Preparation method of selenium / tellurium-doped copper-nickel nanowires

Abstract

The present invention discloses a preparation method of selenium / tellurium-doped copper-nickel nanowires. The preparation method comprises the following steps: 1) placing a copper precursor, a nickel precursor and a surfactant in an organic solvent, and stirring in an inert gas atmosphere and at an appropriate temperature until the solution is uniformly mixed; 2) maintaining stirring, raising the temperature to a first reaction temperature and heating for a period of time; 3) continuously stirring the solution, raising the temperature again to a second reaction temperature and heating for a period of time; 4) dissolving a certain amount of selenium / tellurium powder in oleylamine, and performing ultrasonic dispersion to obtain a selenium / tellurium powder solution for standby; 5) after the reactor is cooled, adding the selenium / tellurium powder solution, maintaining stirring under an inert atmosphere and raising the temperature again to a third reaction temperature and heating for a period of time; 6) after the reactor is cooled, washing the product multiple times and then centrifuging, and performing vacuum drying to obtain a selenium / tellurium-doped copper-nickel nanowire catalyst. The CuNiSe nanowire catalyst is uniformly distributed and has a regular morphology, and the diameter of the nanowires is 30-60 nanometers.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst synthesis, and particularly relates to a preparation method of selenium / tellurium-doped copper-nickel nanowires. Background Art

[0002] With the progress of technology and the consumption of fossil fuels, it is urgent for humans to find a more sustainable energy source. Hydrogen production by electrolysis of water provides a new direction for the development of sustainable energy due to its high efficiency, no consumption of fossil energy, and high product purity. In recent years, noble metals represented by platinum have shown excellent performance as catalytic materials in the hydrogen evolution reaction of electrolysis of water. However, high cost and low reserves are the main obstacles restricting the large-scale application of this technology. Therefore, how to develop non-noble metal catalysts with high hydrogen production efficiency and low price has become a research hotspot in the catalytic field.

[0003] Currently, copper-nickel-based non-noble metal catalysts have been widely concerned due to their high conductivity and low cost. For example, Patent No. Publication No. CN113913859A discloses a cobalt-doped copper-nickel-based alloy catalyst for hydrogen evolution reaction, which has good electrocatalytic performance. Similarly, Chinese Patent Publication No. CN114420956A discloses a carbon-doped copper-nickel-based alloy catalyst for anodic electrocatalysis of direct methanol fuel cells. The above works are all reports on changing the types of doped elements in copper-nickel-based alloys, but there are few reports on the preparation strategy of selenium / tellurium-doped copper-nickel-based nanowire catalysts. Therefore, there is an urgent need to develop a simple and general method to synthesize selenium / tellurium-doped copper-nickel-based nanowire catalysts. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preparation method of selenium / tellurium-doped copper-nickel nanowires; by changing the addition amount of selenium / tellurium powder, the composition of selenium-doped copper-nickel-based nanowires can be precisely regulated, and a CuNiSe nanowire catalyst with uniform distribution and neat morphology can be prepared, and the diameter of the nanowires is 30-60 nanometers.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A preparation method of a selenium / tellurium-doped copper-nickel-based nanowire catalyst, comprising the following steps:

[0007] 1) Place a copper precursor, a nickel precursor, and a surfactant in an organic solvent, and stir in an inert gas atmosphere at an appropriate temperature until the solution is uniformly mixed;

[0008] 2) Keep stirring, raise the temperature to the first reaction temperature and heat for a period of time;

[0009] 3) The solution is continuously stirred, and the temperature is raised again to the second reaction temperature and heated for a period of time;

[0010] 4) Take a certain amount of selenium / tellurium powder and dissolve it in oleylamine, and disperse it by ultrasonic treatment to obtain a selenium / tellurium powder solution for standby;

[0011] 5) After the reactor is cooled, slowly add the selenium / tellurium powder solution, keep stirring under an inert atmosphere, raise the temperature again to the third reaction temperature and heat for a period of time;

[0012] 6) After the reactor is cooled, wash the product multiple times and then centrifuge it, and dry it under vacuum to obtain a selenium / tellurium-doped copper-nickel nanowire catalyst.

[0013] As a further improvement of the technical solution, in step 1), the copper precursor is copper acetylacetonate, the nickel precursor is nickel chloride hexahydrate, and the surfactant is dimethyldioctadecylammonium chloride; the molar ratio of the copper precursor, the nickel precursor and the surfactant is 1-2:1:1-1.5.

[0014] Preferably, in step 1), the organic solvent is oleylamine, and the ratio of the amount of the copper precursor to the organic solvent is 0.8 mmol / 8-10 mL.

[0015] Preferably, in step 1), the inert gas is nitrogen or argon.

[0016] Preferably, in step 1), the appropriate temperature is 60-90 °C, and the stirring time is 30-90 min.

[0017] As a further improvement of the technical solution, in step 2), the first reaction temperature is 170-190 °C, and the period of time is 200-300 min.

[0018] As a further improvement of the technical solution, in step 3), the second reaction temperature is 200-250 °C, and the period of time is 60-100 min.

[0019] As a further improvement of the technical solution, in step 4), the mass concentration of the selenium / tellurium powder solution is 2-5 g / L.

[0020] Preferably, in step 4), the conditions for ultrasonic dispersion are: ultrasonic treatment for 1-5 min at 40%-80% of 400 W power.

[0021] As a further improvement of the technical solution, in step 5), the temperature is reduced to 30-70 °C, the third reaction temperature is 70-110 °C, and the period of time is 60-90 min.

[0022] Preferably, in step 5), the inert atmosphere is nitrogen or argon.

[0023] As a further improvement of the technical solution, in step 6), the washing solvent is ethanol or n-hexane.

[0024] Preferably, in step 6), the rotation speed of the centrifugation is 5000 - 9000 r, and the time is 5 - 10 min.

[0025] Preferably, in step 6), the temperature of the vacuum drying is 40 - 110 °C, and the time is 8 - 24 h.

[0026] Preferably, in step 6), the vacuum degree of the vacuum drying is 0.08 - 0.1 MPa.

[0027] Any range described in the present invention includes the end values and any numerical value between the end values, as well as any sub-range constituted by any numerical value between the end values or the end values.

[0028] Unless otherwise specified, each raw material in the present invention can be obtained by purchasing commercially, and the equipment used in the present invention can adopt conventional equipment in the field or be referred to the existing technology in the field.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The preparation method of the present invention adopts the wet chemical method, and the selenium / tellurium-doped copper-nickel nanowire catalyst is successfully prepared by simple oil-phase synthesis. By changing the dosage of the added selenium powder or tellurium powder, the composition of the nanotube catalyst can be accurately regulated; TEM and HAADF-STEM confirm the nanowire structure of the nanocatalyst, and the diameter of the nanowire is 30 - 60 nanometers; according to the EDX element distribution map and XRD results, it is obtained that CuNiSe and CuNiTe in the nanowire catalyst exist in the form of an alloy, and XPS confirms that copper exists in an amorphous structure; the special selenium / tellurium-doped copper-nickel nanowire structure has potential application prospects in the electrocatalytic hydrogen evolution reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following further describes in detail the specific embodiments of the present invention with reference to the drawings.

[0032] Figure 1 It is the transmission electron microscope image of the sample prepared in Example 1;

[0033] Figure 2 It is the high-angle annular dark-field imaging image of the sample prepared in Example 1;

[0034] Figure 3 It is the element analysis diagram of the sample prepared in Example 1;

[0035] Figure 4 It is the X-ray diffraction pattern of the sample prepared in Example 1;

[0036] Figure 5 X-ray photoelectron spectrum of the sample prepared in Example 1;

[0037] Figure 6 X-ray photoelectron spectrum of the Cu element of the sample prepared in Example 1;

[0038] Figure 7 X-ray photoelectron spectrum of the Ni element of the sample prepared in Example 1;

[0039] Figure 8 X-ray photoelectron spectrum of the Se element of the sample prepared in Example 1;

[0040] Figure 9 X-ray photoelectron spectrum of the O element of the sample prepared in Example 1;

[0041] Figure 10 X-ray photoelectron spectrum of the C element of the sample prepared in Example 1;

[0042] Figure 11 X-ray diffraction pattern of the sample prepared in Example 2;

[0043] Figure 12 Transmission electron micrograph of the sample prepared in Example 2;

[0044] Figure 13 Transmission electron micrograph of the sample prepared in Comparative Example 1;

[0045] Figure 14 Transmission electron micrograph of the sample prepared in Comparative Example 2. Detailed implementation manners

[0046] To illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention.

[0047] As one aspect of the present invention, a preparation method of a selenium / tellurium-doped copper-nickel-based nanowire catalyst includes the following steps:

[0048] 1) Place the copper precursor, nickel precursor and surfactant in an organic solvent, and stir in an inert gas atmosphere and at an appropriate temperature until the solution is uniformly mixed;

[0049] 2) Keep stirring, raise the temperature to the first reaction temperature and heat for a period of time;

[0050] 3) Keep stirring the solution, raise the temperature to the second reaction temperature again and heat for a period of time;

[0051] 4) Take a certain amount of selenium / tellurium powder, dissolve it in oleylamine, and disperse it by ultrasonic treatment to obtain a selenium / tellurium powder solution for later use.

[0052] 5) After the reactor cools down, slowly add the selenium / tellurium powder solution, keep stirring under an inert atmosphere, and then heat it up to the third reaction temperature and heat for a certain period of time.

[0053] 6) After the reactor cools, wash the product multiple times and then centrifuge it, and dry it under vacuum to obtain a selenium / tellurium-doped copper-nickel nanowire catalyst.

[0054] In certain embodiments of the present invention, in step 1), the copper precursor is copper acetylacetonate, the nickel precursor is nickel chloride hexahydrate, and the surfactant is dimethyldioctadecylammonium chloride; the molar ratio of the copper precursor, nickel precursor, and surfactant is 1-2:1:1-1.5.

[0055] In certain embodiments of the present invention, in step 1), the organic solvent is oleylamine, and the ratio of the amount of the copper precursor to the organic solvent is 0.8 mmol / 8-10 mL.

[0056] In certain embodiments of the present invention, in step 1), the inert gas is nitrogen or argon.

[0057] In certain embodiments of the present invention, in step 1), the appropriate temperature is 60-90 °C, and the stirring time is 30-90 min.

[0058] In certain embodiments of the present invention, in step 2), the first reaction temperature is 170-190 °C, and the certain period of time is 200-300 min.

[0059] In certain embodiments of the present invention, in step 3), the second reaction temperature is 200-250 °C, and the certain period of time is 60-100 min.

[0060] In certain embodiments of the present invention, in step 4), the mass concentration of the selenium / tellurium powder solution is 2-5 g / L.

[0061] In certain embodiments of the present invention, in step 4), the conditions for ultrasonic dispersion are: ultrasonic treatment for 1-5 min at 40%-80% of the power of 400 W.

[0062] In certain embodiments of the present invention, in step 5), the temperature is cooled down to 30-70 °C, the third reaction temperature is 70-110 °C, and the certain period of time is 60-90 min.

[0063] In certain embodiments of the present invention, in step 5), the inert atmosphere is nitrogen or argon.

[0064] In certain embodiments of the present invention, in step 6), the washing solvent is ethanol or n-hexane.

[0065] In certain embodiments of the present invention, in step 6), the rotation speed of the centrifugation is 5000 - 9000 r, and the time is 5 - 10 min.

[0066] In certain embodiments of the present invention, in step 6), the temperature of the vacuum drying is 40 - 110 °C, and the time is 8 - 24 h.

[0067] In certain embodiments of the present invention, in step 6), the vacuum degree of the vacuum drying is 0.08 - 0.1 MPa.

[0068] Example 1

[0069] A preparation method of a selenium-doped copper-nickel-based nanowire catalyst includes the following steps:

[0070] 1) Place 0.2094 g of copper acetylacetonate, 0.0951 g of nickel chloride hexahydrate, and 0.3 g of dimethyldioctadecylammonium chloride in 8 mL of oleylamine, and stir at 80 °C for 50 min in a nitrogen atmosphere until the solution is evenly mixed;

[0071] 2) Keep stirring and raise the temperature to the first reaction temperature of 185 °C, and heat for 220 min;

[0072] 3) Keep stirring the solution, raise the temperature to the second reaction temperature again and heat for a period of time;

[0073] 4) Dissolve 5 mg of selenium powder in 2 mL of oleylamine, ultrasonically disperse it to obtain a selenium powder solution of 2.5 g / L for standby;

[0074] 5) Wait for the three-necked flask to cool down to 50 °C and slowly add the selenium powder solution drop by drop. Keep stirring under a N 2 atmosphere, and raise the temperature to 100 °C again and heat for 60 min;

[0075] 6) Wait for the three-necked flask to cool down to room temperature, wash the obtained primary product with a mixed solvent of ethanol and n-hexane for multiple times,

[0076] centrifuge, and dry to obtain a selenium-doped copper-nickel-based nanowire catalyst.

[0077] Figure 1 The transmission electron microscopy image of the sample prepared in Example 1 is shown;

[0078] Figure 2 The high-angle annular dark-field imaging image of the sample prepared in Example 1 is shown;

[0079] Figure 3 The elemental analysis image of the sample prepared in Example 1 is shown;

[0080] Figure 4 shows the X-ray diffraction pattern of the sample prepared in Example 1;

[0081] Figure 5 is the X-ray photoelectron spectrum of the sample prepared in Example 1;

[0082] Figure 6 is the X-ray photoelectron spectrum of the Cu element of the sample prepared in Example 1;

[0083] Figure 7 is the X-ray photoelectron spectrum of the Ni element of the sample prepared in Example 1;

[0084] Figure 8 is the X-ray photoelectron spectrum of the Se element of the sample prepared in Example 1;

[0085] Figure 9 is the X-ray photoelectron spectrum of the O element of the sample prepared in Example 1;

[0086] Figure 10 is the X-ray photoelectron spectrum of the C element of the sample prepared in Example 1.

[0087] After testing, the diameter of the selenium-doped copper-nickel-based nanowires prepared in this example is 30-60 nanometers.

[0088] Example 2

[0089] A preparation method of a tellurium-doped copper-nickel-based nanowire catalyst, comprising the following steps:

[0090] Repeat Example 1, the difference is only that: in step 3), 5 mg of tellurium powder is taken; in step 4), the tellurium powder solution is added to the three-necked flask.

[0091] Figure 11 is the X-ray diffraction pattern of the sample prepared in Example 2;

[0092] Figure 12 is the transmission electron microscope image of the sample prepared in Example 2;

[0093] After testing, the diameter of the tellurium-doped copper-nickel-based nanowires prepared in this example is 30-60 nanometers.

[0094] Comparative Example 1

[0095] A preparation method of a selenium-doped copper-nickel-based nanowire catalyst, comprising the following steps:

[0096] Repeat Example 1, the difference is only that: in step 3), the mass concentration of the selenium powder solution is 1 g / L.

[0097] Figure 13TEM image of the CuNiSe nanowires prepared in this comparative example.

[0098] Upon inspection, obvious mottles exist on the surface of the selenium-doped copper-nickel-based nanowires prepared in this example, and selenium-doped copper-nickel-based nanowires with a smooth and evenly distributed surface are not obtained.

[0099] Thus, it can be seen that when the mass concentration of the selenium / tellurium powder solution is too low, selenium / tellurium cannot be evenly doped on the surface of the copper-nickel-based material.

[0100] Comparative Example 2

[0101] A preparation method of a tellurium-doped copper-nickel-based nanowire catalyst includes the following steps:

[0102] Repeat Example 2, with the difference that in step 3), the mass concentration of the tellurium powder solution is 6 g / L.

[0103] Figure 14 TEM image of the CuNiTe nanowires prepared in this comparative example.

[0104] Upon inspection, a large number of nanoclusters with different sizes exist in the tellurium-doped copper-nickel-based nanowires prepared in this comparative example, and nanowires with regular morphologies are not obtained.

[0105] Thus, it can be seen that when the mass concentration of the selenium / tellurium powder solution is too high, nanowires with regular morphologies cannot be obtained.

[0106] Comparative Example 3

[0107] A preparation method of a selenium-doped copper-nickel-based nanowire catalyst includes the following steps:

[0108] Repeat Example 1, with the difference that in step 1), the copper precursor is copper nitrate and the nickel precursor is nickel nitrate.

[0109] Upon inspection, selenium-doped copper-nickel-based nanowires cannot be prepared in this comparative example.

[0110] Thus, it can be seen that when the used copper precursor and nickel precursor are not suitable, selenium-doped copper-nickel-based nanowires with regular morphologies and uniform dispersion cannot be obtained.

[0111] Comparative Example 4

[0112] A preparation method of a selenium-doped copper-nickel-based nanowire catalyst includes the following steps:

[0113] Repeat Example 1, with the difference that in step 2), the temperature is raised to 150 °C.

[0114] Upon detection, the selenium-doped copper-nickel-based nanowires prepared in this comparative example exhibited a large number of massive agglomerated particles.

[0115] Thus, when the first reaction temperature is too low, uniformly distributed and complete selenium-doped copper-nickel-based nanowires cannot be obtained.

[0116] Comparative Example 5

[0117] A method for preparing a selenium-doped copper-nickel-based nanowire catalyst includes the following steps:

[0118] Repeat Example 1, with the difference that step 2) is cancelled.

[0119] Upon detection, selenium-doped copper-nickel-based nanowires cannot be prepared in this comparative example.

[0120] Thus, when step 2) is cancelled and the reaction temperature is directly increased to the second reaction temperature to start the reaction, selenium-doped copper-nickel-based nanowires cannot be prepared.

[0121] In summary, in the method for preparing a selenium / tellurium-doped copper-nickel-based nanowire catalyst of the present invention, the reaction temperature, reaction atmosphere, solution volume, amount of metal precursor used, etc. are coordinated and cooperate with each other to form a complete technical solution, so that the selenium / tellurium-doped copper-nickel-based nanowire catalyst required by the present invention can be prepared.

[0122] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation manners here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A preparation method of a selenium / tellurium-doped copper-nickel-based nanowire catalyst, characterized in that, it comprises the following steps: 1) Place a copper precursor, a nickel precursor and a surfactant in an organic solvent, and stir in an inert gas atmosphere and at an appropriate temperature until the solution is uniformly mixed; 2) Keep stirring, raise the temperature to the first reaction temperature and heat for a period of time; 3) Keep stirring the solution, raise the temperature again to the second reaction temperature and heat for a period of time; 4) Dissolve a certain amount of selenium / tellurium powder in oleylamine, ultrasonically disperse it to obtain a selenium / tellurium powder solution for standby; 5) After the reactor cools down, add the selenium / tellurium powder solution, keep stirring under an inert atmosphere and raise the temperature again to the third reaction temperature and heat for a period of time; 6) After the reactor cools, wash the product multiple times and then centrifuge it, and vacuum dry it to obtain a selenium / tellurium-doped copper-nickel nanowire catalyst; In step 1), the copper precursor is copper acetylacetonate, the nickel precursor is nickel chloride hexahydrate, and the surfactant is dimethyldioctadecylammonium chloride; the molar ratio of the copper precursor, the nickel precursor and the surfactant is 1-2:1:1-1.5; In step 1), the organic solvent is oleylamine, and the ratio of the amount of the copper precursor to the organic solvent is 0.8 mmol / 8-10 mL; In step 2), the first reaction temperature is 170-190 °C, and the period of time is 200-300 min; In step 3), the second reaction temperature is 200-250 °C, and the period of time is 60-100 min; In step 4), the mass concentration of the selenium / tellurium powder solution is 2-5 g / L; In step 5), the temperature is lowered to 30-70 °C, the third reaction temperature is 70-110 °C, and the period of time is 60-90 min.

2. The preparation method according to claim 1, characterized in that: In step 1), the inert gas is nitrogen or argon.

3. The preparation method according to claim 1, characterized in that: In step 1), the appropriate temperature is 60-90 °C, and the stirring time is 30-90 min.

4. The preparation method according to claim 1, characterized in that: In step 4), the conditions for ultrasonic dispersion are: ultrasonic for 1-5 min at 40%-80% of the power of 400 W.

5. The preparation method according to claim 1, characterized in that: In step 5), the inert atmosphere is nitrogen or argon.

6. The preparation method according to claim 1, characterized in that: In step 6), the washing solvent is ethanol or n-hexane.

7. The preparation method according to claim 1, characterized in that: In step 6), the rotation speed of centrifugation is 5000 - 9000 r, and the time is 5-10 min.

8. The preparation method according to claim 1, characterized in that: In step 6), the temperature of vacuum drying is 40-110 °C, and the time is 8-24 h.

9. The preparation method according to claim 1, characterized in that: In step 6), the vacuum degree of the vacuum drying is 0.08 to 0.1 MPa.

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