CN115382515A

CN115382515A - Graphene-based surface ion imprinting material for selectively adsorbing gallium ions and preparation method and application thereof

Info

Publication number: CN115382515A
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: 2022-11-25
Anticipated expiration: 2042-08-22
Also published as: CN115382515B

Abstract

The invention belongs to the technical field of gallium recovery and extraction, and particularly relates to a graphene-based surface ion imprinting material for selectively adsorbing gallium ions, and a preparation method and application thereof. The preparation method comprises the following steps: (1) Mixing the graphene oxide suspension, the acrylic acid monomer and the template gallium ion solution, adding the cross-linking agent and the 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 by using deionized water until the washing liquid is neutral, and drying to obtain the graphene-based surface ion imprinting material capable of selectively adsorbing the gallium ions. The graphene-based surface ion imprinting material for selectively adsorbing gallium ions can realize selective adsorption of gallium ions, and can be used for selective adsorption of gallium ions in a coal ash pickle liquor.

Description

Graphene-based surface ion imprinting material for selectively adsorbing gallium ions and 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 for 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 technology fields such as semiconductors, solar cells, alloys, medical applications, and the like. Among them, the semiconductor industry has become the largest consumer area for gallium, accounting for about 80% of the total consumption. With the rapid development of the semiconductor industry in China, the market demand of gallium is higher and higher. Because pure gallium ore is not available, the main existing form of the pure gallium ore is associated ore, and gallium is mainly recovered from fly ash, bauxite, red mud, zinc slag and the like. Because of the huge storage capacity and low cost of coal, it is widely used as an energy source for power generation and steel production. Fly ash has increased dramatically in china as a non-volatile residue over the past decades. Therefore, the associated gallium resource in the coal provides 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. The adsorption method has simple process design and flexible operation. The composite adsorbent has the advantages of low cost, high adsorption amount, no waste by-product generation and the like, so that the adsorption method is considered to be an effective and economic method.

But the selectivity of the existing adsorbent is poor, and when the adsorbent is applied to adsorption of gallium in the coal ash pickle liquor, the adsorbent is easily interfered by aluminum ions and ferric ions with the same ionic radius and valence state as gallium ions, so that the adsorption effect of the adsorbent on the gallium ions is influenced; in addition, the fly ash pickle liquor also contains magnesium ions and calcium ions, which also can affect the adsorption effect of gallium ions.

Therefore, 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 an adsorbent in the prior art has a poor selective adsorption effect on gallium (especially under the condition that a solution contains coexisting ions with the same or similar ionic radius and/or valence state as gallium ions).

In order to achieve the above purpose, the invention provides the following technical scheme: a preparation method of graphene-based surface ion imprinting material for selectively adsorbing gallium ions comprises the following steps: (1) Mixing the 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 the viscous product to be neutral by using deionized water, and drying to obtain an intermediate product; (4) And cleaning the intermediate product by using a hydrochloric acid solution to remove template gallium ions, washing the intermediate product by using deionized water until the washing liquid is neutral, and drying the intermediate product to obtain the graphene-based surface ion imprinting material capable of selectively adsorbing the 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 said template gallium ions to said acrylic monomer is (0.024-0.0495): 1000; the volume ratio of the graphene oxide suspension to the acrylic acid monomer is 25.

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), the stirring time at room temperature under the nitrogen atmosphere is 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 capable of selectively adsorbing the gallium ions is prepared by the method.

The invention also provides an 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 selective adsorption of gallium ions in a coal ash pickle liquor.

Has the advantages that:

according to the method, 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 perform chelating coordination with gallium ions, potassium persulfate is used as an initiator, N, N-methylene bisacrylamide is used as a cross-linking agent to perform cross-linking polymerization, finally, gallium ions are removed through acid washing to obtain the graphene-based surface ion imprinting material capable of selectively adsorbing the gallium ions, and the graphene-based surface ion imprinting material capable of selectively adsorbing the gallium ions can realize selective adsorption of the gallium ions.

Compared with the existing gallium ion adsorbing 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 to gallium ions can reach 221.56mg/g, and the adsorption balance can be achieved when the adsorption time is 4 hours.

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

The invention aims at the complex environment in the acid leaching liquid system of the fly ash and has some interfering ions. Therefore, the aluminum ions and ferric ions with the same ionic radius and valence as gallium ions and the magnesium ions and calcium ions which are commonly existing ions in the fly ash are used as coexisting ions, and the ion imprinting material can still reach a certain adsorption amount when the pH value is =3, which shows that the graphene-based surface ion imprinting material for selectively adsorbing gallium ions, which is prepared by the ion imprinting technology, can realize the specific recognition capability on target ions and shows that the interference of other coexisting ions is small.

The graphene-based surface ion imprinting material with the function of selectively adsorbing gallium ions prepared by the invention is used for Al ³⁺ 、Fe ³⁺ 、Ca ²⁺ And Mg ²⁺ The separation factors of the selection can reach 13.73, 4.19, 75.50 and 25.17 respectively.

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

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

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiment(s) of the invention and together with the description serve to explain the invention and not to limit the invention. Wherein:

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

FIG. 2 is a synthetic roadmap for IIP-GO/PAA provided by an embodiment of the present invention;

FIG. 3 is a graph of the adsorption kinetics of IIP-GO/PAA and NIP-GO/PAA on gallium provided by an embodiment of the present invention;

FIG. 4 is an adsorption isotherm of IIP-GO/PAA and NIP-GO/PAA for gallium provided in one embodiment of the present invention;

FIG. 5 is a graph of the adsorption performance of IIP-GO/PAA and NIP-GO/PAA provided by an embodiment of the present invention on gallium at different acidity; in FIG. 5, in 2 histograms corresponding to the same pH, the left histogram represents the adsorption amount (Q) of IIP-GO/PAA, and the right histogram represents the adsorption amount (Q) of NIP-GO/PAA;

FIG. 6 is a drawing illustrating the selective adsorption of Ga by IIP-GO/PAA and NIP-GO/PAA provided by one embodiment of the present invention; in FIG. 6, in the 2 histograms corresponding to the same ion, the left histogram represents the adsorption amount (Q) of IIP-GO/PAA, and the right histogram represents the adsorption amount (Q) of NIP-GO/PAA;

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

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

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

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

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

The surface ion imprinting technology is used for constructing a plurality of imprinting sites on the surface of a matrix carrier, so that the problem that the imprinting sites are easily coated 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 involved reaction principle is shown in figure 1 in the attached figure of the specification. According to the method, 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 perform chelating coordination with gallium ions, potassium persulfate is used as an initiator, N, N-methylene bisacrylamide is used as a cross-linking agent to perform 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 the gallium ions.

In a preferred embodiment of the present invention, the mass ratio of template gallium ions to acrylic acid monomers is (0.012-0.19): 1000 (e.g., 0.012; the volume ratio of the graphene oxide suspension to the acrylic acid monomer is (12.5-25): 1 (for example, 12.5.

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

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 ion imprinting effect; if the mass ratio of the N, N-methylene-bisacrylamide to the potassium persulfate is not proper, the imprinting holes cannot be formed enough to capture enough gallium ions.

In a preferred embodiment of the invention, the graphene oxide suspension is obtained by mixing graphene oxide with deionized water and performing ultrasonic dispersion; the sonication time 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 present invention, in step (3), the drying temperature is 50 to 70 ℃ (e.g., 50 ℃, 60 ℃ or 70 ℃) and the drying time is 6 to 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, which is prepared by the method.

The invention also provides an application of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions, and the application of the graphene-based surface ion imprinting material for selectively adsorbing gallium ions in the coal ash pickle liquor is provided.

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

In the following examples:

acrylic acid (99.5%) was obtained from Tianjin Mao chemical reagent, inc., potassium persulfate (99.99%) was obtained from Shanghai Aladdin reagent, N, N-methylenebisacrylamide (99%) and anhydrous magnesium chloride (99%) were obtained from adamas-beta, anhydrous aluminum chloride (99%) and ferric chloride hexahydrate (99%) were obtained from general reagent, anhydrous calcium chloride (96%) was obtained from Tianjin Kemi European chemical reagent, inc., gallium chloride (99.999%) was obtained from Shanghai Michelin Biochemical technology, inc., graphene oxide was obtained from Hangzhou high-olefin technology, inc., and nitrogen gas having a purity of 99.99% was obtained from Shanxi Yihong gas industry, inc.

Example 1

The preparation method of the graphene-based surface ion imprinted material for selectively adsorbing gallium ions in this embodiment includes the following steps (the synthetic scheme is shown in fig. 2 in the attached figure of the specification):

the first step is as follows: 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.

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

The third step: cooling to room temperature, filtering the suspension, washing the resulting viscous product with copious amounts of deionized water, removing unreacted acrylic acid monomer and excess crosslinker and initiator, and washing to neutrality. Subsequently, the plate was transferred to a petri dish and dried under vacuum at 60 ℃ for 10h.

The fourth step: and (3) washing the sample obtained after the reaction in the third step with 1.0mol/L hydrochloric acid to remove Ga (III) template ions, and repeatedly washing with deionized water until no gallium ions can be detected (detecting by adopting an inductively coupled plasma emission spectrometer (ICP-OES) (avio-200)). And finally, washing the graphene surface ion imprinted material to be neutral by deionized water, and performing vacuum drying at 60 ℃ to obtain the graphene surface ion imprinted material (IIP-GO/PAA for short) capable of selectively adsorbing gallium ions.

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

The experimental results show that: the adsorption capacity of the IIP-GO/PAA in the gallium ion solution with the concentration of 100mg/L to gallium ions is 149.29mg/g; the adsorption capacity of the IIP-GO/PAA in the gallium ion solution with the concentration of 200mg/L to gallium ions 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 includes the following steps:

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

The fourth step: and (3) washing the sample obtained after the reaction in the third step with 1.0mol/L hydrochloric acid to remove Ga (III) template ions, and repeatedly washing with deionized water until no gallium ions can be detected (detecting by adopting an inductively coupled plasma emission spectrometer ICP-OES (avio-200)). Finally, washing the graphene surface with deionized water to be neutral, and carrying out vacuum drying at 60 ℃ to obtain the graphene-based surface ion imprinting material (IIP-GO/PAA for short) capable of selectively adsorbing gallium ions.

A50 mL Erlenmeyer flask was charged with 20mL of a gallium ion solution (pH = 3) at a concentration of 100mg/L, and 6mg of IIP-GO/PAA of this example was added thereto; adsorbing for 4h in a shaking table at a temperature of 25 ℃ and a rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of the IIP-GO/PAA in the embodiment to gallium ions is 111.31mg/g.

Example 3

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

The fourth step: and (3) washing the sample obtained after the reaction in the third step with 1.0mol/L hydrochloric acid to remove Ga (III) template ions, and repeatedly washing with deionized water until no gallium ions can be detected (detecting by adopting an inductively coupled plasma emission spectrometer (ICP-OES) (avio-200)). Finally, washing the graphene surface with deionized water to be neutral, and carrying out vacuum drying at 60 ℃ to obtain the graphene-based surface ion imprinting material (IIP-GO/PAA for short) capable of selectively adsorbing gallium ions.

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 79.55mg/g.

Example 4

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

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

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 90.60mg/g.

Example 5

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

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 121.44mg/g.

Example 6

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

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

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 128.31mg/g.

Example 7

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

The third step: cooling to room temperature, filtering the suspension, washing the resulting viscous product with copious amounts of deionized water to remove unreacted acrylic acid monomer and excess crosslinker and initiator, and washing to neutrality. Subsequently, the plate was transferred to a petri dish and dried under vacuum at 60 ℃ for 10h.

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 33.50mg/g.

Example 8

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

A50 mL Erlenmeyer flask was charged with 20mL of 200mg/L gallium ion solution (pH = 3), to which was added 6mg of IIP-GO/PAA of this example; adsorbing for 4h in a shaking table at a temperature of 25 ℃ and a rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 103.31mg/g.

Example 9

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

The experimental results show that: the adsorption amount of the IIP-GO/PAA in the embodiment to gallium ions is 217.32mg/g.

Example 10

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

The experimental results show that: the adsorption amount of the IIP-GO/PAA in the embodiment to gallium ions is 213.77mg/g.

Example 11

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

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 167.66mg/g.

Example 12

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

The experimental results show that: the adsorption amount of the IIP-GO/PAA of the embodiment on gallium ions is 69.50mg/g.

Comparative example 1

The preparation method of the graphene-based material adsorbing gallium ions of the present comparative example includes the steps of:

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

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

The fourth step: and washing the sample obtained after the reaction in the third step by using 1.0mol/L hydrochloric acid, finally washing the sample to be neutral by using deionized water, and drying the sample in vacuum at the temperature of 60 ℃ to obtain the graphene-based material (NIP-GO/PAA for short) capable of adsorbing gallium ions in the comparative example.

A50 mL Erlenmeyer flask was charged with 20mL of a gallium ion solution (pH = 3) at a concentration of 100mg/L, and 6mg of NIP-GO/PAA of this comparative example was added thereto; adsorbing for 4h in a shaking table at a temperature of 25 ℃ and a rotation speed of 150 r/min.

The experimental results show that: the adsorption amount of NIP-GO/PAA of the comparative example on gallium ions is 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:

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

The fourth step: and (3) washing the sample obtained after the reaction in the third step with 1.0mol/L hydrochloric acid to remove Ga (III) template ions, and repeatedly washing with deionized water until no gallium ions can be detected (detecting by adopting an inductively coupled plasma emission spectrometer (ICP-OES) (avio-200)). And finally, washing the graphene surface with deionized water to be neutral, and performing vacuum drying at 60 ℃ to obtain the graphene-based surface ion imprinting material (IIP-GO/PAA for short) capable of selectively adsorbing gallium ions in the comparative example.

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

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

This comparative example differs from example 1 only in that: the amounts and ratios of N, N-Methylenebisacrylamide (MBA) and potassium persulfate (KPS) were varied and the rest was in accordance with example 1. This is due to the fact that this ratio and amount of N, N-Methylene Bisacrylamide (MBA) and potassium persulfate (KPS) fails to form enough imprinted holes to trap enough gallium ions.

Comparative example 3

The second step is that: adding the graphene oxide suspension obtained in the first step into a three-neck flask, and mixing with 1mL of template gallium ion solution of 2mL of Acrylic Acid (AA) monomer and Ga (III) with the concentration of 100 mg/L; while 10mg of N, N-Methylenebisacrylamide (MBA) as a crosslinking agent in the polymerization of the monomer 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 70 ℃ water bath for 3 hours.

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

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

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

Comparative example 4

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

The fourth step: and (3) washing the sample obtained after the reaction in the third step with 1.0mol/L hydrochloric acid to remove Ga (III) template ions, and repeatedly washing with deionized water until no gallium ions can be detected (detecting by adopting an inductively coupled plasma emission spectrometer ICP-OES (avio-200)). And finally, washing the graphene substrate with deionized water to be neutral, and performing vacuum drying at 60 ℃ to obtain the graphene-based surface ion imprinting material (IIP-GO/PAA for short) for selectively adsorbing the gallium ions in the comparative example.

A 50mL conical flask is taken, 20mL gallium ion solution with concentration of 100mg/L (pH = 3) is added, and 6mg IIP-GO/PAA of the embodiment is added into the conical flask; adsorbing for 4h in a shaking table at a temperature of 25 ℃ and a rotation speed of 150 r/min.

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

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

Experimental example:

1. and (3) testing adsorption kinetics: tests were carried out using the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 as the adsorbent material, respectively.

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

The results of the experiment (kinetic adsorption curve) are shown in fig. 3.

The kinetic adsorption fit parameters for IIP-GO/PAA and NIP-GO/PAA are shown in Table 1 below:

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

The experimental results show that: the IIP-GO/PAA of the example 1 and the IIP-GO/PAA of the comparative example 1 are used as adsorbing materials, and the adsorption equilibrium can be achieved within 4h. Moreover, the figure shows that when the IIP-GO/PAA material in example 1 is adopted as the adsorbing material, the quasi-second order kinetic model is more fit with experimental data, and the adsorption process of gallium ions on the surface of the IIP-GO/PAA adsorbing material is chemical adsorption.

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

2. Isothermal adsorption experiment: tests were carried out using the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 as the adsorbent material, respectively.

The test method comprises the following steps: a50 mL conical flask was charged with 6mg of the adsorbent, and 20mL of gallium ion solution (pH = 3) with a concentration gradient of 10mg/L,25mg/L,50mg/L,100mg/L,200mg/L, and 300mg/L, respectively, were added. Adsorbing for 4h in a shaking table at a temperature of 25 ℃ and a 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 is increased along with the increase of the initial concentration of gallium ions, and the adsorption capacity is basically saturated when the initial concentration of the gallium ions is 200 mg/L.

The results of the experiment (isothermal adsorption curve) are shown in FIG. 4.

The isothermal adsorption fit parameters for IIP-GO/PAA and NIP-GO/PAA are shown in Table 2 below:

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

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

The experimental results show that: the equilibrium adsorption capacity of IIP-GO/PAA of example 1 gradually increased with the increase of initial concentration of gallium ions, and Langmuir (Langmuir) isothermal model was more consistent with experimental data (compared to Freundlich (Freundlich) isothermal model), indicating that the adsorption process of gallium ions on the surface of the adsorbent material is monolayer adsorption.

3. Effect of solution pH on adsorption performance: tests were carried out using the IIP-GO/PAA of example 6 and the NIP-GO/PAA of comparative example 1 as the adsorbent materials, respectively.

The test method comprises the following steps: adding 20mL of 100mg/L gallium ion solution into 50mL conical flask, and adjusting pH gradient of the conical flask solution to 1M (H) ⁺ Concentration 1M, i.e. pH = 0), 1,2,3. Adding 6mg of adsorbing material, adsorbing for 4h in a shaking table at 25 ℃ and 150r/min, and measuring the influence of different pH values on the adsorption performance.

The results of the experiment are shown in FIG. 5.

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

4. Adsorption selectivity performance test: tests were carried out using the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 as the adsorbent material, respectively.

The test method comprises the following steps: a50 mL conical flask was charged with 20mL of a mixed solution of gallium ions, aluminum ions, iron ions, calcium ions and magnesium ions at a concentration of 100mg/L, respectively. Adding 6mg of adsorbing material, adsorbing for 4h in a shaking table at the temperature of 25 ℃ and the rotating speed of 150r/min, and determining the selective adsorption performance of the adsorbing material on gallium ions in the presence of competitive ions.

The results of the experiment are shown in FIG. 6.

The adsorption selectivity parameters of IIP-GO/PAA and NIP-GO/PAA to gallium are shown in the following table 3.

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

The experimental results show that: the IIP-GO/PAA in the embodiment 1 can realize the specific recognition capability on gallium ions and Al ions by means that the adsorption capacity of the gallium imprinted cavity on the gallium ions is obviously higher than that of other ions ³⁺ ，Fe ³⁺ ，Ca ²⁺ ，Mg ²⁺ Are selected to have separation factors of 13.73, 4.19, 75.50 and 25.17, respectively. This shows that the IIP-GO/PAA adsorbing material prepared by the ion imprinting technology has high selective identification on gallium ions.

Considering that some interfering ions exist in the coal ash pickle liquor, the combination of the experimental results shows that the aluminum containing the ions with the same radius and valence as the gallium ions ³⁺ And Fe ³⁺ And the commonly existing ion Ca in the fly ash ²⁺ And Mg ²⁺ When the pH =3 is used as a mixed solution of coexisting ions, the IIP-GO/PAA can still reach a certain adsorption amount, which shows that the IIP-GO/PAA can realize the specific recognition capability of target ions, and other coexisting ions have small interference on the IIP-GO/PAA; the IIP-GO/PAA can be used for extracting gallium in the coal ash pickle liquor.

5. And (3) testing the cyclic regeneration performance: the tests were carried out using the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1 as adsorbent materials.

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

The results of the experiment are shown in FIG. 7.

The experimental results show that: the IIP-GO/PAA of example 1 can still maintain 84.91% of the initial adsorption capacity after being recycled for 5 times.

6. Infrared spectrum detection:

qualitative analysis of the changes in functional groups of the graphene oxide solution, the IIP-GO/PAA of example 1 and the NIP-GO/PAA of comparative example 1, as determined by Fourier Infrared Spectroscopy (FTIR), scanning over a wave number range of 500 to 4000cm ^-1

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

FTIR analysis: at 1382cm ^-1 The peak at (A) can be attributed to the plane vibration of-OH groups at the edge of the graphene oxide thin layer, and compared with GO, the O-H stretching peak is 1382cm ^-1 The disappearance of the peak indicates that the-COOH group of acrylic acid participates in the reaction with the-OH group on the surface of the graphene oxide sheet at the time of forming the polymer. At 1712cm ^-1 The peak at C = O tensile vibration, the intensity of which increases after the addition of acrylic acid. At 1060cm ^-1 The peak value is the C-O-C vibration peak, and the C-O-C absorption peak shifts to a low wave number after the acrylic acid is added. These results indicate that acrylic acid-COOH and graphene oxide-OH react and AA successfully polymerizes to the surface or edges of graphene oxide. Comparing the spectral lines of IIP-GO/PAA and NIP-GO/PAA, during the imprinting process, a certain amount of template ions are embedded into the cavity of the adsorbent and are not removed. Therefore, at 3427cm ^-1 The peak at (A) is the O-H vibrational stretching of the-COOH and-OH groups, with the O-H being completely attenuated, indicating the interaction of-OH with gallium ions. In addition, it can be clearly observed that the spectral lines of IIP-GO/PAA and NIP-GO/PAA have similar positions and main bands, which indicates that the imprinting process has little effect on the main network structure of the polymer. The ion imprinted polymer is also proved to have stability and can stably adsorb gallium ions.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

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

(1) Mixing the graphene oxide suspension, the acrylic acid monomer and the template gallium ion solution, adding the cross-linking agent and the 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 the viscous product to be neutral by using deionized water, and drying to obtain an intermediate product;

(4) And cleaning the intermediate product by using a hydrochloric acid solution to remove template gallium ions, washing the intermediate product by using deionized water until the washing liquid is neutral, and drying the intermediate product to obtain the graphene-based surface ion imprinting material capable of selectively adsorbing the gallium ions.

2. The preparation method of the graphene-based surface ion imprinted material capable of selectively adsorbing gallium ions according to claim 1, wherein 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 (12.5-25): 1, and the concentration of graphene oxide in the graphene oxide suspension is 2.4g/L.

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

the volume ratio of the graphene oxide suspension to the acrylic acid monomer is 25.

4. The method for preparing the graphene-based surface ion imprinted material capable of selectively adsorbing the gallium ions according to any one of claims 1 to 3, wherein the cross-linking agent is N, N-methylenebisacrylamide, and the initiator is potassium persulfate;

the mass ratio of the N, N-methylene bisacrylamide to the potassium persulfate is 1:4.

5. The preparation method of the graphene-based surface ion imprinted material capable of selectively adsorbing gallium ions according to claim 1, wherein the graphene oxide suspension is obtained by mixing graphene oxide with deionized water and performing ultrasonic dispersion;

the ultrasonic time is 0.5-2h.

6. The method for preparing the graphene-based surface ion imprinted material capable of selectively adsorbing the gallium ions according to claim 1, wherein in the step (1), the stirring time at room temperature in the nitrogen environment is 30-60min.

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

8. The method for preparing the graphene-based surface ion imprinted material capable of 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.

9. The graphene-based surface ion imprinting material capable of selectively adsorbing gallium ions, which is prepared by the method according to any one of claims 1 to 8.

10. The application of the graphene-based surface ion imprinted material capable of selectively adsorbing gallium ions according to claim 9 in selective adsorption of gallium ions in a fly ash pickle liquor.