CN114479109B - Preparation and application of a metal-organic framework material containing N and S - Google Patents

Abstract

The patent discloses a preparation and application of N, S-containing metal organic framework material. A metal organic framework material (Zn-AMT) containing N, S functional atoms is prepared by utilizing zinc nitrate hexahydrate and 3-amino-5-mercapto-1, 2, 4-triazole through one-step reaction. The preparation method is simple, the prepared material is used as an adsorbent for treating trivalent gold ions in the aqueous solution, the adsorption capacity is high, the adsorption rate is high, the selective adsorption performance on gold is outstanding, the desorption and the recycling are easy, and a feasible new method is provided for the recycling of noble metals.

Description

Preparation and application of a metal-organic framework material containing N and S

technical field

The invention belongs to the technical field of material preparation, in particular to a method for synthesizing Zn-AMT, a metal-organic framework material containing N and S, and for adsorbing and separating Au(III) ions in aqueous solution.

Background technique

Precious metals are found in extremely low amounts in nature and are usually associated with other mineral deposits. Traditional means of obtaining precious metals are inefficient and consume high energy consumption, which makes it difficult to increase the output of precious metal recycling, while human demand for precious metals is increasing day by day. In order to cope with the contradiction between supply and demand of precious metal resources, recycling precious metals will definitely become the future development direction. The recovery of precious metals not only enables the reuse of scarce resources, but also brings huge economic benefits to the society, and promotes the protection of the ecological environment. This move is conducive to building an ecologically civilized society and promoting national economic development and scientific and technological progress.

Gold is one of the most widely used precious metals, with excellent physical and chemical properties, such as high temperature oxidation resistance, corrosion resistance, electrical resistance, good electrical conductivity, high catalytic activity and strong coordination ability, etc. In industrial applications, gold is known as an industrial vitamin because of its wide range of uses and indispensable functions. At present, the methods applied to the separation of gold ions include chemical precipitation, membrane filtration, ion exchange, adsorption, electrolysis, and biological treatment. Among the above methods, the adsorption method is widely used for the separation of precious metals due to its advantages of low operating cost, simple operation, small environmental impact, and easy industrialization.

In this study, a novel metal-organic framework material Zn-AMT was prepared by using zinc nitrate hexahydrate and 3-amino-5-mercapto-1,2,4-triazole, and the exposed N, S on its surface were used as adsorption sites. point, showing highly efficient and selective adsorption of Au(III) in aqueous solution.

Contents of the invention

The purpose of the present invention is to provide a kind of preparation method that has the N, S metal-organic framework material that has excellent adsorption performance to Au(III) in aqueous solution, and this material has high adsorption capacity, fast adsorption rate, high adsorption capacity to Au(III). Selectivity and high reusability. The technical scheme adopted in the present invention is:

Add a certain amount of Zn(NO ₃ ) ₂ ·6H ₂ O and 3-amino-5-mercapto-1,2,4-triazole into a mixed solvent of DMF and water, and heat it under a certain temperature for a period of time , the reaction solution was cooled to room temperature, and then filtered, washed and dried to obtain Zn-AMT. Use Zn-AMT as an adsorbent to adsorb and separate Au(III) in aqueous solution, use gold trichloride with a purity of 98% to prepare a certain concentration of Au(III) solution, and use 0.1mol/L sodium hydroxide or HNO ₃ After adjusting the pH of the aqueous solution, take a certain volume of solution and add it to a centrifuge tube, add a certain amount of Zn-AMT as an adsorbent, and place it in a constant temperature water bath oscillator at a certain temperature to fully stir for a certain period of time. After the adsorption is completed, take a certain amount of Zn-AMT. Measure the sample, use the atomic absorption spectrometer to measure the concentration of the original solution and the remaining solution after adsorption, and calculate the adsorption amount and adsorption rate. Take a certain volume of thiourea solution and add it to a 50mL centrifuge tube as a desorbent, add 5mg of Zn-AMT material after adsorption, place it in a constant temperature water bath shaker at 15-55°C for 0-45h, and take out the centrifuge tube Carry out centrifugation, and adsorb the Zn-AMT material after desorption again;

Preferably, the volume ratio of the mixed solvent DMF and water used for preparing the material is 1:3-3:1;

Preferably, the molar ratio of Zn(NO ₃ ) ₂ ·6H ₂ O to 3-amino-5-mercapto-1,2,4-triazole is 1:2-1:5;

Preferably, the molar concentration of 3-amino-5-mercapto-1,2,4-triazole is 0.03-0.1mol/L;

Preferably, the reaction temperature is 110-180°C, and the synthesis time is 12h-72h;

Preferably, the prepared Au(III) solution has a concentration of 0-2000mg/L;

Preferably, the pH of the solution is set to 1-6;

Preferably, the adsorption temperature is 15-80°C;

Preferably, the adsorption time is 0-2880min;

Preferably, the concentration of the thiourea solution is greater than 0.2 mol/L.

Compared with the prior art, the present invention has the following advantages:

(1) Metal-organic framework materials containing both functional atoms N and S were prepared by a one-step method, the reaction solvent was green, the reaction temperature was moderate, and the cost of raw materials was low. (2) Zn-AMT can effectively adsorb Au(III) ions in aqueous solution, and the adsorption capacity is as high as 2878 mg/g. The adsorption capacity of the material can be continuously increased by increasing the temperature. (3) The Zn-AMT material is easy to elute and can be reused after desorption. It is a kind of economical material and brings higher economic benefits. (4) The selectivity of Zn-AMT materials to Au(III) is good, which is beneficial to the selective adsorption of trivalent gold ions in complex practical solutions.

[specific implementation plan]

Example 1

Take 600mg of zinc nitrate hexahydrate (2mmol) and 700mg of 3-amino-5-mercapto-1,2,4-triazole (6mmol) into a 250mL beaker, add a mixed solvent containing 100mL DMF and 50mL water, Stir until completely dissolved; move the solution to a reactor that has been preheated to 140°C, and the reaction time at 140°C is 12-72 hours. After the reaction is completed, cool to room temperature, and obtain solid powder by suction filtration, wash with DMF, deionized water and anhydrous methanol solvent several times, and suction filtration; dry the solid in a vacuum oven at 80°C overnight, and grind to obtain a white powder Zn-AMT.

Example 2

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 10.9mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, and add 5mg Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, set the temperature at 25°C, fixed-point sampling and testing, and using an atomic absorption spectrometer to measure the concentration of the original solution and the remaining solution after adsorption, after 20 minutes , the adsorption capacity is 43.6 mg/g, and the adsorption rate is 100%.

Example 3

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 10.9mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, and add 5mg Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 8 minutes, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is determined by an atomic absorption spectrometer. It was determined that the adsorption capacity was 41.1mg/g, and the adsorption rate was 94.2%.

Example 4

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 10.9mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, add 5mg of Example 1. The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 2 minutes, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. Determination, the adsorption capacity is 30.4mg/g, and the adsorption rate is 49.7%.

Example 5

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 93mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, add 5mg of Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 30 minutes, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. , the adsorption capacity is 372.6 mg/g, and the adsorption rate is 100%.

Example 6

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 243.7mg/L, take 20mL of this solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1 mol/L NaOH, add 5mg of Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 4.5 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is determined by an atomic absorption spectrometer. Measured, the adsorption capacity is 939mg/g, and the adsorption rate is 96.3%.

Example 7

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 89mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 5.22 with 0.1mol/L NaOH, add 5mg Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 18 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer , the adsorption capacity is 343mg/g, and the adsorption rate is 96%.

Example 8

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 89mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 7.57 with 0.1mol/L NaOH, and add 5mg Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 18 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer , the adsorption capacity is 193.4 mg/g, and the adsorption rate is 54.2%.

Example 9

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 5 mg/L, take 20 mL of the solution and add it to a 50 mL centrifuge tube, adjust the pH to 3.19 with 0.1 mol/L NaOH, add 5 mg 1. The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 48 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. Determination, the adsorption capacity is 20mg/g, and the adsorption rate is 100%.

Example 10

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 58mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1 mol/L NaOH, add 5mg Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 48 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer , the adsorption capacity is 232 mg/g, and the adsorption rate is 100%.

Example 11

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 105 mg/L, take 20 mL of the solution and add it to a 50 mL centrifuge tube, adjust the pH to 3.19 with 0.1 mol/L NaOH, and add 5 mg. Example 1. The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 48 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. Determination, the adsorption capacity is 419.2mg/g, and the adsorption rate is 99.6%.

Example 12

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 292.7mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, and add 5mg Example 1. The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 48 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. Determination, the adsorption capacity is 1154.6mg/g, and the adsorption rate is 98.6%.

Example 13

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 965.1mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, and add 5mg Example 1. The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 25°C. After 48 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. Determination, the adsorption capacity is 2040.2mg/g, and the adsorption rate is 52.8%.

Example 14

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 1021mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, and add 5mg Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 15°C. After 48 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. , the adsorption capacity is 1317mg/g, and the adsorption rate is 32.2%.

Example 15

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 1021mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, and add 5mg Example 1 The obtained Zn-AMT material is used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature is set at 35°C. After 48 hours, a certain amount of sample is taken, and the concentration of the original solution and the remaining solution after adsorption is measured with an atomic absorption spectrometer. , the adsorption capacity is 2605mg/g, and the adsorption rate is 63.8%.

Example 16

Use gold trichloride with a purity of 98% to prepare an Au(III) solution with a concentration of 1021mg/L, take 20mL of the solution and add it to a 50mL centrifuge tube, adjust the pH to 3.19 with 0.1mol/L NaOH, and add 5mg Example 1 The obtained Zn-AMT material was used as an adsorbent, placed in a constant temperature water bath oscillator for oscillating adsorption, and the temperature was set at 42°C. After 48 hours, a certain amount of sample was taken, and the concentration of the original solution and the remaining solution after adsorption was measured with an atomic absorption spectrometer. , the adsorption capacity is 2878 mg/g, and the adsorption rate is 70.4%.

Example 17

Take 5mg of Zn-AMT material and add 20mL of pH 3.19 containing Au(III), Ni(II), Zn(II), Cu(II), Cd(II) and Co(II) with a concentration of 100mg/L In the mixed solution of ions, shake on a constant temperature water bath shaker at 25°C for 24 hours. After filtering through a microporous membrane, use an atomic absorption spectrophotometer to measure the absorbance of each ion solution before and after adsorption. In this example, the adsorption capacity of the material on Au(III) is 400 mg/g, and it has almost no adsorption effect on other coexisting metal ions.

Example 18

Take 20mL of 0.5mol/L thiourea aqueous solution and add it to a 50mL centrifuge tube as a desorbent, add 5mg of the adsorbed Zn-AMT material, place it in a constant temperature water bath oscillator for desorption, set the temperature at 25°C for 24h Finally, it is filtered and dried, and the desorbed Zn-AMT material is adsorbed again. After repeated use for 3 times, the adsorption performance decreased by only 4%.

The above examples only express several implementations of the present invention, and the descriptions thereof are more specific and detailed, but the technical scope thereof is not limited to the above implementations. For those skilled in the art, various improvements and implementations can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (7)

1. A method for preparing a N, S metal organic framework material Zn-AMT is characterized in that Zn (NO ₃ ) ₂ ·6H ₂ Adding O and 3-amino-5-mercapto-1, 2, 4-triazole into a mixed solvent of DMF and water, wherein the volume ratio of the mixed solvent of DMF to water is 2:1; after the reaction is carried out for 12-72 hours under the airtight heating condition at 140 ℃, the reaction liquid is cooled to the room temperature, and then the Zn-AMT is obtained after suction filtration, washing and drying; adopting Zn-AMT as adsorbent to adsorb and separate Au (III) in water solution, preparing Au (III) solution with certain concentration with 98% gold trichloride, and using 0.1mol/L sodium hydroxide or HNO ₃ After regulating the pH value of the aqueous solution, adding a certain volume of solution into a centrifuge tube, adding a certain amount of Zn-AMT as an adsorbent, placing the centrifuge tube in a constant-temperature water bath oscillator at a certain temperature, fully stirring for a certain time, taking a certain amount of sample after the adsorption is finished, measuring the concentrations of the original solution and residual liquid after the adsorption by using an atomic absorption spectrometer, and calculating the adsorption quantity and the adsorption rate; adding a certain volume of thiourea solution into a 50mL centrifuge tube as a desorbing agent, adding 5mg of the Zn-AMT material after adsorption, placing the mixture into a constant-temperature water bath oscillator at 15-55 ℃ for oscillation desorption for 0-45h, taking out the centrifuge tube for centrifugal separation, and adsorbing the Zn-AMT material after desorption again.

2. The method for preparing a metal-organic framework material Zn-AMT comprising N, S according to claim 1, wherein the molar concentration of 3-amino-5-mercapto-1, 2, 4-triazole is 0.03-0.1mol/L.

3. The method for preparing the organic framework material Zn-AMT containing N, S as claimed in claim 1, wherein the concentration of the prepared Au (III) solution is more than 0mg/L and less than or equal to 2000 mg/L.

4. A method for preparing a Zn-AMT containing N, S metal organic framework material according to claim 1, characterized in that the pH of the solution is set to 1-6.

5. The method for preparing the organic framework material Zn-AMT containing N, S as claimed in claim 1, wherein the adsorption temperature is 15-80 ℃.

6. The method for preparing the organic framework material Zn-AMT containing N, S according to claim 1, wherein the adsorption time is more than 0min and less than or equal to 2880 min.

7. The method for preparing the organic framework material Zn-AMT containing N, S as claimed in claim 1, wherein the concentration of the thiourea solution is more than 0.2mol/L.