CN111569875A - Copper/porous carbon nanorod material, preparation method and application - Google Patents

Abstract

The invention provides a copper/porous carbon nanorod material, a preparation method and an application, wherein the copper/porous carbon nanorod material is composed of copper nanoparticles coated by porous carbon nanorods. First, dissolving trimesic acid and sodium hydroxide or potassium hydroxide in an aqueous solution, adding an aqueous solution of a soluble metal copper salt, and stirring at room temperature to prepare a copper trimesic acid (Cu-BTC) precursor; The BTC precursor is calcined in a protective atmosphere, and the copper/porous carbon nanorod material is obtained after cooling. The organic solvent, high temperature, high pressure and other means required in the existing MOF preparation process are abandoned, and the normal temperature aqueous solution method is used for preparation, and the preparation process is simple and environmentally friendly. The prepared copper/porous carbon nanorod material has excellent catalytic degradation effect on phenolic and amine compounds in wastewater.

Description

A kind of copper/porous carbon nanorod material, preparation method and application

technical field

The invention belongs to the technical field of preparation of water treatment materials, and relates to a copper/porous carbon nanorod composite material, a preparation method and application.

Background technique

Wastewater containing phenolic compounds and amine compounds is one of the most harmful and polluting industrial wastewaters in the world today. If these wastewaters are not treated, they can pollute the atmosphere, water, soil and food when they are directly discharged and irrigated to farmland. Therefore, phenolic and amine compounds have received more and more attention. At present, many methods have been used for phenolic and amine compounds, such as adsorption, catalysis, membrane separation, extraction, precipitation, activated sludge and biofilm, etc. Among them, the sodium borohydride-assisted catalytic reduction method is considered to be a promising method due to its simplicity and rapidity. However, some traditional catalyst materials, such as noble metals such as Au and Ag, cannot be practically applied due to the limitations of price and catalytic performance. Therefore, we propose to prepare a copper-based metal-organic framework-derived copper/carbon nanorod material for the degradation of phenolic and amine compounds.

Metal-organic frameworks (MOFs) are a class of crystalline porous materials with periodic network structure formed by the self-assembly of inorganic metal centers (metal ions or metal clusters) and organic ligands. Due to the stable structure of MOF materials, the existence of a large number of organic ligands, and the uniform distribution of metal ions, many researchers use it as a template to synthesize derivative materials with different structures and components, generally including carbon materials, metal compounds, metal compound carbon composites Material. MOF-derived materials have now been widely used in the fields of energy storage and conversion, such as lithium-ion batteries, lithium-sulfur batteries, supercapacitors and electrocatalysis, but in the field of wastewater treatment, especially in the removal of phenolic compounds from water. There are fewer reports. For example, Zhao et al. and Niu et al. used Cu-MOF prepared by solvothermal method as a precursor, and obtained copper-based carbon composites after calcination. It was found that these two copper-based carbon composites can be used as catalysts to catalyze the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) (X.Zhao, Y.Tan, F.Wu,H .Niu,Z.Tang,Y.Cai,J.P.Giesy,Sci.TotalEnviron,2016,571,380-387; H.Niu,S.Liu,Y.Cai,F.Wu,X.Zhao,Micropo.Mesopo.Mater. , 2016, 2019, 48-53). However, the preparation of these reported Cu-MOF precursors mostly requires the use of organic solvents, high temperature, high pressure and other means, which are harmful to the environment and unfavorable for industrial mass production. In order to solve these problems, we use cheap and easily available trimesic acid ligands, and react with metallic copper salts in aqueous phase to obtain copper trimesic acid precursors by precipitation at room temperature.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the organic solvents, high temperature, high pressure and other means required in most of the existing MOF preparation processes, and to propose a simple, efficient and novel copper/porous carbon nanorod material and The preparation method thereof is used for the degradation of phenolic and amine compounds.

In order to achieve the above object, the technical scheme proposed by the present invention is:

A copper/porous carbon nanorod material is characterized in that it comprises copper nanoparticles and porous carbon nanorods, the copper nanoparticles are distributed in the porous carbon nanorod matrix, and the average length of the carbon nanorods is 200-1500nm, and the average length is 200-1500 nm. The diameter is 50-200 nm, the average size of the copper nanoparticles is 20-80 nm, and the specific surface area of the copper/porous carbon nanorod material is 50-200 m ² /g.

The preparation method of the copper/porous carbon nanorod material comprises the following steps:

(1) dissolving trimesic acid (H ₃ BTC) and sodium hydroxide or potassium hydroxide in an aqueous solution, adding an aqueous solution of a soluble metal copper salt, mixing and stirring at room temperature, and then centrifugal washing and drying to obtain isobenzene Copper triformate (Cu-BTC) precursor;

(2) calcining the Cu-BTC precursor obtained in step (1) under a protective atmosphere, and cooling to obtain the copper/porous carbon nanorod material.

Further, in the step (1), the material ratio of the trimesic acid and sodium hydroxide or potassium hydroxide is 1:3; the aqueous solution concentration of the trimesic acid is 0.01-0.1mol /L.

Further, in the step (1), the soluble metal copper salt is one or more of copper sulfate, copper acetate, copper nitrate, and copper chloride.

Further, in the step (1), the concentration of the metal copper salt aqueous solution is 0.01-0.1 mol/L.

Further, in the step (1), the mixing time is 5-120min. The drying conditions were 70°C, 12h.

Further, in the step (2), the protective atmosphere is nitrogen or argon; the heating rate of the calcination is 1-10°C/min, the calcination time is 1-24 hours, and the calcination temperature is 500-1000°C °C.

The application of the copper/porous carbon nanorod material is used as a catalyst for the degradation of phenolic or amine compounds.

Further, the phenolic or amine compound is p-nitrophenol, o-nitrophenol or p-nitroaniline.

Compared with the prior art, the advantages of the present invention are:

(1) Using relatively cheap ligands and metal salts as raw materials, the price is cheap.

(2) Abandoning most of the organic solvents, high temperature, high pressure and other means required in the MOF preparation process, and adopting the normal temperature aqueous solution method for preparation, the preparation process is simple and environmentally friendly.

(3) Porous copper-carbon nanorods can be prepared in large quantities, which has a high application prospect.

(4) The prepared copper-carbon nanorods have excellent catalytic degradation performance for phenolic and amine compounds that are difficult to degrade in wastewater treatment due to their unique morphology and structural characteristics.

Description of drawings

In FIG. 1 (a) is the SEM image of the Cu-BTC precursor of Example 1; (b) is the XRD pattern of the Cu-BTC precursor prepared in Example 1.

FIG. 2 is an SEM image of the copper/carbon nanorods prepared in Example 1. FIG.

FIG. 3 is the TEM spectrum of the copper/carbon nanorods prepared in Example 1. FIG.

FIG. 4 is the XRD pattern of the copper/carbon nanorods prepared in Example 1. FIG.

5 is the nitrogen adsorption-desorption isotherm of the copper/carbon nanorods prepared in Example 1.

(a), (b) and (c) in Figure 6 are the UV-vis spectra of the copper/carbon nanorods prepared in Example 1 for the catalytic degradation of 4-NP, O-NP and 4-NA, respectively.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

Example 1:

The preparation process of the copper/carbon nanorod material of the present embodiment is as follows:

(1) dissolve 2mmol trimesic acid and 6mmol sodium hydroxide in 25mL aqueous solution, stir at room temperature until completely dissolved; dissolve 3mmol copper acetate in 25mL deionized water, and continue stirring at room temperature for a period of time until completely dissolved , to obtain copper acetate aqueous solution; mix the aqueous solution of trimesic acid and sodium hydroxide with copper acetate aqueous solution, stir at room temperature for 5 min; centrifuge, and wash 3 times with deionized water or ethanol; After drying for 12h, the Cu-BTC precursor can be obtained;

(2) The Cu-BTC precursor obtained in step (1) was heated to 800°C for 2 hours at a temperature of 5°C/min in a tube furnace in a nitrogen atmosphere to obtain a copper/carbon nanorod material.

In the prepared copper/carbon nanorod material, the copper nanoparticles are distributed in the porous carbon nanorod matrix, the average length of the carbon nanorods is 500 nm, the average diameter is 100 nm, and the average size of the copper nanoparticles is 26 nm. The specific surface area of the carbon nanorod material was 103 m ² /g.

FIG. 1 is an SEM image and an XRD pattern of the Cu-BTC precursor prepared in this example, and it can be seen from FIG. 1 that Cu-BTC nanorods are obtained. Fig. 2, Fig. 3, Fig. 4, Fig. 5 are the SEM images, TEM images, XRD images and nitrogen adsorption-desorption isotherms of the copper/carbon nanorod composites prepared in the present embodiment. It can be seen from the test results that, After calcination, copper/carbon nanorod composites were obtained, and the copper-carbon composites maintained the nanorod morphology of the Cu-BTC precursor, and the copper nanoparticles were dispersed in the carbon nanorod matrix.

The method for the catalytic degradation of p-nitrophenol, o-nitrophenol and p-nitroaniline by the copper/carbon nanorod material obtained in the present embodiment, the steps are as follows:

(1) p-nitrophenol, o-nitrophenol and p-nitroaniline were dissolved in deionized water respectively, and 0.01mol/L aqueous solutions of p-nitrophenol, o-nitrophenol and p-nitroaniline were prepared respectively; Dissolve sodium hydride in water to prepare a 0.1 mol/L sodium borohydride aqueous solution; ultrasonically disperse the copper/carbon nanorod composite material in water to prepare a 2 mg/mL copper/carbon nanorod material aqueous dispersion.

(2) To a standard quartz cuvette with a 1.0 cm optical path and a volume of 4 mL, 2.5 mL of sodium borohydride aqueous solution and 25 μL of p-nitrophenol, o-nitrophenol or p-nitroaniline aqueous solution were sequentially added, and then 10 μL of copper/ Aqueous dispersion of carbon nanorod material. After adding the copper/carbon nanorod material, measure the UV-Vis absorption spectrum at intervals;

FIG. 6 is an ultraviolet-visible absorption spectrum curve of the copper/carbon nanorod material prepared in this example as a catalyst to degrade p-nitrophenol, o-nitrophenol and p-nitroaniline. As can be seen from Figure 6, after adding the copper-carbon nanorod catalyst prepared in this example, p-nitrophenol, o-nitrophenol and p-nitroaniline can be completely degraded.

Example 2:

The preparation process of the copper/carbon nanorod material of the present embodiment is as follows:

(1) 2mmol trimesic acid and 6mmol sodium hydroxide were dissolved in 25mL aqueous solution, stirred at room temperature until completely dissolved; 3mmol copper sulfate was dissolved in 25mL deionized water, and continued stirring at room temperature for a period of time until completely dissolved , mix trimesic acid and sodium hydroxide aqueous solution with copper sulfate aqueous solution, stir at room temperature for 1.5 hours; centrifuge, and wash 3 times with deionized water or ethanol; Cu-BTC precursor can be obtained;

(2) The obtained Cu-BTC precursor was calcined in a tube furnace in nitrogen atmosphere at a temperature of 10°C/min to 800°C for 1.5 hours to obtain a copper/carbon nanorod material.

In the copper/carbon nanorod material prepared in this example, the copper nanoparticles are distributed in the porous carbon nanorod matrix, the carbon nanorods have an average length of 1000 nm, an average diameter of 80 nm, and an average size of copper nanoparticles The specific surface area of the porous carbon nanorod material was 65 m ² /g.

Example 3:

The preparation process of the copper/carbon nanorod composite material of the present embodiment is as follows:

(1) 2mmol trimesic acid and 6mmol potassium hydroxide were dissolved in 100mL aqueous solution, and stirred at room temperature until completely dissolved; 3mmol copper nitrate was dissolved in 50mL ionized water, and continued stirring at room temperature for a period of time until completely dissolved ; Mix trimesic acid and sodium hydroxide aqueous solution with copper nitrate aqueous solution, stir at room temperature for 1.5 hours; centrifuge, and wash with deionized water or ethanol 3 times; Cu-BTC precursor can be obtained;

(2) The obtained Cu-BTC precursor was heated up to 700°C for 3 hours in a tube furnace in nitrogen atmosphere at 8°C/min to obtain a copper/carbon nanorod material.

In the copper/carbon nanorod composite material prepared in this example, copper nanoparticles are distributed in the porous carbon nanorod matrix, the average length of the carbon nanorods is 800 nm, the average diameter is 70 nm, and the average size of the copper nanoparticles is 40 nm. The specific surface area of the copper/porous carbon nanorod material was 74 m ² /g.

Example 4:

The preparation process of the copper/carbon nanorod composite material of the present embodiment is as follows:

(1) 4mmol trimesic acid and 12mmol potassium hydroxide were dissolved in 50mL aqueous solution, stirred at room temperature until completely dissolved; 4mmol copper chloride was dissolved in 50mL deionized water, and at room temperature, stirring was continued for a period of time until completely Dissolve; mix trimesic acid and sodium hydroxide aqueous solution with copper chloride aqueous solution, stir at room temperature for 2 hours; centrifuge, and wash 3 times with deionized water or ethanol; dry at 70°C for 12 hours in a blast drying oven , the Cu-BTC precursor can be obtained;

(2) The obtained Cu-BTC precursor was calcined in a tube furnace in nitrogen atmosphere at 4°C/min to 1000°C for 1 hour to obtain a copper/carbon nanorod material.

In the copper/carbon nanorod composite material prepared in this example, copper nanoparticles are distributed in the porous carbon nanorod matrix, the average length of the carbon nanorods is 1200 nm, the average diameter is 80 nm, and the average size of the copper nanoparticles is 60 nm. The specific surface area of the copper/porous carbon nanorod material was 90 m ² /g.

Example 5:

The preparation process of the copper/carbon nanorod composite material of the present embodiment is as follows:

(1) 4mmol trimesic acid and 6mmol sodium hydroxide were dissolved in 50mL aqueous solution, and stirred at room temperature until completely dissolved; 2mmol copper nitrate and 2mmol copper acetate were dissolved in 50mL ionized water, and continued stirring for a period at room temperature time until completely dissolved; mix trimesic acid and sodium hydroxide aqueous solution with copper acetate aqueous solution, stir at room temperature for 0.5 hours; centrifuge, and wash 3 times with deionized water or ethanol; dry in a blast drying oven at 70°C After drying for 12h, the Cu-BTC precursor can be obtained;

(2) The obtained Cu-BTC precursor was heated up to 850°C for 2 hours in a tube furnace in nitrogen atmosphere at 3°C/min to obtain a copper/carbon nanorod material.

In the copper/carbon nanorod composite material prepared in this example, copper nanoparticles are distributed in the porous carbon nanorod matrix, the average length of the carbon nanorods is 800 nm, the average diameter is 50 nm, and the average size of the copper nanoparticles is 25 nm. The specific surface area of the copper/porous carbon nanorod material was 80 m ² /g.

The embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or All modifications belong to the protection scope of the present invention.

Claims (9)

1. The copper/porous carbon nanorod material is characterized by comprising copper nanoparticles and porous carbon nanorods, wherein the copper nanoparticles are distributed in a porous carbon nanorod matrix, the average length of the carbon nanorods is 200-1500nm, the average diameter of the carbon nanorods is 50-200nm, and the copper nanoparticles are flatThe average size is 20-80nm, and the specific surface area of the copper/porous carbon nanorod material is 50-200m²/g。

2. The method for preparing the copper/porous carbon nanorod material according to claim 1, comprising the following steps:

(1) mixing trimesic acid (H)₃BTC) and sodium hydroxide or potassium hydroxide are dissolved in the aqueous solution, the aqueous solution of soluble metal copper salt is added, the mixture is mixed and stirred at normal temperature, and then the precursor of copper trimesate (Cu-BTC) is obtained after centrifugal washing and drying;

(2) and (2) calcining the precursor obtained in the step (1) in a protective atmosphere, and cooling to obtain the copper/porous carbon nanorod material.

3. The production method according to claim 2, wherein in the step (1), the mass ratio of the trimesic acid and the sodium hydroxide or potassium hydroxide is 1: 3; the concentration of the aqueous solution of the trimesic acid is 0.01-0.1 mol/L.

4. The method according to claim 2, wherein in the step (1), the soluble metal copper salt is one or more of copper sulfate, copper acetate, copper nitrate and copper chloride.

5. The method according to claim 2, wherein in the step (1), the concentration of the aqueous solution of the copper metal salt is 0.01 to 0.1 mol/L.

6. The production method according to claim 2, wherein in the step (1), the mixing stirring time is 5 to 120 min. The drying condition is 70 ℃ and 12 h.

7. The production method according to claim 2, wherein in the step (2), the protective atmosphere is nitrogen or argon; the temperature rise rate of the calcination is 1-10 ℃/min, the calcination time is 1-24 hours, and the calcination temperature is 500-1000 ℃.

8. The use of the copper/porous carbon nanorod material according to claim 1, characterized in that it is a catalyst for the degradation of phenolic or amine compounds.

9. The use of the copper/porous carbon nanorod material according to claim 8, wherein the phenolic or amine compound is p-nitrophenol, o-nitrophenol or p-nitroaniline.

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