ONE-DIMENSIONAL CORALLOID NiS/Ni3S4@PPy@MoS2-BASED WAVE ABSORBER, AND PREPARATION METHOD AND USE THEREOF

Abstract

The present disclosure belongs to the technical field of wave absorbing materials, and discloses a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber, and a preparation method and use thereof. A preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber includes the following steps. Preparing one-dimensional Ni nanowires by a reduction method. Coating a layer of polypyrrole (PPy) on the Ni nanowires by an in-situ polymerization method using pyrrole as a monomer, to obtain Ni@PPy nanowires. Coating MoS.sub.2 nanorods on the Ni@PPy nanowires by a hydrothermal synthesis method. Meanwhile, Ni as a sacrificial template is vulcanized into NiS/Ni.sub.3S.sub.4 to prepare the one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber. The wave absorber has a novel surface morphology and simple preparation process.

Claims

1. A method for preparing a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber, comprising the steps of: (1) preparing one-dimensional Ni nanowires by a reduction method; (2) coating the Ni nanowires with a layer of polypyrrole (PPy) by an in-situ polymerization method using pyrrole as a monomer to obtain Ni@PPy nanowires; and (3) coating the Ni@PPy nanowires with MoS.sub.2 nanorods by a hydrothermal synthesis method.

2. The method according to claim 1, wherein: step (1) comprises the steps of: dissolving NaOH in ethylene glycol, stirring to obtain a solution, adding a hydrazine hydrate solution as a reducing agent to the solution, followed by continuous stirring; placing an obtained mixed solution in a constant-temperature water bath with an external magnetic field, followed by adding a NiCl.sub.2.6H.sub.2O ethylene glycol solution dropwise with a syringe; and after standing, collecting the Ni nanowires with a magnet, followed by washing with absolute ethanol and deionized water, and conducting freeze-drying; step (2) comprises the steps of: dispersing sodium dodecylbenzenesulfonate (SDBS) and the pyrrole in the deionized water under sonication, and adding the Ni nanowires to an obtained mixture under the sonication; after mechanically stirring the mixture, adding a FeCl.sub.3 aqueous solution; continuing to conduct aggregation; separating a precipitate with the magnet, followed by washing and freeze-drying to obtain the Ni@PPy nanowires; and step (3) comprises the steps of: under ultrasonication, dissolving Na.sub.2MoO.sub.4 and thioacetamide in the deionized water, adding the Ni@PPy nanowires, and mechanically stirring an obtained mixed solution continuously; transferring the entire mixed solution to an autoclave for reaction; and after the reaction is completed, separating a precipitate, and washing by centrifugation, followed by freeze-drying to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

3. The method according to claim 2, wherein the step (1) comprises: dissolving 1.2 g of the NaOH in 35 mL of the ethylene glycol, stirring for 1 h to obtain the solution, adding 10 mL of the hydrazine hydrate solution as the reducing agent to the solution, followed by continuous stirring for 0.5 h; placing the obtained mixed solution in the constant-temperature water bath at 80° C. with the external magnetic field, followed by adding 15 mL of the NiCl.sub.2.6H.sub.2O ethylene glycol solution dropwise with the syringe; after standing for 5 min, collecting the Ni nanowires with the magnet, followed by washing 3 times with the absolute ethanol and the deionized water, and conducting freeze-drying at −60° C.

4. The method according to claim 2, wherein the step (1) comprises: adding 15 mL of the NiCl.sub.2.6H.sub.2O ethylene glycol solution dropwise with the syringe; and after standing for 5 min, collecting the Ni nanowires with the magnet, followed by washing 3 times with the absolute ethanol and the deionized water, and conducting freeze-drying at −60° C.

5. The method according to claim 2, wherein the step (2) comprises: dispersing 0.013 g of the SDBS and 0.1 mL of the pyrrole in 50 mL of the deionized water under sonication, and adding 0.05 g to 0.07 g of the Ni nanowires to the obtained mixture under the sonication; after mechanically stirring the mixture for 2 h, adding 5 mL of the FeCl.sub.3 aqueous solution; continuing to conduct aggregation for 2 h; and separating the precipitate with the magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

6. The method according to claim 2, wherein the step (3) comprises: under ultrasonication, dissolving 0.04 g to 0.08 g of the Na.sub.2MoO.sub.4 and 0.08 g to 0.16 g of the thioacetamide in 20 mL of the deionized water, adding 0.04 g of the Ni@PPy nanowires, and mechanically stirring the obtained mixed solution continuously for 30 min; transferring the entire mixed solution to the autoclave for reaction at 200° C. for 12 h; and after the reaction is completed, separating the precipitate and washing by centrifugation, followed by freeze-drying at 60° C. to obtain the NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

7. The method according to claim 2, wherein: the FeCl.sub.3 aqueous solution has a concentration of 0.29 mol/L; and the NiCl.sub.2.6H.sub.2O ethylene glycol solution has a concentration of 0.1 mol/L.

8. A one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber prepared by the method according to claim 1.

9. The wave absorber according to claim 8, wherein: step (1) comprises the steps of: dissolving NaOH in ethylene glycol, stirring to obtain a solution, adding a hydrazine hydrate solution as a reducing agent to the solution, followed by continuous stirring; placing an obtained mixed solution in a constant-temperature water bath with an external magnetic field, followed by adding a NiCl.sub.2.6H.sub.2O ethylene glycol solution dropwise with a syringe; and after standing, collecting the Ni nanowires with a magnet, followed by washing with absolute ethanol and deionized water, and conducting freeze-drying; step (2) comprises the steps of: dispersing sodium dodecylbenzenesulfonate (SDBS) and the pyrrole in the deionized water under sonication, and adding the Ni nanowires to an obtained mixture under the sonication; after mechanically stirring the mixture, adding a FeCl.sub.3 aqueous solution; continuing to conduct aggregation; and separating a precipitate with the magnet, followed by washing and freeze-drying to obtain the Ni@PPy nanowires; and step (3) comprises the steps of: under ultrasonication, dissolving Na.sub.2MoO.sub.4 and thioacetamide in the deionized water, adding the Ni@PPy nanowires, and mechanically stirring an obtained mixed solution continuously; transferring the entire mixed solution to an autoclave for reaction; and after the reaction is completed, separating a precipitate and washing by centrifugation, followed by freeze-drying to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

10. The wave absorber according to claim 9, wherein the step (1) comprises: dissolving 1.2 g of the NaOH in 35 mL of the ethylene glycol, stirring for 1 h to obtain the solution, adding 10 mL of the hydrazine hydrate solution as the reducing agent to the solution, followed by continuous stirring for 0.5 h; placing the obtained mixed solution in the constant-temperature water bath at 80° C. with the external magnetic field, followed by adding 15 mL of the NiCl.sub.2.6H.sub.2O ethylene glycol solution dropwise with the syringe; and after standing for 5 min, collecting the Ni nanowires with the magnet, followed by washing 3 times with the absolute ethanol and the deionized water, and conducting freeze-drying at −60° C.

11. The wave absorber according to claim 9, wherein the step (1) comprises: adding 15 mL of the NiCl.sub.2.6H.sub.2O ethylene glycol solution dropwise with the syringe; and after standing for 5 min, collecting the Ni nanowires with the magnet, followed by washing 3 times with the absolute ethanol and the deionized water, and conducting freeze-drying at −60° C.

12. The wave absorber according to claim 9, wherein the step (2) comprises: dispersing 0.013 g of the SDBS and 0.1 mL of the pyrrole in 50 mL of the deionized water under sonication, and adding 0.05 g to 0.07 g of the Ni nanowires to the obtained mixture under the sonication; after mechanically stirring the mixture for 2 h, adding 5 mL of the FeCl.sub.3 aqueous solution; continuing to conduct aggregation for 2 h; and separating the precipitate with the magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

13. The wave absorber according to claim 9, wherein the step (3) comprises: under ultrasonication, dissolving 0.04 g to 0.08 g of the Na.sub.2MoO.sub.4 and 0.08 g to 0.16 g of the thioacetamide in 20 mL of the deionized water, adding 0.04 g of the Ni@PPy nanowires, and mechanically stirring the obtained mixed solution continuously for 30 min; transferring the entire mixed solution to the autoclave for reaction at 200° C. for 12 h; and after the reaction is completed, separating the precipitate and washing by centrifugation, followed by freeze-drying at 60° C. to obtain the NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

14. The wave absorber according to claim 9, wherein: the FeCl.sub.3 aqueous solution has a concentration of 0.29 mol/L; and the NiCl.sub.2.6H.sub.2O ethylene glycol solution has a concentration of 0.1 mol/L.

15. A method for improving wireless communication, comprising the step of using the wave absorber according to claim 8.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Illustrative embodiments of the present disclosure are described in detail below with reference to the attached drawing figures.

[0027] FIG. 1 shows a method for preparing a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber according to an embodiment of the disclosure.

[0028] FIG. 2 shows a scanning electron microscope (SEM) image of products of each step of Example 1 provided by the present disclosure, where (a) and (b) are Ni nanowires, (c) and (d) are Ni@PPy nanowires, and (e) and (f) are coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

[0029] FIG. 3 shows an X-ray photoelectron spectroscopy (XPS) diagram of a product of Example 1 provided by the present disclosure, where (a) is a total spectrum, (b) is an N is spectrum, (c) is a Ni 2p spectrum, (d) is a Mo 3d spectrum, and (e) is an S 2p spectrum.

[0030] FIG. 4 shows a schematic diagram of electromagnetic parameters and wave absorption performance analysis of a coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 sample prepared in Example 1 provided by the present disclosure.

DETAILED DESCRIPTION

[0031] The following describes some non-limiting exemplary embodiments of the invention with reference to the accompanying drawings. The described embodiments are merely a part rather than all of the embodiments of the invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the disclosure shall fall within the scope of the disclosure.

[0032] the present disclosure provides a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber, and a preparation method and use thereof. The present disclosure will be described in detail below in conjunction with the accompanying drawings.

[0033] As shown in FIG. 1, the preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber includes the following steps:

[0034] S101: preparing one-dimensional Ni nanowires by a reduction method.

[0035] S102: coating a layer of PPy on the Ni nanowires by an in-situ polymerization method using pyrrole as a monomer, to obtain Ni@PPy nanowires.

[0036] S103: coating MoS.sub.2 nanorods on the Ni@PPy nanowires by a hydrothermal synthesis method.

[0037] For the preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber provided by the present disclosure, those of ordinary skill in the art may also implement other steps. The preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber shown in FIG. 1 is only one example.

[0038] The technical solutions of the present disclosure will be further described below in conjunction with some examples.

[0039] The present disclosure provides a preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber. In this experiment, the one-dimensional Ni nanowires are prepared by reduction method, the Ni@PPy nanowires are coated with a layer of PPy by in-situ polymerization method using the pyrrole as a monomer, and the Ni@PPy nanowires are coated with a layer of MoS.sub.2 nanorods by hydrothermal synthesis method. Meanwhile, the Ni as a sacrificial template is vulcanized into NiS/Ni.sub.3S.sub.4 to obtain the one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 wave absorber. The wave absorber has an excellent performance, novel structure and desirable prospect for use.

Example 1

[0040] A preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber included the following steps:

[0041] (1) Preparation of one-dimensional Ni nanowires: 1.2 g of NaOH was dissolved in 35 mL of ethylene glycol, followed by stirring for 1 h to obtain a solution, 10 mL of a hydrazine hydrate solution as a reducing agent was added to the solution, followed by stirring for 0.5 h to obtain a mixed solution. The mixed solution was placed in a constant-temperature water bath at 80° C. with an external magnetic field, followed by adding 15 mL of a NiCl.sub.2.6H.sub.2O ethylene glycol solution (0.1 mol/L) dropwise to the mixed solution with a syringe. After standing for 5 min, Ni nanowires were collected with a magnet, followed by washing 3 times with absolute ethanol and deionized water, and freeze-drying was conducted at −60° C.

[0042] (2) Preparation of one-dimensional Ni@PPy nanowires: 0.013 g of SDBS and 0.1 mL of pyrrole were dispersed in 50 mL of the deionized water under sonication, and 0.07 g of the Ni nanowires were added to a resulting mixture under the sonication. After mechanically stirring the mixture for 2 h, 5 mL of a FeCl.sub.3 aqueous solution (0.29 mol/L) was added, followed by continuing polymerization for another 2 h. A precipitate was separated with a magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

[0043] (3) Preparation of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 wave absorber: under ultrasonication, 0.04 g of Na.sub.2MoO.sub.4 and 0.08 g of thioacetamide were dissolved in 20 mL of the deionized water, 0.04 g of the Ni@PPy nanowires were added, and a resulting mixed solution was continuously and mechanically stirred for 30 min. The entire mixed solution was transferred to an autoclave for reaction at 200° C. for 12 h. After the reaction was completed, a precipitate was separated and washed by centrifugation, followed by freeze-drying at −60° C. to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

Example 2

[0044] A preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber included the following steps:

[0045] (1) Preparation of one-dimensional Ni nanowires: 1.2 g of NaOH was dissolved in 35 mL of ethylene glycol, followed by stirring for 1 h to obtain a solution, 10 mL of a hydrazine hydrate solution as a reducing agent was added to the solution, followed by stirring for 0.5 h to obtain a mixed solution. The mixed solution was placed in a constant-temperature water bath at 80° C. with an external magnetic field, followed by adding 15 mL of a NiCl.sub.2.6H.sub.2O ethylene glycol solution (0.1 mol/L) dropwise to the mixed solution with a syringe. After standing for 5 min, Ni nanowires were collected with a magnet, followed by washing 3 times with absolute ethanol and deionized water, and freeze-drying was conducted at −60° C.

[0046] (2) Preparation of one-dimensional Ni@PPy nanowires: 0.013 g of SDBS and 0.1 mL of pyrrole were dispersed in 50 mL of the deionized water under sonication, and 0.06 g of the Ni nanowires were added to a resulting mixture under the sonication. After mechanically stirring the mixture for 2 h, 5 mL of a FeCl.sub.3 aqueous solution (0.29 mol/L) was added, followed by continuing polymerization for another 2 h. A precipitate was separated with a magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

[0047] (3) Preparation of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 wave absorber: under ultrasonication, 0.04 g of Na.sub.2MoO.sub.4 and 0.08 g of thioacetamide were dissolved in 20 mL of the deionized water, 0.04 g of the Ni@PPy nanowires were added, and a resulting mixed solution was continuously and mechanically stirred for 30 min. The entire mixed solution was transferred to an autoclave for reaction at 200° C. for 12 h. After the reaction was completed, a precipitate was separated and washed by centrifugation, followed by freeze-drying at −60° C. to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

Example 3

[0048] A preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber included the following steps:

[0049] (1) Preparation of one-dimensional Ni nanowires: 1.2 g of NaOH was dissolved in 35 mL of ethylene glycol, followed by stirring for 1 h to obtain a solution, 10 mL of a hydrazine hydrate solution as a reducing agent was added to the solution, followed by stirring for 0.5 h to obtain a mixed solution. The mixed solution was placed in a constant-temperature water bath at 80° C. with an external magnetic field, followed by adding 15 mL of a NiCl.sub.2.6H.sub.2O ethylene glycol solution (0.1 mol/L) dropwise to the mixed solution with a syringe. After standing for 5 min, Ni nanowires were collected with a magnet, followed by washing 3 times with absolute ethanol and deionized water, and freeze-drying was conducted at −60° C.

[0050] (2) Preparation of one-dimensional Ni@PPy nanowires: 0.013 g of SDBS and 0.1 mL of pyrrole were dispersed in 50 mL of the deionized water under sonication, and 0.05 g of the Ni nanowires were added to a resulting mixture under the sonication. After mechanically stirring the mixture for 2 h, 5 mL of a FeCl.sub.3 aqueous solution (0.29 mol/L) was added, followed by continuing polymerization for another 2 h. A precipitate was separated with a magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

[0051] (3) Preparation of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 wave absorber: under ultrasonication, 0.04 g of Na.sub.2MoO.sub.4 and 0.08 g of thioacetamide were dissolved in 20 mL of the deionized water, 0.04 g of the Ni@PPy nanowires were added, and a resulting mixed solution was continuously and mechanically stirred for 30 min. The entire mixed solution was transferred to an autoclave for reaction at 200° C. for 12 h. After the reaction was completed, a precipitate was separated and washed by centrifugation, followed by freeze-drying at −60° C. to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

Example 4

[0052] A preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber included the following steps:

[0053] (1) Preparation of one-dimensional Ni nanowires: 1.2 g of NaOH was dissolved in 35 mL of ethylene glycol, followed by stirring for 1 h to obtain a solution, 10 mL of a hydrazine hydrate solution as a reducing agent was added to the solution, followed by stirring for 0.5 h to obtain a mixed solution. The mixed solution was placed in a constant-temperature water bath at 80° C. with an external magnetic field, followed by adding 15 mL of a NiCl.sub.2.6H.sub.2O ethylene glycol solution (0.1 mol/L) dropwise to the mixed solution with a syringe. After standing for 5 min, Ni nanowires were collected with a magnet, followed by washing 3 times with absolute ethanol and deionized water, and freeze-drying was conducted at −60° C.

[0054] (2) Preparation of one-dimensional Ni@PPy nanowires: 0.013 g of SDBS and 0.1 mL of pyrrole were dispersed in 50 mL of the deionized water under sonication, and 0.05 g of the Ni nanowires were added to a resulting mixture under the sonication. After mechanically stirring the mixture for 2 h, 5 mL of a FeCl.sub.3 aqueous solution (0.29 mol/L/L) was added, followed by continuing polymerization for another 2 h. A precipitate was separated with a magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

[0055] (3) Preparation of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 wave absorber: under ultrasonication, 0.06 g of Na.sub.2MoO.sub.4 and 0.12 g of thioacetamide were dissolved in 20 mL of the deionized water, 0.04 g of the Ni@PPy nanowires were added, and a resulting mixed solution was continuously and mechanically stirred for 30 min. The entire mixed solution was transferred to an autoclave for reaction at 200° C. for 12 h. After the reaction was completed, a precipitate was separated and washed by centrifugation, followed by freeze-drying at −60° C. to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

Example 5

[0056] A preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber included the following steps:

[0057] (1) Preparation of one-dimensional Ni nanowires: 1.2 g of NaOH was dissolved in 35 mL of ethylene glycol, followed by stirring for 1 h to obtain a solution, 10 mL of a hydrazine hydrate solution as a reducing agent was added to the solution, followed by stirring for 0.5 h to obtain a mixed solution. The mixed solution was placed in a constant-temperature water bath at 80° C. with an external magnetic field, followed by adding 15 mL of a NiCl.sub.2.6H.sub.2O ethylene glycol solution (0.1 mol/L) dropwise to the mixed solution with a syringe. After standing for 5 min, Ni nanowires were collected with a magnet, followed by washing 3 times with absolute ethanol and deionized water, and freeze-drying was conducted at −60° C.

[0058] (2) Preparation of one-dimensional Ni@PPy nanowires: 0.013 g of SDBS and 0.1 mL of pyrrole were dispersed in 50 mL of the deionized water under sonication, and 0.05 g of the Ni nanowires were added to a resulting mixture under the sonication. After mechanically stirring the mixture for 2 h, 5 mL of a FeCl.sub.3 aqueous solution (0.29 mol/L) was added, followed by continuing polymerization for another 2 h. A precipitate was separated with a magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

[0059] (3) Preparation of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 wave absorber: under ultrasonication, 0.08 g of Na.sub.2MoO.sub.4 and 0.16 g of thioacetamide were dissolved in 20 mL of the deionized water, 0.04 g of the Ni@PPy nanowires were added, and a resulting mixed solution was continuously and mechanically stirred for 30 min. The entire mixed solution was transferred to an autoclave for reaction at 200° C. for 12 h. After the reaction was completed, a precipitate was separated and washed by centrifugation, followed by freeze-drying at −60° C. to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

Example 6

[0060] A preparation method of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2-based wave absorber included the following steps:

[0061] (1) Preparation of one-dimensional Ni nanowires: 1.2 g of NaOH was dissolved in 35 mL of ethylene glycol, followed by stirring for 1 h to obtain a solution, 10 mL of a hydrazine hydrate solution as a reducing agent was added to the solution, followed by stirring for 0.5 h to obtain a mixed solution. The mixed solution was placed in a constant-temperature water bath at 80° C. with an external magnetic field, followed by adding 15 mL of a NiCl.sub.2.6H.sub.2O ethylene glycol solution (0.1 mol/L) dropwise to the mixed solution with a syringe. After standing for 5 min, Ni nanowires were collected with a magnet, followed by washing 3 times with absolute ethanol and deionized water, and freeze-drying was conducted at −60° C.

[0062] (2) Preparation of one-dimensional Ni@PPy nanowires: 0.013 g of SDBS and 0.1 mL of pyrrole were dispersed in 50 mL of the deionized water under sonication, and 0.05 g of the Ni nanowires were added to a resulting mixture under the sonication. After mechanically stirring the mixture for 2 h, 5 mL of a FeCl.sub.3 aqueous solution (0.29 mol/L) was added, followed by continuing polymerization for another 2 h. A precipitate was separated with a magnet, followed by washing and freeze-drying at −60° C. to obtain the Ni@PPy nanowires.

[0063] (3) Preparation of a one-dimensional coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 wave absorber: under ultrasonication, 0.1 g of ammonium molybdate and 0.2 g of thiourea were dissolved in 20 mL of the deionized water, 0.04 g of the Ni@PPy nanowires were added, and a resulting mixed solution was continuously and mechanically stirred for 30 min. The entire mixed solution was transferred to an autoclave for reaction at 200° C. for 12 h. After the reaction was completed, a precipitate was separated and washed by centrifugation, followed by freeze-drying at −60° C. to obtain NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

[0064] The technical effects of the disclosure will be described in detail below in conjunction with the accompanying drawings.

[0065] FIG. 2 shows a SEM image of products of each step of Example 1, where (a) and (b) are Ni nanowires, (c) and (d) are Ni@PPy nanowires, and (e) and (f) are coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 nanowires.

[0066] FIG. 3 shows an XPS diagram of a product of Example 1, where (a) is a total spectrum, (b) is an N is spectrum, (c) is a Ni 2p spectrum, (d) is a Mo 3d spectrum, and (e) is an S 2p spectrum.

[0067] In the present disclosure, the electromagnetic parameters and wave-absorbing properties of the coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 samples with different doping (30%, 40% and 50%) prepared in Example 1 were analyzed using a vector network analyzer, and the results were shown in FIG. 4. In the FIG. 4, (c.sub.1) (c.sub.2) (c.sub.3) in are reflection loss curves and three-dimensional reflection loss diagrams of the coralloid NiS/Ni.sub.3S.sub.4@PPy@MoS.sub.2 samples with 50% doping prepared in Example 1 under different thicknesses. From (c.sub.1) in FIG. 4, it can be found that when the thickness is 2.29 mm, the wave absorber has an optimal absorption performance, with a minimum reflection loss of −51.29 dB, a corresponding frequency of 10.1 GHz, an effective absorption bandwidth of less than −10 dB of 3.24 GHz, which shows an excellent absorption performance.

[0068] The foregoing are merely descriptions of the specific embodiments of the present disclosure, and the protection scope of the present disclosure is not limited thereto. Any modification, equivalent replacement, improvement, etc. made within the technical scope of the present disclosure by a person skilled in the art according to the spirit and principle of the present disclosure shall fall within the protection scope of the present disclosure.

[0069] Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present disclosure. Embodiments of the present disclosure have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present disclosure.

[0070] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Unless indicated otherwise, not all steps listed in the various figures need be carried out in the specific order described.