CN117903009A - A room temperature phase pyroelectric material and preparation method thereof - Google Patents

Abstract

The invention discloses a room temperature phase pyroelectric material and a preparation method thereof, which relate to the technical field of pyroelectric materials, and have a chemical formula of C ₄H₁₄N₂OPbCl₄ and are prepared as follows: stirring and cooling 2-dimethylaminoethylamine in an ice-water bath, then dropwise adding hydrogen peroxide solution into the mixture, and stirring for reaction; vacuum drying the reaction liquid after the reaction is finished to obtain the nitrogen oxide of the 2-dimethylaminoethylamine; adding the nitrogen oxide of 2-dimethylaminoethylamine and lead chloride into concentrated hydrochloric acid solution, heating in an oil bath, and stirring for reaction to obtain the pyroelectric material. The pyroelectric material has a perovskite structure, reversible phase change reaction occurs at the phase change temperature of 27 ℃, and current is generated at the polar shaft end of the crystal in the phase change process; the phase transition temperature at room temperature enables the pyroelectric material to work in a relatively stable temperature range, provides reliable energy collection performance, and has good application value in the directions of waste heat utilization, self-sustaining systems and the like.

Description

A room temperature phase pyroelectric material and preparation method thereof

Technical Field

The present invention relates to the technical field of pyroelectric materials, and in particular to a room temperature phase pyroelectric material and a preparation method thereof.

Background technique

Room-temperature pyroelectric materials are of great significance in energy harvesting. They exhibit the characteristics of realizing pyroelectric effect at room temperature, providing a new way for effective energy conversion.

Pyroelectric materials can convert small temperature changes in the surrounding environment into electrical energy, which makes them have great potential in waste heat utilization. By integrating such materials into devices or systems, waste heat generated by industrial processes, mechanical movements or other systems can be effectively utilized and converted into electrical energy, thereby improving energy efficiency.

The energy conversion properties of pyroelectric materials make them a key component in self-sustaining energy systems. The materials can capture tiny temperature changes from the surrounding environment to provide a reliable autonomous energy source for wireless sensors, low-power electronics or other remote devices, reducing reliance on traditional batteries.

Compared with some other energy harvesting technologies, pyroelectric materials can usually achieve energy conversion without external stimulation. This gives them unique advantages in some special environments or scenarios where continuous external energy input cannot be provided.

At present, most pyroelectric materials are high-temperature pyroelectric materials or low-temperature pyroelectric materials, which have a limited application range and are difficult to use on a large scale. The phase transition temperature of pyroelectric materials at room temperature means that they can achieve efficient energy conversion in temperature fluctuations in the natural environment, which enables such materials to fully exert their pyroelectric effect under common room temperature conditions, thereby improving the efficiency of energy conversion. Since room temperature is the typical temperature range for daily life and most industrial applications, the phase transition temperature of pyroelectric materials matches room temperature to make it more practical. Therefore, it is of great significance to develop a room temperature phase pyroelectric material.

Summary of the invention

Based on the technical problems existing in the background technology, the present invention proposes a room temperature phase pyroelectric material and a preparation method thereof. The material has a perovskite structure and undergoes a reversible phase change reaction at a phase change temperature of 27°C.

The present invention provides a room temperature phase pyroelectric material, the chemical formula of which is C ₄ H ₁₄ N ₂ OPbCl ₄ .

Further, the Curie temperature of the pyroelectric material is 27°C;

When the temperature is less than 27°C, the pyroelectric material belongs to the monoclinic Cc space group;

When the temperature is greater than 27° C., the pyroelectric material belongs to the monoclinic C2/C space group.

The method for preparing the room temperature phase pyroelectric material proposed by the present invention comprises the following steps:

1) stirring 2-dimethylaminoethylamine in an ice-water bath to cool it down, then dropping a hydrogen peroxide solution thereinto, and stirring to react;

2) vacuum drying the reaction solution obtained after the reaction in step 1) to obtain the nitrogen oxide of 2-dimethylaminoethylamine;

3) Add the nitrogen oxide of 2-dimethylaminoethylamine and lead chloride into concentrated hydrochloric acid solution, heat in an oil bath, stir and react to obtain a pyroelectric material.

Furthermore, in step 1), 2-dimethylaminoethylamine is stirred in an ice-water bath for 20-30 minutes for cooling.

Furthermore, in step 1), the mass volume ratio of 2-dimethylaminoethylamine to hydrogen peroxide solution is 1:11-13 g/ml, and the mass percentage concentration of the hydrogen peroxide solution is 30%.

Furthermore, in step 1), the reaction is stirred for 46-50 hours.

Furthermore, in step 3), the oil bath heating temperature is 75-85° C., and the reaction is stirred for 2-4 hours.

Furthermore, in step 3), the mass volume ratio of the nitrogen oxide of 2-dimethylaminoethylamine, lead chloride and concentrated hydrochloric acid is 4:5:180-240 (g/g/mL), and the mass percentage concentration of the concentrated hydrochloric acid solution is 36%.

Compared with the prior art, the beneficial effects of this application are mainly reflected in the following aspects:

1. The pyroelectric material of the present invention is a perovskite structure, which undergoes a reversible phase change reaction at a phase change temperature of 27°C. During the phase change process, the polar axis end of the crystal will generate current; the phase change temperature at room temperature enables the pyroelectric material to operate within a relatively stable temperature range, providing reliable energy collection performance. Compared with materials that require extremely high or low temperature conditions, the working conditions at room temperature are easier to achieve, reducing the engineering complexity and stability challenges of the material.

2. The pyroelectric material of the present invention has great application value in waste heat utilization, self-sustaining systems, etc. It can realize the conversion of ambient temperature changes into electrical energy, effectively solve the waste of waste heat, and improve the sustainable utilization of energy. Compared with traditional energy collection technology, the pyroelectric material of this system can realize energy conversion without external excitation or high temperature conditions. This makes it show excellent applicability in special environments or scenarios where continuous external energy input cannot be provided.

3. The preparation method of the pyroelectric material of the present invention is easy to operate and detect.

The phase transition temperature advantage of the pyroelectric material of the present invention at room temperature makes it easier to achieve efficient energy conversion in various practical applications, thereby showing broad application potential in energy collection and related fields.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a low-temperature single crystal structure of a room-temperature pyroelectric material in an embodiment of the present invention;

FIG2 is a high temperature single crystal structure of a room temperature pyroelectric material according to an embodiment of the present invention;

FIG3 is an XRD pattern of a room temperature pyroelectric material in an embodiment of the present invention;

FIG4 is a diagram of the pyroelectric coefficient of the room temperature pyroelectric material in an embodiment of the present invention, wherein curve a is a temperature-polarization intensity curve, and curve b is a temperature-charge curve.

Detailed ways

The technical solution of the present invention is described in detail below through specific embodiments.

Example 1

The present invention provides a perovskite material with room temperature pyroelectric phase transition characteristics, the chemical composition of which is C ₄ H ₁₄ N ₂ OPbCl _4. The pyroelectric phase transition temperature of the material is 27°C, which is in the room temperature phase, and can be used for energy collection in many occasions.

The method for preparing the room temperature phase pyroelectric material comprises the following steps:

1) Add 4.4 g of 2-dimethylaminoethylamine into a round-bottom flask, place it in an ice-water bath, and stir for 20 minutes; then dropwise add 50 mL of 30% hydrogen peroxide solution and stir to react for 48 hours;

2) The reaction solution obtained after the reaction was completed was vacuum dried to obtain 4.5 g of an oily liquid, which was confirmed to be the nitrogen oxide of 2-dimethylaminoethylamine by nuclear magnetic resonance;

3) 400 mg of the nitrogen oxide of 2-dimethylaminoethylamine and 500 mg of lead chloride were added to a round-bottom flask, and 20 mL of concentrated hydrochloric acid solution was added. The mixture was heated to 80° C. in an oil bath and stirred for 3 h to obtain a pyroelectric material.

The pyroelectric material prepared in Example 1 was tested. Figure 1 shows the low-temperature phase stacking mode of the low-temperature phase pyroelectric material, the unit cell parameters at different temperatures and the arrangement of molecules; Figure 2 shows the high-temperature phase stacking mode of the high-temperature phase pyroelectric material, the unit cell parameters at different temperatures and the arrangement of molecules; Figure 3 is the PXRD spectrum obtained from the experimental test of the pyroelectric material, and it can be concluded that the high-temperature phase pyroelectric perovskite material is a uniform phase.

The room temperature phase pyroelectric perovskite material prepared in Example 1 was analyzed. High quality single crystals of appropriate size were selected under a polarized light microscope and subjected to X-ray diffraction using a molybdenum target at 102K and 333K using a variable temperature single crystal X-ray diffractometer Bruker CD6000. The X-ray diffraction structure of the single crystal was determined. The single crystal structure was analyzed and refined using the OLEX2 software equipped with the SHELXTL97 software package. The specific data of the crystal structure of the compound are shown in Table 1.

Table 1 Crystallographic parameters of room temperature pyroelectric materials prepared in Example 1

The pyroelectric coefficient of the pyroelectric material of Example 1 was tested. As shown in FIG. 4 , the pyroelectric material quickly entered the phase change stage at 27° C.

The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims (8)

1. A room temperature phase pyroelectric material is characterized in that the chemical formula is C ₄H₁₄N₂OPbCl₄.

2. The room temperature phase pyroelectric material according to claim 1, wherein said pyroelectric material has a curie temperature of 27 ℃;

when the temperature is less than 27 ℃, the pyroelectric material belongs to monoclinic Cc space group;

When the temperature is higher than 27 ℃, the pyroelectric material belongs to monoclinic C2/C space group.

3. The method for preparing a room temperature phase pyroelectric material according to claim 1 or 2, comprising the steps of:

1) Stirring and cooling 2-dimethylaminoethylamine in an ice-water bath, then dropwise adding hydrogen peroxide solution into the mixture, and stirring for reaction;

2) Vacuum drying the reaction liquid obtained after the reaction in the step 1) is finished to obtain the nitrogen oxide of the 2-dimethylaminoethylamine;

3) Adding the nitrogen oxide of 2-dimethylaminoethylamine and lead chloride into concentrated hydrochloric acid solution, heating in an oil bath, and stirring for reaction to obtain the pyroelectric material.

4. The method for preparing a room temperature phase pyroelectric material according to claim 3, wherein in the step 1), 2-dimethylaminoethylamine is stirred in an ice water bath for 20 to 30 minutes for cooling treatment.

5. The method for preparing a room temperature phase pyroelectric material according to claim 3, wherein in the step 1), the mass volume ratio g/ml of the 2-dimethylaminoethylamine and hydrogen peroxide solution is 1:11-13, wherein the mass percentage concentration of the hydrogen peroxide solution is 30%.

6. The method for preparing a room temperature phase pyroelectric material according to claim 3, wherein in the step 1), the reaction is stirred for 46 to 50 hours.

7. The method for preparing a room temperature phase pyroelectric material according to claim 3, wherein in the step 3), the heating temperature of the oil bath is 75-85 ℃, and the stirring reaction is carried out for 2-4 hours.

8. The method for preparing a room temperature phase pyroelectric material according to claim 3, wherein in the step 3), the mass volume ratio g/g/mL of the nitrogen oxide of 2-dimethylaminoethylamine, lead chloride and concentrated hydrochloric acid is 4:5:180-240, wherein the mass percentage concentration of the concentrated hydrochloric acid solution is 36%.