CN107452865B - Gold nanoparticle-coated nanosheet structure Sb2Te3Method for manufacturing thermoelectric material - Google Patents

Abstract

Gold nanoparticle-coated nanosheet structure Sb₂Te₃A method of making a thermoelectric material comprising the steps of: firstly, a solvent thermal method is used for preparing binary pure phase Sb₂Te₃Washing and drying the powder, and then preparing 0.01 mol/L HAuCl₄Aqueous solution, 0.1% wt of AgNO₃Aqueous solution, 0.1% wt Na₃C₆H₅O₇An aqueous solution; then 1ml of HAuCl was added to 100ml of boiling aqueous solution in turn₄、20~40μl AgNO₃And 1-6 ml of Na₃C₆H₅O₇Mixed solution, and 0.197 g of Sb₂Te₃Powder; finally, centrifugally washing and drying the mixed solution to obtain a powder product of 1% Au @ Sb₂Te₃. Effectively promote pure-phase nanosheet structure Sb₂Te₃Thermoelectric figure of merit of (1), composite Sb obtained₂Te₃Compared with the original structure, the ZT value of the thermoelectric material can be improved by more than 1 time.

Description

Gold nanoparticle-coated nanosheet structure Sb2Te3Method for manufacturing thermoelectric material

Technical Field

The invention relates to a material preparation method, in particular to Sb with a gold nanoparticle-coated nanosheet structure₂Te₃A method for manufacturing thermoelectric materials belongs to the technical field of material synthesis.

Background

The thermoelectric material is an advanced material which statically realizes the interconversion of heat energy and electric energy through the movement of current carriers, and the research related to the thermoelectric material is more and more along with the improvement of the awareness of environmental protection and energy conservation of people; the thermoelectric conversion efficiency of the thermoelectric material mainly depends on the figure of merit ZT, and the higher the ZT value of the thermoelectric material, the better. Sb₂Te₃The compounds are currently in useOne of the most mature commercial thermoelectric materials is the thermoelectric material with the best performance in the temperature range of 200 ℃ to room temperature.

In recent years, nano-structured thermoelectric materials (nano-sheets, nano-dots, nano-wires and nano-crystals) have the potential of greatly improving the ZT value; wherein the nano-sheet structure Sb is synthesized by a solvothermal method₂Te₃Thermoelectric materials are a hot point of research in nanostructured thermoelectric materials due to the large reduction in thermal conductivity and the presence of structural anisotropy. However, the nanosheet structure Sb₂Te₃The thermoelectric material shows extremely low thermal conductivity due to the increase of the grain boundaries of the nano material compared with the micro-structured material; and the carrier is also scattered and inhibited during transportation, so that the power factor is degraded, and the ZT value reaches about 0.35 at 500K.

Disclosure of Invention

The invention aims at the prior Sb with a nanosheet structure₂Te₃The thermoelectric material has the problems that the power factor has a degradation sign, the ZT value reaches about 0.35 at 500K, and the like, and provides a gold nanoparticle coated nanosheet structure Sb₂Te₃A method for manufacturing a thermoelectric material.

In order to achieve the purpose, the technical solution of the invention is as follows: gold nanoparticle-coated nanosheet structure Sb₂Te₃A method of making a thermoelectric material comprising the steps of:

step one, preparing binary pure phase Sb by using a solvothermal method₂Te₃Powder is centrifugally washed and dried, and the morphology of the powder is observed by a scanning electron microscope to confirm that the powder is of a nano-sheet structure;

step two, preparing 0.01 mol/L HAuCl₄An aqueous solution;

step three, preparing 0.1 wt% AgNO₃An aqueous solution;

step four, preparing 0.1 wt% of Na₃C₆H₅O₇An aqueous solution;

step five, adding 1ml HAuCl into 100ml boiling water solution in sequence₄、20～40μlAgNO₃And 1 to 6ml of Na₃C₆H₅O₇Mixed solution, and 0.197 g of Sb₂Te₃Powder is mixed and stirred evenly;

step six, after the mixed solution in the step five reacts for 15min in a boiling state, stopping heating and naturally cooling, continuously stirring the reaction solution for 2 hours in the cooling process, and finally centrifugally washing and drying to obtain a powder product of 1% Au @ Sb₂Te₃。

Compared with the prior art, the invention has the beneficial effects that:

1. the raw material formula is simple, and the process flow is simple and easy to control; through product performance uniformity tests, thermoelectric properties of products of 5 synthesis batches are compared, and ZT value deviation is within 5%, so that the obtained products are high in performance uniformity.

2. The invention provides 1% Au @ Sb₂Te₃The concentration of the compound is the optimal Au addition concentration, and under the concentration of 1% Au, a proper amount of extra electrons can be provided, so that the negative influence of the energy filtering effect on the reduction of the electron mobility is compensated; further, experiments prove that at the concentration, the conductivity of the material is increased to a certain degree, and the conductivity is reduced by other Au concentrations (0.5% Au, 2% Au, 3% Au and 4% Au are synthesized by the same method).

Drawings

FIG. 1 shows Sb synthesized in the production of 1% Au concentration according to the present invention₂Te₃And scanning electron microscope topography of the thermoelectric material.

FIG. 2 shows Sb synthesized in the product of the present invention with 0.5% Au concentration₂Te₃And scanning electron microscope topography of the thermoelectric material.

FIG. 3 shows Sb synthesized in the case of the product of the present invention having a 2% Au concentration₂Te₃And scanning electron microscope topography of the thermoelectric material.

FIG. 4 shows Sb synthesized in the product of the present invention at 4% Au concentration₂Te₃And scanning electron microscope topography of the thermoelectric material.

FIG. 5 shows Sb synthesized by the present invention₂Te₃Thermoelectric material XRD phase analysis pattern.

FIG. 6 shows Sb synthesized by the present invention₂Te₃Graph of ZT value measurements for thermoelectric materials.

Detailed Description

The invention is described in further detail below with reference to the following description of the drawings and the detailed description.

Gold nanoparticle-coated nanosheet structure Sb₂Te₃Method for producing thermoelectric material by reducing HAuCl with citric acid₄The method reduces Au nanoparticles to Sb₂Te₃On the surface of (2), some Au nanoparticles are in Sb₂Te₃The surface of the nanosheet is coated with a thin layer, and other nanosheets are embedded in the corners of the hexagonal plate, so that a conductive channel and a bridge between different nanosheet layers are built, a metal-semiconductor heterojunction is formed, and the Sb with a pure-phase hexagonal nanosheet structure obtained by the traditional solvent thermosynthesis method is improved₂Te₃ZT value of (1). In hexagonal nanosheet structure Sb₂Te₃Under the premise that the synthesis condition and ZT value of the thermoelectric material are fixed, the method can effectively improve the Sb with the pure-phase hexagonal nanosheet structure₂Te₃ZT value of (a): when the gold content was controlled at 1% (1% Au @ Sb)₂Te₃I.e. Au and binary pure phase Sb₂Te₃1 percent of mass ratio), optimal effect, ZT value and hexagonal nanosheet structure Sb₂Te₃Compared with the thermoelectric material, the thermoelectric material can be improved by 1.3 times. The method specifically comprises the following steps:

step one, preparing binary pure phase Sb by using a solvothermal method₂Te₃And (3) powder is centrifugally washed and dried, and the morphology of the powder is observed by a scanning electron microscope to confirm that the powder is of a nanosheet structure.

Step two, preparing 0.01 mol/L HAuCl₄(chloroauric acid) aqueous solution.

Step three, preparing 0.1 wt% AgNO₃(silver nitrate) aqueous solution.

Step four, preparing 0.1 wt% of Na₃C₆H₅O₇(sodium citrate) aqueous solution.

Step five, adding 1ml HAuCl into 100ml boiling water solution in sequence₄、20～40μlAgNO₃And 1 to 6ml of Na₃C₆H₅O₇Mixed solution, and 0.197 g of Sb₂Te₃Powder and evenly stirred.

Step six, the mixed solution in the step five reacts for 15min under the boiling state, and then the heating is stopped for natural cooling; to ensure that the gold nanoparticles are in Sb₂Te₃Uniformly coating the nano-chip, continuously stirring the reaction solution for 2 hours in the cooling process, and finally centrifugally washing and drying to obtain a powder product of 1% Au @ Sb₂Te₃。

Referring to fig. 1 to 6, the product is SEM-morphologically characterized, and as can be seen from fig. 1 to 4, Au particles and Sb₂Te₃The heterogeneous distribution junctions between the nanosheets are clearly visible. The XRD phase composition of the product is characterized, and as can be seen from figure 5, Sb₂Te₃The phase composition of the thermoelectric material is elementary substance Au + binary pure phase Sb₂Te₃The composite material of (1). Thermoelectric performance ZT value measurement was carried out after sintering the product powder into a block, and as can be seen from FIG. 6, at 500K, 1% Au @ Sb₂Te₃The ZT value of (A) is up to 0.8, compared with that of binary pure phase Sb₂Te₃The ZT value of 0.35 is improved by 1.3 times.

The first embodiment is as follows:

step one, preparing binary pure phase Sb by using a solvothermal method₂Te₃And (3) centrifugally washing and drying the powder, observing the morphology of the powder by a scanning electron microscope, and determining that the powder is of a nanosheet structure.

Step two, preparing 0.01 mol/L HAuCl₄(chloroauric acid) aqueous solution.

Step three, preparing 0.1 wt% AgNO₃(silver nitrate) aqueous solution.

Step four, preparing 0.1 wt% of Na₃C₆H₅O₇(sodium citrate) aqueous solution.

Step five, adding 1ml HAuCl into 100ml boiling water solution in sequence₄、20μlAgNO₃And 1ml Na₃C₆H₅O₇Mixed solution, and 0.197 g of Sb₂Te₃Powder and evenly stirred.

Step six, mixing in step fiveStopping heating and naturally cooling after the mixed solution reacts for 15min in a boiling state, and ensuring that the gold nanoparticles are in Sb₂Te₃Uniformly coating the nano-chip, continuously stirring the reaction solution for 2 hours in the cooling process, and finally centrifugally washing and drying to obtain a powder product of 1% Au @ Sb₂Te₃。

Example two:

step one, preparing binary pure phase Sb by using a solvothermal method₂Te₃And (3) centrifugally washing and drying the powder, observing the morphology of the powder by a scanning electron microscope, and determining that the powder is of a nanosheet structure.

Step two, preparing 0.01 mol/L HAuCl₄(chloroauric acid) aqueous solution.

Step three, preparing 0.1 wt% AgNO₃(silver nitrate) aqueous solution.

Step four, preparing 0.1 wt% of Na₃C₆H₅O₇(sodium citrate) aqueous solution.

Step five, adding 1ml HAuCl into 100ml boiling water solution in sequence₄、30μlAgNO₃And 3ml Na₃C₆H₅O₇Mixed solution, and 0.197 g of Sb₂Te₃Powder and evenly stirred.

Step six, after the mixed solution in the step five reacts for 15min in a boiling state, stopping heating and naturally cooling, and in order to ensure that the gold nanoparticles are in Sb₂Te₃Uniformly coating the nano-chip, continuously stirring the reaction solution for 2 hours in the cooling process, and finally centrifugally washing and drying to obtain a powder product of 1% Au @ Sb₂Te₃。

Example three:

step one, preparing binary pure phase Sb by using a solvothermal method₂Te₃And (3) centrifugally washing and drying the powder, observing the morphology of the powder by a scanning electron microscope, and determining that the powder is of a nanosheet structure.

Step two, preparing 0.01 mol/L HAuCl₄(chloroauric acid) aqueous solution.

Step three, preparing 0.1 wt% AgNO₃(silver nitrate) aqueous solution.

Step four, preparing 0.1 wt% of Na₃C₆H₅O₇(sodium citrate) aqueous solution.

Step five, adding 1ml HAuCl into 100ml boiling water solution in sequence₄、40μlAgNO₃And 6ml Na₃C₆H₅O₇Mixed solution, and 0.197 g of Sb₂Te₃Powder and evenly stirred.

Step six, after the mixed solution in the step five reacts for 15min in a boiling state, stopping heating and naturally cooling, and in order to ensure that the gold nanoparticles are in Sb₂Te₃Uniformly coating the nano-chip, continuously stirring the reaction solution for 2 hours in the cooling process, and finally centrifugally washing and drying to obtain a powder product of 1% Au @ Sb₂Te₃。

The invention synthesizes Sb with a nanosheet structure by a solvothermal method₂Te₃Dispersing the powder in a specific solvent, generating gold nanoparticles through chemical reaction between the solvents, and then immediately attaching the gold particles to the surfaces of the nanosheets dispersed in the solvent, thereby forming a nanoparticle-coated nanosheet structure; thereby effectively improving the pure phase nanosheet structure Sb₂Te₃The thermoelectric figure of merit of (A) is composite Sb obtained by coating nano sheets with gold nanoparticles₂Te₃Compared with the original structure, the ZT value of the thermoelectric material can be improved by more than 1 time.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention relates, several simple deductions or substitutions may be made without departing from the spirit of the invention, and the above-mentioned structures should be considered as belonging to the protection scope of the invention.

Claims (1)

1. Gold nanoparticle-coated nanosheet structure Sb₂Te₃The method for manufacturing the thermoelectric material is characterized by comprising the following steps of:

step one, preparing binary pure phase S by using a solvothermal methodb₂Te₃Powder is centrifugally washed and dried, and the morphology of the powder is observed by a scanning electron microscope to confirm that the powder is of a nano-sheet structure;

step two, preparing 0.01 mol/L HAuCl₄An aqueous solution;

step three, preparing 0.1 wt% AgNO₃An aqueous solution;

step four, preparing 0.1 wt% of Na₃C₆H₅O₇An aqueous solution;

step five, adding 1ml of HAuCl into 100ml of boiling water in turn₄20 to 40. mu.l of the above AgNO in an aqueous solution₃An aqueous solution and 1 to 6ml of the above Na₃C₆H₅O₇An aqueous solution, and 0.197 g of Sb₂Te₃Powder is mixed and stirred evenly;

step six, after the mixed solution in the step five reacts for 15min in a boiling state, stopping heating and naturally cooling, continuously stirring the reaction solution for 2 hours in the cooling process, and finally centrifugally washing and drying to obtain a powder product of 1% Au @ Sb₂Te₃。

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