1. A preparation method of a small-size multi-element transition metal sulfide/carbon black powder nano composite material is characterized in that the preparation method of the small-size multi-element transition metal sulfide/carbon black powder nano composite material is specifically completed according to the following steps:

firstly, preparing a surfactant solution:

dissolving a sulfonate anionic surfactant and a polymer surfactant into water to obtain a surfactant solution;

secondly, preparing a precursor solution:

dissolving copper salt, nickel salt, tin salt and sulfur source into water, adding 10-20% by mass of citric acid, and stirring to obtain a precursor solution;

thirdly, adding carbon black:

adding carbon black into the precursor solution, heating and stirring to obtain a precursor solution containing the carbon black;

fourthly, hydrothermal reaction:

putting the precursor solution containing the carbon black into a hydrothermal reaction kettle, carrying out hydrothermal reaction, and taking out a reaction product from the reaction kettle naturally cooled to room temperature after the hydrothermal reaction is finished;

fifthly, separation, extraction and drying:

firstly, putting a reaction product into distilled water for ultrasonic cleaning, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning, finally centrifuging, and removing supernatant to obtain a solid substance;

and fifthly, repeating the fifth step, and drying at room temperature to obtain the small-size multi-element transition metal sulfide/carbon black powder nano composite material.

2. The preparation method of the small-size multi-transition metal sulfide/carbon black powder nanocomposite material as claimed in claim 1, wherein the mass ratio of the sulfonate anionic surfactant to the polymer surfactant in the step one is (4-15): 1; the volume ratio of the total mass of the sulfonate anionic surfactant and the polymer surfactant to water in the step one is (0.1-0.5): 100.

3. The method for preparing a small-sized multiple transition metal sulfide/carbon black powder nanocomposite as claimed in claim 1, wherein the sulfonate anionic surfactant in the step one is sodium dodecylbenzene sulfonate, sodium hexadecyl sulfonate or sodium alpha-olefin sulfonate; the polymer surfactant in the step one is polyethylene glycol 2000, polyethylene glycol 4000, polyvinyl alcohol, polyacrylamide or polyvinylpyrrolidone.

4. The method as claimed in claim 1, wherein the mass ratio of the copper salt, the nickel salt, the tin salt and the sulfur source in the second step is (6-10): 3-5): 6-8): 6-9); the volume ratio of the total mass of the copper salt, the nickel salt, the tin salt and the sulfur source to the water in the step two is (1.3-10): 100; the volume ratio of the citric acid with the mass fraction of 10-20% to the water in the second step is (10-5) to 1; the stirring speed in the step two is 100 r/min-300 r/min, and the stirring time is 10 min-30 min.

5. The method for preparing small-sized multi-element transition metal sulfide/carbon black powder nano composite material according to claim 1, wherein the copper salt in the second step is CuSO₄·5H₂O、CuCl₂·2H₂O or Cu (NO)₃)₂·6H₂O; the nickel salt in the second step is NiSO₄·6H₂O、NiCl₂·6H₂O or Ni (NO)₃)₂·6H₂O。

6. The method for preparing small-sized multi-element transition metal sulfide/carbon black powder nanocomposite material according to claim 1, wherein the tin salt in the second step is SnCl₄·5H₂O or SnCl₂·2H₂O; the sulfur source in the second step is thiourea, mercaptan or thioether.

7. The preparation method of the small-size multi-transition metal sulfide/carbon black powder nanocomposite material according to claim 1, wherein the mass ratio of the carbon black to the total mass of the copper salt, the nickel salt, the tin salt and the sulfur source in the precursor solution in the third step is (5-15): 100; and the heating and stirring temperature in the step three is 40-45 ℃, the stirring speed is 250-300 r/min, and the stirring time is 20-40 min.

8. The method for preparing a small-sized multielement transition metal sulfide/carbon black powder nanocomposite as claimed in claim 1, wherein the temperature of the hydrothermal reaction in the fourth step is 120-200 ℃, and the time of the hydrothermal reaction is 10-25 h.

9. The preparation method of the small-size multi-element transition metal sulfide/carbon black powder nanocomposite material according to claim 1, wherein in the fifth step, firstly, the reaction product is placed into distilled water for ultrasonic cleaning for 10-15 min, then is placed into absolute ethyl alcohol for ultrasonic cleaning for 10-15 min, finally is centrifuged for 5-10 min at a centrifugation speed of 3000-5000 r/min, and supernatant liquid is discarded to obtain a solid substance.

10. The method for preparing a small-sized multielement transition metal sulfide/carbon black powder nano composite material according to claim 1, wherein the number of times of repeating the fifth step is 3-5 in the fifth step; and the drying time in the fifth step is 2-12 h.

Background

Cu₂NiSnS₄(Copper Nickel Tin sulfide) is a multi-element transition metal sulfide formed by Cu, Ni, Sn element and S element under specific reaction condition. It has received a great deal of attention from the field of new material precursors because it has characteristics of typical p-type semiconductor materials and thus exhibits excellent electrical properties, catalytic properties, and crystal anisotropy. Especially plays an important role in the fields of novel solar materials and semiconductor materials, so that Cu₂NiSnS₄Is expected to become a novel high-efficiency energy conversion material. Cu₂NiSnS₄The Ni element is added, and when an outer layer electron is acted by an external magnetic field, the Ni element shows unusual magnetic moment change, shows good dielectric loss and magnetic loss capacity and is applied to the field of electromagnetic energy conversion. In conclusion, the multi-transition metal sulfide has potential application value in the field of photoelectromagnetic application.

For Cu at present₂NiSnS₄Reports on the nano material reveal the excellent electrical property of the nano material. Sarkar S et al (Materials Letters,2015,152:155-₂NiSnS₄Materials, and experiments prove Cu₂NiSnS₄The p-type semiconductor is a p-type semiconductor, shows good electrical properties by virtue of holes of the material, has a large area and is agglomerated due to the fact that the preparation process is not well controlled, and may be a main reason for influencing the electrochemical properties and not reaching a higher value. Yuan S et al (ACS applied materials)&Interfaces,2016,8(14):9178-₂NiSnS₄Clustering, and testing and analyzing to find that the reversible capacity of the material is 837mAhg^-1. Meanwhile, the nano-silver conductive powder has good cycling stability and rate as an electrode material. These properties confirm the excellent electrochemical performance of the material, and the law of electrical energy storage and release also reveals that the material may have a strong dielectric relaxation phenomenon on its surface under the influence of an external electric field. On the other hand, Yang et al (Materials Letters 166(2016):101-₂NiSnS₄And (3) powder. It was revealed that it exhibited superparamagnetism at a temperature of 5K and paramagnetism at a temperature of 300K, which is likely related to the distance between Ni — Ni in the crystal. The report further explains the potential of the material on the magnetic performance, and also proves that the material can influence an external magnetic field, but the preparation method is complicated, the sample particles of the material are too large, and if Cu is used, the sample particles are too large₂NiSnS₄The particles are controlled in the nanometer level, which further improves the magnetic performance of the material. Chinese patent "preparation method of copper-nickel-tin-sulfur nanocrystal" (publication number: CN109956504A) proposes that Cu is prepared by ball milling method₂NiSnS₄The nano crystal is prepared by mixing compounds containing copper, nickel, tin and sulfur according to a certain proportion, and successfully preparing Cu through ball milling, annealing, calcining and other processes₂NiSnS₄A nanocrystal. The method has simple process and high yield, but the particle size of the final finished product is difficult to regulate and control, and the method may appearThe particle appearance is not uniform, and the method is difficult to be applied to precise instruments with higher requirements on the nano particles. Wang et al (Materials Letters,2014,124:148-150.) propose a method for preparing Cu by solvothermal method using vinyl alcohol as solvent₂NiSnS₄Method for preparing nano particles and successfully preparing flower-shaped Cu with uniform particle size₂NiSnS₄And (3) granules. Although this method solves the problem of non-uniform particle size, it is not suitable for industrial production due to the high cost of solvent heat. Cu₂NiSnS₄The nano-particles are semiconductor materials with excellent photoelectric and magnetic properties, and are widely applied to photoelectric energy conversion instruments with high conversion efficiency requirements. Most of the current patents relate to the application of this material for solar energy conversion, and the application of its electromagnetic absorption potential is also less reported. On one hand, the material is not ideal for the absorption and conversion capability of electromagnetic waves with high energy due to the limitation of the energy band of the material, and the heat energy generated in the absorption process influences the performance of the material. On the other hand, Cu is currently used₂NiSnS₄The mainstream preparation method of the nano particles also has the defects of complex operation, higher cost, difficult control of particle size and the like, so that the material is difficult to be applied to the existing instruments and equipment on a large scale.

Disclosure of Invention

The invention aims to solve the problem of the existing nano Cu₂NiSnS₄High production cost, complex operation, uneven grain diameter, difficult control and poor wave-absorbing performance, and provides a preparation method of the small-size multi-element transition metal sulfide/carbon black powder nano composite material.

A preparation method of a small-size multi-element transition metal sulfide/carbon black powder nano composite material is specifically completed according to the following steps:

firstly, preparing a surfactant solution:

dissolving a sulfonate anionic surfactant and a polymer surfactant into water to obtain a surfactant solution;

secondly, preparing a precursor solution:

dissolving copper salt, nickel salt, tin salt and sulfur source into water, adding 10-20% by mass of citric acid, and uniformly mixing to obtain a precursor solution;

thirdly, adding carbon black:

adding carbon black into the precursor solution, heating and stirring to obtain a precursor solution containing the carbon black;

fourthly, hydrothermal reaction:

putting the precursor solution containing the carbon black into a hydrothermal reaction kettle, carrying out hydrothermal reaction, and taking out a reaction product from the reaction kettle naturally cooled to room temperature after the hydrothermal reaction is finished;

fifthly, separation, extraction and drying:

firstly, putting a reaction product into distilled water for ultrasonic cleaning, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning, finally centrifuging, and removing supernatant to obtain a solid substance;

and fifthly, repeating the fifth step, and drying at room temperature to obtain the small-size multi-element transition metal sulfide/carbon black powder nano composite material.

The principle and the advantages of the invention are as follows:

the invention prepares the Cu by using the environment-friendly cheap hydrothermal reaction₂NiSnS₄The composite material with the nano-crystal loaded on the carbon black powder and smaller size solves the problem of preparing the nano-Cu on the one hand₂NiSnS₄High production cost, complex operation, uneven grain diameter and difficult control. On the other hand, a novel electromagnetic wave absorbing material with multiple absorption paths is explored, and not only is carbon black powder utilized to make up for Cu₂NiSnS₄The deficiencies in heat transfer and electrical properties also broaden the Cu₂NiSnS₄Exerts the Cu to the maximum extent on the frequency range of the electromagnetic waves₂NiSnS₄The nano material has the electromagnetic wave absorption potential, and the excellent characteristics of the carbon black powder are utilized to further improve the wave absorption performance of the material.

The invention has the advantages that:

according to the invention, inorganic salt with low price is used as a copper source, a nickel source and a tin source, and thiourea and carbon black powder with low price are used as raw materials, so that the raw material cost is greatly saved;

secondly, the composite material nano-particles are prepared by a hydrothermal method, the method is simple to operate, energy-saving and environment-friendly, the reaction solution is low in price and easy to obtain, and meanwhile, the nano-particles prepared by the method are uniform in size and regular in shape;

thirdly, the invention combines the reaction characteristics of the hydrothermal method and configures surfactants with different proportions, thereby effectively controlling the growth of the nano particles during the reaction and realizing the effective control of the size of the nano particles, and the size of the nano particles is related to the influence on electromagnetic waves with different frequency bands and energies₂NiSnS₄The particle size realizes the absorption of complex electromagnetic wave absorption frequency band;

fourthly, the material prepared by the invention utilizes Cu₂NiSnS₄The carbon black powder is utilized to further compensate Cu while the excellent electromagnetic wave absorption performance of the nano particles₂NiSnS₄The nano-particle is short in electrical and thermodynamic properties, so that the absorption and application capacity of the composite material is further enhanced;

the invention solves the problem of dispersion of unmodified carbon black powder in aqueous solution and realizes the loading of the carbon black powder on small-size nano particles;

sixth, the invention utilizes hydrothermal method, has reduced the preparation cost of the material, has simplified the production preparation flow, and it is easy to introduce surfactant in the aqueous solution to limit crystal growth, make Cu prepared₂NiSnS₄The nano particles are not only small in size but also uniform in distribution, and the Cu is prepared by the method₂NiSnS₄The size of the nano particles is 5-70 nanometers, and the agglomeration phenomenon does not occur.

The method for preparing the small-size multi-element transition metal sulfide/carbon black powder nano composite material is suitable for industrial production.

Drawings

FIG. 1 shows small-sized Cu prepared in example one₂NiSnS₄TEM image of/carbon black powder nanocomposite;

FIG. 2 shows small-sized Cu prepared in example two₂NiSnS₄TE of/carbon black powder nano composite materialAn M diagram;

FIG. 3 shows small-sized Cu prepared in example one₂NiSnS₄XRD pattern of/carbon black powder nano composite material;

FIG. 4 shows small-sized Cu prepared in example two₂NiSnS₄XRD pattern of/carbon black powder nano composite material;

FIG. 5 shows small-sized Cu prepared in example one₂NiSnS₄The electromagnetic wave absorption diagram of the carbon black powder nano composite material;

FIG. 6 shows small-sized Cu prepared in example two₂NiSnS₄The electromagnetic wave absorption diagram of the carbon black powder nano composite material.

Detailed Description

The following examples further illustrate the present invention but are not to be construed as limiting the invention. Modifications and substitutions to methods, procedures, or conditions of the invention may be made without departing from the spirit of the invention.

The first embodiment is as follows: the preparation method of the small-size multi-element transition metal sulfide/carbon black powder nano composite material is specifically completed according to the following steps:

firstly, preparing a surfactant solution:

dissolving a sulfonate anionic surfactant and a polymer surfactant into water to obtain a surfactant solution;

secondly, preparing a precursor solution:

dissolving copper salt, nickel salt, tin salt and sulfur source into water, adding 10-20% by mass of citric acid, and stirring to obtain a precursor solution;

thirdly, adding carbon black:

adding carbon black into the precursor solution, heating and stirring to obtain a precursor solution containing the carbon black;

fourthly, hydrothermal reaction:

putting the precursor solution containing the carbon black into a hydrothermal reaction kettle, carrying out hydrothermal reaction, and taking out a reaction product from the reaction kettle naturally cooled to room temperature after the hydrothermal reaction is finished;

fifthly, separation, extraction and drying:

firstly, putting a reaction product into distilled water for ultrasonic cleaning, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning, finally centrifuging, and removing supernatant to obtain a solid substance;

and fifthly, repeating the fifth step, and drying at room temperature to obtain the small-size multi-element transition metal sulfide/carbon black powder nano composite material.

The second embodiment is as follows: the present embodiment differs from the present embodiment in that: the mass ratio of the sulfonate anionic surfactant to the polymer surfactant in the first step is (4-15) to 1; the volume ratio of the total mass of the sulfonate anionic surfactant and the polymer surfactant to water in the step one is (0.1-0.5): 100. Other steps are the same as in the first embodiment.

The third concrete implementation mode: the present embodiment differs from the first or second embodiment in that: the sulfonate anionic surfactant in the step one is sodium dodecyl benzene sulfonate, sodium hexadecyl sulfonate or sodium alpha-olefin sulfonate; the polymer surfactant in the step one is polyethylene glycol 2000, polyethylene glycol 4000, polyvinyl alcohol, polyacrylamide or polyvinylpyrrolidone. The other steps are the same as in the first or second embodiment.

The fourth concrete implementation mode: the difference between this embodiment and one of the first to third embodiments is as follows: the mass ratio of the copper salt, the nickel salt, the tin salt and the sulfur source in the second step is (6-10): 3-5): 6-8): 6-9; the volume ratio of the total mass of the copper salt, the nickel salt, the tin salt and the sulfur source to the water in the step two is (1.3-10): 100; the volume ratio of the citric acid with the mass fraction of 10-20% to the water in the second step is (10-5) to 1; the stirring speed in the step two is 100 r/min-300 r/min, and the stirring time is 10 min-30 min. The other steps are the same as those in the first to third embodiments.

The fifth concrete implementation mode: the difference between this embodiment and one of the first to fourth embodiments is: the copper salt in the step two is CuSO₄·5H₂O、CuCl₂·2H₂O or Cu (NO)₃)₂·6H₂O; the nickel salt in the second step is NiSO₄·6H₂O、NiCl₂·6H₂O or Ni (NO)₃)₂·6H₂And O. The other steps are the same as those in the first to fourth embodiments.

The sixth specific implementation mode: the difference between this embodiment and one of the first to fifth embodiments is as follows: the tin salt in the step two is SnCl₄·5H₂O or SnCl₂·2H₂O; the sulfur source in the second step is thiourea, mercaptan or thioether. The other steps are the same as those in the first to fifth embodiments.

The seventh embodiment: the difference between this embodiment and one of the first to sixth embodiments is: the mass ratio of the carbon black in the third step to the total mass of the copper salt, the nickel salt, the tin salt and the sulfur source in the precursor solution is (5-15): 100; and the heating and stirring temperature in the step three is 40-45 ℃, the stirring speed is 250-300 r/min, and the stirring time is 20-40 min. The other steps are the same as those in the first to sixth embodiments.

The specific implementation mode is eight: the difference between this embodiment and one of the first to seventh embodiments is: the temperature of the hydrothermal reaction in the fourth step is 120-200 ℃, and the time of the hydrothermal reaction is 10-25 h. The other steps are the same as those in the first to seventh embodiments.

The specific implementation method nine: the difference between this embodiment and the first to eighth embodiments is: and fifthly, firstly putting the reaction product into distilled water for ultrasonic cleaning for 10-15 min, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning for 10-15 min, finally centrifuging the reaction product for 5-10 min under the condition that the centrifugation speed is 3000-5000 r/min, and removing the supernatant to obtain a solid substance. The other steps are the same as those in the first to eighth embodiments.

The detailed implementation mode is ten: the difference between this embodiment and one of the first to ninth embodiments is as follows: in the fifth step, the times of repeating the fifth step are 3 to 5; and the drying time in the fifth step is 2-12 h. The other steps are the same as those in the first to ninth embodiments.

The present invention will be described in detail below with reference to the accompanying drawings and examples.

The following examples were used to demonstrate the beneficial effects of the present invention:

the first embodiment is as follows: small-size Cu₂NiSnS₄The preparation method of the carbon black powder nano composite material comprises the following steps:

firstly, preparing a surfactant solution:

adding sodium dodecyl benzene sulfonate and polyethylene glycol 2000 into water, and continuously stirring at a stirring speed of 150r/min until the sodium dodecyl benzene sulfonate and the polyethylene glycol 2000 are dissolved in the water to obtain a surfactant solution;

the mass ratio of the sodium dodecyl benzene sulfonate to the polyethylene glycol 2000 in the step one is 7: 1;

the volume ratio of the total mass of the sodium dodecyl benzene sulfonate and the polyethylene glycol 2000 to the water in the step one is 0.2: 100;

secondly, preparing a precursor solution:

mixing CuSO₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂Dissolving O and thiourea in water, adding 14% citric acid by mass, and continuously stirring for 15min at a stirring speed of 150r/min to obtain a precursor solution;

CuSO described in step two₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂The mass ratio of O to thiourea is 8:4:7: 8;

CuSO described in step two₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂The volume ratio of the total mass of O and thiourea to water is 1.38: 100;

the volume ratio of the citric acid with the mass fraction of 14% to the water in the step two is 7: 50;

thirdly, adding carbon black:

adding carbon black into the precursor solution, and continuously stirring for 30min under the conditions that the stirring speed is 250r/min and the temperature is 40 ℃ to obtain the precursor solution containing the carbon black;

the mass of the carbon black in the step three and the CuSO in the precursor solution₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂The total mass ratio of O to thiourea is 10: 100;

fourthly, hydrothermal reaction:

putting the precursor solution containing the carbon black into a hydrothermal reaction kettle, reacting for 10 hours at the hydrothermal reaction temperature of 200 ℃, and taking out a reaction product from the reaction kettle naturally cooled to room temperature after the hydrothermal reaction is finished;

fifthly, separation, extraction and drying:

firstly, putting a reaction product into distilled water for ultrasonic cleaning, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning, finally centrifuging, and removing supernatant to obtain a solid substance;

putting the reaction product into distilled water for ultrasonic cleaning for 10min, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning for 10min, finally centrifuging the reaction product for 10min under the condition that the centrifugal speed is 4000r/min, and removing supernatant liquid to obtain a solid substance; the power of the ultrasonic cleaning is 120W;

②, repeating the fifth step for 3 times, and drying for 12 hours at room temperature to obtain small-size Cu₂NiSnS₄Carbon black powder nano composite material.

Example two: small-size Cu₂NiSnS₄The preparation method of the carbon black powder nano composite material is specifically completed according to the following steps:

firstly, preparing a surfactant solution:

adding sodium dodecyl benzene sulfonate and polyethylene glycol 2000 into water, and continuously stirring at a stirring speed of 150r/min until the sodium dodecyl benzene sulfonate and the polyethylene glycol 2000 are dissolved in the water to obtain a surfactant solution;

the mass ratio of the sodium dodecyl benzene sulfonate to the polyethylene glycol 2000 in the step one is 4: 1;

the volume ratio of the total mass of the sodium dodecyl benzene sulfonate and the polyethylene glycol 2000 to the water in the step one is 0.2: 100;

secondly, preparing a precursor solution:

mixing CuSO₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂Dissolving O and thiourea in water, adding 14% citric acid by mass, and continuously stirring for 15min at a stirring speed of 150r/min to obtain a precursor solution;

CuSO described in step two₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂The mass ratio of O to thiourea is 8:4:7: 8;

CuSO described in step two₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂The volume ratio of the total mass of O and thiourea to water is 1.38: 100;

the volume ratio of the citric acid with the mass fraction of 14% to the water in the step two is 7: 50;

thirdly, adding carbon black:

adding carbon black into the precursor solution, and continuously stirring for 30min under the conditions that the stirring speed is 250r/min and the temperature is 40 ℃ to obtain the precursor solution containing the carbon black;

the mass of the carbon black in the step three and the CuSO in the precursor solution₄·5H₂O、NiSO₄·6H₂O、SnCl₄·5H₂The total mass ratio of O to thiourea is 10: 100;

fourthly, hydrothermal reaction:

putting the precursor solution containing the carbon black into a hydrothermal reaction kettle, reacting for 20 hours at the hydrothermal reaction temperature of 200 ℃, and taking out a reaction product from the reaction kettle naturally cooled to room temperature after the hydrothermal reaction is finished;

fifthly, separation, extraction and drying:

firstly, putting a reaction product into distilled water for ultrasonic cleaning, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning, finally centrifuging, and removing supernatant to obtain a solid substance;

putting the reaction product into distilled water for ultrasonic cleaning for 10min, then putting the reaction product into absolute ethyl alcohol for ultrasonic cleaning for 10min, finally centrifuging the reaction product for 10min under the condition that the centrifugal speed is 4000r/min, and removing supernatant liquid to obtain a solid substance; the power of the ultrasonic cleaning instrument used in the fifth step is 120W;

②, repeating the fifth step for 3 times, and drying for 12 hours at room temperature to obtain small-size Cu₂NiSnS₄Carbon black powder nano composite material.

FIG. 1 shows small-sized Cu prepared in example one₂NiSnS₄TEM image of/carbon black powder nanocomposite;

as can be seen from FIG. 1, Cu produced by the method of this embodiment₂NiSnS₄The nano particles are spherical, are completely loaded on the surface of the carbon black powder, have no agglomeration phenomenon, are uniformly dispersed on the surface of the carbon black powder and are sparse in number. Cu₂NiSnS₄The nanoparticles are uniform in size, with the majority of the sizes being 5 nm.

FIG. 2 shows small-sized Cu prepared in example two₂NiSnS₄TEM image of/carbon black powder nanocomposite;

in fig. 2, the aggregation of the carbon black powder is increased due to the change of the use ratio of the surfactant, and part of the carbon black powder is agglomerated. Meanwhile, Cu loaded on the surface of carbon black powder₂NiSnS₄The nano particles are more compact and form Cu with the diameter of 30 nm-70 nm₂NiSnS₄And (4) clustering.

FIG. 3 shows small-sized Cu prepared in example one₂NiSnS₄XRD pattern of/carbon black powder nano composite material;

as can be seen from fig. 3, the diffraction peaks at 28.475 °, 33.026 °, 47.357 °, 56.214 ° and 76.442 ° of 2 θ correspond to Cu, respectively₂NiSnS₄The (111), (200), (220), (311) and (331) crystal planes of the crystal, which is compatible with Cu₂NiSnS₄(PDF #26-0552) the standard cards matched, indicating that the product produced was indeed Cu₂NiSnS₄. The wider 'steamed bun' peak appearing at the 2 theta position of 20-30 degrees is the characteristic peak of the carbon black powder, so that the carbon black powder and Cu can be separated out₂NiSnS₄The nano-particle has good loading condition, and different substances have less shielding condition on X-rays.

FIG. 4 shows small-sized Cu prepared in example two₂NiSnS₄XRD pattern of/carbon black powder nano composite material;

as can be seen from the comparison between fig. 4 and fig. 3, by changing the ratio of different surfactants, a stronger characteristic peak can still be shown at the corresponding crystal face of the standard card, and it is also proved that the ratio of the surfactants used in the second embodiment is feasible. In addition, the characteristic peak of FIG. 3 at the (002) crystal plane is weaker than that of FIG. 2, because the ratio of the surfactant is changed so that Cu in example 2 is present₂NiSnS₄The nano particles are easy to agglomerate, the shielding condition of the carbon black powder is serious, and the characteristic peak intensity of the carbon material is reduced.

Small-sized Cu prepared in example one₂NiSnS₄Mixing the carbon black powder nano composite material with paraffin according to the weight ratio of 1:4, preparing a hollow cylinder, and then carrying out electromagnetic wave absorption performance test by using a vector network analyzer, wherein the test is shown in figure 5;

FIG. 5 shows small-sized Cu prepared in example one₂NiSnS₄The electromagnetic wave absorption diagram of the carbon black powder nano composite material;

as can be seen from FIG. 5, the small-sized Cu prepared in the first example₂NiSnS₄When the thickness of the carbon black powder nano composite material and paraffin is 5mm after being mixed according to the weight ratio of 1:4, the reflectivity of 3.28GHz electromagnetic waves reaches-27.8 dB, and the wave absorbing value is optimal; the electromagnetic wave reflectivities were-19.5 and-18.9 dB at thicknesses of 3mm and 4mm, respectively, and a wider (> 4GHz) absorption band appeared at a thickness of 2 mm. This shows that small size Cu was prepared as in example one₂NiSnS₄The thickness of the carbon black powder nano composite material mixed with paraffin according to the weight ratio of 1:4 is 2-5mm, and the carbon black powder nano composite material has better absorption effect on S-band electromagnetic waves and C-band electromagnetic waves.

Small-sized Cu prepared in example two₂NiSnS₄Mixing the carbon black powder nano composite material with paraffin according to the weight ratio of 1:4, making into a hollow cylinder, and then carrying out electromagnetic wave absorption performance test by using a vector network analyzer, as shown in figure 6;

FIG. 6 shows small-sized Cu prepared in example two₂NiSnS₄The electromagnetic wave absorption diagram of the carbon black powder nano composite material;

as can be seen from FIG. 6, small-sized Cu was prepared in example two₂NiSnS₄The carbon black powder nano composite material and paraffin wax are mixed according to the weight ratio of 1:4, the thickness of the mixture is 5mm, the optimal absorption effect is still shown at 3.28GHz, and the electromagnetic wave reflectivity is-20.7 dB. Compared with the first embodiment, the wave absorbing capability is reduced when the thickness is larger. When the thickness is 3mm and 4mm, the wave absorbing capability of the material has no obvious change. At a thickness of 2mm, still more consistent with that shown in FIG. 4, a wider (> 4GHz) absorption band occurs, but a stronger peak of-17.5 dB occurs in the 10-11GHz band. In summary, by controlling the proportion of the surfactant, Cu can be effectively controlled₂NiSnS₄The dispersion, agglomeration and growth conditions of the nano particles on the carbon black powder also change the size of the electromagnetic wave absorption unit, thereby changing the absorption strength of the composite material to electromagnetic waves in different frequency bands. This means that Cu can be adjusted by changing the addition ratio of the surfactant₂NiSnS₄The size and dispersion condition of the carbon black powder nano composite material particles can meet the electromagnetic wave absorption requirements in different working conditions.