CN115382515B

CN115382515B - Graphene-based surface ion imprinting material capable of selectively adsorbing gallium ions as well as preparation method and application thereof

Info

Publication number: CN115382515B
Application number: CN202211004231.0A
Authority: CN
Inventors: 刘伟峰; 张曼曼; 梁畅; 刘旭光
Original assignee: Taiyuan University of Technology
Current assignee: Taiyuan University of Technology
Priority date: 2022-08-22
Filing date: 2022-08-22
Publication date: 2024-05-28
Anticipated expiration: 2042-08-22
Also published as: CN115382515A

Abstract

The invention belongs to the technical field of gallium recovery and extraction, and particularly relates to a graphene-based surface ion imprinting material capable of selectively adsorbing gallium ions, and a preparation method and application thereof. The preparation method of the invention comprises the following steps: (1) Mixing graphene oxide suspension, acrylic acid monomer and template gallium ion solution, adding a cross-linking agent and an initiator, and stirring at room temperature in a nitrogen environment; (2) heating to 40-90 ℃, and stirring for reaction for 1-4h; (3) Cooling, filtering, collecting a viscous product, cleaning, and drying to obtain an intermediate product; (4) And (3) cleaning the intermediate product by adopting a hydrochloric acid solution, removing template gallium ions, washing the intermediate product by deionized water until the washing solution is neutral, and drying to obtain the graphene-based surface ion imprinting material for selectively adsorbing the gallium ions. The graphene-based surface ion imprinting material for selectively adsorbing gallium ions can realize the selective adsorption of gallium ions, and can be used for the selective adsorption of gallium ions in fly ash pickle liquor.

Description

Graphene-based surface ion imprinting material capable of selectively adsorbing gallium ions as well as preparation method and application thereof

Technical Field

The invention belongs to the technical field of gallium recovery and extraction, and particularly relates to a graphene-based surface ion imprinting material capable of selectively adsorbing gallium ions, and a preparation method and application thereof.

Background

Gallium is a rare metal and is widely used in various high and new technical fields such as semiconductors, solar cells, alloys, medical applications, and the like. The semiconductor industry has become the largest consumer area of gallium, accounting for about 80% of the total consumption. With the rapid development of semiconductor industry in China, the market demand of gallium is also higher and higher. Because pure gallium ore is not available, the main existing form is associated ore, and the recovery of gallium is mainly recovered from fly ash, bauxite, red mud, zinc slag and the like. Because of its huge reserves and low cost, it is widely used as an energy source for power generation and iron and steel production. Fly ash has increased dramatically in china as a non-volatile residue over the past decades. So the accompanying gallium resources in the coal provide a new idea for solving the problem of gallium resource shortage.

Currently, the most widespread methods for extracting gallium include adsorption, solvent extraction, ion exchange, and electrochemical methods. Wherein the adsorption method has simple process design and flexible operation. The composite adsorbent has advantages of low cost, high adsorption amount, no waste byproducts, etc., so that the adsorption method is considered to be a relatively efficient and economical method.

However, the existing adsorbent has poor selectivity, and is easy to be interfered by aluminum ions and ferric ions with the same ionic radius and valence state as gallium ions when being applied to adsorption of gallium in the fly ash pickle liquor, so that the adsorption effect of the adsorbent on the gallium ions is affected; in addition, the fly ash pickle liquor also contains magnesium ions and calcium ions, and can also influence the adsorption effect of gallium ions.

Accordingly, there is a need to provide an improved solution to the above-mentioned deficiencies of the prior art.

Disclosure of Invention

The invention aims to provide a graphene-based surface ion imprinting material for selectively adsorbing gallium ions, and a preparation method and application thereof, so as to solve or improve the problem that the selective adsorption effect of an adsorbent in the prior art on gallium (especially in the case that a solution contains coexisting ions with the same or similar ionic radius and/or valence state as gallium ions) is poor.

In order to achieve the above object, the present invention provides the following technical solutions: a preparation method of graphene-based surface ion imprinting material for selectively adsorbing gallium ions comprises the following steps: (1) Mixing graphene oxide suspension, acrylic acid monomer and template gallium ion solution, adding a cross-linking agent and an initiator, and stirring at room temperature in a nitrogen environment; (2) heating to 40-90 ℃, and stirring for reaction for 1-4h; (3) Cooling, filtering the suspension, collecting a viscous product, washing with deionized water to neutrality, and drying to obtain an intermediate product; (4) And (3) cleaning the intermediate product by adopting a hydrochloric acid solution, removing template gallium ions, washing with deionized water until the washing solution is neutral, and drying to obtain the graphene-based surface ion imprinting material for selectively adsorbing gallium ions.

Preferably, the mass ratio of the template gallium ions to the acrylic monomer is (0.012-0.19): 1000; the volume ratio of the graphene oxide suspension to the acrylic acid monomer is (12.5-25) 1, and the concentration of graphene oxide in the graphene oxide suspension is 2.4g/L.

Preferably, the mass ratio of the template gallium ions to the acrylic monomer is (0.024-0.0495): 1000; the volume ratio of the graphene oxide suspension to the acrylic acid monomer is 25:1.

Preferably, the cross-linking agent is N, N-methylene bisacrylamide, and the initiator is potassium persulfate; the mass ratio of the N, N-methylene bisacrylamide to the potassium persulfate is 1:4.

Preferably, the graphene oxide suspension is obtained by mixing graphene oxide with deionized water and performing ultrasonic dispersion; the ultrasonic time is 0.5-2h.

Preferably, in the step (1), stirring is performed at room temperature under a nitrogen atmosphere for 30-60min.

Preferably, in the step (3), the drying temperature is 50-70 ℃ and the drying time is 6-10h.

Preferably, in the step (4), the concentration of the hydrochloric acid solution is 0.5-2mol/L.

The invention also provides a graphene-based surface ion imprinting material for selectively adsorbing gallium ions, which adopts the following technical scheme: the graphene-based surface ion imprinting material for selectively adsorbing the gallium ions is prepared by adopting the method.

The invention also provides application of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions, which adopts the following technical scheme: the graphene-based surface ion imprinting material for selectively adsorbing gallium ions is applied to the selective adsorption of gallium ions in fly ash pickle liquor.

The beneficial effects are that:

According to the invention, a surface ion imprinting technology is adopted, graphene oxide with rich functional groups is used as a matrix material, acrylic acid is used as a functional monomer to carry out chelating coordination with gallium ions, potassium persulfate is used as an initiator, N, N-methylene bisacrylamide is used as a cross-linking agent to carry out cross-linking polymerization, and finally, the gallium ions are removed through acid washing to obtain a graphene-based surface ion imprinting material for selectively adsorbing the gallium ions, so that the graphene-based surface ion imprinting material for selectively adsorbing the gallium ions can realize the selective adsorption of the gallium ions.

Compared with the existing gallium ion adsorption material, the gallium ion graphene-based surface ion imprinting material with high adsorption capacity and high selectivity prepared by the invention has larger adsorption capacity, the adsorption capacity of gallium ions can reach 221.56mg/g, and the adsorption equilibrium is reached when the adsorption time is 4 hours.

The graphene-based surface ion imprinting material for selectively adsorbing gallium ions, which is prepared by the invention, has the maximum adsorption capacity to Ga (III) when the pH value is 3. Thus, further studies were performed with ph=3 as the optimal acidity. In addition, the adsorption capacity of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions is obviously higher than that of a non-imprinting material under all acidity conditions.

The invention aims at complex environments in a fly ash pickle liquor system, and has a plurality of interfering ions. Therefore, the invention uses aluminum ions and ferric ions with the same ionic radius and valence state as gallium ions and the magnesium ions and calcium ions which are the common ions in fly ash as coexisting ions, and the ion imprinting material can still reach a certain adsorption capacity at the pH value of 3, which indicates that the graphene-based surface ion imprinting material which selectively adsorbs gallium ions and is prepared by utilizing the ion imprinting technology can realize the specific recognition capability to target ions and indicates that the interference of other coexisting ions is smaller.

The selective separation factors of the graphene-based surface ion imprinting material with the selective adsorption of gallium ions, prepared by the invention, on Al ³⁺、Fe³⁺、Ca²⁺ and Mg ²⁺ can reach 13.73, 4.19, 75.50 and 25.17 respectively.

The graphene-based surface ion imprinting material with the selective adsorption of gallium ions has the advantages of simple preparation method, sensitive adsorption, energy conservation compared with other selective recovery means, and good circulating effect. The adsorption capacity is 84.91% of the first adsorption capacity after the adsorption is recycled for 5 times.

The graphene-based surface ion imprinting material for selectively adsorbing gallium ions, which is prepared by the invention, can effectively adsorb gallium ions, and has higher selectivity in a mixed solution than other adsorbents. And the whole preparation process is quicker and simpler, and the adsorption quantity reaches a higher level in the same field. Can be recycled for multiple times, and has practical practicability.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. Wherein:

fig. 1 is a reaction schematic diagram of a graphene-based surface ion imprinting material for selectively adsorbing gallium ions according to an embodiment of the present invention;

FIG. 2 is a synthetic route diagram of an IIP-GO/PAA according to one embodiment of the present invention;

FIG. 3 is a graph showing adsorption kinetics of IIP-GO/PAA and NIP-GO/PAA to gallium according to one embodiment of the present invention;

FIG. 4 shows adsorption isotherms of IIP-GO/PAA and NIP-GO/PAA for gallium provided in one embodiment of the invention;

FIG. 5 is a graph showing the adsorption performance of the IIP-GO/PAA and NIP-GO/PAA to gallium at different acidity according to one embodiment of the present invention; in FIG. 5, the left bar graph represents the adsorption amount (Q) of IIP-GO/PAA and the right bar graph represents the adsorption amount (Q) of NIP-GO/PAA in the 2 bar graphs corresponding to the same pH;

FIG. 6 is a selective absorption diagram of gallium by IIP-GO/PAA and NIP-GO/PAA according to one embodiment of the present invention; in FIG. 6, the left bar graph represents the adsorption amount (Q) of IIP-GO/PAA and the right bar graph represents the adsorption amount (Q) of NIP-GO/PAA in the 2 bar graphs corresponding to the same ion;

FIG. 7 is an experimental chart of adsorption-desorption cycles of the IIP-GO/PAA adsorption of gallium ions according to one embodiment of the present invention; in FIG. 7, the left bar graph represents the adsorption amount (Q) of IIP-GO/PAA and the right bar graph represents the adsorption amount (Q) of NIP-GO/PAA in the 2 bar graphs corresponding to the same cycle number;

FIG. 8 is an infrared spectrum of IIP-GO/PAA, NIP-GO/PAA and GO according to one embodiment of the present invention.

Detailed Description

The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the invention, fall within the scope of protection of the invention.

The present invention will be described in detail with reference to examples. It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.

Aiming at the problem that the existing adsorbent for gallium ion recovery has poor selective adsorption effect on gallium (especially in the case that the solution contains coexisting ions with the same or similar ionic radius and/or valence state as gallium ions), the invention provides a preparation method of graphene-based surface ion imprinting material for selectively adsorbing gallium ions, which comprises the following steps: (1) Mixing graphene oxide suspension, acrylic acid monomer and template gallium ion solution, adding a cross-linking agent and an initiator, and stirring at room temperature in a nitrogen environment; (2) Heating to 40-90deg.C (40 deg.C, 60 deg.C, 80 deg.C or 90 deg.C), stirring for 1-4 hr (1 hr, 2 hr, 3hr or 4 hr, for example); (3) Cooling, filtering the suspension, collecting a viscous product, washing with deionized water to neutrality, and drying to obtain an intermediate product; (4) And (3) cleaning the intermediate product by adopting a hydrochloric acid solution, removing template gallium ions, washing the intermediate product by deionized water until the washing solution is neutral, and drying to obtain the graphene-based surface ion imprinting material for selectively adsorbing gallium ions.

The surface ion imprinting technology is to construct a plurality of imprinting sites on the surface of a matrix carrier, so that the problem that the imprinting sites are easy to coat is effectively avoided, and the accessibility of the imprinting sites is improved. The surface ion imprinting technology is used as an advanced ion separation technology and is combined with an adsorption method, so that target ions can be accurately identified and adsorbed. In the preparation process of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions, the related reaction principle is shown in figure 1 of the specification. According to the invention, graphene oxide with rich functional groups is used as a matrix material, acrylic acid is used as a functional monomer to carry out chelating coordination with gallium ions, potassium persulfate is used as an initiator, N, N-methylene bisacrylamide is used as a cross-linking agent to carry out cross-linking polymerization, and finally gallium ions are removed through acid washing to obtain the graphene-based gallium surface ion imprinting material capable of selectively adsorbing gallium ions.

In a preferred embodiment of the invention, the mass ratio of template gallium ions to acrylic monomer is (0.012-0.19): 1000 (e.g., 0.012:1000, 0.05:1000, 0.1:1000, or 0.19: 1000); the volume ratio of graphene oxide suspension to acrylic acid monomer is (12.5-25) 1 (e.g., 12.5:1, 15:1, 17.5:1, 20:1, 22.5:1, or 25:1), and the concentration of graphene oxide in the graphene oxide suspension is 2.4g/L.

In a preferred embodiment of the invention, the mass ratio of template gallium ions to acrylic monomer is (0.024-0.0495): 1000 (e.g., 0.024:1000, 0.036:1000, or 0.0495: 1000); the volume ratio of graphene oxide suspension to acrylic acid monomer was 25:1.

In the preferred embodiment of the invention, the cross-linking agent is N, N-methylene bisacrylamide, and the initiator is potassium persulfate; the mass ratio of the N, N-methylene bisacrylamide to the potassium persulfate is 1:4. The mass ratio of the N, N-methylene bisacrylamide to the potassium persulfate can obviously influence the effect of ion imprinting; if the mass ratio of N, N-methylenebisacrylamide to potassium persulfate is not suitable, then insufficient imprinted vacancies may be formed to trap enough gallium ions.

In the preferred embodiment of the invention, the graphene oxide suspension is obtained by mixing graphene oxide with deionized water and performing ultrasonic dispersion; the time of the ultrasound is 0.5-2h (e.g., 0.5h, 1h, 1.5h, or 2 h).

In a preferred embodiment of the present invention, in step (1), the stirring time at room temperature under nitrogen atmosphere is 30-60min (e.g., 30min, 40min, 50min or 60 min).

In a preferred embodiment of the invention, in step (3), the drying temperature is 50-70 ℃ (e.g. 50 ℃, 60 ℃ or 70 ℃), and the drying time is 6-10 hours (e.g. 6 hours, 7 hours, 8 hours, 9 hours or 10 hours).

In a preferred embodiment of the present invention, in step (4), the concentration of the hydrochloric acid solution is 0.5 to 2mol/L (e.g., 0.5mol/L, 1mol/L, 1.5mol/L or 2 mol/L).

The invention also provides a graphene-based surface ion imprinting material for selectively adsorbing gallium ions, and the graphene-based surface ion imprinting material for selectively adsorbing gallium ions is prepared by adopting the method.

The invention also provides application of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions, and application of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions in selective adsorption of gallium ions in fly ash pickle liquor.

The graphene-based surface ion imprinting material for selectively adsorbing gallium ions, and the preparation method and application thereof are described in detail by specific examples.

In the following examples:

Acrylic acid (99.5%) was purchased from Tianjin metallocene chemical Co., ltd., potassium persulfate (99.99%) was purchased from Shanghai Aba Ding Shiji Co., ltd., N, N-methylenebisacrylamide (99%) and anhydrous magnesium chloride (99%) were all purchased from adamas-beta, anhydrous aluminum chloride (99%) and ferric chloride hexahydrate (99%) were all purchased from GENERAL REAGENT, anhydrous calcium chloride (96%) was purchased from Tianjin chemical Co., mimo chemical Co., ltd., gallium chloride (99.999%) was purchased from Shanghai Michelin Biochemical Co., ltd., graphene oxide was purchased from Hangzhou Hirsh, and nitrogen gas having a purity of 99.99% was purchased from Shanxi rainbow gas industry Co., ltd.

Example 1

The preparation method of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions in the embodiment comprises the following steps (a synthetic route diagram is shown in figure 2 of the accompanying drawings of the specification):

the first step: 10mL of graphene oxide solution (12 g/L) was ultrasonically dispersed in 40mL of deionized water for 1.5h to obtain a uniform graphene oxide suspension.

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

And a third step of: cooled to room temperature, the suspension was filtered, the resulting viscous product was washed with copious amounts of deionized water, unreacted acrylic monomer and excess crosslinker and initiator were removed, and washed to neutrality. Subsequently, the mixture was transferred to a dish and dried under vacuum at 60℃for 10 hours.

Fourth step: and (3) eluting the sample obtained after the third step by using 1.0mol/L hydrochloric acid to remove Ga (III) template ions, and repeatedly washing with deionized water until gallium ions are not detected (detection is performed by using an inductively coupled plasma emission spectrometer ICP-OES (avio-200)). Finally, washing with deionized water to neutrality, and vacuum drying at 60 ℃ to obtain the graphene-based surface ion imprinting material (IIP-GO/PAA for short) for selectively adsorbing gallium ions.

Taking two 50mL conical flasks, adding 20mL of gallium ion solution (pH=3) with a concentration of 100mg/L and a concentration of 200mg/L respectively, and adding 6mg of IIP-GO/PAA of the embodiment to each conical flask respectively; adsorbing for 4h in a shaker at 25deg.C and rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment to gallium ions in the gallium ion solution with the concentration of 100mg/L is 149.29mg/g; the adsorption amount of gallium ions in the gallium ion solution with the concentration of 200mg/L of the IIP-GO/PAA of the embodiment is 221.56mg/g.

Example 2

The preparation method of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions in the embodiment comprises the following steps:

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 65℃for 3 hours.

A50 mL Erlenmeyer flask was charged with 20mL of 100mg/L gallium ion solution (pH=3), to which 6mg of the IIP-GO/PAA of this example was added; adsorbing for 4h in a shaker at 25deg.C and rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 111.31mg/g.

Example 3

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 80℃for 3 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 79.55mg/g.

Example 4

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 0.25mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 90.60mg/g.

Example 5

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 0.5mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 121.44mg/g.

Example 6

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 2mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 128.31mg/g.

Example 7

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 4mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 33.50mg/g.

Example 8

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a 40℃water bath for 4 hours.

A 50mL conical flask was charged with 20mL of a gallium ion solution (ph=3) at a concentration of 200mg/L, to which 6mg of IIP-GO/PAA of this example was added; adsorbing for 4h in a shaker at 25deg.C and rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 103.31mg/g.

Example 9

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 90℃for 1 hour.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 217.32mg/g.

Example 10

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 90℃for 4 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 213.77mg/g.

Example 11

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 0.25mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 4 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 167.66mg/g.

Example 12

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 4mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 4 hours.

The experimental results show that: the adsorption amount of gallium ions by the IIP-GO/PAA of this example was 69.50mg/g.

Comparative example 1

The preparation method of the graphene-based material for adsorbing gallium ions of the comparative example comprises the following steps:

the first step: 10mL of graphene oxide solution (12 g/L) was sonicated in 40mL of deionized water for 1.5h to a uniform graphene oxide suspension.

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-neck flask to react with 2mL of Acrylic Acid (AA) monomer; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

Fourth step: washing the sample obtained after the third step reaction with 1.0mol/L hydrochloric acid, washing with deionized water to neutrality, and vacuum drying at 60deg.C to obtain graphene-based material (NIP-GO/PAA for short) for adsorbing gallium ions.

A 50mL conical flask was taken and charged with 20mL of 100mg/L gallium ion solution (ph=3), to which 6mg of NIP-GO/PAA of this comparative example was added; adsorbing for 4h in a shaker at 25deg.C and rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of NIP-GO/PAA to gallium ions in this comparative example was 77.73mg/g.

Comparative example 2

The preparation method of the graphene-based surface ion imprinting material for adsorbing gallium ions in the comparative example comprises the following steps:

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously, 5mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the polymerization of the monomers and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30 minutes. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

Fourth step: and (3) eluting the sample obtained after the third step by using 1.0mol/L hydrochloric acid to remove Ga (III) template ions, and repeatedly washing with deionized water until gallium ions are not detected (detection is performed by using an inductively coupled plasma emission spectrometer ICP-OES (avio-200)). Finally, washing with deionized water to neutrality, and vacuum drying at 60 ℃ to obtain the graphene-based surface ion imprinting material (IIP-GO/PAA for short) for selectively adsorbing gallium ions in the comparative example.

A 50mL conical flask was taken, 20mL of gallium ion solution (ph=3) at a concentration of 100mg/L was added, and 6mg of IIP-GO/PAA of this comparative example was added to the conical flask; adsorbing for 4h in a shaker at 25deg.C and rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of gallium ions in the gallium ion solution with the concentration of 100mg/L of the IIP-GO/PAA of the comparative example is 84.79mg/g.

This comparative example differs from example 1 only in that: the amounts and proportions of N, N-Methylenebisacrylamide (MBA) and potassium persulfate (KPS) were varied, and the remainder was consistent with example 1. This is because the ratio and amount of N, N-Methylenebisacrylamide (MBA) and potassium persulfate (KPS) fail to form enough imprinted vacancies to trap enough gallium ions.

Comparative example 3

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 2mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the polymerization of the monomers and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

The experimental results show that: the adsorption amount of gallium ions in the gallium ion solution with the concentration of 100mg/L of the IIP-GO/PAA of the comparative example is 23.31mg/g.

This comparative example differs from example 1 only in that: nitrogen was not selected as a shielding gas to initiate polymerization of the monomers during the reaction, and the remainder was the same as in example 1.

Comparative example 4

And a second step of: adding the graphene oxide suspension obtained in the first step into a three-necked flask, and mixing with 1mL of Acrylic Acid (AA) monomer and 1mL of template gallium ion solution of Ga (III) with the concentration of 100 mg/L; simultaneously 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the monomer polymerization process and 40mg of potassium persulfate (KPS) as a polymerization initiator were slowly added to the suspension, and stirred at room temperature under a nitrogen atmosphere for 30min. Subsequently, the mixture was reacted in a water bath at 70℃for 3 hours.

A50 mL Erlenmeyer flask was taken, 20mL of 100mg/L gallium ion solution (pH=3) was added, and 6mg of the IIP-GO/PAA of this example was added to the Erlenmeyer flask; adsorbing for 4h in a shaker at 25deg.C and rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of gallium ions in the gallium ion solution with the concentration of 100mg/L of the IIP-GO/PAA of the comparative example is 41.51mg/g.

This comparative example differs from example 1 only in that: the amounts of acrylic acid added were varied and the remainder was the same as in example 1. The results indicate that the amount of acrylic acid monomer used plays an important role in the adsorption of gallium ions.

Experimental example:

1. Adsorption kinetics test: the tests were performed using the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 as the adsorption materials, respectively.

The testing method comprises the following steps: a50 mL Erlenmeyer flask was charged with 20mL of 100mg/L gallium ion solution (pH=3), and 6mg of the adsorbent material was added thereto. And (3) adsorbing 5min,15min,30min,1h,2h,4h,8h and 12h respectively in a shaking table with the temperature of 25 ℃ and the rotating speed of 150r/min, and measuring the influence of different contact time on the adsorption performance.

The experimental results (kinetic adsorption curve) are shown in FIG. 3.

Kinetic adsorption fitting parameters of IIP-GO/PAA and NIP-GO/PAA are shown in Table 1 below:

TABLE 1 kinetic adsorption fitting parameters for IIP-GO/PAA and NIP-GO/PAA

The experimental results show that: the adsorption equilibrium was reached within 4 hours using the IIP-GO/PAA of example 1 and the IIP-GO/PAA of comparative example 1 as the adsorption materials. Moreover, from the graph, it can be seen that when the IIP-GO/PAA of the embodiment 1 is adopted as the adsorption material, the quasi-second-level kinetic model is more in accordance with experimental data, which indicates that the adsorption process of gallium ions on the surface of the IIP-GO/PAA adsorption material is chemical adsorption.

When the adsorption time is 4h, the adsorption equilibrium is reached.

2. Isothermal adsorption experiments: the tests were performed using the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 as the adsorption materials, respectively.

The testing method comprises the following steps: a50 mL Erlenmeyer flask was charged with 6mg of the adsorbent material, and 20mL of gallium ion solution (pH=3) having a concentration gradient of 10mg/L,25mg/L,50mg/L,100mg/L,200mg/L,300mg/L, respectively, was added. Adsorbing for 4h in a shaker at 25deg.C and rotation speed of 150 r/min. The effect of different initial gallium ion concentrations on the adsorption performance was determined.

The experimental results show that: the adsorption capacity of the material increases with the increase of the initial concentration of gallium ions, and the adsorption capacity is basically saturated when the initial concentration of gallium ions is 200 mg/L.

The experimental results (isothermal adsorption curves) are shown in fig. 4.

Isothermal adsorption fitting parameters for IIP-GO/PAA and NIP-GO/PAA are shown in Table 2 below:

TABLE 2 isothermal adsorption fitting parameters for IIP-GO/PAA and NIP-GO/PAA

Wherein the Q _m value of IIP-GO/PAA corresponding to example 1 in Table 2 is a fitting value, the actual measured Q _m value is 221.56mg/g.

The experimental results show that: as the initial concentration of gallium ions increases, the equilibrium adsorption capacity of IIP-GO/PAA of example 1 also increases, and Langmuir (Langmuir) isothermal model more closely matches experimental data (compared to frank (Freundlich) isothermal model), indicating that the adsorption process of gallium ions on the surface of the adsorbent material occurs as monolayer adsorption.

3. Influence of solution pH on adsorption properties: the tests were performed using the IIP-GO/PAA of example 6 and the NIP-GO/PAA of comparative example 1 as the adsorption materials, respectively.

The testing method comprises the following steps: a50 mL Erlenmeyer flask was charged with 20mL of 100mg/L gallium ion solution, and the Erlenmeyer flask solution pH gradient was adjusted to 1M (H ⁺ concentration 1M, i.e., pH=0), 1,2,3. 6mg of the adsorbent material was added thereto, and the mixture was adsorbed for 4 hours in a shaker at 25℃and a rotation speed of 150r/min, and the influence of different pH values on the adsorption performance was measured.

The experimental results are shown in FIG. 5.

The experimental results show that: the adsorbent materials of example 6 IIP-GO/PAA and comparative example 1 NIP-GO/PAA have higher adsorption capacities at ph=3.

4. Adsorption selection performance test: the tests were performed using the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 as the adsorption materials, respectively.

The testing method comprises the following steps: a50 mL conical flask was taken, and 20mL of a mixed solution of gallium ion, aluminum ion, iron ion, calcium ion and magnesium ion at a concentration of 100mg/L, respectively, was added. 6mg of the adsorption material is added, the adsorption is carried out for 4 hours in a shaking table with the temperature of 25 ℃ and the rotating speed of 150r/min, and the selective adsorption performance of the adsorption material on gallium ions in the presence of competing ions is measured.

The experimental results are shown in FIG. 6.

The adsorption selectivity parameters for gallium for IIP-GO/PAA and NIP-GO/PAA are shown in Table 3 below.

TABLE 3 adsorption selectivity parameters for gallium for IIP-GO/PAA and NIP-GO/PAA

The experimental results show that: the IIP-GO/PAA of example 1 has significantly higher adsorption capacity for gallium ions than other ions by virtue of the gallium imprinted cavity, i.e. can realize specific recognition capability for gallium ions, and the selective separation factors for Al ³⁺,Fe³⁺,Ca²⁺,Mg²⁺ are 13.73, 4.19, 75.50 and 25.17, respectively. This demonstrates that the IIP-GO/PAA adsorption material prepared by using the ion imprinting technology has high selective recognition on gallium ions.

Considering that although some interference ions exist in the fly ash pickle liquor, the experimental result shows that, for the mixed solution containing Al ³⁺ and Fe ³⁺ with the same ionic radius and valence state as gallium ions and normal-existing ions Ca ²⁺ and Mg ²⁺ in the fly ash as coexisting ions, at the pH value of=3, the IIP-GO/PAA of the invention can still reach a certain adsorption quantity, which indicates that the IIP-GO/PAA of the invention can realize the specific identification capability to target ions, and other coexisting ions have smaller interference to the IIP-GO/PAA of the invention; the IIP-GO/PAA can be used for extracting gallium from fly ash pickle liquor.

5. And (3) testing the cyclic regeneration performance: the test was performed using IIP-GO/PAA of example 1 and NIP-GO/PAA of comparative example 1 as the adsorption materials.

The testing method comprises the following steps: and (3) cleaning the adsorbed material with 1mol/L hydrochloric acid solution, and desorbing. After drying, repeated adsorption experiments were carried out (adsorption of gallium ion solution with pH=3 and concentration of 100mg/L, adsorption in a shaker with a temperature of 25℃and a rotation speed of 150r/min for 4 hours; the amounts of IIP-GO/PAA of example 1 and NIP-GO/PAA of comparative example 1 were 6mg, respectively, and the amount of gallium ion solution was 20 mL), and reusability of the materials was determined.

The experimental results are shown in FIG. 7.

The experimental results show that: the IIP-GO/PAA of example 1 retains 84.91% of the initial adsorption capacity after 5 cycles.

6. And (3) infrared spectrum detection:

qualitative analysis of the graphene oxide solution, the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 were performed by measuring the functional groups by means of a Fourier infrared spectrometer (FTIR), scanning wave number ranges of 500-4000 cm ^-1

The infrared spectra of IIP-GO/PAA, NIP-GO/PAA and GO are shown in FIG. 8.

FTIR analysis: the peak at 1382cm ^-1 can be attributed to the planar vibration of the-OH groups at the edges of the graphene oxide sheet, and the peak at 1382cm ^-1 of the O-H stretching peak disappeared in comparison to GO, indicating that the-COOH groups of acrylic acid are involved in the reaction with the-OH groups on the surface of the graphene oxide sheet at the time of polymer formation. The peak at 1712cm ^-1 was a tensile vibration of c=o, the intensity of which increased after the acrylic acid addition. The peak at 1060cm ^-1 belongs to the C-O-C vibration peak, and the absorption peak of C-O-C shifts to low wavenumber after acrylic acid is added. These results indicate that-COOH of acrylic acid and-OH of graphene oxide reacted and AA was successfully polymerized to the surface or edge of graphene oxide. Comparing the spectral lines of IIP-GO/PAA and NIP-GO/PAA, during imprinting a certain number of template ions are embedded in the cavities of the adsorbent and are not removed. Thus, the peak at 3427cm ^-1 is the O-H vibratory stretching of the-COOH and-OH groups, with the O-H completely weakening, indicating that-OH interacts with gallium ions. In addition, it is clearly observed that the lines of IIP-GO/PAA and NIP-GO/PAA have similar positions and main bands, indicating that the imprinting process has little effect on the main network structure of the polymer. This also demonstrates that the ion imprinted polymer has stability and can stably adsorb gallium ions.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The preparation method of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions is characterized by comprising the following steps of:

(1) Mixing graphene oxide suspension, acrylic acid monomer and template gallium ion solution, adding a cross-linking agent and an initiator at the same time, and stirring at room temperature for 30-60min under a nitrogen environment;

(2) Heating to 40-90 ℃, and stirring for reacting for 1-4h;

(3) Cooling, filtering the suspension, collecting a viscous product, washing with deionized water to neutrality, and drying to obtain an intermediate product;

(4) Washing the intermediate product by adopting hydrochloric acid solution, removing template gallium ions, washing the intermediate product by deionized water until washing liquid is neutral, and drying to obtain the graphene-based surface ion imprinting material for selectively adsorbing gallium ions;

The mass ratio of the template gallium ions to the acrylic acid monomer is (0.012-0.19): 1000; the volume ratio of the graphene oxide suspension to the acrylic acid monomer is 25:1, and the concentration of graphene oxide in the graphene oxide suspension is 2.4g/L;

The cross-linking agent is N, N-methylene bisacrylamide, the initiator is potassium persulfate, and the mass ratio of the N, N-methylene bisacrylamide to the potassium persulfate is 1:4;

The graphene oxide suspension is obtained by mixing graphene oxide with deionized water and performing ultrasonic dispersion for 0.5-2 hours.

2. The method for preparing a graphene-based surface ion imprinting material for selectively adsorbing gallium ions according to claim 1, wherein a mass ratio of the template gallium ions to the acrylic acid monomer is (0.024-0.0495): 1000.

3. The method for preparing graphene-based surface ion imprinting material for selectively adsorbing gallium ions according to claim 1, wherein in the step (3), the drying temperature is 50-70 ℃ and the drying time is 6-10h.

4. The method for preparing graphene-based surface ion imprinting material for selectively adsorbing gallium ions according to claim 1, wherein in the step (4), the concentration of the hydrochloric acid solution is 0.5-2mol/L.

5. A graphene-based surface ion imprinting material for selectively adsorbing gallium ions, wherein the graphene-based surface ion imprinting material for selectively adsorbing gallium ions is prepared by the method according to any one of claims 1 to 4.

6. The use of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions according to claim 5 in selective adsorption of gallium ions in fly ash pickle liquor.