CN113265662A

CN113265662A - Method for enhancing oxidation resistance of copper as material

Info

Publication number: CN113265662A
Application number: CN202110748103.6A
Authority: CN
Inventors: 隋永明; 刘瑀墨; 邹勃
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2021-07-02
Filing date: 2021-07-02
Publication date: 2021-08-17

Abstract

The invention discloses a method for enhancing the oxidation resistance of copper as a bulk material, and belongs to the technical field of improving the oxidation resistance of transition metals. The preparation method comprises the following steps: preparing a sodium citrate solution by using nitrogen-saturated deionized water as a solvent, mixing and sealing a bulk material copper and the sodium citrate solution in a stainless steel reaction kettle, heating to 190 ℃ within 40 minutes, keeping the temperature for 24 hours, naturally cooling, washing and the like. The method has the advantages of simple operation, low cost and no pollution, can be applied in large scale, and the synthesized Cu-TA has stronger oxidation resistance in air, strong alkaline solution and strong corrosive solution and can keep the original electrical conductivity and thermal conductivity of Cu.

Description

Method for enhancing oxidation resistance of copper as material

Technical Field

The invention belongs to the technical field of improving the oxidation resistance of transition metal, and particularly relates to a method for improving the oxidation resistance of bulk material copper.

Background

In daily production and life, the noble metals Au, Ag and Cu are used everywhere. Cu is one of the earliest metals found by humans and is also the first metal for human production. Cu has good thermal conductivity, electrical conductivity, ductility and overall non-toxicity, compared with noble metal silver, the electrical conductivity of copper is slightly smaller (94%), but the storage capacity in earth crust is more than 1000 times of silver, so that the Cu can be an effective substitute of Ag and can effectively reduce the cost for manufacturing devices.

However, Cu is easily oxidized, so how to improve the oxidation resistance of Cu becomes an important issue of concern. Various surface modifications have been attempted to slow down oxidative processes such as alloying and electroplating by preventing the Cu atoms from coming into direct contact with air, but these tend to degrade some physical properties (e.g., thermal and electrical conductivity and color) and introduce deleterious elements such as chromium and nickel. Although efforts have been made to develop surface passivation techniques that utilize organic molecules, inorganic materials, or carbon-based materials as oxidation inhibitors, there have been limited success.

Therefore, the method for improving the oxidation resistance of the Cu, which is green, pollution-free and applicable in large scale, has important academic significance and application value on the premise of not influencing the electrical conductivity and the thermal conductivity of the Cu.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method overcomes the defects in the prior art, is simple to operate, is green and pollution-free on the premise of not influencing the electrical conductivity and the thermal conductivity of Cu, and can be applied on a large scale. The method adopts a hydrothermal method: the temperature is 190 ℃, and the copper foil is hydrothermally treated by a sodium citrate solution.

The invention adopts the following specific technical scheme:

a method for enhancing the oxidation resistance of copper as a material of a body comprises the following steps:

1) putting deionized water into a three-type bottle, introducing nitrogen into the deionized water for 1 hour through a Leideke system, and removing impurity gas in the deionized water to obtain nitrogen-saturated deionized water;

2) preparing a sodium citrate solution with the concentration of 7.3 millimoles per liter by taking nitrogen-saturated deionized water as a solvent and sodium citrate as a solute, and stirring the solution uniformly;

3) mixing copper and sodium citrate solution and sealing in a stainless steel reaction kettle;

4) placing the stainless steel reaction kettle in the step 3) into a forced air drying oven, heating to 190 ℃ within 40 minutes, and keeping the temperature at 190 ℃ for 24 hours to obtain Cu-TA treated by sodium citrate;

5) and naturally cooling to room temperature, washing the free sodium citrate on the surface of the Cu-TA by deionized water, and then sucking the surface by using filter paper to obtain the bulk material copper Cu-TA with enhanced oxidation resistance.

The bulk material copper is preferably 2 x 2cm²Square copper platinum.

Has the advantages that:

1. in the invention, only one reagent of sodium citrate participates in the preparation of Cu-TA, the operation is simple, the cost is low, and the method can be applied in large scale.

2. The reagent sodium citrate participating in the synthesis is non-toxic, and avoids any pollution to the environment.

3. The Cu-TA synthesized by the method has stronger oxidation resistance in air, strong alkaline solution and strong corrosive solution.

4. The Cu-TA prepared by the method not only has good oxidation resistance, but also keeps the original electrical conductivity and thermal conductivity of Cu.

Drawings

FIG. 1 is a scanning electron micrograph of Cu-TA and pure Cu obtained in example 1.

FIG. 2 is an X-ray diffraction pattern of Cu-TA obtained as a sample in example 1.

FIG. 3 is an X-ray diffraction pattern of the untreated cuproplatin of example 1.

FIG. 4 is an optical photograph of Cu-TA and pure Cu obtained in example 1.

FIG. 5 is an optical photograph of Cu-TA and pure Cu of example 2 after being left in a 0.1M NaOH solution for 8 hours.

FIG. 6 is a Raman image of Cu-TA and Cu from example 2 after 8 hours in 0.1M NaOH solution.

FIG. 7 is an optical photograph of Cu-TA and pure Cu of example 3 after heating at 160 ℃ for one hour in air.

FIG. 8 is a Raman image of Cu-TA and pure Cu of example 3 after heating in air at 160 ℃ for one hour.

FIG. 9 is an XRD pattern of Cu-TA in air at room temperature for 60 days in example 3.

FIG. 10 shows Cu-TA and Cu in H in example 4₂O₂(30%) optical photograph of the solution after 1 hour.

FIG. 11 shows Cu-TA and Cu in H in example 4₂O₂(30%) raman spectrum after standing in solution for 1 hour.

Detailed Description

For the understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

Example 1: preparation of Cu-TA

And putting the deionized water into a three-type bottle, introducing nitrogen into the deionized water for 1 hour through a Leideke system, and removing impurity gases in the deionized water to obtain the nitrogen-saturated deionized water. 10ml of deionized water saturated with nitrogen is taken as a solvent, sodium citrate is taken as a solute, a sodium citrate solution with the concentration of 7.3 millimole per liter is prepared, and the mixture is stirred uniformly. Cutting copper foil into 2 × 2cm²Mixed with 10mL of sodium citrate solution and sealed in a 50mL stainless steel reaction kettle. The reaction kettle is placed in a forced air drying oven, heated to 190 ℃ within 40 minutes, kept at 190 ℃ for 24 hours, and naturally cooled to room temperature after reaction. And (3) taking the copper foil out of the reaction kettle, washing the free sodium citrate on the copper foil by using deionized water, and then sucking the surface by using filter paper to obtain the copper foil (Cu-TA) treated by the sodium citrate.

FIG. 1 is a scanning electron microscope photograph of Cu-TA prepared according to the present invention and untreated copper. It can be clearly seen that the surface of the Cu treated by the sodium citrate is smoother, and a protective layer is formed. The XRD pattern characterizes the product Cu-TA of example 1 as well as the untreated copper foil as pure copper (see fig. 2, fig. 3). The comparison with the standard copper XRD spectrogram completely accords with the JCPDS 85-1326 card. Wherein 43.5 deg., 50.7 deg., 74.12 deg., correspond to the {111}, {200}, {220} crystal planes of copper, respectively. FIG. 4 is an optical photograph of the product Cu-TA of example 1 and an untreated copper foil.

Example 2: testing of antioxidant Properties under alkaline conditions

To investigate the antioxidant capacity of the product Cu-TA of example 1 in a strongly alkaline solution, 2X 2cm prepared in example 1 was used²The Cu-TA of (A) is put into 0.1M NaOH solution and stored for 8 hours at 25 ℃; taking 2X 2cm²The same procedure was performed for the pure copper foil of (1). As shown in FIG. 5, which is an optical photograph of Cu-TA and pure copper foil after being stored in 0.1M NaOH solution at 25 deg.C for 8 hours at room temperature, it can be seen that the surface of Cu-TA is still smooth and not oxidized, but the pure copper foil is oxidized and blackened. FIG. 6 is a Raman image of Cu-TA and untreated copper foil, the Raman spectrum of Cu-TA in FIG. 6 has no peaks, which indicates that Cu-TA is not oxidized, and the oxide diffraction peak of Cu in FIG. 6 shows that CuO has been oxidized to form CuO. The comparison of the two proves the strong oxidation resistance of the Cu-TA.

Example 3: antioxidant Property test in air

To investigate the antioxidant capacity of the Cu-TA product of example 1 in air, 2X 2cm²The Cu-TA (g) was placed in an open bottle and placed in a forced air drying oven and stored at 160 ℃ for 1 hour. Taking 2X 2cm²The same procedure was performed for the pure copper foil of (1). Fig. 7 is an optical photograph after 1 hour, and it can be seen that the Cu-TA surface is still smooth and flat, not oxidized, while the pure copper foil has been oxidized to black. Fig. 8 is raman images of Cu-TA and pure copper foil, respectively, where Cu-TA in fig. 8 has no impurity peak, which can indicate that Cu-TA is not oxidized, and the presence of an oxide diffraction peak in the Cu raman spectrum in fig. 8 indicates that pure copper foil has been oxidized to form CuO. The comparison of the two proves the strong oxidation resistance of the Cu-TA.

To demonstrate the persistence of oxidation resistance of the Cu-TA product of example 1, FIG. 9 is an XRD pattern of Cu-TA left in air for 90 days, with only Cu diffraction peaks present and no other copper oxide diffraction peaks present. Thus, the Cu-TA product of example 1 demonstrated a long-lasting strong oxidation resistance.

Example 4: h₂O₂(30%) antioxidant Property test in solution

To investigate the antioxidant capacity of Cu-TA, 2X 2cm²Is put in H₂O₂(30%) was stored at 25 ℃ for 1 hour. Taking 2X 2cm simultaneously²The same procedure was performed for the pure copper foil of (1). FIG. 10 is an optical photograph after 1 hour, and it can be seen that the Cu-TA surface is still smooth and flatAnd the copper foil is not oxidized, and the pure copper foil is oxidized and blackened. FIG. 11 is a Raman image of Cu-FA and Cu, respectively, the absence of a hetero peak in the Raman spectrum of Cu-TA indicates that Cu-TA is not oxidized, and the presence of a CuO peak in the Raman spectrum of Cu indicates that pure copper foil has been oxidized to form CuO. The comparison of the two proves the strong oxidation resistance of the Cu-TA.

Claims

1. A method for enhancing the oxidation resistance of copper as a material of a body comprises the following steps:

2) preparing a sodium citrate solution with the concentration of 7.3-7.4 millimoles per liter by taking nitrogen-saturated deionized water as a solvent and sodium citrate as a solute, and stirring the solution uniformly;

2. A method of enhancing the oxidation resistance of a bulk material, as defined in claim 1, wherein said bulk material copper is 2 x 2cm²Square copper platinum.