CN108480623B

CN108480623B - Macroscopic preparation method of carbon-coated metal nanoparticles

Info

Publication number: CN108480623B
Application number: CN201810379138.5A
Authority: CN
Inventors: 兰金叻; 王佳煜; 金玉强; 于运花; 杨小平
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2018-04-25
Filing date: 2018-04-25
Publication date: 2020-12-15
Anticipated expiration: 2038-04-25
Also published as: CN108480623A

Abstract

The invention relates to a macroscopic preparation method of carbon-coated metal nano particles, which solves the technical problems of high cost and low yield of the carbon-coated metal nano particles prepared by the existing method, and comprises the following steps: (1) weighing commercial micromolecular metal organic salt, placing the commercial micromolecular metal organic salt in a crucible, and placing the crucible in a carbonization furnace; (2) under the specific atmosphere which is kept continuously, controlling the heating rate to be 2-5 ℃/min, heating to 400-700 ℃, and preserving heat for 2-3 h; (3) and after the temperature of the furnace body is naturally reduced to the room temperature, taking out the crucible to prepare the carbon/metal nano composite. The invention can be widely used in the fields of magnetic recording, electromagnetic shielding, electrostatic printing, electrocatalysis, lithium/sodium ion secondary battery cathode materials and medical antibacterial materials.

Description

Macroscopic preparation method of carbon-coated metal nanoparticles

Technical Field

The invention relates to the field of material preparation, in particular to a macro preparation method of carbon-coated metal nanoparticles.

Background

Since the discovery of substance-fillable carbon nanotubes in 1991, coating of a second phase substance such as metal nanoparticles with a carbon shell has been extensively studied by researchers. The existence of the external carbon shell solves the outstanding problems existing in the nano-particles: 1. instability of the material itself: easy agglomeration and easy oxidation; 2. certain metallotoxicity attacks biological substrates.

At present, the synthesis methods of the metal nano particles and the carbon composite mainly comprise an arc discharge method, a chemical vapor deposition method, a liquid phase impregnation method and a pyrolysis method. In comparison, the arc discharge method has complex equipment, difficult control of process parameters, more byproducts brought by high-temperature reaction and higher cost; similarly, although the chemical vapor deposition method has a relatively simple process, the product separation is relatively difficult, and the purity needs to be improved; the liquid phase impregnation method sometimes results in a product with large gaps between carbon layers and particles and a low yield. Typical pyrolysis processes produce desirable carbon-coated metal nanoparticles and also find metal and carbon sources that match decomposition temperatures and solubilities.

Disclosure of Invention

The invention aims to solve the problems of high cost and low yield of carbon-coated metal nano-particles prepared by the existing production method, and provides a preparation method which is simple in production process, low in cost and capable of realizing macro preparation of the carbon-coated metal nano-particles.

Therefore, the invention provides a macroscopic preparation method of carbon-coated metal nano particles, which comprises the following steps: (1) weighing commercial micromolecular metal organic salt, placing the commercial micromolecular metal organic salt in a crucible, and placing the crucible in a carbonization furnace; (2) under the specific atmosphere which is kept continuously, controlling the heating rate to be 2-5 ℃/min, heating to 400-700 ℃, and preserving heat for 2-3 h; (3) and after the temperature of the furnace body is naturally reduced to the room temperature, taking out the crucible to prepare the carbon/metal nano composite. The commercialized small molecular metal organic salt in the step (1) is one or more of citrate, acetate or antimony potassium tartrate. The citrate is one or more of ferric citrate, bismuth citrate, cobalt citrate, ferric ammonium citrate, nickel citrate, zinc citrate, titanium citrate, zirconium citrate, stannic citrate, magnesium citrate or copper citrate. The acetate comprises one or more of antimony acetate, lead acetate and zinc acetate. In the step (2), the specific atmosphere is nitrogen, argon or a mixed gas of hydrogen and argon, and the volume ratio of the hydrogen to the argon is 1: 19.

Aiming at the defects of the prior art, the invention develops a novel universal method for carbon-coated metal nanoparticles, and the method directly adopts commercial metal organic salts as precursors, thereby reducing the reaction cost, being more environment-friendly and leading the synthesis of carbon-coated metal to be simpler and more convenient. The preparation process is simple and easy to implement, has good controllability, can prepare the compound of various metal nano particles and carbon in one step, and is convenient for industrial popularization and application; the preparation process of the invention directly uses commercial micromolecule metal organic salt as a precursor, has high product purity and good uniformity, greatly reduces the cost, and is environment-friendly and pollution-free. In addition, the method can obtain powder with smaller particle size by adjusting different treatment temperatures.

Drawings

FIG. 1 is an XRD pattern of carbon/metal Bi nanoparticles prepared in examples 1-3 of the present invention.

FIG. 2 is a TEM image of carbon/metal Bi nanoparticles prepared in example 3 of the present invention.

Fig. 3 is a graph of the lithium battery cycling performance of carbon/metal Bi nanoparticles prepared in examples 1-3 of the present invention.

Detailed Description

The invention will be better understood from the following examples. However, those skilled in the art will readily appreciate that the description of the embodiments is only for illustrating the present invention and should not be taken as limiting the invention as described in the claims.

Example 1

(1) Weighing 10g of commercial bismuth citrate, placing the commercial bismuth citrate into a crucible, and placing the crucible into a carbonization furnace;

(2) controlling the heating rate to be 2 ℃/min under the continuously maintained nitrogen atmosphere, heating to 400 ℃, and preserving heat for 2 h;

(3) and after the temperature of the furnace body is naturally reduced to the room temperature, taking out the crucible to obtain the carbon/metal Bi nanoparticle composite.

Example 2

(2) controlling the heating rate to be 4 ℃/min under the continuously maintained argon atmosphere, heating to 550 ℃, and preserving heat for 2.5 h;

Example 3

(2) controlling the heating rate to be 5 ℃/min under the continuously maintained nitrogen atmosphere, heating to 700 ℃, and preserving heat for 3 h;

Example 4

(1) Weighing 10g of commercial tin citrate, placing the weighed tin citrate into a crucible, and placing the crucible into a carbonization furnace;

(2) in sustained maintenance of H₂Controlling the heating rate to be 5 ℃/min under the/Ar mixed atmosphere, heating to 400 ℃, and preserving heat for 3 h;

(3) and after the temperature of the furnace body is naturally reduced to the room temperature, taking out the crucible to obtain the carbon/metal Sn nanoparticle composite.

Example 5

(1) Weighing 10g of commercial antimony potassium tartrate, placing the weighed antimony potassium tartrate in a crucible, and placing the crucible in a carbonization furnace;

(2) controlling the heating rate to be 2 ℃/min under the continuously maintained nitrogen atmosphere, heating to 700 ℃, and preserving heat for 2 h;

(3) and after the temperature of the furnace body is naturally reduced to the room temperature, taking out the crucible to obtain the carbon/metal Sb nanoparticle composite.

Fig. 1 and 2 show that at three temperatures (500 ℃, 600 ℃, 700 ℃), the product is a composite of metal Bi nanoparticles and C, and when the composite is used as a lithium battery negative electrode, the composite shows excellent cycling stability, the reversible capacity is greatly improved compared with bulk Bi metal, and the lithium storage performance is better than that of the commercial graphite negative electrode shown in fig. 3.

Claims

1. A macro preparation method of carbon-coated metal nano particles is characterized by comprising the following steps: (1) weighing commercial micromolecular metal organic salt, placing the commercial micromolecular metal organic salt in a crucible, and placing the crucible in a carbonization furnace; (2) under the specific atmosphere which is kept continuously, controlling the heating rate to be 2-5 ℃/min, heating to 400-700 ℃, and preserving heat for 2-3 h; (3) after the temperature of the furnace body is naturally reduced to room temperature, taking out the crucible to prepare carbon-coated metal nano particles; the commercialized small molecular metal organic salt in the step (1) is one or more of citrate, acetate or antimony potassium tartrate; the specific atmosphere in the step (2) is nitrogen, argon or a mixed gas of hydrogen and argon; in the hydrogen and argon gas mixed gas, the volume ratio of hydrogen to argon gas is 1: 19.

2. the macro-preparation method of carbon-coated metal nanoparticles of claim 1, wherein the citrate is one or more of ferric citrate, bismuth citrate, cobalt citrate, ferric ammonium citrate, nickel citrate, zinc citrate, titanium citrate, zirconium citrate, tin citrate, magnesium citrate, or copper citrate.

3. The macro-scale preparation method of carbon-coated metal nanoparticles of claim 1, wherein the acetate comprises one or more of antimony acetate, lead acetate, and zinc acetate.