阅读说明：本技术 一种碲锰镉纳米粉体及其制备方法 (Cadmium manganese telluride nano powder and preparation method thereof ) 是由 俞鹏飞 邵汀荃 刘文斐 高攀登 蒋璧如 祁永武 赵鹏 于 2021-06-08 设计创作，主要内容包括：本发明涉及一种碲锰镉纳米粉体及其制备方法,包括：镉盐、锰盐和亚碲酸盐为反应原料,添加柠檬酸钠与巯基丙酸作为稳定剂,硼氢化物为还原剂,利用水热反应制备；镉盐、锰盐和亚碲酸盐中Cd、Mn和Te的摩尔比为：1:(0.1～0.5):(1.1～1.5)；镉盐、柠檬酸钠和巯基丙酸的摩尔比为：1:(0.1～1):(1～5)。本工艺方法操作简单,无需保护气氛,粉体尺寸可控,反应温度低,制得产物为纯相闪锌矿结构。该粉体可用于辐射探测器、太阳能电池原料和光催化等领域。(The invention relates to cadmium manganese telluride nano powder and a preparation method thereof, wherein the preparation method comprises the following steps: cadmium salt, manganese salt and tellurite are used as reaction raw materials, sodium citrate and mercaptopropionic acid are added to be used as stabilizing agents, borohydride is used as a reducing agent, and the catalyst is prepared by hydrothermal reaction; the mol ratio of Cd, Mn and Te in the cadmium salt, the manganese salt and the tellurite is as follows: 1 (0.1-0.5) and 1.1-1.5); the mol ratio of the cadmium salt to the sodium citrate to the mercaptopropionic acid is as follows: 1 (0.1-1) and (1-5). The process method is simple to operate, does not need protective atmosphere, has controllable powder size and low reaction temperature, and the prepared product is of a pure-phase sphalerite structure. The powder can be used in the fields of radiation detectors, solar cell raw materials, photocatalysis and the like.)

1. A preparation method of cadmium manganese telluride nano powder is characterized by comprising the following steps:

cadmium salt, manganese salt and tellurite are used as reaction raw materials, sodium citrate and mercaptopropionic acid are added, and the catalyst is prepared by hydrothermal reaction;

the mol ratio of Cd, Mn and Te in the cadmium salt, the manganese salt and the tellurite is as follows: 1 (0.1-0.5) and 1.1-1.5);

the mol ratio of the cadmium salt to the sodium citrate to the mercaptopropionic acid is as follows: 1 (0.1-1) and (1-5).

2. The method for preparing cadmium telluride-manganese-cadmium nanopowder as claimed in claim 1, wherein borohydride is further added, and the molar ratio of cadmium salt to borohydride is 1 (10-40).

3. The method for preparing tellurium-manganese-cadmium nano-powder according to claim 2, wherein the borohydride is sodium borohydride or potassium borohydride and is dissolved in ethanol before being added.

4. The method for preparing cadmium telluride nano powder as claimed in claim 1, 2 or 3, wherein the cadmium salt is cadmium chloride, the manganese salt is manganese chloride, and the tellurite is sodium tellurite or potassium tellurite.

5. The preparation method of cadmium telluride as in claim 1, 2 or 3 wherein the temperature of hydrothermal reaction is 120-200 ℃; the time of the hydrothermal reaction is 2-48 h.

6. The method for preparing tellurium-manganese-cadmium nano powder as claimed in claim 1, 2 or 3, wherein the filling rate of the reaction kettle in the hydrothermal reaction is 60-80%.

7. The method for preparing cadmium telluride nano powder as in claim 1, 2 or 3, further comprising washing and drying the hydrothermal reaction product, wherein the washing comprises washing the hydrothermal reaction product with water and absolute ethyl alcohol in sequence, and the drying temperature is 60-80 ℃.

8. A preparation method of cadmium manganese telluride nano powder is characterized in that cadmium salt, manganese salt and tellurite are used as reaction raw materials, and the molar ratio of Cd, Mn and Te in the cadmium salt, the manganese salt and the tellurite is as follows: 1 (0.1-0.5) and 1.1-1.5); adding a stabilizer, a protective agent and a reducing agent, and preparing by hydrothermal reaction;

the method specifically comprises the following steps:

a) preparing a mixed solution of cadmium salt and manganese salt: mixing and dissolving cadmium chloride and manganese chloride, and adding a stabilizer and a protective agent;

b) preparing a tellurium source solution: dissolving sodium tellurite;

c) preparing CdMnTe nano powder: injecting the tellurium source solution into the mixed solution in the step a), adjusting the pH value to be strong alkaline, and adding a reducing agent to obtain a tellurium-manganese-cadmium precursor suspension; transferring the tellurium-manganese-cadmium precursor suspension to a hydrothermal reaction kettle, carrying out hydrothermal reaction for 2-48 h at the temperature of 120-200 ℃, and separating, washing and drying the reactants in sequence to obtain the tellurium-manganese-cadmium precursor suspension.

9. The method for preparing cadmium telluride nano powder according to claim 8, wherein the pH value is 10-14; the stabilizer is sodium citrate, the protective agent is mercaptopropionic acid, and the reducing agent is sodium borohydride or potassium borohydride; the mol ratio of the cadmium salt to the sodium citrate to the mercaptopropionic acid is as follows: 1 (0.1-1) and (1-5); the molar ratio of the cadmium salt to the borohydride is 1 (10-40);

washing comprises the step of washing the hydrothermal reaction product sequentially by water and absolute ethyl alcohol, wherein the drying temperature is 60-80 ℃.

10. The cadmium telluride manganese nano powder is characterized by being prepared by the preparation method of the cadmium telluride manganese nano powder as set forth in any one of claims 1 to 9.

Technical Field

The invention belongs to the field of inorganic material preparation, relates to tellurium-manganese-cadmium nano powder and a preparation method thereof, and more particularly relates to tellurium-manganese-cadmium nano powder with a pure-phase zinc blende structure and a method for preparing the same by a hydrothermal method.

Background

With the development of modern industrial technologies and production to the micro-scale and multi-level, different types of radiation detectors play a vital role in the fields of medical treatment, environment, industrial monitoring, solar energy, electronic and universe research, and the like. At present, semiconductor radiation detector materials are mainly focused on the research of wide-bandgap compound semiconductor materials. Cadmium manganese telluride (CdMnTe) is of a zinc blende structure, has the advantages of large crystal forbidden band width, high resistivity, large carrier mobility and long service life, has special photoelectric properties, and is an ideal material for a semiconductor radiation detector. The crystal growth technology (such as Bridgman method, moving heater method and the like) needs to synthesize the polycrystalline material at high temperature and then grow at high temperature, so that the energy consumption is high. The CdMnTe prepared by the sputtering technology has high cost and various defects in the crystal. Therefore, the prepared nano-grade pure-phase CdMnTe powder is used as a raw material, and the CdMnTe crystal meeting the requirements of the detector is further synthesized, which is beneficial to solving the problem.

The main preparation methods of the CdTe-based nano material are divided into an organic metal method and an aqueous phase method. The aqueous phase synthesis method has the advantages of small pollution in the preparation process, low cost, simple operation, low toxicity, high repeatability and the like, and is favored. At present, few reports about the preparation of the ternary alloy CdMnTe nano material in a water phase are reported. The prepared CdTe-based nano material is quantum dot, and is mainly used in the fields of luminescence, fluorescent probe, biomedicine and the like. In 2015, Gao et al reported that CdS quantum dots were prepared hydrothermally using acetylcysteine as a stabilizer (Synthesis and characterization of high-quality water-soluble CdMnTequantum dots capped by N-acetyl-L-cysteine through hydrothermal method, Journal of Luminescence 159(2015) 32-37). In the preparation process, Te powder reacts with sodium borohydride to obtain toxic NaHTe, and then the toxic NaHTe reacts with N₂Under the protection of gas, CdMnTe quantum dots can be synthesized. Therefore, the preparation process is complicated, and the prepared quantum dots contain impurities and are not pure phases.

Disclosure of Invention

The invention aims to provide tellurium-manganese-cadmium nano powder and a preparation method thereof, which have the advantages of simple process, no need of protective atmosphere, controllable powder size and low reaction temperature.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of cadmium manganese telluride nano powder comprises the following steps: cadmium salt, manganese salt and tellurite are used as reaction raw materials, sodium citrate and mercaptopropionic acid are added, and the catalyst is prepared by hydrothermal reaction; the mol ratio of Cd, Mn and Te in the cadmium salt, the manganese salt and the tellurite is as follows: 1 (0.1-0.5) and 1.1-1.5); the mol ratio of the cadmium salt to the sodium citrate to the mercaptopropionic acid is as follows: 1 (0.1-1) and (1-5).

Optionally, borohydride is further added, and the molar ratio of the cadmium salt to the borohydride is 1 (10-40).

Optionally, the borohydride is sodium borohydride or potassium borohydride, and is dissolved in ethanol before addition.

Optionally, the cadmium salt is cadmium chloride, the manganese salt is manganese chloride, and the tellurite is sodium tellurite or potassium tellurite.

Optionally, the temperature of the hydrothermal reaction is 120-200 ℃; the time of the hydrothermal reaction is 2-48 h.

Optionally, the filling rate of the reaction kettle in the hydrothermal reaction is 60-80%.

Optionally, washing and drying the product of the hydrothermal reaction, wherein the washing comprises washing the product of the hydrothermal reaction sequentially with water and absolute ethyl alcohol, and the drying temperature is 60-80 ℃.

A method for preparing cadmium manganese telluride nano powder comprises the following steps of taking cadmium salt, manganese salt and tellurite as reaction raw materials, wherein the molar ratio of Cd, Mn and Te in the cadmium salt, the manganese salt and the tellurite is as follows: 1 (0.1-0.5) and 1.1-1.5); adding a stabilizer, a protective agent and a reducing agent, and preparing by hydrothermal reaction;

the method specifically comprises the following steps:

a) preparing a mixed solution of cadmium salt and manganese salt: mixing and dissolving cadmium chloride and manganese chloride, and adding a stabilizer and a protective agent;

b) preparing a tellurium source solution: dissolving sodium tellurite;

c) preparing CdMnTe nano powder: injecting the tellurium source solution into the mixed solution in the step a), adjusting the pH value to be strong alkaline, and adding a reducing agent to obtain a tellurium-manganese-cadmium precursor suspension; transferring the tellurium-manganese-cadmium precursor suspension to a hydrothermal reaction kettle, carrying out hydrothermal reaction for 2-48 h at the temperature of 120-200 ℃, and separating, washing and drying the reactants in sequence to obtain the tellurium-manganese-cadmium precursor suspension.

Optionally, the pH is 10-14; the stabilizer is sodium citrate, the protective agent is mercaptopropionic acid, and the reducing agent is sodium borohydride or potassium borohydride; the mol ratio of the cadmium salt to the sodium citrate to the mercaptopropionic acid is as follows: 1 (0.1-1) and (1-5); the molar ratio of the cadmium salt to the borohydride is 1 (10-40);

washing comprises the step of washing the hydrothermal reaction product sequentially by water and absolute ethyl alcohol, wherein the drying temperature is 60-80 ℃.

The cadmium manganese telluride nano powder is prepared by the preparation method of the cadmium manganese telluride nano powder.

Compared with the prior art, the invention has the advantages that:

the method for preparing the zinc blende tellurium manganese cadmium nano powder is a hydrothermal method, and has the advantages of small toxicity in the preparation process, low cost, simplicity in operation, low synthesis temperature and uniform powder size. The tellurium-manganese-cadmium powder synthesized by the method has a zinc blende structure, is good in crystallinity, has a particle size range of 20-100 nm, is spherical or approximately spherical in particle morphology, and is good in dispersibility. The method has the advantages that the raw materials are easy to obtain, the industrial production is easy, and the prepared pure-phase perovskite-structure tellurium-manganese-cadmium nano powder can be directly used in the application fields of radiation detector crystal preparation, solar cell raw materials, photocatalysis and the like.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is an XRD spectrum of cadmium telluride powder obtained in examples 1-5;

FIG. 2 is the EDS spectrum of the cadmium telluride powder obtained in example 5;

FIG. 3 is an SEM photograph of cadmium manganese telluride powder obtained in examples 1 to 4;

FIG. 4 is an ultraviolet-visible light absorption spectrum of the cadmium manganese telluride powder obtained in examples 1 to 4;

FIG. 5 is a photoluminescence spectrum of the cadmium manganese telluride powder obtained in examples 1 to 4.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, not all embodiments, and do not limit the present invention in any way, and all technical solutions using the embodiments, including simple changes made to the embodiments, belong to the protection scope of the present invention.

According to the preparation method of the tellurium-manganese-cadmium nano powder, the tellurium-manganese-cadmium nano powder is of a pure-phase zinc blende structure, cadmium chloride and manganese chloride are used as a cadmium source and a manganese source, sodium tellurite is used as a tellurium source, sodium citrate and mercaptopropionic acid are used as a stabilizing agent and a protecting agent, sodium borohydride is used as a reducing agent, a pH regulating agent is used for controlling a solution to be strong alkaline, and the tellurium-manganese-cadmium nano powder is obtained through a hydrothermal reaction. CdCl₂，MnCl₂And Na₂TeO₃(or K)₂TeO₃) The molar ratio of molecules, or the molar ratio of Cd, Mn and Te atoms, and the molar ratio of Cd, Mn and Te in the cadmium salt, the manganese salt and the tellurite are as follows: 1 (0.1-0.5) and 1.1-1.5); the mol ratio of the cadmium salt to the sodium citrate to the mercaptopropionic acid is as follows: 1 (0.1-1) and (1-5) refer to CdCl₂(cadmium salt), Na₃C₆H₅O₇·2H₂O (sodium citrate) and C₃H₅O₂Molar ratio of S (mercaptopropionic acid) molecules. The method specifically comprises the following steps:

a) preparing a mixed solution of cadmium salt and manganese salt: mixing and dissolving cadmium chloride and manganese chloride, and adding a stabilizer and a protective agent;

b) preparing a tellurium source solution: dissolving sodium tellurite (dissolving with deionized water, and using the dissolved amount of deionized water);

c) preparing CdMnTe nano powder: injecting the tellurium source solution into the mixed solution in the step a), adjusting the pH value to be strong alkaline, and adding a reducing agent to obtain a tellurium-manganese-cadmium precursor suspension; transferring the tellurium-manganese-cadmium precursor suspension to a hydrothermal reaction kettle, carrying out hydrothermal reaction for 2-48 h at the temperature of 120-200 ℃, and separating, washing and drying the reactants in sequence to obtain the tellurium-manganese-cadmium precursor suspension.

The molar ratio of cadmium chloride to manganese chloride in the step (a) is 1 (0.1-0.5), the stabilizing agent and the protective agent are sodium citrate and mercaptopropionic acid, the sodium citrate is chemically-analyzed pure solid particles, and the mercaptopropionic acid is a solution with the volume fraction of 98%; the pH regulator is sodium hydroxide or potassium hydroxide, and the concentration is 1-4 mol/L; the pH value is 10-14.

In the step (c), the reducing agent is sodium borohydride, and the molar ratio of cadmium chloride to sodium borohydride is 1 (10-40); the filling rate of the reaction kettle in the hydrothermal reaction is 60-80%; washing and drying the product of the hydrothermal reaction to obtain zinc blende tellurium, manganese and cadmium powder, wherein the washing comprises washing the product of the hydrothermal reaction sequentially through water and absolute ethyl alcohol, and the drying temperature is 60-80 ℃.

Example 1:

according to the mol ratio of the cadmium source to the manganese source of 1:0.5, 0.4568g of cadmium chloride and 0.1980g of manganese chloride are weighed, 30ml of deionized water is added to prepare a mixed solution, and the mixed solution is magnetically stirred; weighing 0.0664g of sodium citrate according to the molar ratio of the cadmium source to the sodium citrate of 1:0.1, and adding the sodium citrate into the solution; then adding 10 drops of mercaptopropionic acid with the volume fraction of 98 percent to form suspension, and magnetically stirring for 10 min; according to the mol ratio of the cadmium source to the tellurite of 1:1.5, 0.6645g of sodium tellurite is weighed to be dissolved (dissolved amount) by deionized water, added under the condition of magnetic stirring, and the pH value is adjusted to be 14 by a pH regulator (4mol/L sodium hydroxide solution); weighing 1.3617g of sodium borohydride according to the molar ratio of the cadmium source to the sodium borohydride being 1:18, dissolving the sodium borohydride in ethanol, and adding the sodium borohydride under the condition of magnetic stirring to finally prepare a tellurium-manganese-cadmium hydrothermal reaction precursor suspension; transferring the obtained precursor suspension into a hydrothermal reaction kettle, carrying out hydrothermal reaction at 120 ℃ for 24 hours, and carrying out accelerated cooling on the reaction kettle to room temperature under the flow impact of normal-temperature water. And pouring out supernatant liquor, adding the product into a centrifuge tube, centrifuging for 5min, washing, sequentially washing for 2-3 times according to the sequence of water and absolute ethyl alcohol, and drying in a drying oven at 60 ℃ to obtain the tellurium-manganese-cadmium powder.

The sample of cadmium manganese telluride powder obtained is labeled as sample 1, as shown in fig. 1, 3, 4 and 5. Grinding the obtained powder, preparing a sample, and performing XRD detection, wherein the powder has a sphalerite structure and no impurity phase exists; and (3) carrying out scanning electron microscope detection on the sample, wherein the particle appearance is spherical or approximately spherical, the average grain size is about 40nm, and the observation shows that the dispersibility is better and the distribution is concentrated. Carrying out ultraviolet-visible absorption spectrum analysis on the sample, wherein the sample has stronger absorption in an ultraviolet region of 370 nm; and (3) carrying out photoluminescence spectrum analysis on the sample, wherein a strong and narrow luminescence band is formed in the range of 720-740 nm, and the quality of the sample is good.

Example 2:

according to the mol ratio of the cadmium source to the manganese source of 1:0.5, 0.2284g of cadmium chloride and 0.0990g of manganese chloride are weighed, 30ml of deionized water is added to prepare a mixed solution, and the mixed solution is magnetically stirred; weighing 0.0333g of sodium citrate according to the molar ratio of the cadmium source to the sodium citrate of 1:0.1, and adding the sodium citrate into the solution; then adding 10 drops of mercaptopropionic acid with the volume fraction of 98 percent to form suspension, and magnetically stirring for 10 min; according to the mol ratio of the cadmium source to the tellurite of 1:1.5, 0.3324g of sodium tellurite is weighed to be dissolved (dissolved amount) by deionized water, added under the condition of magnetic stirring, and the pH value is adjusted to be 14 by a pH regulator (4mol/L sodium hydroxide solution); weighing 0.6807g of sodium borohydride according to the molar ratio of the cadmium source to the sodium borohydride being 1:18, dissolving the sodium borohydride in ethanol, and adding the sodium borohydride under the condition of magnetic stirring to finally prepare a tellurium-manganese-cadmium hydrothermal reaction precursor suspension; transferring the obtained precursor suspension into a hydrothermal reaction kettle, carrying out hydrothermal reaction at 140 ℃ for 24 hours, and accelerating cooling the reaction kettle to room temperature under the flow impact of normal-temperature water. And pouring out supernatant liquor, adding the product into a centrifuge tube, centrifuging for 5min, washing, sequentially washing for 2-3 times according to the sequence of water and absolute ethyl alcohol, and drying in a drying oven at 60 ℃ to obtain the tellurium-manganese-cadmium powder.

The sample of the obtained tellurium-manganese-cadmium powder is marked as sample 2, and the test results are respectively shown in fig. 1, 3, 4 and 5. Grinding the obtained powder, preparing a sample, and performing XRD detection, wherein the powder has a sphalerite structure and no impurity phase exists; and (3) carrying out scanning electron microscope detection on the sample, wherein the particle appearance is spherical or approximately spherical, the average grain size is about 60nm, and the observation shows that the dispersibility is better and the distribution is concentrated. Carrying out ultraviolet-visible absorption spectrum analysis on the sample, wherein the sample has stronger absorption in an ultraviolet region of 370 nm; and (3) carrying out photoluminescence spectrum analysis on the sample, wherein a strong and narrow luminous band exists in the range of 720-740 nm, and the quality of the sample is better.

Example 3:

according to the mol ratio of the cadmium source to the manganese source of 1:0.5, 0.2204g of cadmium chloride and 0.0958g of manganese chloride are weighed, 30ml of deionized water is added to prepare a mixed solution, and the mixed solution is magnetically stirred; weighing 0.0293g of sodium citrate according to the molar ratio of the cadmium source to the sodium citrate of 1:0.1, and adding the sodium citrate into the solution; then adding 10 drops of mercaptopropionic acid with the volume fraction of 98 percent to form suspension, and magnetically stirring for 10 min; according to the mol ratio of the cadmium source to the tellurite of 1:1.5, 0.3212g of sodium tellurite is weighed to be dissolved (dissolved amount) by deionized water, added under the condition of magnetic stirring, and the pH value is adjusted to be 11 by a pH regulator (4mol/L sodium hydroxide solution); weighing 0.6569g of sodium borohydride according to the molar ratio of the cadmium source to the sodium borohydride being 1:18, dissolving the sodium borohydride in ethanol, and adding the sodium borohydride under the condition of magnetic stirring to finally prepare a tellurium-manganese-cadmium hydrothermal reaction precursor suspension; transferring the obtained precursor suspension into a hydrothermal reaction kettle, carrying out hydrothermal reaction at 180 ℃ for 24 hours, and carrying out accelerated cooling on the reaction kettle to room temperature under the flow impact of normal-temperature water. And pouring out supernatant liquor, adding the product into a centrifuge tube, centrifuging for 5min, washing, sequentially washing for 2-3 times according to the sequence of water and absolute ethyl alcohol, and drying in a drying oven at 60 ℃ to obtain the tellurium-manganese-cadmium powder.

The sample of the obtained tellurium-manganese-cadmium powder is marked as sample 3, and the test results are respectively shown in fig. 1, 3, 4 and 5. Grinding the obtained powder, preparing a sample, and performing XRD detection, wherein the powder has a sphalerite structure and no impurity phase exists; and (3) carrying out scanning electron microscope detection on the sample, wherein the particle appearance is spherical or approximately spherical, the average grain size is about 80nm, and the observation shows that the dispersibility is better and the distribution is concentrated. Carrying out ultraviolet-visible absorption spectrum analysis on the sample, wherein the sample has stronger absorption in an ultraviolet region of 370 nm; and (3) carrying out photoluminescence spectrum analysis on the sample, wherein a strong and narrow luminous band exists in the range of 720-740 nm, and the quality of the sample is better.

Example 4:

weighing 0.1523g of cadmium chloride and 0.0669g of manganese chloride according to the molar ratio of the cadmium source to the manganese source of 1:0.5, adding 30ml of deionized water to prepare a mixed solution, and magnetically stirring; weighing 0.1326g of sodium citrate according to the molar ratio of the cadmium source to the sodium citrate of 1:0.1, and adding the sodium citrate into the solution; then adding 10 drops of mercaptopropionic acid with the volume fraction of 98 percent to form suspension, and magnetically stirring for 10 min; weighing 0.2214g of sodium tellurite to be dissolved by deionized water (dissolving amount) according to the molar ratio of the cadmium source to the tellurite of 1:1.5, adding the sodium tellurite under the condition of magnetic stirring, and adjusting the pH value to be 11 by using a pH regulator (4mol/L sodium hydroxide solution); weighing 0.4536g of sodium borohydride according to the molar ratio of the cadmium source to the sodium borohydride being 1:18, dissolving the sodium borohydride in ethanol, adding the sodium borohydride under the condition of magnetic stirring, adjusting the pH value to 12, and finally preparing a precursor suspension of the tellurium-manganese-cadmium hydrothermal reaction; transferring the obtained precursor suspension into a hydrothermal reaction kettle, carrying out hydrothermal reaction at 160 ℃ for 24 hours, and carrying out accelerated cooling on the reaction kettle to room temperature under the flow impact of normal-temperature water. And pouring out supernatant liquor, adding the product into a centrifuge tube, centrifuging for 5min, washing, sequentially washing for 2-3 times according to the sequence of water and absolute ethyl alcohol, and drying in a drying oven at 60 ℃ to obtain the tellurium-manganese-cadmium powder.

The sample of the obtained tellurium-manganese-cadmium powder is marked as sample4, and the test results are respectively shown in fig. 1, 3, 4 and 5. Grinding the obtained powder, preparing a sample, and performing XRD detection, wherein the powder has a sphalerite structure and no impurity phase exists; and (3) carrying out scanning electron microscope detection on the sample, wherein the particle appearance is spherical or approximately spherical, the average grain size is about 90nm, and the observation shows that the dispersibility is better and the distribution is concentrated. Carrying out ultraviolet-visible absorption spectrum analysis on the sample, wherein the sample has stronger absorption in an ultraviolet region of 370 nm; and (3) carrying out photoluminescence spectrum analysis on the sample, wherein a strong and narrow luminous band exists in the range of 720-740 nm, and the quality of the sample is better.

The results, taken together with figures 1, 3, 4 and 5, show that sample4 is relatively good, XRD shows the best crystalline quality, the strongest diffraction peak and the strongest luminescence in the uv-visible and photoluminescence spectra.

Example 5:

according to the mol ratio of the cadmium source to the manganese source of 1:0.5, 0.4568g of cadmium chloride and 0.1980g of manganese chloride are weighed, 30ml of deionized water is added to prepare a mixed solution, and the mixed solution is magnetically stirred; according to the mol ratio of the cadmium source to the tellurite of 1:1.5, 0.6645g of sodium tellurite is weighed to be dissolved (dissolved amount) by deionized water, added under the condition of magnetic stirring, and the pH value is adjusted to be 14 by a pH regulator (4mol/L sodium hydroxide solution); weighing 1.3617g of sodium borohydride according to the molar ratio of the cadmium source to the sodium borohydride being 1:18, dissolving the sodium borohydride in ethanol, and adding the sodium borohydride under the condition of magnetic stirring to finally prepare a tellurium-manganese-cadmium hydrothermal reaction precursor suspension; transferring the obtained precursor suspension into a hydrothermal reaction kettle, carrying out hydrothermal reaction at 120 ℃ for 24 hours, and carrying out accelerated cooling on the reaction kettle to room temperature under the flow impact of normal-temperature water. And pouring out supernatant liquor, adding the product into a centrifuge tube, centrifuging for 5min, washing, sequentially washing with absolute ethyl alcohol and water for 2-3 times, and drying in a drying oven at 60 ℃ to obtain the tellurium-manganese-cadmium powder.

The sample of the obtained tellurium-manganese-cadmium powder is marked as sample 0. Grinding the obtained powder, preparing sample, and performing XRD detection, wherein the powder has sphalerite structure and mixed phase Mn (OH) as shown in figure 1₂And Te. FIG. 2EDS energy spectrum test shows that the powder contains oxygen element and hetero-phase Mn (OH)₂The oxygen-containing elements are consistent. Example 5 was identical to the synthesis conditions of example 1, except that sodium citrate and mercaptopropionic acid were not added as reducing and protecting agents during the synthesis of example 5, resulting in the presence of a heterogeneous phase in the product.

In examples 1 to 4, when the pH at the time of forming the precursor was less than 10, the crystallinity was poor or the sphalerite tellurium-manganese-cadmium powder could not be formed. If the hydrothermal reaction temperature is lower than 120 ℃, the zinc blende tellurium, manganese and cadmium powder with good crystallinity cannot be obtained. The washing process is carried out according to the sequence of water and absolute ethyl alcohol, otherwise, other substances are remained, and pure-phase tellurium-manganese-cadmium powder cannot be obtained.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.