合均匀,得到前驱体溶液,通过高压气体将前驱体溶液分散到火焰中燃烧、反应,得到纳米钙钛矿化合物。本发明通过火焰喷射分解法可一步由前驱体合成钙钛矿化合物,显著降低钙钛矿化合物的合成时间,并且获得的钙钛矿化合物纯度高、性质均匀,容易进行工业放大。(The invention belongs to the technical field of nano material preparation, and particularly relates to a preparation method of a perovskite compound. Dissolving a precursor of the perovskite compound in a solvent, uniformly mixing to obtain a precursor solution, dispersing the precursor solution into flame through high-pressure gas, and combusting and reacting to obtain the nano perovskite compound. The invention can synthesize the perovskite compound from the precursor by one step through a flame spray decomposition method, obviously reduces the synthesis time of the perovskite compound, and the obtained perovskite compound has high purity and uniform property and is easy to be industrially amplified.)

1. A preparation method of a perovskite compound is characterized in that a precursor of the perovskite compound is dissolved in a solvent and uniformly mixed to obtain a precursor solution, and the precursor solution is dispersed into flame through high-pressure gas to be combusted and reacted to obtain the nano perovskite compound.

2. The process for producing a perovskite compound as claimed in claim 1, wherein the perovskite compound has the structural formula ABO₃Wherein A is one of calcium, cesium, barium, strontium, potassium, sodium, rubidium, lanthanum or cerium, B is one of titanium, cobalt, aluminum, manganese, thallium, cerium or zirconium, O is an oxygen atom, and A and B are two different metal elements respectively.

3. The process for producing a perovskite compound according to claim 2, wherein the precursor of the perovskite compound is a precursor of A and a precursor of B.

4. The process according to claim 3, wherein the precursor of A is one or more selected from nitrate, acetate, citrate and 1-methylhexanoate of A, and the precursor of B is one or more selected from nitrate, acetate, citrate and 1-methylhexanoate of B.

5. The process for preparing a perovskite compound according to claim 1, wherein the solvent is one or more of water, ethanol, benzene, toluene, xylene or ethyl acetate.

6. The process for producing a perovskite compound according to claim 1, wherein the concentration of the precursor solution is 0.1 to 3.5 mol/L.

7. The process for producing a perovskite compound according to claim 1, wherein the high-pressure gas is oxygen, the pressure of the high-pressure gas is 0.1 to 1.5MPa, and the flow rate at which the precursor solution is dispersed in the flame is 5 to 30 mL/min.

8. The process for producing a perovskite compound according to claim 1, wherein the flame is a methane-oxygen flame.

9. The process for producing a perovskite compound according to claim 1, wherein the particle size of the nano perovskite compound is 5 to 500 nm.

10. The process for producing a perovskite compound according to claim 1, wherein the nano perovskite compound is captured and collected by a collector having a getter device and a filter.

Technical Field

The invention belongs to the technical field of nano material preparation, and particularly relates to a preparation method of a perovskite compound.

Background

Perovskites are a class of multifunctional metal oxide composites whose structure is generally composed of a site ion coordinated with 12 oxygen atoms in the closest cubic packing and a site ion coordinated with 6 oxygen atoms occupying the octahedral center in the cubic close packing. Due to the unique structure and properties of perovskite, perovskite is easy to be modified by means of changing the types of ions at A site and B site, adding other metal ions and the like, so that perovskite is deeply researched and widely applied and can be used in the fields of solar cells, thermal catalysis, photocatalysis and the like.

The existing preparation methods of perovskite compounds comprise a sol-gel method, a precipitation method, a hydrothermal synthesis method, a high-temperature solid phase method, a high-energy ball milling method and the like. The most applied methods are sol-gel method, precipitation method and hydrothermal method. The main advantage of chemical synthesis is the controllable composition and structure. The chemical synthesis method has the advantage that the property and the structure of the perovskite compound can be accurately controlled by changing the composition, the reaction conditions and other means, but the synthesis steps are complicated, so that the quality of the perovskite synthesized in different batches is difficult to keep constant, and the cost is high. Therefore, a method for synthesizing perovskite compounds with simple steps is needed.

The flame spray decomposition method is a simple and rapid method for preparing functional nano particles, can be used for preparing solid oxides, composite metal oxides and the like, and can be used in the fields of catalysis, wave absorption, superhard structural materials, antibiosis and the like. Jonathan Horlyck et al prepared a nickel-cobalt bimetallic catalyst for catalytic methane reforming reactions using flame spray decomposition to achieve good catalytic effect (Chemical Engineering Journal 352(2018) 572-580). Gold-nickel bimetallic catalyst prepared by Jessica N.G.Stanley and the like by using flame spray decomposition method and used for catalyzing CO₂Reduction to methane, showing good catalytic properties (Chemical Engineering Science 194(2019) 94-104). Wuzi Jian et al prepared wear-resistant materials by flame spray decomposition method showed good mechanical properties (material protection 2015, 3/8 (10): 44-47). This indicates that the flame spray decomposition method can be used to prepare nanomaterials having specific functions.

Disclosure of Invention

The invention aims to provide a preparation method of a perovskite compound, which can remarkably reduce the synthesis time of the perovskite compound, and the obtained perovskite compound has high purity and uniform property and is easy to be industrially amplified.

The preparation method of the perovskite compound comprises the steps of dissolving a precursor of the perovskite compound in a solvent, uniformly mixing to obtain a precursor solution, dispersing the precursor solution into flame through high-pressure gas, and combusting and reacting to obtain the nano perovskite compound.

The structural formula of the perovskite compound is ABO₃Wherein A is one of calcium, cesium, barium, strontium, potassium, sodium, rubidium, lanthanum or cerium, and B is one of titanium, cobalt, aluminum, manganese, thallium, cerium or zirconiumOne, O is oxygen atom, A and B are two different metal elements respectively.

The precursor of the perovskite compound is a precursor of A and a precursor of B.

The precursor of A is one or more of nitrate, acetate, citrate or 1-methyl hexanoate of A.

The precursor of B is one or more of nitrate, acetate, citrate or 1-methyl hexanoate of B.

The solvent is one or more of water, ethanol, benzene, toluene, xylene or ethyl acetate.

The concentration of the precursor solution is 0.1-3.5mol/L, and the molar ratio of A to B is 1: 1.

The high-pressure gas is oxygen, the pressure of the high-pressure gas is 0.1-1.5MPa, and the flow rate of the precursor solution dispersed into the flame is 5-30 mL/min.

The flame is methane-oxygen flame.

The particle size of the nano perovskite compound is 5-500 nm.

The nano perovskite compound is captured and collected by a collector with a gas suction device and a filter membrane.

The preparation method of the perovskite compound comprises the steps of dissolving a precursor of the perovskite compound in a solvent, uniformly mixing to obtain a precursor solution, dispersing the precursor solution into flame through high-pressure gas (namely, dispersed oxygen), burning and reacting, and entering a collector under the protection of an oxygen gas wall (namely, protected oxygen) to obtain the nano perovskite compound.

The flow rate of the protective oxygen is 1-5L/min, the flow rate of the dispersed oxygen is 2-10L/min, the flow rate of the methane is 1-4L/min, and the flow rate ratio of the dispersed oxygen to the methane is 2-5: 1.

The type and the crystal size of the perovskite compound obtained by the invention are determined by XRD and electron microscope.

Aiming at the problems of complicated steps, difficult quality control and difficult industrial amplification of the traditional perovskite preparation method. The method comprises the steps of dissolving a precursor in a solvent, dispersing a solution containing the precursor into methane-oxygen flame by using high-pressure gas, and synthesizing the nano-grade perovskite compound in one step, wherein the size of the perovskite compound can be adjusted by changing the concentration and the feeding rate of the precursor solution, the flow rate and the pressure of the dispersing gas.

The invention has the following beneficial effects:

the invention can synthesize the perovskite compound from the precursor by one step through a flame spray decomposition method, obviously reduces the synthesis time of the perovskite compound, and the obtained perovskite compound has high purity and uniform property and is easy to be industrially amplified.

Drawings

Fig. 1 is an XRD pattern and an electron micrograph of the perovskite compound prepared in example 1.

Detailed Description

The present invention is further described below with reference to examples.

Example 1

5g of calcium nitrate and 10.4g of tetrabutyl titanate are dissolved in 50mL of ethanol, the solution is injected into dispersed oxygen at the speed of 5mL/min by a micro-injection pump, and then the dispersed solution is dispersed into methane-oxygen flame for combustion and reaction under the protection of oxygen around a spray head, wherein the flow rate of methane is 1.9L/min, the flow rate of protected oxygen is 4.2L/min, the flow rate of dispersed oxygen is 2.5L/min, and the pressure of dispersed oxygen is 0.17 MPa. The perovskite compound particles generated in the flame are collected by a collector.

As shown in fig. 1, no other impurity peaks were observed by XRD. An electron microscope image shows that the prepared perovskite compound is uniform in texture. The grain size is 15.2nm calculated by the Sherle formula, which is consistent with the grain size shown by an electron microscope picture.

Example 2

5g of cesium nitrate and 5.1g of cobalt citrate are dissolved in 50mL of water, and are injected into dispersed oxygen at the rate of 5mL/min by a micro-injection pump, and then the cesium nitrate and the 5.1g of cobalt citrate are dispersed into methane-oxygen flame for combustion and reaction under the protection of oxygen around a spray head, wherein the flow rate of methane is 2.3L/min, the flow rate of protected oxygen is 4.6L/min, the flow rate of dispersed oxygen is 3L/min, and the pressure of the dispersed oxygen is 0.2 MPa. The perovskite compound particles generated in the flame are collected by a collector.

No other impurity peaks appear through XRD measurement, and the grain size is 23.4nm through calculation of a Sherle formula.

Example 3

Dissolving 5g of 2-lanthanum ethylhexanoate and 4.1g of 2-manganese ethylhexanoate in 50mL of dimethylbenzene, injecting the mixed solution into dispersed oxygen at the speed of 6mL/min by using a micro-injection pump, dispersing the mixed solution into methane-oxygen flame for combustion and reaction under the protection of oxygen around a spray head, wherein the flow rate of methane is 1.5L/min, the flow rate of the protected oxygen is 4.2L/min, the flow rate of the dispersed oxygen is 2.1L/min, and the pressure of the dispersed oxygen is 0.3 MPa. The perovskite compound particles generated in the flame are collected by a collector.

No other impurity peaks appear through XRD measurement, and the grain size is 10.6nm through calculation of a Sherle formula.

Example 4

Dissolving 5g of barium acetate and 11.1g of 2-cerium ethyl hexanoate in 50mL of ethyl acetate, injecting the solution into dispersed oxygen at the speed of 5mL/min by using a micro-injection pump, dispersing the solution into methane-oxygen flame for combustion and reaction under the protection of oxygen around a spray head, wherein the flow rate of methane is 1.9L/min, the flow rate of protected oxygen is 4.2L/min, the flow rate of dispersed oxygen is 3.5L/min, and the pressure of dispersed oxygen is 0.17 MPa. The perovskite compound particles generated in the flame are collected by a collector.

No other impurity peaks appear through XRD measurement, and the grain size is 25.6nm through Sherle formula calculation.