A tellurium / carbon diselenide composite material, a preparation method and application thereof

Abstract

The application belongs to the technical field of new energy materials, and particularly relates to a tellurium / carbon diselenide composite material and a preparation method and application thereof. The tellurium / carbon diselenide composite material comprises reduced graphene oxide and tellurium / carbon diselenide nanorods embedded in the reduced graphene oxide; the tellurium / carbon diselenide nanorod is in a core-shell structure, the shell of the core-shell structure is carbon diselenide, and the core of the core-shell structure is tellurium. The tellurium / carbon diselenide nanorod is embedded in the reduced graphene oxide, so that the tellurium / carbon diselenide nanorod is not prone to aggregation and is uniformly dispersed. The one-dimensional structure of the tellurium / carbon diselenide nanorod can shorten the path of electron transmission, has an efficient channel for electron transmission, has a larger specific surface area, can obtain more active sites, and improves the catalytic and adsorption performance. Meanwhile, the core-shell structure combines selenium and tellurium materials and has high flexibility. In addition, the preparation process is simple, does not need high temperature and high pressure, has low cost, and is conducive to large-scale production and application.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of new energy materials, and particularly relates to a tellurium / carbon diselenide composite material and a preparation method and application thereof. BACKGROUND

[0002] Carbon diselenide (CSe2) is the only common selenium-carbon compound at present, which is a yellow liquid with a pungent odor at normal temperature and pressure. Liquid CSe2 can form a black highly disordered solid carbon diselenide polymer (CSe2)x under the conditions of 0.5 GPa and 100 DEG C or under low-temperature conditions for a long time. Solid carbon diselenide is a semiconductor material with a band gap width of about 2 eV, and has good electrical conductivity, adsorption and catalytic properties, and good application potential in the fields of photoelectricity and sensing.

[0003] At present, the preparation of carbon diselenide and its composite materials usually needs to be carried out under high temperature and high pressure. Some studies have obtained hexagonal carbon selenium compounds by mixing graphite powder or diamond powder with selenium powder and ball milling under high temperature (1800-2300 DEG C) and high pressure (9.6-12.5 GPa). Some studies have prepared carbon diselenide nanofilm modified conductive carbon cloth (CSe2NF / CC) composite materials by using a hydrothermal method, which is to uniformly stir the conductive carbon cloth and Se powder in a hydrazine hydrate solution, then react in a Teflon-lined stainless steel autoclave at a temperature of 180 DEG C for 8 h, and finally wash and dry to obtain the final product. The preparation method under high temperature and high pressure has high energy consumption and high cost, which is not conducive to large-scale popularization and application. In addition, the content of carbon diselenide in the synthesized composite material is low, the content of carbon diselenide in the carbon diselenide composite material is not higher than 10%, and the tellurium / carbon diselenide nanorods are prone to aggregation and uneven distribution, so that the utilization rate of Te and CSe2 in practical application is low.

[0004] Therefore, it is urgent to provide a composite material with high carbon diselenide content, high Te and CSe2 utilization rate, and simple preparation process, mild process conditions and low cost. SUMMARY

[0005] The present application aims to solve one or more technical problems in the prior art, and at least provide a beneficial choice or create conditions. The present application provides a tellurium / carbon diselenide composite material with high carbon diselenide content, high Te and CSe2 utilization rate, and simple preparation process, mild process conditions and low cost.

[0006] The inventive concept of the present application: in the prepared tellurium / carbon diselenide composite material, the tellurium / carbon diselenide nanorods are embedded in the reduced graphene oxide, so that the tellurium / carbon diselenide nanorods are not easy to agglomerate and are uniformly dispersed. In addition, the nanomaterials such as the tellurium / carbon diselenide nanorods have a unique morphology, so that the path of electron transmission can be shortened in the radial direction, and a high-efficiency channel for electron transmission is provided in the axial direction. In addition, the specific surface area is large, and more active sites can be obtained, so that the catalytic and adsorption properties are improved. At the same time, the tellurium / carbon diselenide nanorod has a core-shell structure, the shell is carbon diselenide, and the core is tellurium. The core-shell structure combines two materials of selenium and tellurium with complementary properties, so that the limitations of a certain material can be partially or completely eliminated, and better energy storage capacity than a single material structure can be obtained, and high flexibility is provided.

[0007] Therefore, the first aspect of the present application provides a tellurium / carbon diselenide composite material.

[0008] Specifically, a tellurium / carbon diselenide composite material comprises reduced graphene oxide and tellurium / carbon diselenide nanorods embedded in the reduced graphene oxide; the tellurium / carbon diselenide nanorod has a core-shell structure, the shell of the core-shell structure is carbon diselenide, and the core of the core-shell structure is tellurium.

[0009] Preferably, in the composite material, the mass ratio of the tellurium, carbon diselenide and reduced graphene oxide is (2.7-3.3):(3.5-4.5):3.

[0010] Further preferably, in the composite material, the mass ratio of the tellurium, carbon diselenide and reduced graphene oxide is 3:4:3.

[0011] Preferably, the length of the tellurium / carbon diselenide nanorod is 35-110 nm; the diameter of the tellurium / carbon diselenide nanorod is 10-40 nm.

[0012] Further preferably, the length of the tellurium / carbon diselenide nanorod is 40-100 nm; the diameter of the tellurium / carbon diselenide nanorod is 12-35 nm.

[0013] Preferably, the diameter of the core is 5-15 nm; the thickness of the shell is 5-25 nm.

[0014] Further preferably, the diameter of the core is 5-12 nm; the thickness of the shell is 7-23 nm.

[0015] The second aspect of the present application provides a preparation method of the tellurium / carbon diselenide composite material according to the first aspect of the present application.

[0016] Specifically, the preparation method of the tellurium / carbon diselenide composite material comprises the following steps:

[0017] The surfactant, graphene oxide, tellurium hydride, and selenium hydride are mixed and reacted to prepare the tellurium / carbon diselenide composite material.

[0018] Preferably, the method for preparing the tellurium / carbon diselenide composite material specifically comprises the following steps:

[0019] The mixed solution of the tellurium hydride and selenium hydride is added to the mixed solution containing the surfactant and graphene oxide, and reacted to prepare the tellurium / carbon diselenide composite material.

[0020] Preferably, in the mixed solution of the tellurium hydride and selenium hydride, the molar ratio of the tellurium hydride to selenium hydride is 0.9-1.1:1.8-2.2.

[0021] Further preferably, in the mixed solution of the tellurium hydride and selenium hydride, the molar ratio of the tellurium hydride to selenium hydride is 1:2.

[0022] Preferably, the tellurium hydride comprises sodium telluride; and the selenium hydride comprises sodium selenide.

[0023] Preferably, the method for preparing the mixed solution of sodium telluride and sodium selenide specifically comprises the following steps:

[0024] The sodium borohydride, tellurium powder, and selenium powder are mixed in a solvent to obtain the mixed solution of sodium telluride and sodium selenide.

[0025] Preferably, the molar ratio of the sodium borohydride, tellurium powder, and selenium powder is 27:6-8:4-6.

[0026] Further preferably, the molar ratio of the sodium borohydride, tellurium powder, and selenium powder is 27:8:4.

[0027] Preferably, the solvent is water; further preferably, the solvent is deionized water.

[0028] Preferably, the sodium borohydride, tellurium powder, and selenium powder are mixed in the solvent and then reacted in a reaction bottle.

[0029] Specifically, the reaction bottle is sealed with a rubber stopper, and a stainless steel needle is inserted into the top end of the rubber stopper to ensure that H2 generated in the reaction is discharged in time.

[0030] Preferably, the reaction of the sodium borohydride, tellurium powder, and selenium powder is carried out in an ice water bath.

[0031] Preferably, the temperature of the reaction is 0-10°C; further preferably, the temperature of the reaction is 0-5°C.

[0032] Preferably, the reaction time is 7.5-8.5h; further preferably, the reaction time is 8h.

[0033] Preferably, magnetic stirring is used in the reaction process to make the reaction proceed uniformly and slowly.

[0034] Specifically, a white sodium tetra-boride precipitate is produced after the reaction, and the supernatant is a mixed solution of sodium telluride and sodium selenide.

[0035] Preferably, the stainless steel needle at the top of the rubber plug is pulled out, and the supernatant is a mixed solution of sodium telluride and sodium selenide.

[0036] Preferably, the preparation method of the mixed solution containing the surfactant and the graphene oxide specifically includes the following steps:

[0037] The aqueous solution of graphene oxide and the surfactant are mixed in a solvent to prepare a mixed solution containing the surfactant and the graphene oxide.

[0038] Preferably, the mass ratio of the graphene oxide to the surfactant is 1:300-1100.

[0039] Further preferably, the mass ratio of the graphene oxide to the surfactant is 1:337.5-1012.5.

[0040] Preferably, the amount ratio of the surfactant to the solvent is 280-1350mg:40mL.

[0041] Further preferably, the amount ratio of the surfactant to the solvent is 310-1240mg:40mL.

[0042] Preferably, the surfactant is polyvinylpyrrolidone (PVP).

[0043] Preferably, the solvent is water; further preferably, the solvent is deionized water.

[0044] Preferably, the mixed solution of the telluride and the selenide is quickly added to the mixed solution containing the surfactant and the graphene oxide under the action of intense magnetic stirring.

[0045] Preferably, the rotation speed of the magnetic stirring is 700-1300r / min; further preferably, the rotation speed of the magnetic stirring is 800-1200r / min; more preferably, the rotation speed of the magnetic stirring is 1000r / min.

[0046] Preferably, the amount ratio of the graphene oxide and the mixed solution of tellurium hydride, selenium hydride is 0.7-0.9mg:0.18-0.45mL.

[0047] Further preferably, the amount ratio of the graphene oxide and the mixed solution of tellurium hydride, selenium hydride is 0.8mg:0.2-0.4mL.

[0048] Preferably, the reaction for preparing the tellurium / carbon diselenide composite material is carried out under a protective atmosphere.

[0049] Preferably, the protective atmosphere is argon.

[0050] Specifically, a water pump is used to replace the atmosphere in the three-necked flask with argon, and a rubber plug is used to seal to avoid oxygen from entering.

[0051] Preferably, the reaction is carried out after the mixed solution of tellurium hydride, selenium hydride is added into the mixed solution containing the surfactant and graphene oxide.

[0052] Preferably, the reaction is carried out in a water bath.

[0053] Preferably, the temperature of the reaction is 35-65℃, and the time of the reaction is 3-24h.

[0054] Further preferably, the temperature of the reaction is 40-60℃, and the time of the reaction is 4-12h.

[0055] More preferably, the temperature of the reaction is 50℃, and the time of the reaction is 6h.

[0056] Preferably, the reaction further includes the processes of centrifugation, washing and freeze-drying of the solution after the reaction.

[0057] Preferably, the speed of centrifugation is 5500-11000rpm, and the time of centrifugation is 4-6min.

[0058] Further preferably, the speed of centrifugation is 6000-10000rpm, and the time of centrifugation is 4.5-5.5min.

[0059] Preferably, deionized water is used for washing.

[0060] Preferably, the temperature of freeze-drying is -45~-30℃, and the time of freeze-drying is 22-26h.

[0061] Further preferably, the temperature of freeze-drying is -40~-35℃, and the time of freeze-drying is 23-25h.

[0062] Specifically, the tellurium / carbon diselenide composite material can be prepared by a solution method at a temperature of 40-60 DEG C, and the process is simple, the reaction condition is mild, and the cost is low.

[0063] The third aspect of the present application provides application of the tellurium / carbon diselenide composite material in the first aspect of the present application in the field of photoelectricity and sensing.

[0064] Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects:

[0065] (1) In the composite material, the tellurium / carbon diselenide nanorod is embedded in the reduced graphene oxide, so that the tellurium / carbon diselenide nanorod is not easy to agglomerate and is uniformly dispersed. In addition, the one-dimensional nano material has a unique morphology, so that the path of electron transmission can be shortened in the radial direction, and an efficient channel for electron transmission is provided in the axial direction; and the specific surface area is large, so that more active sites can be obtained, thereby improving the catalytic and adsorption properties.

[0066] (2) The tellurium / carbon diselenide nanorod has a core-shell structure, the shell is carbon diselenide, and the core is tellurium; the core-shell structure combines two materials of selenium and tellurium with complementary properties, so that the limitations of a certain material can be partially or completely eliminated, and better energy storage capacity than a single material structure can be obtained, and high flexibility is provided.

[0067] (3) The preparation process is simple, and high-temperature and high-pressure process conditions are not required; the tellurium / carbon diselenide composite material can be prepared by a one-step solution method at a temperature of 40-60 DEG C, the cost is low, mass production and application are facilitated, and good economic benefits are provided. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 The XRD graph of the Te@CSe2NRs / rGO composite material prepared in Example 1 of the present application is shown in the figure;

[0069] Figure 2 The TEM graph of the Te@CSe2NRs / rGO composite material prepared in Example 1 of the present application is shown in the figure;

[0070] Figure 3 The HRTEM graph of the Te@CSe2NRs / rGO composite material prepared in Example 1 of the present application is shown in the figure. DETAILED DESCRIPTION

[0071] In order to make those skilled in the art more clearly understand the technical scheme of the present application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0072] The raw materials, reagents or devices used in the following examples, if not specifically stated, can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0073] Example 1

[0074] A preparation method of a Te@CSe2NRs / rGO composite material, comprising the following steps:

[0075] (1) 0.34 g of NaBH4 was dissolved in 6 mL of deionized water, 0.17 g of Te powder and 0.21 g of Se powder were quickly added, and the reaction bottle was sealed with a rubber plug, a stainless steel needle was inserted at the top of the rubber plug to ensure that the generated H2 was discharged in time; during the reaction, the reaction bottle was cooled in an ice water bath and magnetically stirred to make the reaction uniform and slow; after 8 h of reaction, the black Te powder and Se powder disappeared, and white sodium tetraborate precipitate was generated; the stainless steel needle was pulled out, and the supernatant was taken after standing to obtain a mixed solution of NaHTe and NaHSe (NaHTe: 0.22 mol / L, NaHS: 0.44 mol / L);

[0076] (2) 310 mg of PVP and 0.4 mL of graphene oxide (GO) aqueous solution (2 g / L) were completely dispersed in 40 mL of deionized water to obtain a mixed solution containing PVP and GO;

[0077] (3) The atmosphere in the three-necked reaction flask was replaced with argon using a water pump, and the rubber plug was sealed to prevent oxygen from entering; then, 0.3 mL of the mixed solution of NaHTe and NaHSe prepared in step (1) was quickly injected into the mixed solution containing PVP and GO prepared in step (2) through a syringe under vigorous magnetic stirring; the three-necked reaction flask was placed in a water bath at 50°C, and NaHTe and NaHSe were allowed to react with GO; after 6 h of reaction, centrifugation was performed at a speed of 10000 rpm for 5 min, and the product was washed with deionized water three times, and then freeze-dried for 24 h to obtain the Te@CSe2NRs / rGO composite material.

[0078] Example 2

[0079] A preparation method of a Te@CSe2NRs / rGO composite material, comprising the following steps:

[0080] (1) The preparation process of the mixed solution of NaHTe and NaHSe is the same as that of Example 1;

[0081] (2) 620 mg of PVP and 0.4 mL of GO aqueous solution (2 g / L) were completely dispersed in 40 mL of deionized water to obtain a mixed solution containing PVP and GO;

[0082] (3) using a water pump to replace the atmosphere in the three-necked reaction flask with argon and seal it with a rubber plug to avoid oxygen entering; then, under vigorous magnetic stirring, inject 0.3 mL of the NaHTe and NaHSe mixed solution prepared in step (1) into the mixed solution containing PVP and GO prepared in step (2) through a syringe; place the three-necked reaction flask in a water bath at 50°C to allow NaHTe and NaHSe to fully react with GO, centrifuge at 10,000 rpm for 5 min after 6 h of reaction, wash three times with deionized water, and then freeze-dry for 24 h to prepare the Te@CSe2NRs / rGO composite material.

[0083] Example 3

[0084] A method for preparing a Te@CSe2NRs / rGO composite material, comprising the following steps:

[0085] (1) The preparation process of the NaHTe and NaHSe mixed solution is the same as that in Example 1;

[0086] (2) Disperse 1240 mg of PVP and 0.4 mL of a GO aqueous solution (2 g / L) completely in 40 mL of deionized water to obtain a mixed solution containing PVP and GO;

[0087] (3) using a water pump to replace the atmosphere in the three-necked reaction flask with argon and seal it with a rubber plug to avoid oxygen entering; then, under vigorous magnetic stirring, inject 0.3 mL of the NaHTe and NaHSe mixed solution prepared in step (1) into the mixed solution containing PVP and GO prepared in step (2) through a syringe; place the three-necked reaction flask in a water bath at 50°C to allow NaHTe and NaHSe to fully react with GO, centrifuge at 10,000 rpm for 5 min after 6 h of reaction, wash three times with deionized water, and then freeze-dry for 24 h to prepare the Te@CSe2NRs / rGO composite material.

[0088] Example 4

[0089] A method for preparing a Te@CSe2NRs / rGO composite material, comprising the following steps:

[0090] (1) The preparation process of the NaHTe and NaHSe mixed solution is the same as that in Example 1;

[0091] (2) Disperse 620 mg of PVP and 0.4 mL of a GO aqueous solution (2 g / L) completely in 40 mL of deionized water to obtain a mixed solution containing PVP and GO;

[0092] (3) The atmosphere in the three-necked flask was replaced with argon using a water pump, and a rubber plug was used to seal the three-necked flask to prevent oxygen from entering. Then, 0.4 mL of the mixed solution of NaHTe and NaHSe prepared in step (1) was quickly injected into the mixed solution containing PVP and GO prepared in step (2) through a syringe under vigorous magnetic stirring. The three-necked flask was placed in a water bath at 50°C, and NaHTe and NaHSe were allowed to fully react with GO. After 6 h of reaction, centrifugation was performed at a speed of 10,000 rpm for 5 min, and the product was washed with deionized water three times, and then freeze-dried for 24 h to obtain the Te@CSe2NRs / rGO composite material.

[0093] Example 5

[0094] A method for preparing a Te@CSe2NRs / rGO composite material, comprising the following steps:

[0095] (1) The preparation process of the mixed solution of NaHTe and NaHSe is the same as that in Example 1.

[0096] (2) 620 mg of PVP and 0.4 mL of a GO aqueous solution (2 g / L) were completely dispersed in 40 mL of deionized water to obtain a mixed solution containing PVP and GO.

[0097] (3) The atmosphere in the three-necked flask was replaced with argon using a water pump, and a rubber plug was used to seal the three-necked flask to prevent oxygen from entering. Then, 0.4 mL of the mixed solution of NaHTe and NaHSe prepared in step (1) was quickly injected into the mixed solution containing PVP and GO prepared in step (2) through a syringe under vigorous magnetic stirring. The three-necked flask was placed in a water bath at 50°C, and NaHTe and NaHSe were allowed to fully react with GO. After 6 h of reaction, centrifugation was performed at a speed of 10,000 rpm for 5 min, and the product was washed with deionized water three times, and then freeze-dried for 24 h to obtain the Te@CSe2NRs / rGO composite material.

[0098] Performance test

[0099] 1. XRD test

[0100] The Te@CSe2NRs / rGO composite material prepared in Example 1 was subjected to XRD test, and the results are shown in FIG. 1, wherein the abscissa 2Theta (Degree) represents the diffraction angle 2θ (°), and the ordinate Intensity represents the diffraction intensity. Figure 1

[0101] As shown in FIG. 1, the diffraction peaks of the Te@CSe2NRs / rGO composite material prepared in Example 1 are consistent with the standard card of Te@CSe2NRs / rGO composite material (PDF card No. 00-001- 1191), which indicates that the Te@CSe2NRs / rGO composite material is successfully prepared. Figure 1 ​It can be seen that the XRD curve of the composite material is completely consistent with the characteristic peak of carbon diselenide (JCPDS card number 39-0753), and the peak at 27-28° corresponds to the Te element, indicating that a Te and CSe2 material with good crystallinity has been synthesized.

[0102] 2. TEM test

[0103] The Te@CSe2NRs / rGO composite material prepared in Example 1 was subjected to TEM testing, and the results are as follows: Figure 2 As shown. By Figure 2 It can be seen that Te and CSe2 in the composite material are nanorod structures and are uniformly distributed without agglomeration. The diameter of the nanorods is 13-17 nm and the length of the nanorods is 40-56 nm.

[0104] 3. HRTEM test

[0105] The Te@CSe2NRs / rGO composite material prepared in Example 1 was subjected to HRTEM testing, and the results are as follows: Figure 3 As shown. From the Te@CSe2NRs nanorods indicated by the arrow, we can see that there are obvious lattice stripes in the middle, which correspond to Te, while the part of the nanorod that does not show obvious lattice corresponds to CSe2 that has been destroyed by high electron energy; other nanorods show Te@CSe2 nanorods that are completely encapsulated by Te, that is, the tellurium / carbon diselenide nanorods have a core-shell structure, with Te and CSe2 being the core and shell, respectively, and the nanorods are uniformly embedded in rGO.

[0106] 4. Determination of carbon diselenide content

[0107] The carbon diselenide content of the Te@CSe2NRs / rGO composite material prepared in Example 1 was determined by thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS). The carbon diselenide content in the Te@CSe2NRs / rGO composite material of Example 1 was 40%.

[0108] In summary, the application provides a Te@CSe2NRs / rGO composite material, adopts PVP as a surfactant, GO as a base material and oxidant for synthesizing the composite material, and a mixed aqueous solution of NaHTe and NaHSe as source materials of Te and CSe2, to synthesize Te and CSe2 nanorods with small size and uniform embedding in rGO, to avoid the agglomeration and uneven dispersion of the nanorods, to be conducive to improving the utilization rate of Te and CSe2 materials in practical application, and to have a high content of carbon diselenide in the composite material, which can reach 40%. In addition, the application uses a one-step solution method to prepare the composite material under the temperature condition of 40-60 DEG C, has a simple preparation process, does not need a high-temperature and high-pressure process, has low energy consumption, and takes less time, solves the defects that the current synthesis methods of carbon diselenide and its composite material generally involve a high-cost process of high temperature and high pressure or the content of carbon diselenide in the composite material is low, and is conducive to large-scale production and application.

[0109] The above examples are only used to illustrate the technical solutions of the application and not to limit the protection scope of the application. Although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced equivalently without departing from the essence and scope of the technical solutions of the application.

Claims

1. A composite material, characterized in that, It includes reduced graphene oxide and tellurium / carbon diselenide nanorods embedded in the reduced graphene oxide; the tellurium / carbon diselenide nanorods have a core-shell structure, the shell of the core-shell structure is carbon diselenide, and the core of the core-shell structure is tellurium; The tellurium / carbon diselenide nanorods have a length of 35-110 nm and a diameter of 10-40 nm. The diameter of the core is 5-15 nm; the thickness of the shell is 5-25 nm.

2. The composite material according to claim 1, characterized in that, In the composite material, the mass ratio of tellurium, carbon diselenide, and reduced graphene oxide is (2.7-3.3):(3.5-4.5):

3.

3. The method for preparing the composite material according to any one of claims 1-2, characterized in that, Includes the following steps: The composite material is prepared by mixing surfactant, graphene oxide, telluride, and selenide and reacting them.

4. The preparation method according to claim 3, characterized in that, Includes the following steps: The mixed solution of the telluride and selenide is added to a mixed solution containing the surfactant and graphene oxide, and the reaction is carried out to obtain the composite material.

5. The preparation method according to claim 4, characterized in that, In the mixed solution of tellurium hydride and selenium hydride, the molar ratio of tellurium hydride to selenium hydride is 0.9-1.1:1.8-2.

2.

6. The preparation method according to claim 4, characterized in that, The mass ratio of the graphene oxide to the surfactant is 1:300-1100; and / or the volume ratio of the graphene oxide to the mixed solution of the telluride and selenide is 0.7-0.9 mg:0.18-0.45 mL.

7. The preparation method according to claim 4, characterized in that, The reaction temperature is 35-65℃, and the reaction time is 3-24h.

8. The application of the composite material according to any one of claims 1-2 in the fields of optoelectronics and sensing.

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