Cuprous telluride and a method for producing the same

Abstract

The application belongs to the technical field of metal compounds, and discloses a preparation method of cuprous telluride, which comprises the following steps: step 1: elemental tellurium and elemental copper are respectively divided into 2-10 parts, and one part of tellurium and one part of copper are alternately loaded into a crucible; step 2: the crucible is placed in a high-temperature atmosphere furnace, inert gas is filled to make the pressure in the furnace rise to 0.5-1.0 MPa; step 3: the temperature is raised to 800-1000 DEG C, and the temperature is kept for 2-4 hours, then the temperature is raised to 1200-1400 DEG C, and the temperature is kept for 5-8 hours, and the cuprous telluride can be obtained after the reaction is completed and the temperature is cooled to room temperature. According to the application, the elemental tellurium is completely melted into tellurium liquid at 800-1000 DEG C, and the elemental copper is reacted with the outer surface of the tellurium liquid to form a cuprous telluride coating layer, then the temperature is raised to 1200-1400 DEG C, so that the cuprous telluride coating layer is melted, and the tellurium liquid and the melted copper liquid are reacted to form the cuprous telluride. Compared with the technical means of directly raising the temperature to 1200-1400 DEG C, the reaction time at 1200-1400 DEG C can be effectively reduced, so that the volatilization amount of tellurium is further reduced, and the purity of the prepared cuprous telluride is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal compounds, in particular to a cuprous telluride and a preparation method thereof. BACKGROUND

[0002] The cuprous telluride is a blue-black octahedral crystal, the relative density is 7.27 g / cm3, the melting point is about 900 DEG C, and is obtained by melting electrolytic copper and pure tellurium in a crucible covered with a protective layer of sodium chloride and potassium chloride. It is insoluble in hydrochloric acid and sulfuric acid, and soluble in bromine water.

[0003] The existing cuprous telluride is mainly produced by melting electrolytic copper and pure tellurium in a crucible covered with a protective layer of sodium chloride and potassium chloride. However, the cuprous telluride prepared by this method contains a large amount of chloride ions or potassium and sodium ions, which affects its purity and further affects its good performance.

[0004] Based on the above reasons, Chinese patent 201610838896.X discloses a method, which comprises the following steps: mixing elemental copper and elemental tellurium, and heating the mixture under vacuum conditions to obtain cuprous telluride.

[0005] The preparation method disclosed in the application uses fewer raw material components. After adding elemental copper and elemental tellurium, no additional raw materials are needed, and cuprous telluride can be prepared without high pressure. The cuprous telluride prepared by the method has high quality and high purity.

[0006] However, the method mixes elemental copper and elemental tellurium, and needs to be placed in a coated quartz tube under vacuum sealing, i.e. negative pressure, and then heated in a heating furnace to obtain cuprous telluride. The method is complex to operate, has high difficulty coefficient in coating and sealing, and has low yield. In addition, the method synthesizes under negative pressure, so that the raw materials are not uniformly mixed in the molten state, and the quality of the prepared product cannot be guaranteed.

[0007] Therefore, it is necessary to develop a cuprous telluride preparation method that is simpler, low in cost, high in purity, and high in yield. SUMMARY

[0008] One of the purposes of the present application is to provide a cuprous telluride preparation method to solve the problems of low yield, poor product quality and purity caused by the complexity and difficulty of the cuprous telluride preparation method in the prior art.

[0009] Another purpose of the present application is to provide a cuprous telluride prepared by the cuprous telluride preparation method provided by the present application, which has the advantages of high purity and good quality, can be effectively mass-produced, and the preparation cost is effectively controlled.

[0010] To achieve the above-mentioned purposes, the present application provides a cuprous telluride preparation method, which comprises the following steps:

[0011] Step 1: divide the elemental tellurium and the elemental copper into 2-10 portions respectively, and alternately put one portion of the elemental tellurium and one portion of the elemental copper into the crucible;

[0012] Step 2: put the crucible into a high-temperature atmosphere furnace, and fill in inert gas to make the pressure in the furnace reach 0.5-1.0 MPa;

[0013] Step 3: heat to 800-1000℃, and keep the temperature for 2-4 hours, then heat to 1200-1400℃ again, and keep the temperature for 5-8 hours, and then cool to room temperature to obtain the cuprous telluride.

[0014] Further, the molar ratio of the elemental tellurium and the elemental copper is 1.001-1.005:2.

[0015] Further preferably, the molar ratio of the elemental tellurium and the elemental copper can be selected from 1.001:2, 1.002:2, 1.003:2, 1.004:2 and 1.005:2.

[0016] Preferably, the inert gas is one of nitrogen, argon, neon, krypton, xenon and radon.

[0017] Preferably, the elemental tellurium is one of tellurium ingot, tellurium block and tellurium powder.

[0018] Preferably, the elemental copper is one of copper ingot, copper block and copper powder.

[0019] Further, the specific operation of Step 2 is as follows: put the crucible into a high-temperature atmosphere furnace, open the gas inlet valve and the gas outlet valve of the high-temperature atmosphere furnace, and pass in the inert gas at a flow rate of 5 L / min for 30-40 min, then close the gas outlet valve of the high-temperature atmosphere furnace to make the pressure in the furnace reach 0.5-1.0 MPa.

[0020] Further, the specific operation of Step 3 is as follows: heat to 800-1000℃ at a heating rate of 0.5-2℃ / min, keep the temperature for 2-4 hours, then heat to 1200-1400℃ at a heating rate of 5-10℃ / min, keep the temperature for 5-8 hours, and then cool to room temperature to obtain the cuprous telluride.

[0021] Preferably, the cooling rate of Step 3 is 2-4℃ / min.

[0022] The application further discloses a cuprous telluride prepared by the above preparation method.

[0023] Advantages

[0024] Compared with the prior art, the application has at least the following advantages:

[0025] (1) The application discloses a preparation method of cuprous telluride, and the boiling point of tellurium is improved by filling inert gas to improve the environmental pressure, so that the volatilization of tellurium is effectively reduced in the 1200-1400 DEG C holding reaction stage;

[0026] (2) The application ensures that the elemental tellurium is completely melted into tellurium liquid by holding at 800-1000 DEG C, and then reacts with the outer surface of elemental copper to generate a cuprous telluride coating layer, and then the temperature is increased to 1200-1400 DEG C to make the cuprous telluride coating layer melt, so that the tellurium liquid and the molten copper liquid react to generate all cuprous telluride, compared with the technical means of directly increasing the temperature to 1200-1400 DEG C, the holding reaction time at 1200-1400 DEG C can be effectively reduced, thereby further reducing the volatilization amount of tellurium, and ensuring the purity of the prepared cuprous telluride;

[0027] (3) The application adopts high temperature of 1200-1400 DEG C to perform the synthesis reaction of cuprous telluride, effectively avoiding the problem that when the reaction temperature is lower than 1140 DEG C, the cuprous telluride is generated to form a solid to coat the unreacted tellurium or copper, thereby hindering the reaction;

[0028] (4) The application adopts the molar ratio of elemental tellurium and elemental copper as 1.001-1.005:2, and adds a little excess tellurium, so as to make up for the volatilization of tellurium at high temperature of 1200-1400 DEG C, and avoid the problem that too much excess tellurium leads to the reduction of the purity of the finally obtained cuprous telluride. DETAILED DESCRIPTION

[0029] The application will be further described below in combination with examples, but does not constitute any limitation to the application, and any limited modification made within the scope of the claims of the application is still within the scope of the claims of the application.

[0030] In order to explain the technical content of the application in detail, the application will be further explained in combination with the embodiments.

[0031] In the following examples and comparative examples, the tellurium blocks and copper blocks all adopt tellurium blocks and copper blocks with purity of 99.999%.

[0032] Example 1

[0033] A cuprous telluride is prepared by the following steps:

[0034] Step 1: 10.01 mol of tellurium blocks and 20 mol of copper blocks are respectively divided into 10 parts, and one part of tellurium and one part of copper are alternately loaded into the crucible;

[0035] Step 2: Put the crucible into the high-temperature atmosphere furnace, open the gas inlet valve and the gas outlet valve of the high-temperature atmosphere furnace, and pass nitrogen at a flow rate of 5 L / min for 40 min, then stop passing nitrogen after the pressure in the furnace is increased to 0.5 MPa by closing the gas outlet valve of the high-temperature atmosphere furnace;

[0036] Step 3: Increase the temperature to 800℃ at a temperature increasing rate of 0.5℃ / min, and keep the temperature for 4 h, then increase the temperature to 1400℃ at a temperature increasing rate of 5℃ / min, and keep the temperature for 5 h, and then cool to room temperature at a cooling rate of 2℃ / min after the reaction is completed, to obtain cuprous telluride.

[0037] Example 2

[0038] A cuprous telluride is prepared by the following steps:

[0039] Step 1: Divide 10.05 mol of tellurium blocks and 20 mol of copper blocks into 8 parts respectively, and alternately put one part of tellurium and one part of copper into the crucible;

[0040] Step 2: Put the crucible into the high-temperature atmosphere furnace, open the gas inlet valve and the gas outlet valve of the high-temperature atmosphere furnace, and pass nitrogen at a flow rate of 5 L / min for 30 min, then stop passing nitrogen after the pressure in the furnace is increased to 1 MPa by closing the gas outlet valve of the high-temperature atmosphere furnace;

[0041] Step 3: Increase the temperature to 1000℃ at a temperature increasing rate of 2℃ / min, and keep the temperature for 2 h, then increase the temperature to 1200℃ at a temperature increasing rate of 10℃ / min, and keep the temperature for 8 h, and then cool to room temperature at a cooling rate of 4℃ / min after the reaction is completed, to obtain cuprous telluride.

[0042] Example 3

[0043] A cuprous telluride is prepared by the following steps:

[0044] Step 1: Divide 10.03 mol of tellurium blocks and 20 mol of copper blocks into 8 parts respectively, and alternately put one part of tellurium and one part of copper into the crucible;

[0045] Step 2: Put the crucible into the high-temperature atmosphere furnace, open the gas inlet valve and the gas outlet valve of the high-temperature atmosphere furnace, and pass nitrogen at a flow rate of 5 L / min for 30 min, then stop passing nitrogen after the pressure in the furnace is increased to 0.8 MPa by closing the gas outlet valve of the high-temperature atmosphere furnace;

[0046] Step 3: Increase the temperature to 900℃ at a temperature increasing rate of 1℃ / min, and keep the temperature for 3 h, then increase the temperature to 1300℃ at a temperature increasing rate of 8℃ / min, and keep the temperature for 6 h, and then cool to room temperature at a cooling rate of 3℃ / min after the reaction is completed, to obtain cuprous telluride.

[0047] Example 4

[0048] A cuprous telluride is prepared by the following steps:

[0049] Step 1: 10.05 mol of tellurium blocks and 20 mol of copper blocks are each divided into 5 portions, and one portion of tellurium and one portion of copper are alternately loaded into a crucible;

[0050] Step 2: The crucible is placed in a high-temperature atmosphere furnace, the gas inlet valve and the gas outlet valve of the high-temperature atmosphere furnace are opened, nitrogen is introduced at a flow rate of 5 L / min for 30 min, then the gas outlet valve of the high-temperature atmosphere furnace is closed to raise the pressure in the furnace to 1 MPa, and the introduction of nitrogen is stopped;

[0051] Step 3: The temperature is raised to 1000℃ at a rate of 1℃ / min, and then raised to 1400℃ at a rate of 8℃ / min, and kept for 5h, and then cooled to room temperature at a rate of 3℃ / min to obtain the cuprous telluride.

[0052] Example 5

[0053] Step 1: 10.02 mol of tellurium blocks and 20 mol of copper blocks are each divided into 2 portions, and one portion of tellurium and one portion of copper are alternately loaded into a crucible;

[0054] Step 2: The crucible is placed in a high-temperature atmosphere furnace, the gas inlet valve and the gas outlet valve of the high-temperature atmosphere furnace are opened, nitrogen is introduced at a flow rate of 5 L / min for 30 min, then the gas outlet valve of the high-temperature atmosphere furnace is closed to raise the pressure in the furnace to 0.8 MPa, and the introduction of nitrogen is stopped;

[0055] Step 3: The temperature is raised to 900℃ at a rate of 1℃ / min, and then raised to 1300℃ at a rate of 8℃ / min, and kept for 7h, and then cooled to room temperature at a rate of 3℃ / min to obtain the cuprous telluride.

[0056] Comparative Example 1

[0057] Generally the same as Example 5, except that the step 3 is changed to: the temperature is raised to 1300℃ at a rate of 8℃ / min, and kept for 10h, and then cooled to room temperature at a rate of 3℃ / min to obtain the cuprous telluride.

[0058] Comparative Example 2

[0059] Generally the same as Example 5, except that the step 3 is changed to: the temperature is raised to 1300℃ at a rate of 8℃ / min, and kept for 7h, and then cooled to room temperature at a rate of 3℃ / min to obtain the cuprous telluride.

[0060] Comparative Example 3

[0061] The procedure is substantially the same as Example 5, except that in Step 1, 10 mol of tellurium blocks and 20 mol of copper blocks are each divided into two portions, and one portion of tellurium and one portion of copper are alternately loaded into the crucible.

[0062] Comparative Example 4

[0063] The procedure is substantially the same as Example 5, except that in Step 1, 10.1 mol of tellurium blocks and 20 mol of copper blocks are each divided into two portions, and one portion of tellurium and one portion of copper are alternately loaded into the crucible.

[0064] The contents of tellurium and copper in the cuprous telluride obtained in Examples 1-5 and Comparative Examples 1-4 are detected by XRD, and the results are shown in Table 1.

[0065] Table 1: Contents of tellurium and copper in the cuprous telluride obtained in Examples 1-5 and Comparative Examples 1-4

[0066]

[0067]

[0068] According to the results in Table 1, it can be seen that:

[0069] According to the comparison of the results of Example 5 and Comparative Example 1, it can be seen that, by keeping the temperature at 800-1000 ℃, the elemental tellurium is completely melted into tellurium liquid, and at the same time, the elemental copper reacts with the outer surface of the elemental copper to form a cuprous telluride coating layer. Then, by increasing the temperature to 1200-1400 ℃, the cuprous telluride coating layer is melted, so that the tellurium liquid and the melted copper liquid react to form cuprous telluride. Compared with the technical means of directly increasing the temperature to 1200-1400 ℃, the reaction time at 1200-1400 ℃ can be effectively reduced, thereby further reducing the volatilization amount of tellurium and ensuring the purity of the prepared cuprous telluride. In Comparative Example 1, the volatilization amount of tellurium is relatively large, resulting in a large amount of unreacted copper in the obtained cuprous telluride. After cutting open the cuprous telluride product obtained in Comparative Example 1, a large number of yellow spots are found inside, which are unreacted copper.

[0070] In Comparative Example 2, the overall reaction time is relatively short, although there is not too much volatilization of tellurium, the contents of tellurium and copper in the obtained cuprous telluride product are still within the normal range. However, after cutting open the cuprous telluride product obtained in Comparative Example 2, a large number of yellow spots and patches are found inside, indicating that the reaction time is insufficient, and the tellurium and copper have not yet fully flowed and contacted to react to form cuprous telluride.

[0071] According to the comparison of the results of the embodiment 5 and the comparative example 3, the comparative example 4, a little excess tellurium is added in the present application, so as to make up the volatilization of tellurium at the high temperature holding stage of 1200-1400 ℃, and meanwhile avoid the problem that too much excess tellurium leads to the reduction of the purity of the finally obtained cuprous telluride.

[0072] The embodiments presented herein are merely examples selected according to a combination of all possible embodiments. The appended claims should not be limited by the embodiments described herein. Some numerical ranges include sub-ranges within them, and variations in these ranges should also be covered by the appended claims.

Claims

1. A method for producing cuprous telluride, characterized by, The method comprises the following steps: Step 1: divide the elemental tellurium and the elemental copper into 2-10 portions respectively, and alternately put one portion of the elemental tellurium and one portion of the elemental copper into a crucible; Step 2: put the crucible into a high-temperature atmosphere furnace, and fill inert gas to make the pressure in the furnace reach 0.5-1.0 MPa; Step 3: heat to 800-1000 DEG C, and keep the temperature for 2-4 h, then heat to 1200-1400 DEG C again, and keep the temperature for 5-8 h, and then cool to room temperature to obtain the cuprous telluride; The molar ratio of the elemental tellurium and the elemental copper is 1.001-1.005:

2.

2. The method for producing cuprous telluride according to claim 1, characterized by, The specific operation of the step 2 is as follows: put the crucible into the high-temperature atmosphere furnace, open the gas inlet valve and the gas outlet valve of the high-temperature atmosphere furnace, and then fill the inert gas at a flow rate of 5 L / min for 30-40 min, and then close the gas outlet valve to make the pressure in the furnace reach 0.5-1.0 MPa.

3. The method for preparing cuprous telluride according to claim 1, characterized in that, The specific operation of the step 3 is as follows: heat to 800-1000 DEG C at a heating rate of 0.5-2 DEG C / min, keep the temperature for 2-4 h, then heat to 1200-1400 DEG C at a heating rate of 5-10 DEG C / min, keep the temperature for 5-8 h, and then cool to room temperature to obtain the cuprous telluride.

4. The method of claim 3, wherein the cuprous telluride is prepared by the process of claim 1 or 2. The cooling rate of the step 3 is 2-4 DEG C / min.

5. A cuprous telluride characterized by, The cuprous telluride is prepared by the method according to any one of claims 1-4.

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