A method for preparing compositionally tunable multi-component nanoalloy powders with controllable carbon structure coating using plasma.

Abstract

This invention provides a method for preparing a multi-component nano-alloy powder with controllable carbon structure coating using plasma. The powder has a coating structure, wherein the coating layer consists of one or both of amorphous carbon and graphite, with a thickness of 5-50 nm; the core is an alloy particle with a particle size ranging from 5-200 nm. This invention uses sublimable cyclopentadienyl metal compounds as both the carbon and metal sources, and plasma as the synthesis environment, reducing reactant toxicity and environmental pollution. The preparation speed is relatively fast, which is beneficial for mass production. The carbon content and structure of the carbon-coated nano-alloy powder, as well as its crystallinity and alloy composition, can be controlled by adjusting the plasma generator power, the residence time of the carrier gas in the plasma region, and the carrier gas flow rate.

Description

Technical Field

[0001] This invention belongs to the field of nanofunctional powder materials and powder preparation technology, specifically relating to a multi-component nanoalloy powder with controllable carbon structure coating and its preparation method. Background Technology

[0002] Metallic magnetic nanoparticles, due to their excellent magnetic and electrical conductivity, have wide applications in catalysis, batteries, sensors, powder metallurgy, and magnetohydrodynamics. However, their performance degrades easily due to oxidation when exposed to air and water. Graphene, a single-layer material composed of carbon atoms arranged in a honeycomb structure, possesses excellent electrical and thermal conductivity, mechanical strength, and chemical stability. Therefore, composite materials formed by carbon-coating metallic nanoparticles can improve their electrical and thermal conductivity and mechanical properties, and effectively prevent the oxidation of the nanoparticles. This composite material can be well applied in various fields such as electromagnetic shielding materials, electromagnetic wave absorbing materials, wastewater treatment, catalysis, battery electrodes, and magnetohydrodynamics.

[0003] Currently, the main methods for synthesizing carbon-coated nano-metal particles include chemical vapor deposition, pyrolysis, and arc discharge. In these methods, carbon sources and reducing agents must be used to help carbon grow on metal powders, and the carbon content, carbon structure, and crystallinity of the products cannot be controlled.

[0004] The application publication number is CN1161973595A, the publication date is June 2, 2023, and the patent name is: A method for preparing graphene-coated metal nanoparticles. It invented a method for preparing graphene-coated metal nanoparticles, which uses tartrate metal as raw material to obtain graphene-coated metal nanoparticles by pyrolysis at high temperature.

[0005] The application publication number is CN114572971A, the publication date is June 3, 2022, and the patent name is: A method for preparing graphene on the surface of copper powder. It invented a method for coating graphene on the surface of copper powder, which uses methane as a carbon source and calcines it at high temperature to obtain graphene-coated copper powder.

[0006] The application publication number is CN11103248A, the publication date is May 29, 2020, and the patent title is: A method for preparing graphene-coated transition metal carbide nanocapsules and their application in microwave catalysis. The method involves placing a metal block on a DC arc plasma device, introducing hydrogen, inert gas, carbon-containing gas, etc., and then evaporating the metal through a DC arc. After cooling, graphene-coated metal carbide nanocapsules are formed.

[0007] The above methods each have their own advantages, but they are also accompanied by many problems, such as complex preparation processes, long production cycles, high manufacturing costs, high risk of gas sources used, and simple product structures, which affect the production and application of carbon-coated metal nanoparticles. Summary of the Invention

[0008] To address the problems existing in the above-mentioned background technology, the present invention aims to provide a new method for preparing carbon-coated nano-alloy powder.

[0009] This invention uses cyclopentadienyl metal compounds as the sole raw material, sublimates them, and then introduces them into a plasma reaction chamber via a carrier gas. Without adding an additional carbon source, it can rapidly generate carbon-coated nano-alloy powders with controllable carbon content and structure, controllable crystallinity of the metal core, and controllable alloy composition in one step.

[0010] The technical principle of this invention is:

[0011] Taking advantage of the sublimation property of metallocene compounds, they are first sublimated into a gaseous state in a heating chamber. Then, ammonia gas is introduced to carry the metallocene compound vapor into a plasma reaction chamber. Under the action of plasma, the chemical bonds of the metallocene compound break, forming C atoms, H atoms, and CH atoms. x Active atoms such as functional groups and metal atoms, as well as a large amount of metal carbon compounds, aggregate to form nanocrystal nuclei. During the cooling process, due to the large temperature difference between the inside and outside of the particles, carbon gradually precipitates from the inside, forming a coating layer. After cooling, carbon-coated nanoalloy powder is obtained.

[0012] The release of H radicals from the decomposition of different free radicals in an NH3 plasma exhibits energy differences. The ion state of the NH3 plasma can be controlled by adjusting the power of the plasma generator. NH2+e - →NH+H+e - NH+e - →N+H+e - Through collisional dissociation, NH3, NH2, and NH radicals release H radicals, which then react with CH radicals released from the cyclopentadiene group. x Free radicals react with C free radicals to form stable CH compounds, which are then released in gaseous form, thereby controlling the C content and structure of the product.

[0013] The residence time t of the carrier gas in the plasma region is controlled by controlling the length L of the plasma region and the gas flow rate Q. L - plasma region length, Q - carrier gas flow rate, A - inlet pipe cross-sectional area) to achieve control over the crystallinity of the product core;

[0014] The molar ratio of cyclopentadienyl metal compounds entering the plasma reaction region per unit time can be controlled by controlling the flow rate of the carrier gas, so as to achieve adjustable product composition. For example, in Example 2, the ammonia flow rate of the ferrocene fluidized bed is 2 slpm (liters / minute), and the ammonia flow rate of the nickel-ferrocene fluidized bed is 2 slpm. The product has an Fe to Ni atomic ratio of 1:1, that is, the metal core is FeNi.

[0015] To achieve the above objectives, the technical solution of the present invention is as follows:

[0016] Step 1: After evacuating the plasma reaction chamber, fill it with nitrogen gas, then evacuate again and fill it with argon gas until the entire reaction chamber is filled with argon gas to a density of 10. 5 Pa, meaning to isolate from air;

[0017] Step 2: Introduce ammonia gas to adjust the partial pressure of ammonia gas, and turn on the power supply of the plasma generator to obtain a stable ammonia plasma flow;

[0018] Step 3: Sublimate the metallocene compound in multiple sublimation chambers respectively;

[0019] Step 4: Introduce ammonia gas into the sublimation chamber and adjust the ammonia gas flow rate to send the cyclopentadienyl metal compound vapor into the plasma region through the ammonia gas.

[0020] Step 5: Adjust the plasma generator power and the length of the plasma region;

[0021] Step 6: The vapor of cyclohexane metal compounds and ammonia gas begin to react in a plasma reactor at a set power and zone length to generate carbon-coated nano-alloy powder.

[0022] Step 6: Cool the reaction chamber to room temperature under ammonia protection conditions and collect the powder, which is carbon-coated nano-alloy powder.

[0023] The metallocene compound used is ferrocene (C2). 10 H 10 Fe), nickel cadmium (C) 10 H 10 Ni), cobalt-1,C 10 H 10 Co) and manganese dicerocene (C) 10 H 10 Mn serves as both a metal source and a carbon source.

[0024] Furthermore, the temperature of the ferrocene sublimation chamber is set to 100-160℃, the temperature of the nickel ferrocene sublimation chamber is set to 120-160℃, the temperature of the cobalt ferrocene sublimation chamber is set to 40-100℃, and the temperature of the manganese ferrocene sublimation chamber is set to 110-150℃. The carrier gas is ammonia, and the gas flow rate Q is adjustable.

[0025] The molar ratio of cyclopentadienyl metal compounds entering the plasma reaction region per unit time is controlled by adjusting the carrier gas flow rate. This allows for the determination of elements A, B, C, and D (Fe, Co, Ni, Mn), and molar fractions of each component (x, y, z, p). The chemical formula is A. x B y C z D p The alloy core, where x+y+z+p=1, x,y,z,p≥0, and at least two of these variables>0, ultimately achieves adjustable phase and continuously adjustable composition. For example, in Example 2, the ammonia flow rate in the ferrocene fluidized bed is 2 slpm (liters / minute), and the ammonia flow rate in the nickel-ferrocene fluidized bed is 2 slpm. The product has an Fe / Ni atomic ratio of 1:1, meaning the metal core is FeNi.

[0026] The plasma generator types include one or more of inductively coupled plasma, microwave coupled plasma, and capacitively coupled plasma, with adjustable generator power and adjustable effective plasma region in the reaction chamber.

[0027] Furthermore, the residence time t of the carrier gas in the plasma region is controlled by controlling the plasma region length L and the gas flow rate Q. L - plasma region length, Q - carrier gas flow rate, A - inlet pipe cross-sectional area) to achieve control over the crystallinity of the product core.

[0028] Furthermore, the ion state of the NH3 plasma can be controlled by adjusting the power of the plasma generator. NH2+e - →NH+H+e - NH+e - →N+H+e - Through collisional dissociation, NH3, NH2, and NH radicals release H radicals, which then react with CH radicals released from the cyclopentadiene group. x Free radicals combine with C free radicals to form stable CH compounds, which are then released in gaseous form, thereby controlling the carbon content and structure of the product.

[0029] The advantages of this invention are:

[0030] (1) Using metallocene compounds as metal and carbon sources and plasma as the reaction environment reduces pollution from reactants. No additional carbon source gas is needed, making the experiment safer and conducive to mass production.

[0031] (2) By adjusting the flow rate of the carrier gas during the preparation process, the molar ratio of cyclopentadienyl metal compounds entering the plasma reaction region per unit time can be controlled, and binary, ternary, and quaternary carbon-coated nanoalloy powders with different compositions and contents can be obtained.

[0032] (3) By adjusting the length of the plasma region during the preparation process, the residence time of the gas flow in the plasma region can be controlled, thereby achieving the regulation of the crystallinity of the metal core.

[0033] (4) During the preparation process, the carbon content and structure can be controlled by adjusting the power of the plasma generator to control the degree of carrier gas decomposition.

[0034] (5) The carbon-coated nano-alloy powder prepared by the method of the present invention has a small and uniform particle size, good sphericity, and a simple and fast preparation process.

[0035] (6) The carbon-coated nanoparticles prepared by the method of the present invention have good electrical properties, magnetic properties and chemical stability, and have broad application prospects in catalysis, electromagnetic wave absorption, electromagnetic wave shielding, battery electrodes, magnetofluids and other fields. Attached Figure Description

[0036] Figure 1 The images show the XRD and TEM images of the carbon-coated nano-alloy powder prepared in Example 1.

[0037] Figure 2 The images show the XRD and TEM images of the carbon-coated nano-alloy powder prepared in Example 2.

[0038] Figure 3 The images show the XRD and TEM images of the carbon-coated nano-alloy powder prepared in Example 3.

[0039] Figure 4 The images show the XRD and TEM images of the carbon-coated nano-alloy powder prepared in Example 4.

[0040] Figure 5 The images show the XRD and TEM images of the carbon-coated nano-alloy powder prepared in Example 5.

[0041] Figure 6 Schematic diagram of a plasma reaction device with controllable plasma region length. Detailed Implementation

[0042] The present invention will be further described below with reference to embodiments and accompanying drawings, but should not be construed as limiting the present invention.

[0043] The method for preparing controllable carbon structure-coated, compositionally adjustable multi-component nano-alloy powder proposed in this invention includes the following steps:

[0044] After evacuating the plasma reaction chamber, nitrogen gas is introduced, followed by another evacuation and then argon gas is introduced until the entire reaction chamber is filled with argon gas, reaching a density of 10. 5 Pa, meaning to isolate from air;

[0045] Ammonia gas is introduced to adjust the partial pressure of ammonia gas, and the power supply of the plasma generator is turned on to obtain a stable ammonia plasma flow.

[0046] Metallocene compounds were sublimated in multiple sublimation chambers.

[0047] In a plasma reactor, carbonyl metal compound vapor and ammonia gas react to generate carbon-coated nano-alloy powder at a set power and zone length.

[0048] Ammonia gas was introduced into the sublimation chamber and the ammonia gas flow rate was adjusted to send the cyclopentadienyl metal compound vapor into the plasma region through the ammonia gas.

[0049] Adjust the plasma generator power and the length of the plasma region;

[0050] The reaction chamber was cooled to room temperature under ammonia protection conditions, and the collected powder was carbon-coated nano-alloy powder.

[0051] The equipment used can be an existing plasma generating device. In this embodiment, the equipment disclosed in patent CN104851548A is specifically used.

[0052] The specific preparation process of the carbon-coated nano-alloy powder in the examples is as follows:

[0053] Example 1:

[0054] Using ferrocene and nickel styrene as raw materials, the plasma reaction chamber was evacuated and then filled with nitrogen. This process was repeated, followed by evacuation and then filling with argon until the entire reaction chamber was filled with argon gas, reaching a density of 10. 5 Pa, isolated from air. The first stage plasma generator power was set to 3kW, the second stage plasma generator power was set to 0kW, and the third stage plasma generator power was set to 0kW, with a total power of 3kW. Ammonia gas was used to excite stable ammonia plasma, and the effective reaction length of the gas flow through the plasma region was 10cm. The temperature of the ferrocene sublimation chamber was set to 130℃, and the temperature of the nickel serotonide sublimation chamber was set to 150℃. 2 slpm of ammonia gas was introduced into the ferrocene fluidized bed, and 1.125 slpm of ammonia gas was introduced into the nickel serotonide fluidized bed. The vapors of both were introduced into the plasma flame, and carbon-coated nano-Fe was obtained through plasma reaction. 0.64 Ni 0.36 The alloy powder, and the XRD pattern of the product are shown below. Figure 1 As shown in (a), the TEM image is as follows: Figure 1 As shown in (b) and (c).

[0055] Depend on Figure 1 As shown in (a), the product phase prepared in Example 1 consists of carbon and Fe. 0.64 Ni 0.36 Composed of. Figure 1 As shown in (b) and (c), the prepared product exhibits a distinct coating structure, with an amorphous carbon layer coating the core. Measurements of the interplanar spacing of the core revealed it to be approximately 0.207 nm, which is consistent with the properties of Fe. 0.64 Ni 0.36 (111) The interplanar spacings are similar, consistent with the XRD data. The XRD diffraction peaks are low in intensity and wide, which proves that the prepared carbon-coated Fe... 0.64 Ni 0.36 Low crystallinity.

[0056] Example 2:

[0057] Using ferrocene and nickel styrene as raw materials, the plasma reaction chamber was evacuated and then filled with nitrogen. This process was repeated, followed by evacuation and then filling with argon until the entire reaction chamber was filled with argon gas, reaching a density of 10. 5 Pa, isolated from air. The power of the first-stage plasma generator was set to 3kW, the power of the second-stage plasma generator was set to 0kW, and the power of the third-stage plasma generator was set to 0kW, with a total power of 3kW. Ammonia gas was used to excite stable ammonia plasma, and the effective reaction length of the gas flow through the plasma region was 10cm. The temperature of the ferrocene sublimation chamber was set to 130℃, and the temperature of the nickel dicene sublimation chamber was set to 150℃. 2slpm of ammonia gas was introduced into each of the two sublimation chambers to carry the ferrocene and nickel dicene vapors into the plasma flame. After plasma reaction, carbon-coated nano-FeNi alloy powder was obtained. The XRD pattern of the product is shown in the figure. Figure 2 As shown in (a), the TEM image is as follows: Figure 2 As shown in (b) and (c).

[0058] Depend on Figure 2 As shown in (a), the product phase prepared in Example 2 consists of carbon and FeNi. Figure 2 As can be seen from (b) and (c), the prepared product has a distinct coating structure, with an amorphous carbon layer coating the core.

[0059] Example 3:

[0060] Using ferrocene and nickel styrene as raw materials, the plasma reaction chamber was evacuated and then filled with nitrogen. This process was repeated, followed by evacuation and then filling with argon until the entire reaction chamber was filled with argon gas, reaching a density of 10. 5Pa, isolated from air. The power of the first-stage plasma generator was set to 3kW, the power of the second-stage plasma generator was set to 0kW, and the power of the third-stage plasma generator was set to 0kW, with a total power of 3kW. Ammonia gas was used to excite stable ammonia plasma, and the effective reaction length of the gas flow through the plasma region was 10cm. The temperature of the ferrocene sublimation chamber was set to 130℃, and the temperature of the nickel ferrocene sublimation chamber was set to 150℃. 2 slpm of ammonia gas was introduced into the ferrocene fluidized bed, and 6 slpm of ammonia gas was introduced into the nickel ferrocene fluidized bed. The vapors of both were introduced into the plasma flame, and carbon-coated nano-FeNi3 alloy powder was obtained through plasma reaction. The XRD pattern of the product is shown in the figure. Figure 3 As shown in (a), the TEM image is as follows: Figure 3 As shown in (b) and (c).

[0061] Depend on Figure 3 As shown in (a), the product phase prepared in Example 3 consists of carbon and FeNi3. Figure 3 As can be seen from (b) and (c), the prepared product has a distinct coating structure, with an amorphous carbon layer coating the core.

[0062] Example 4:

[0063] Using ferrocene and nickel styrene as raw materials, the plasma reaction chamber was evacuated and then filled with nitrogen. This process was repeated, followed by evacuation and then filling with argon until the entire reaction chamber was filled with argon gas, reaching a density of 10. 5 Pa, isolated from air. The power of the first-stage plasma generator was set to 4.5kW, the power of the second-stage plasma generator was set to 4.5kW, and the power of the third-stage plasma generator was set to 4.5kW, with a total power of 13.5kW. Ammonia gas was used to excite stable ammonia plasma, and the effective reaction length of the gas flow through the plasma was 30cm. The temperature of the ferrocene sublimation chamber was set to 130℃, and the temperature of the nickel dicene sublimation chamber was set to 150℃. Ammonia gas at 2slpm was introduced into each of the two sublimation chambers to carry the ferrocene and nickel dicene vapors into the plasma flame. After plasma reaction, carbon-coated nano-FeNi alloy powder was obtained. The XRD pattern of the product is shown in the figure. Figure 4 As shown in (a), the TEM image is as follows: Figure 4 As shown in (b) and (c).

[0064] Depend on Figure 4 As shown in (a), the product phase prepared in Example 1 consists of carbon and FeNi. Figure 1As shown in (b) and (c), the prepared product exhibits a distinct core-shell structure, with the core encapsulated by multiple layers of graphene sheets. Measurements of the interplanar spacing of the core and shell revealed that the core's interplanar spacing is approximately 0.206 nm, similar to that of FeNi(111) and consistent with XRD data. The shell's interplanar spacing is approximately 0.35 nm, similar to that of the (002) plane of graphene, indicating that the shell is composed of multiple layers of graphene. The high intensity and sharpness of the XRD diffraction peaks demonstrate the high crystallinity of the prepared sample.

[0065] Example 5:

[0066] Using ferrocene and nickel styrene as raw materials, the plasma reaction chamber was evacuated and then filled with nitrogen. This process was repeated, followed by evacuation and then filling with argon until the entire reaction chamber was filled with argon gas, reaching a density of 10. 5 Pa, isolated from air. The power of the first-stage plasma generator was set to 4.5kW, the power of the second-stage plasma generator was set to 4.5kW, and the power of the third-stage plasma generator was set to 4.5kW, with a total power of 13.5kW. Ammonia gas was used to excite stable ammonia plasma, and the effective reaction length of the gas flow through the plasma was 30cm. The temperature of the ferrocene sublimation chamber was set to 130℃, and the temperature of the nickel serotonide sublimation chamber was set to 150℃. 2 slpm of ammonia gas was introduced into the ferrocene fluidized bed, and 6 slpm of ammonia gas was introduced into the nickel serotonide fluidized bed. The vapors of both were introduced into the plasma flame, and carbon-coated nano-FeNi3 alloy powder was obtained through plasma reaction. The XRD pattern of the product is shown in the figure. Figure 5 As shown in (a), the TEM image is as follows: Figure 5 As shown in (b) and (c).

[0067] Depend on Figure 5 As shown in (a), the product phase prepared in Example 1 consists of carbon and FeNi3. Figure 5 As can be seen from (b) and (c), the prepared product has a distinct core-shell structure, with the core being covered by a multi-layered graphene shell.

[0068] Example 6:

[0069] Using ferrocene, nickel succinate, and cobalt succinate as raw materials, the plasma reaction chamber was evacuated and then filled with nitrogen. This process was repeated, followed by evacuation and then filling with argon gas until the entire reaction chamber was filled with argon gas to a density of 10. 5After isolating the air and setting the reaction section power, ammonia gas was used to excite a stable ammonia plasma. The temperature of the ferrocene sublimation chamber was set to 130℃, the nickel ferrocene sublimation chamber to 150℃, and the cobalt ferrocene sublimation chamber to 60℃. X slpm of ammonia gas was introduced into the ferrocene fluidized bed, Y slpm of ammonia gas into the nickel ferrocene fluidized bed, and Z slpm of ammonia gas into the cobalt ferrocene fluidized bed. The vapors of these three gases were introduced into the plasma flame, and carbon-coated nano-Fe was obtained through plasma reaction. X Ni Y Co Z Alloy powder.

[0070] Example 7:

[0071] Using ferrocene, nickel succinate, cobalt succinate, and manganese succinate as raw materials, the plasma reaction chamber was evacuated and then filled with nitrogen. This process was repeated, followed by evacuation and then filling with argon gas until the entire reaction chamber was filled with argon gas to a density of 10. 5 After isolating the air and setting the reaction section power, ammonia gas was used to excite a stable ammonia plasma. The temperature of the ferrocene sublimation chamber was set to 130℃, the nickel ferrocene sublimation chamber to 150℃, the cobalt ferrocene sublimation chamber to 60℃, and the manganese ferrocene sublimation chamber to 120℃. Xslpm ammonia gas was introduced into the ferrocene fluidized bed, Yslpm ammonia gas into the nickel ferrocene fluidized bed, Zslpm ammonia gas into the cobalt ferrocene fluidized bed, and Pslpm ammonia gas into the manganese ferrocene fluidized bed. The vapors of these four gases were introduced into the plasma flame, and carbon-coated nano-Fe2 was obtained through plasma reaction. X Ni Y Co Z Mn P Alloy powder.

[0072] The above embodiments are merely illustrative of the technical solution for those skilled in the art and are not intended to limit the invention. Any modifications or improvements made based on the technical solution of this invention are within the scope of protection of this invention.

Claims

1. A method for preparing a multi-component nano-alloy powder with controllable carbon structure coating and adjustable composition, characterized in that, The prepared multi-component nano-alloy powder has a coating structure, wherein the coating layer is composed of carbon and the coating layer thickness is 5-50 nm; the core is a binary, ternary or quaternary alloy particle with controllable crystallinity, with a particle size of 5-200 nm and a spherical shape. Includes the following steps: After evacuating the plasma reaction chamber, nitrogen gas is introduced, followed by another evacuation and then argon gas is introduced until the entire reaction chamber is filled with argon gas, reaching a density of 10. 5 Pa, meaning to isolate from air; Ammonia gas is introduced to adjust the partial pressure of ammonia gas, and the power supply of the plasma generator is turned on to obtain a stable ammonia plasma flow. The cyclopentadiene metal compounds were sublimated in multiple sublimation chambers; the temperature of the ferrocene sublimation chamber was set to 100-160℃, the temperature of the nickel cyclopentadiene sublimation chamber was set to 120-160℃, the temperature of the cobalt cyclopentadiene sublimation chamber was set to 40-100℃, and the temperature of the manganese cyclopentadiene sublimation chamber was set to 110-150℃; the carrier gas was ammonia; the carrier gas flow rate Q was adjustable. Ammonia gas was introduced into the sublimation chamber to send the vapor of cyclopentadienyl metal compounds into the plasma region. Adjust the plasma generator power and the length of the plasma region; In a plasma reactor, carbonyl metal compound vapor and ammonia gas react to generate carbon-coated nano-alloy powder at a set power and zone length. The reaction chamber is cooled to room temperature under ammonia protection conditions, and the collected powder is carbon-coated nano-alloy powder.

2. The method according to claim 1, characterized in that, The plasma generator type includes one or more of inductively coupled plasma generators, microwave plasma generators, and capacitively coupled plasma generators, with adjustable generator power and adjustable effective plasma region in the reaction chamber.

3. The method according to claim 1, characterized in that, Plasma reaction regions of different lengths can be obtained by adjusting the lengths of inductive and capacitive plasma arc columns and the number of microwave plasma layers.

4. The controllable carbon structure-coated, compositionally tunable multi-component nano-alloy powder prepared by the method of claim 1, characterized in that, Its magnetic core phases are represented by A, B, C, and D, which represent Fe, Co, Ni, and Mn elements, respectively, and x, y, z, and p, which represent the mole fraction of each component. Its chemical formula is... ,in , And at least two of them are variables .

5. The controllable carbon structure-coated, compositionally tunable multi-component nano-alloy powder prepared by the method of claim 1, characterized in that... The carbon structure is one or both of amorphous carbon and graphitic carbon.

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