Preparation method of anionic dye adsorption and degradation material and adsorption and degradation material

Abstract

A preparation method of an anion dye adsorption and degradation material of the present invention includes: dissolving LiF and Ti3AlC2 in an HCl solution, washing, dissolving, ultrasonically treating, centrifuging, and drying the reaction product to obtain MXene; dispersing MXene in an ethylenediamine solution, then adding Zn(NO3)2·6H2O and thiourea, washing and drying the reaction product to obtain an MXene / ZnS composite; dispersing the MXene / ZnS composite in water to obtain a suspension; adding cellulose and chitosan to a lithium bromide solution to obtain a mixed solution, adding the suspension to the mixed solution to obtain a composite material; washing, soaking, and drying the composite material to obtain an anion dye adsorption and degradation material. The obtained adsorption and degradation material can perform photocatalytic degradation after adsorbing an anion dye, improving the treatment efficiency of anion dye wastewater. The present invention also provides an anion dye adsorption and degradation material.

Description

Technical Field

[0001] The present invention belongs to the technical field of adsorption and photocatalytic materials, and particularly relates to a preparation method of an anion dye adsorption and degradation material and an adsorption and degradation material. Background Art

[0002] In today's world, the environmental pollution problem caused by dyes is becoming increasingly serious. The polluted water not only affects the survival of aquatic organisms but also causes diseases in humans, such as typhoid, hepatitis, stomachache, and even death. Dyes with different chemical structures have different properties and applications. Dyes can be classified into anion dyes and cation dyes according to their chemical structures. Among them, anion dyes cause greater harm to human health, such as Congo red, Eriochrome Black T, methylene blue, and methyl orange.

[0003] Traditional sewage treatment methods include flocculation / coagulation, membrane filtration, precipitation, osmosis, ion exchange, adsorption, etc. Among them, adsorption is widely used in the treatment of dye pollutants due to its simple operation, high selectivity, low energy consumption, and environmental friendliness. Currently, existing adsorbents cannot further treat the adsorbed anion dyes, resulting in low treatment efficiency of traditional adsorbents for anion dye sewage. Summary of the Invention

[0004] In order to solve the problem of insufficient treatment efficiency of traditional adsorbents for anion dye sewage, the present invention provides a preparation method of an anion dye adsorption and degradation material. The adsorption and degradation material prepared by this method can photocatalytically degrade the adsorbed anion dye after adsorption, thereby improving the treatment efficiency of anion dye sewage.

[0005] The present invention also provides an anion dye adsorption and degradation material.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention provides a preparation method of an anion dye adsorption and degradation material, and the preparation method includes:

[0008] Dissolve LiF and Ti3AlC2 in HCl solution and continuously stir. After the reaction is completed, wash, dissolve, ultrasonically treat, and centrifuge the product in sequence. The obtained precipitate is dried to obtain MXene;

[0009] Disperse the MXene in ethylenediamine solution, then add Zn(NO3)2·6H2O and thiourea, and react at 140 - 160 °C. Wash and dry the obtained product to obtain an MXene / ZnS composite;

[0010] Disperse the MXene / ZnS composite in water to obtain an MXene / ZnS suspension;

[0011] Cellulose and chitosan are added to a lithium bromide solution to obtain a mixed solution, and the MXene / ZnS suspension is added to the mixed solution and fully dissolved to obtain a MXene / ZnS / cellulose-chitosan composite material;

[0012] The MXene / ZnS / cellulose-chitosan composite material is washed and then soaked in water, ethanol and tert-butanol in sequence, and after drying, an anion dye adsorption and degradation material is obtained.

[0013] Further, the mass ratio of the LiF to the Ti3AlC2 is 8:5;

[0014] The mass ratio of the MXene, Zn(NO3)2·6H2O and thiourea is 50:89:23;

[0015] The mass ratio of the MXene / ZnS composite, microcrystalline cellulose and chitosan is 1:1:1;

[0016] In the MXene / ZnS suspension, the mass fraction of the MXene / ZnS composite is 4.76%, in the mixed solution, the mass fraction of the microcrystalline cellulose is 1.22%, and the volume ratio of the mixed solution to the MXene / ZnS suspension is 1:1.

[0017] Further, the LiF and Ti3AlC2 are dissolved in an HCl solution and then continuously stirred. After the reaction is completed, the product is washed, dissolved, ultrasonically treated and centrifuged in sequence, and the obtained precipitate is dried to obtain MXene, specifically including:

[0018] The LiF and Ti3AlC2 are dissolved in the HCl solution and continuously stirred. After the reaction ends, the product is washed repeatedly with water until the pH value of the supernatant reaches 6, and then washed 3 times with ethanol and water respectively;

[0019] The washed product is dispersed in water and ultrasonically treated in an N2 environment, and then the precipitate is collected by centrifugation and freeze-dried to obtain few-layer MXene.

[0020] Further, the MXene is dispersed in an ethylenediamine solution, and then Zn(NO3)2·6H2O and thiourea are added, and the reaction is carried out at 140-160 °C. The obtained product is washed and dried to obtain a MXene / ZnS composite, specifically including:

[0021] Disperse the MXene uniformly in a 40.7% ethylenediamine solution, where the mass concentration of the MXene is 0.18%. Then add Zn(NO3)2·6H2O and thiourea, and react at 140 - 160 °C for 10 h. After cooling, wash the product 3 times with water and ethanol respectively, and obtain the MXene / ZnS composite through freeze-drying.

[0022] Further, add cellulose and chitosan to the lithium bromide solution to obtain a mixed solution, and add the MXene / ZnS suspension to the mixed solution and dissolve it fully to obtain the MXene / ZnS / cellulose-chitosan composite material, which specifically includes:

[0023] Dissolve lithium bromide in water to obtain a lithium bromide solution, add cellulose and chitosan to the lithium bromide solution, then add the MXene / ZnS suspension, stir well to obtain a mixed system, stir the mixed system at 110 °C to dissolve cellulose and chitosan fully, and then cool to obtain the MXene / ZnS / cellulose-chitosan composite material.

[0024] Further, wash the MXene / ZnS / cellulose-chitosan composite material, and then soak it in water, ethanol and tert-butanol in sequence, and obtain the anion dye adsorption and degradation material through drying, which specifically includes:

[0025] Wash the MXene / ZnS / cellulose-chitosan composite material repeatedly with water to remove lithium bromide, then soak it in water, ethanol and tert-butanol in sequence, and obtain the anion dye adsorption and degradation material through freeze-drying.

[0026] Further, the soaking treatment in water, ethanol and tert-butanol in sequence specifically includes:

[0027] Then soak it in the solvents water, ethanol and tert-butanol in sequence, where each solvent is soaked 3 times and the soaking time for each time is 2 h.

[0028] Based on the same inventive concept, the present invention provides an anion dye adsorption and degradation material, which is prepared by the preparation method of the above-mentioned anion dye adsorption and degradation material.

[0029] Based on the same inventive concept, the present invention also provides the use of an anion dye adsorption and degradation material in treating sewage containing anion dyes.

[0030] Further, the anion dye includes at least one of methyl blue, eriochrome black T and acid blue 80.

[0031] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0032] 1. A preparation method of an anion dye adsorption and degradation material according to the present invention. In this method, MX and ZnS are compounded with cellulose and chitosan to develop a MXene / ZnS / cellulose-chitosan material with a Schottky heterostructure. The Schottky heterostructure of this material can effectively separate electrons and holes, and then generate various active substances beneficial to photocatalytic degradation, increasing the photocatalytic performance. The MXene / ZnS / cellulose-chitosan material can photocatalytically degrade anion dyes after adsorbing them, and has excellent adsorption and photocatalytic performance, effectively improving the treatment efficiency of anion dye wastewater.

[0033] 2. An anion dye adsorption and degradation material according to the present invention. This material is composed of MX, ZnS, cellulose and chitosan, and has good thermal stability. It can adsorb anion dyes such as methyl blue, eriochrome black T and acid blue 80 through electrostatic interaction and hydrogen bonding, which belongs to a monolayer chemisorption process. In the photocatalytic process, the polymer matrix formed by chitosan and cellulose mainly plays the role of stabilizing MXene / ZnS and adsorbing dyes, ZnS mainly provides photo-generated carriers, and MXene mainly separates electrons and holes. After the MXene / ZnS / cellulose-chitosan material is recycled 4 times, the synergistic ability of adsorption and photocatalytic degradation is relatively stable. The MXene / ZnS / cellulose-chitosan material of the present invention has broad application prospects in adsorption and photocatalytic degradation applications. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 Schematic diagram of the preparation method of the MXene / ZnS / cellulose-chitosan composite material and its adsorption and photocatalytic degradation effects on anion dyes.

[0036] Figure 2Adsorption and degradation performance diagrams of MXene / ZnS / cellulose-chitosan composites prepared with different mass ratios of MXene / ZnS, cellulose, and chitosan for anionic dyes, where: A - C are the adsorption performances of MXene / ZnS / cellulose-chitosan composites prepared with different mass ratios of MXene / ZnS, cellulose, and chitosan for methylene blue, eriochrome black T, and acid blue 80; D - F are the overall removal capabilities of MXene / ZnS / cellulose-chitosan composites prepared with different mass ratios of MXene / ZnS, cellulose, and chitosan for methylene blue, eriochrome black T, and acid blue 80.

[0037] Figure 3 SEM diagrams of MXene, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials, where: A - C are the SEM diagrams of MXene, D - F are the SEM diagrams of MXene / ZnS, and G - I are the SEM diagrams of MXene / ZnS / cellulose-chitosan materials.

[0038] Figure 4 Adsorption curves of MXene / ZnS / cellulose-chitosan materials for anionic dyes, where: A is the static adsorption curve of MXene / ZnS / cellulose-chitosan materials for methylene blue, eriochrome black T, and acid blue 80; B is the dynamic adsorption curve of MXene / ZnS / cellulose-chitosan materials for methylene blue, eriochrome black T, and acid blue 80.

[0039] Figure 5 Adsorption performance and photocatalytic degradation curves of MXene / ZnS / cellulose-chitosan materials for anionic dyes, where: A is the static adsorption and photocatalytic degradation curves of MXene / ZnS / cellulose-chitosan materials for methylene blue, eriochrome black T, and acid blue 80; B is the dynamic adsorption and photocatalytic degradation curves of MXene / ZnS / cellulose-chitosan materials for methylene blue, eriochrome black T, and acid blue 80.

[0040] Figure 6 Comparison diagrams of the adsorption and degradation performances of MXene, ZnS, cellulose-chitosan composites, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials for anionic dyes, where: A - C are the comparison diagrams of the adsorption and degradation performances of blank, MXene, ZnS, cellulose-chitosan composites, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials for methylene blue, eriochrome black T, and acid blue 80 (ordinate is the residual liquid dye concentration / initial solution dye concentration).

[0041] Figure 7Physicochemical property test diagrams of ZnS, MXene / ZnS, and MXene / ZnS cellulose-chitosan materials, where: A is the UV-Vis diffuse reflectance spectra of ZnS, MXene / ZnS, and MXene / ZnS cellulose-chitosan materials; B are the Tacu’s plots of the three materials; C and D are the photoluminescence spectra and photocurrent response test results of ZnS, MXene / ZnS, and MXene / ZnS cellulose-chitosan materials, respectively; E and F are the electron spin resonance spectra of MXene / ZnS and MXene / ZnS cellulose-chitosan materials, respectively.

[0042] Figure 8 Practical application results of MXene / ZnS / cellulose-chitosan materials, where: A and B are the liquid chromatograms of methylene blue in tap water and pond water before and after treatment with MXene / ZnS / cellulose-chitosan materials, respectively; C and D are the removal rates of methylene blue in tap water and pond water by MXene / ZnS / cellulose-chitosan materials, respectively. Detailed implementation manners

[0043] The present invention will be specifically described below in combination with the detailed implementation manners and examples, and the advantages and various effects of the present invention will be presented more clearly therefrom. Those skilled in the art should understand that these detailed implementation manners and examples are used to illustrate the present invention, rather than to limit the present invention.

[0044] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In case of contradiction, this specification shall prevail.

[0045] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0046] The overall idea of this application is as follows:

[0047] In traditional sewage treatment methods, the adsorption method is widely used in the treatment of dye pollutants due to its simple operation, high selectivity, low energy consumption, and environmental friendliness. Currently, existing adsorbents cannot further treat the adsorbed anionic dyes, resulting in low treatment efficiency of traditional adsorbents for anionic dye sewage.

[0048] Based on this, the present invention introduces semiconductor photocatalysis technology, which is considered a promising pollutant treatment method due to its high efficiency, energy conservation, and no secondary pollution.

[0049] After analyzing and comparing the advantages and disadvantages of different pollutant treatment methods, the inventors of this application selected a method of synergistic treatment of adsorption and photodegradation, catalytically degrading anionic dyes while adsorbing them, and improving the treatment efficiency of anionic dye wastewater. Specifically, the present invention selects ZnS as a semiconductor photocatalyst, MXene as a co-catalyst, and cellulose and chitosan as polymer matrices with both adsorption and stabilization functions. MXene, ZnS / MXene and ZnS / MXene / cellulose-chitosan materials are prepared in sequence by a step-by-step synthesis method. And in the present invention, we compare the performance differences of the composite ZnS / MXene / cellulose-chitosan material and MXene, ZnS / MXene, ZnS and cellulose chitosan polymers in the adsorption and degradation synergy of three anionic dyes, and investigate the performance of ZnS / MXene / cellulose-chitosan materials.

[0050] The results show that the ZnS / MXene / cellulose-chitosan material of the present invention has excellent adsorption and photocatalytic degradation performance for three anionic dyes, and is stable and reusable. In the study of the adsorption performance of MXene / ZnS / cellulose-chitosan materials, methyl blue, chrome black T and acid blue 80 reached saturation adsorption for the three compounds at concentrations of 900, 600 and 400 μg / mL, respectively, and the saturated adsorption amounts were 1.28, 0.49 and 0.23 g / g, respectively. The adsorption of anionic dyes by MXene / ZnS / cellulose-chitosan materials is a single-layer chemical adsorption.

[0051] Specifically, the present invention provides a method for preparing an anionic dye adsorption degradation material, the preparation method comprising:

[0052] LiF and Ti3AlC2 are dissolved in HCl solution and stirred continuously. After the reaction is completed, the product is washed, dissolved, ultrasonically treated and centrifuged in sequence. The obtained precipitate is dried to obtain MXene.

[0053] The MXene is dispersed in an ethylenediamine solution, and then Zn(NO3)2·6H2O and thiourea are added, and the reaction is carried out at 140-160°C, and the obtained product is washed and dried to obtain a MXene / ZnS composite;

[0054] dispersing the MXene / ZnS composite in water to obtain a MXene / ZnS suspension;

[0055] Adding cellulose and chitosan to a lithium bromide solution to obtain a mixed solution, adding the MXene / ZnS suspension to the mixed solution and fully dissolving the mixture to obtain a MXene / ZnS / cellulose-chitosan composite material;

[0056] Wash the MXene / ZnS / cellulose-chitosan composite material, and then soak it in water, ethanol, and tert-butanol in sequence, and after drying, an anion dye adsorption and degradation material is obtained.

[0057] Further, the mass ratio of the LiF to the Ti3AlC2 is 8:5.

[0058] The mass ratio of the MXene, Zn(NO3)2·6H2O, and thiourea is 50:89:23.

[0059] The mass ratio of the MXene / ZnS composite, microcrystalline cellulose, and chitosan is 1:1:1.

[0060] In the MXene / ZnS suspension, the mass fraction of the MXene / ZnS composite is 4.76%, in the mixed solution, the mass fraction of the microcrystalline cellulose is 1.22%, and the volume ratio of the mixed solution to the MXene / ZnS suspension is 1:1.

[0061] In the present invention, the purpose of adopting the above ratio for the mass ratio of the MXene, Zn(NO3)2·6H2O, and thiourea is that Zn(NO3)2·6H2O and thiourea react in an equimolar mass ratio. Being lower or higher than this ratio will result in an unsatisfactory composite effect of the MXene and ZnS, as well as waste of Zn(NO3)2·6H2O and thiourea.

[0062] Further, dissolve the LiF and Ti3AlC2 in the HCl solution and then continuously stir. After the reaction is completed, wash the product, dissolve it, perform ultrasonic treatment, and centrifuge it in sequence. The obtained precipitate is dried to obtain MXene, specifically including:

[0063] Dissolve the LiF and Ti3AlC2 in the HCl solution and continuously stir. After the reaction ends, wash the product repeatedly with water until the pH value of the supernatant reaches 6, and then wash it 3 times with ethanol and water respectively.

[0064] Disperse the washed product in water, perform ultrasonic treatment in an N2 environment, and then centrifuge to collect the precipitate, and obtain few-layer MXene (few-layer: compared with multi-layer, it is a material with only a few layers stacked) after freeze-drying treatment.

[0065] In the present invention, the purpose of dissolving LiF and Ti3AlC2 in HCl solution and then continuously stirring is to make HCl react with LiF to generate HF with stronger acidity, and HF further etches the Al layer of Ti3AlC2. The purposes of washing, dissolving, ultrasonic treatment and centrifugation of the product in sequence are to wash the remaining reactants such as HCl and HF remaining in the material; dissolving in water after ultrasonic treatment is to disperse MXene to obtain more few-layer MXene; centrifugation is to separate the product MXene from the solution to obtain the precipitate part, that is, the product MXene.

[0066] Further, the MXene is dispersed in an ethylenediamine solution, then Zn(NO3)2·6H2O and thiourea are added, and the reaction is carried out at 140 - 160 °C. The obtained product is washed and dried to obtain an MXene / ZnS composite, which specifically includes:

[0067] The MXene is uniformly dispersed in a 40.7% ethylenediamine solution, then Zn(NO3)2·6H2O and thiourea are added, and the reaction is carried out at 140 - 160 °C for 10 h. After cooling, the product is washed 3 times with water and ethanol respectively, and then freeze-dried to obtain an MXene / ZnS composite.

[0068] In the present invention, the MXene is uniformly dispersed in a 40.7% ethylenediamine solution, then Zn(NO3)2·6H2O and thiourea are added. Zn(NO3)2·6H2O and thiourea will react to form ZnS. The reaction temperature of 140 - 160 °C is beneficial to the complete reaction of Zn(NO3)2·6H2O and thiourea. Lower or higher than this temperature will lead to incomplete reaction of Zn(NO3)2·6H2O and thiourea and low ZnS yield.

[0069] Further, cellulose and chitosan are added to a lithium bromide solution to obtain a mixed solution, and the MXene / ZnS suspension is added to the mixed solution and fully dissolved to obtain an MXene / ZnS / cellulose-chitosan composite, which specifically includes:

[0070] Lithium bromide is dissolved in water to obtain a lithium bromide solution. Cellulose and chitosan are added to the lithium bromide solution, and then the MXene / ZnS suspension is added. The mixture is fully stirred to obtain a mixed system. The mixed system is stirred at 110 °C to fully dissolve cellulose and chitosan, and then cooled to obtain an MXene / ZnS / cellulose-chitosan composite.

[0071] In the present invention, the purpose of adding cellulose and chitosan to the lithium bromide solution is to effectively dissolve cellulose and chitosan.

[0072] Furthermore, the MXene / ZnS / cellulose-chitosan composite material is washed, and then soaked in water, ethanol and tert-butanol in sequence, and dried to obtain an anionic dye adsorption degradation material, which specifically includes:

[0073] The MXene / ZnS / cellulose-chitosan composite material is repeatedly washed with water to remove lithium bromide, and then soaked in water, ethanol and tert-butanol in sequence, and freeze-dried to obtain an anionic dye adsorption degradation material.

[0074] In the present invention, the washed MXene / ZnS / cellulose-chitosan composite material is sequentially immersed in water, ethanol and tert-butanol for the purpose of preventing the porous network structure of the MXene / ZnS / cellulose-chitosan composite material from shrinking and collapsing during the freeze-drying process. The principle is to replace the solvent to make the MXene / ZnS / cellulose-chitosan composite material swell and shrink repeatedly, thereby enhancing its internal three-dimensional network structure.

[0075] The anionic dye adsorption and degradation material ZnS / MXene / CC prepared by the present invention uses ZnS as a semiconductor photocatalyst, MXene as a co-catalyst, and cellulose and chitosan as polymer matrices with both adsorption and stabilization functions. Among them, ZnS, as an important semiconductor photocatalyst, can quickly generate electron-hole pairs under appropriate light, and further generate a negative reduction potential that is conducive to the degradation of substances. In addition, ZnS is relatively friendly to the environment and is not easy to cause secondary pollution to the system. However, when ZnS is used as a simple photocatalyst, it has outstanding disadvantages such as unsatisfactory reaction under the action of visible light and too low specific surface area. In order to improve the photocurrent response and inhibit the rapid recombination of carriers, the present invention prepares a composite material by doping non-metal and metal; in order to improve the surface-to-volume ratio and quantum confinement effect, the present invention prepares ZnS nanoparticles, but the nanoparticles are easy to agglomerate in the reaction and are difficult to recover. In view of this problem, the present invention stabilizes the ZnS nanoparticles by adding a polymer matrix, thereby obtaining a material that can adsorb anionic dyes, efficiently photocatalytically degrade dyes, and is easy to reuse.

[0076] In the preparation raw materials of the ZnS / MXene / cellulose-chitosan material of the present invention, MXene is a general term for two-dimensional metal carbides, nitrides, and carbonitrides, which is produced by chemical exfoliation of the MAX phase. The general formula of the MAX phase is Mn+1AXn, where M is an early transition metal, A is a group 13 and 14 element, X is carbon and / or nitrogen, and n is a number with a range of 1 to 3. The MAX phase is exfoliated by removing the A layer sandwiched between the M layer and the X layer, and -O, -OH, and / or -F groups corresponding to the surrounding environment are modified at the surface ends to obtain MXene. The full-spectrum absorption effect of MXene can improve the utilization rate of sunlight, which is beneficial to the photocatalytic reaction of ZnS under visible light. Moreover, the quasi-metallic property of MXene can significantly promote the separation and migration of photo-generated carriers and improve the photoelectric effect of ZnS.

[0077] In the preparation raw materials of the ZnS / MXene / cellulose-chitosan material of the present invention, chitosan and cellulose are two relatively green and environmentally friendly polymers. Both have rich functional groups, such as hydroxyl groups and amino groups, and can be combined together by chemical cross-linking to form a polymer matrix. This matrix has a three-dimensional pore structure, good hydrophilicity, permeability, and flexibility, which helps to stabilize ZnS nanoparticles. In addition, due to the electrostatic adsorption and hydrogen bond interactions between the hydroxyl and amino groups of this matrix and dye molecules, it can almost adsorb all anionic dyes.

[0078] Next, the preparation method and adsorption and degradation materials of an anionic dye adsorption and degradation material of the present application will be described in detail in combination with examples and experimental data.

[0079] Example 1

[0080] For the preparation method of an anionic dye adsorption and degradation material in this example, the reagents used are as follows:

[0081] LiF, Ti3AlC2, HCl, ethanol, ethylenediamine, Zn(NO3)2·6H2O, thiourea, lithium bromide, microcrystalline cellulose, chitosan, eriochrome black T, methyl blue, acid blue 80, sodium hydroxide.

[0082] Specifically, as Figure 1 shown, a preparation method of an anionic dye adsorption and degradation material includes the following steps:

[0083] (1) Preparation of MXene

[0084] Weigh 4.8 g of LiF and 3 g of Ti3AlC2 powder and dissolve them in 60 mL of HCl solution (9 M), and stir magnetically for 24 h. After the reaction, wash the product with ultrapure water, centrifuge at 3500 rpm for 5 min, and wash repeatedly until the pH value of the supernatant reaches 6. Then wash with ethanol 3 times, then wash with ultrapure water 3 times, centrifuge at 3500 rpm for 5 min to obtain the product. Disperse the obtained product into 200 mL of deionized water and ultrasonically treat it for 1 h under a N2 atmosphere. After centrifugation, collect the product and dry it in vacuum at -50 °C for 48 h to obtain few-layer MXene.

[0085] (2) Preparation of MXene / ZnS composite

[0086] Weigh 50 mg of MXene and disperse it in 16 mL of ultrapure water and 11 mL of ethylenediamine solution, and stir the mixture magnetically for 30 min to make it uniformly dispersed. Then, 0.3 mmol of Zn(NO3)2·6H2O and 0.3 mmol of CH4N2S (thiourea) are added to the mixed solution. Finally, put the mixed solution into a stainless steel autoclave with a capacity of 50 mL and react at 140 - 160 °C for 10 h, and cool to room temperature. Wash the product 3 times with ultrapure water and ethanol respectively, centrifuge and pour off the washing liquid, and dry the product in vacuum at -50 °C for 48 h.

[0087] (3) MXene / ZnS / cellulose-chitosan composite

[0088] Disperse MXene / ZnS in 1 mL of ultrapure water to obtain a MXene / ZnS suspension. Weigh 3 g of LiBr (lithium bromide) and dissolve it in 1 mL of water, add microcrystalline cellulose and chitosan to it, and pour the dispersed MXene / ZnS suspension into it, and stir magnetically at room temperature for 2 min. Then place the mixed system in an oil bath, heat it to 110 °C, and stir magnetically for about 4 min (the cellulose and chitosan are completely dissolved) to obtain a uniform system. Pour the reacted mixture into a glass dish and cool to room temperature to obtain the MXene / ZnS / cellulose-chitosan composite.

[0089] (4) Immerse the obtained MXene / ZnS / cellulose-chitosan composite in distilled water to wash away LiBr, and repeat the washing. Use silver nitrate to check for the residual lithium bromide in the washing liquid until no precipitation occurs, indicating that the lithium bromide washing is complete. To prevent the porous network structure of the hydrogel from shrinking and collapsing during the drying process, the hydrogel is subjected to solvent immersion treatment in the order of water → ethanol → tert-butanol (3 times for each solvent, 2 h for each exchange). Finally, dry it in vacuum at -50 °C for 48 h.

[0090] In this example, the effects of the addition amounts of MXene / ZnS, cellulose, and chitosan on the material properties of the MXene / ZnS / cellulose-chitosan material were investigated. First, composite materials with different ratios were prepared, and then the adsorption and photocatalytic degradation properties of each material for methylene blue, Eriochrome Black T, and Acid Blue 80 were investigated respectively. Figure 2 A-C show the adsorption properties of the MXene / ZnS / cellulose-chitosan composite materials prepared from MXene / ZnS, cellulose, and chitosan with different mass ratios for the three dyes. Figure 2 D-F show the overall removal capabilities (including adsorption and photocatalytic degradation) of the MXene / ZnS / cellulose-chitosan composite materials prepared from MXene / ZnS, cellulose, and chitosan with different mass ratios for the three dyes. By comparison, it was found that when the mass ratio of MXene / ZnS: chitosan: cellulose was 1:1:1 (labeled as 50:50:50 in the figure), the adsorption and photocatalytic degradation effects of the composite material on the dyes were relatively ideal. The adsorption amount of methylene blue was 0.64 g / g, and the synergistic removal amount of adsorption and degradation was 0.66 g / g. The adsorption amount of Eriochrome Black T was 0.19 g / g, and the synergistic removal amount of adsorption and degradation was 0.41 g / g. The adsorption amount of Acid Blue 80 was 0.1 g / g, and the synergistic removal amount of adsorption and degradation was 0.18 g / g. The synergistic removal amount of adsorption and degradation was higher than the simple adsorption amount, indicating that the MXene / ZnS / cellulose-chitosan material had both adsorption and photocatalytic degradation effects on the three dyes.

[0091] In the present invention, MXene / ZnS mainly plays a role in photocatalytic degradation of dyes, and the more the addition amount, the better the catalytic effect. The chitosan-cellulose cross-linked layer mainly plays an adsorption role, taking into account the adsorption performance and photocatalytic degradation performance of the material. Equal mass ratios of MXene / ZnS, cellulose, and chitosan were selected. Chitosan contains abundant amino groups, and the protonated amino groups can adsorb anionic dyes through electrostatic interactions. Therefore, a certain proportion of chitosan can ensure the adsorption performance of the material. However, the stability of chitosan is poor, especially in acidic solutions, it is difficult to maintain a complete structure. Cellulose has good mechanical properties. When it is compounded with chitosan, it can improve the mechanical properties of the composite material, enhance the three-dimensional network structure and stability of the material. In addition, cellulose has a large number of hydroxyl groups, which can form hydrogen bonds with dyes and provide sufficient adsorption sites.

[0092] Example 2

[0093] In this example, SEM analysis was performed on the anion dye adsorption and degradation material prepared in Example 1. Among them, the mass ratio of MXene / ZnS, chitosan, and cellulose was 1:1:1.

[0094] In this example, SEM was used to analyze the apparent morphology of MXene, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials. Figure 3 A-C are SEM images of MXene. Figure 3 D-F are SEM images of MXene / ZnS. Figure 3 G-I are SEM images of MXene / ZnS / cellulose-chitosan materials. As Figure 3 shown in A-C, pure MXene has an obvious lamellar structure, and there are dispersed aggregates on the lamellae, which are considered to be nano-aggregates with smaller particle sizes. As Figure 3 shown in D-F, the MXene lamellae become fragmented structures, and the ZnS particles accumulate into clusters and are evenly dispersed between the MXene lamellae. As Figure 3 shown in G-I, a network structure cross-linked by cellulose and chitosan was prepared on the periphery of MXene / ZnS.

[0095] Example 3

[0096] In this example, the adsorption performance and photocatalytic degradation performance of the MXene / ZnS / cellulose-chitosan material prepared in Example 1 were tested.

[0097] 1. Adsorption performance test

[0098] (1) Static adsorption: Prepare target dye solutions with different concentration gradients (specific gradients: 5, 10, 20, 50, 100, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, and 1000 μg / mL), with the solution pH being neutral. Take 2 mL of the target dye solution and 1 mg of the material, and shake it on a shaker for 12 h in the dark. Take the remaining solution and measure the concentration of the remaining solution.

[0099] As Figure 4 shown in A, the static adsorption curves of the MXene / ZnS / cellulose-chitosan material for methylene blue, eriochrome black T, and acid blue 80 are shown. It can be found that when the dye concentration is at a relatively low level, the adsorption capacity increases with the increase of the dye concentration and then reaches saturated adsorption. When the concentrations of methylene blue, eriochrome black T, and acid blue 80 are 900, 600, and 400 μg / mL respectively, the MXene / ZnS / cellulose-chitosan composite material reaches saturated adsorption for the three compounds, and the adsorption capacities are 1.28, 0.49, and 0.23 g / g respectively.

[0100] (2) Dynamic adsorption: Through static adsorption, select the dye concentration at which the composite material reaches saturated adsorption (specifically: the initial concentrations of methylene blue, eriochrome black T, and acid blue 80 are 900, 600, and 200 μg / mL in sequence). Prepare relevant solutions. Take 2 mL of the target dye solution and 1 mg of the material, place them on a shaker and shake for 6 h under dark conditions, and sample and measure the concentration of the remaining solution at 0, 15, 30, 45, 60, 90, 120, 180, 240, 300, and 360 min respectively.

[0101] Such as Figure 4 B is the dynamic adsorption curve of the MXene / ZnS / cellulose-chitosan material for methylene blue, eriochrome black T, and acid blue 80. It can be found that the adsorption rate of methylene blue increases rapidly from 0 to 200 min, slows down from 200 to 300 min, and reaches adsorption equilibrium after 300 min; the adsorption rate of eriochrome black T increases rapidly from 0 to 60 min, slows down from 60 to 100 min, and reaches adsorption equilibrium after 100 min; the adsorption rate of acid blue 80 increases rapidly from 0 to 30 min, slows down from 30 to 150 min, and reaches adsorption equilibrium after 150 min. During the rising stage of the adsorption rate, since the adsorption sites are very sufficient, the dye combines with the material rapidly; due to the reduction of adsorption sites, the adsorption rate slows down, and the adsorption amount no longer increases when the adsorption sites are saturated.

[0102] 2. Test on the synergistic effect of adsorption and photocatalytic degradation

[0103] (1) Static adsorption and degradation: Prepare target dye solutions with different concentration gradients. Take 2 mL of the target dye solution and 1 mg of the material, place them in a photocatalytic reactor, carry out photocatalytic degradation for 8 h, take the remaining solution, and measure the concentration of the remaining solution.

[0104] Such as Figure 5A shows the static adsorption and photocatalytic degradation curves of the MXene / ZnS / cellulose-chitosan material for methylene blue, Eriochrome Black T, and Acid Blue 80. The MXene / ZnS / cellulose-chitosan material reaches the saturation state of the adsorption-degradation synergy when the concentrations of methylene blue, Eriochrome Black T, and Acid Blue are 6, 2, and 1 mg / mL, respectively, and the saturated removal amounts of the three dyes are 5.6, 2.0, and 0.51 g / g, respectively. When the dye concentration is low, there are sufficient reaction sites on the material, and the adsorption and degradation amounts increase with the increase of the initial dye concentration. While adsorbing the dye, the composite material will catalyze the generation of free radicals, and under the action of free radical oxidation, the dye adsorbed on the material is continuously degraded. When the dye concentration reaches a certain value, the free radicals catalyzed by the composite material are occupied by dye molecules, and in addition, the degradation products will also compete with dye molecules for free radicals. At this time, the composite material reaches the saturation state of adsorption and degradation, and the removal amount of the dye no longer increases with the increase of the dye concentration. However, as the dye is continuously degraded, a certain amount of adsorption sites and free radicals are released, so the adsorption and degradation amount of the composite material still shows a slow growth trend. In addition, the removal amounts of the three dyes by the adsorption-degradation synergy are higher than the simple adsorption amount, indicating that the dye is further degraded after adsorption. Generally speaking, the MXene / ZnS / cellulose-chitosan material has excellent removal ability for the three anionic dyes.

[0105] (2) Dynamic adsorption and degradation: Select the dye concentrations at the plateau stage through static adsorption and degradation: methylene blue, Eriochrome Black T, and Acid Blue 80 are 7, 3, and 1 mg / mL in sequence. Prepare the relevant solutions, take 2 mL of the target dye solution and 1 mg of the material, place them in a photocatalytic reactor, and carry out photocatalytic degradation for 6 h. Samples are taken at 0, 5, 15, 30, 60, 120, 180, 240, 300, and 360 min to measure the concentration of the remaining solution.

[0106] As Figure 5 B shows the dynamic adsorption and photocatalytic degradation curves of the MXene / ZnS / cellulose-chitosan material for methylene blue, Eriochrome Black T, and Acid Blue 80. With the increase of time, the removal amounts of the three anionic dyes by the MXene / ZnS / cellulose-chitosan material continuously increase. Until after 2 h, the removal amount of the dye by the material no longer increases significantly with the increase of time, which is because the sites on the composite material tend to be saturated, and with adsorption and degradation, the dye concentration in the solution continuously decreases, and even all are adsorbed and degraded.

[0107] 3. Comparative study on the adsorption and photocatalytic degradation performance of different materials

[0108] (1) Comparison of adsorption and photocatalytic degradation performance of different materials: Select the dye concentrations at the plateau stage: methylene blue, eriochrome black T, and acid blue 80 are 7, 3, and 1 mg / mL in sequence. Prepare the relevant solutions. Take 2 mL of the target dye solution and add 1 mg of MX, ZnS, cellulose-chitosan composite, MXene / ZnS, and MXene / ZnS / cellulose-chitosan composite material respectively. First, place them under dark conditions and shake them on a shaker at 75 rpm for 1 h for adsorption, and sample at different time points from 0 to 60 min to measure the dye concentration in the solution. After adsorption, transfer the samples to a photocatalytic reactor for photocatalytic degradation experiments, and sample at different time points (60 - 120 min) to measure the concentration of the remaining solution.

[0109] As Figure 6 A - C are the comparison diagrams of the adsorption and degradation performance of methylene blue, eriochrome black T, and acid blue 80 by blank, MXene, ZnS, cellulose-chitosan composite, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials respectively (the vertical coordinate is the dye concentration of the remaining solution / the dye concentration of the initial solution). MXene and cellulose-chitosan materials only have adsorption effects on the three dyes and do not have obvious photocatalytic degradation effects. While ZnS has good photocatalytic degradation performance but weak adsorption performance. It can be found that the adsorption performance and photocatalytic degradation performance of MXene / ZnS are both superior to those of individual MXene and ZnS, indicating that the combination of the two not only improves the adsorption performance of the material but also helps the occurrence of photocatalytic degradation. In addition, the adsorption and degradation performance of MXene / ZnS / cellulose-chitosan material for the three dyes are both superior to the other four materials, indicating that the combination of the four materials (MXene, ZnS, cellulose, and chitosan) is beneficial to the final removal effect of the dyes.

[0110] (2) Comparison of the optical properties of the materials

[0111] The band gaps of ZnS, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials are discussed by using ultraviolet-visible diffuse reflectance spectroscopy and Tacu’s plot analysis method. And, photoluminescence spectroscopy and photocurrent tests are used to evaluate the separation efficiency of electrons and holes in the three materials. In addition, in order to further confirm the active substances, electron spin resonance tests are carried out on MX / ZnS and MX / ZnS / cellulose-chitosan materials.

[0112] Figure 7 A is the ultraviolet-visible diffuse reflectance spectrum of ZnS, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials, Figure 7 B are the Tacu’s plots of the three materials. As Figure 7As shown in Figure B, the band gaps of ZnS, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials are 3.34, 2.68, and 2.07 eV, respectively. It can be seen that after the combination of ZnS, MXene, and cellulose-chitosan, the band gap of the material changes, that is, the optical properties change. ZnS is a semiconductor catalyst with a certain photocatalytic ability for dyes. However, due to its relatively wide band gap, the degradation effect needs to be improved. After adding MXene, a Schottky heterojunction structure is formed, and photo-generated carriers are generated under light illumination. Among them, the holes remain in the valence band of ZnS, while the electrons accumulate in MXene, realizing the effective separation of electrons and holes and improving the photocatalytic performance of the material. The effective separation of photo-generated carriers is a necessary condition for photocatalysis, and photo-generated carriers are necessary substances for catalyzing the generation of free radicals to degrade pollutants. Therefore, the effective separation of electrons and holes can greatly improve the photocatalytic degradation performance of the material.

[0113] Figure 7 C and Figure 7 D are the photoluminescence spectra and photocurrent response test results of ZnS, MXene / ZnS, and MXene / ZnS / cellulose-chitosan materials, respectively. In the photoluminescence spectrum, the greater the spectral peak intensity, the lower the separation efficiency of electrons and holes. In the photocurrent test, the greater the photocurrent, the higher the separation efficiency of electrons and holes. As Figure 7 shown in Figure C, the photoluminescence spectrum intensity of ZnS is much greater than that of MXene / ZnS and MXene / ZnS / cellulose-chitosan materials, indicating that the addition of MXene promotes the separation of electrons and holes in ZnS. As Figure 7 shown in Figure D, the order of photocurrent response of the three materials is: MXene / ZnS / cellulose-chitosan material > MXene / ZnS > ZnS. It can be seen that the MXene / ZnS / cellulose-chitosan material has a high electron-hole separation efficiency and good photocatalytic effect, further indicating that the combination of MXene, ZnS, cellulose, and chitosan can effectively improve the material's ability to treat pollutants.

[0114] Figure 7 E and Figure 7Figures F are the electron spin resonance spectra of MXene / ZnS and MXene / ZnS cellulose-chitosan materials. Both materials can catalyze the generation of superoxide radicals and hydroxyl radicals. In addition, it can be found from the spectral intensity that the catalytic effect of the MXene / ZnS cellulose-chitosan material is better than that of MXene / ZnS. According to the Schottky heterojunction theory, MXene plays the role of an "electron trap". After MXene and ZnS come into contact, the migration path of photo-generated carriers will be changed, electrons enter MXene from ZnS, and their Fermi levels reach consistency. The electron concentration in ZnS decreases, reducing the possibility of recombination with holes, thereby improving the semiconductor photocatalytic performance. Subsequently, electrons react with oxygen to generate superoxide radicals, and hydroxyl radicals are generated under the action of holes. Finally, the anionic dye is photocatalytically degraded under the action of various active substances. In this process, MXene and ZnS exchange energy frequently and are prone to accumulation, resulting in a decrease in the electron-hole separation effect. After adding cellulose and chitosan, the photocatalyst can be fixed and the catalytic effect can be stabilized. Therefore, the MXene / ZnS cellulose-chitosan material has better performance in catalyzing the generation of free radicals than MXene / ZnS.

[0115] It can be concluded from the above results that the MXene / ZnS cellulose-chitosan material mainly catalyzes the generation of superoxide radicals, hydroxyl radicals and holes under visible light to degrade anionic dyes. The combination of MXene, ZnS, cellulose and chitosan has successfully improved the adsorption and photocatalytic performance of the material.

[0116] 4. Practical application test

[0117] Through the above systematic research, the MXene / ZnS / cellulose-chitosan material has been proven to have excellent adsorption and photocatalytic degradation performance for anionic dyes. To further explore the treatment ability of this material for anionic dyes in complex systems, we carried out relevant experiments with pond water and tap water.

[0118] Pond water and tap water were respectively taken to prepare solutions of the target dye with concentrations of 50, 100 and 200 μg / mL. For each sample, 2 mL of the target dye solution and 5 mg of the material were taken and placed in a photocatalytic reactor for reaction for 120 min. Samples were taken at 0 - 120 min to measure the concentration of the remaining solution. Figure 8 A and Figure 8 B are the liquid chromatograms of methylene blue in tap water and pond water before and after treatment with the MXene / ZnS / cellulose-chitosan material, Figure 8 C and Figure 8D represents the removal rates of methylene blue in tap water and pond water by the MXene / ZnS / cellulose-chitosan material. The MXene / ZnS / cellulose-chitosan material can remove 50 mg / L of methylene blue in tap water and pond water by 100%, and the removal rates for methylene blue at concentrations of 100 and 200 mg / L also remain above 80%. It can be seen that the MXene / ZnS / cellulose-chitosan material has an ideal removal effect on methylene blue in the actual water system.

[0119] In summary, the present invention first developed a MXene / ZnS / cellulose-chitosan composite material with a Schottky heterostructure by compounding MX, ZnS with cellulose and chitosan for removing anionic dyes. Through process optimization, it was found that the mass ratio of MXene / ZnS:chitosan:cellulose of 1:1:1 had an ideal adsorption and photocatalytic degradation effect on dyes. The MXene / ZnS / cellulose-chitosan material has excellent adsorption and photocatalytic degradation properties for anionic dyes, and the removal capacities for methylene blue, Eriochrome Black T and Acid Blue 80 can reach 5.6, 2.0 and 0.51 g / g. The MXene / ZnS / cellulose-chitosan material has a Schottky heterostructure, which can effectively separate electrons and holes, and then generate various active substances beneficial to photocatalytic degradation, increasing the photocatalytic performance. During the photocatalytic process, chitosan and cellulose mainly play the role of stabilizing MXene / ZnS and adsorbing dyes, ZnS mainly plays the role of providing photoexcited carriers, and MXene mainly plays the role of separating electrons and holes. UV-visible diffuse reflectance spectroscopy and Tacu’s plot analysis show that the combination of ZnS, MXene, chitosan and cellulose can affect the optical properties and band gap of the material. Additionally, through photoluminescence spectroscopy and photocurrent response tests, it was found that the combination of several materials successfully improved the separation efficiency of photoexcited carriers in the composite material, further proving that the MXene / ZnS / cellulose-chitosan material has excellent photocatalytic performance. Finally, when the MXene / ZnS / cellulose-chitosan material was applied to the actual systems of pond water and tap water, it was found that it has excellent removal ability for anionic dyes. It can be seen that the MXene / ZnS / cellulose-chitosan material has broad application prospects in adsorption and photocatalytic degradation applications.

[0120] Finally, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0121] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0122] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A preparation method of an anion dye adsorption and degradation material, characterized in that, The preparation method includes: Dissolve LiF and Ti3AlC2 in an HCl solution and then continuously stir. After the reaction is completed, wash, dissolve, ultrasonically treat, and centrifuge the product in sequence. Dry the obtained precipitate to obtain MXene; Disperse the MXene in an ethylenediamine solution, then add Zn(NO3)2·6H2O and thiourea, and react at 140 - 160 °C. Wash and dry the obtained product to obtain an MXene / ZnS composite; Disperse the MXene / ZnS composite in water to obtain an MXene / ZnS suspension; Add cellulose and chitosan to a lithium bromide solution to obtain a mixed solution. Add the MXene / ZnS suspension to the mixed solution and fully dissolve it to obtain an MXene / ZnS / cellulose-chitosan composite material; Wash the MXene / ZnS / cellulose-chitosan composite material, then soak it in water, ethanol, and tert-butanol in sequence, and dry it to obtain an anion dye adsorption and degradation material.

2. The preparation method of an anion dye adsorption and degradation material according to claim 1, characterized in that, The mass ratio of the LiF to the Ti3AlC2 is 8:5; The mass ratio of the MXene, Zn(NO3)2·6H2O, and thiourea is 50:89:23; The mass ratio of the MXene / ZnS composite, microcrystalline cellulose, and chitosan is 1:1:1; In the MXene / ZnS suspension, the mass fraction of the MXene / ZnS composite is 4.76%. In the mixed solution, the mass fraction of the microcrystalline cellulose is 1.22%. The volume ratio of the mixed solution to the MXene / ZnS suspension is 1:

1.

3. The preparation method of an anion dye adsorption and degradation material according to claim 1, characterized in that, The step of dissolving LiF and Ti3AlC2 in an HCl solution and then continuously stirring, washing, dissolving, ultrasonically treating, and centrifuging the product in sequence after the reaction is completed, and drying the obtained precipitate to obtain MXene specifically includes: Dissolve LiF and Ti3AlC2 in an HCl solution and continuously stir. After the reaction ends, wash the product repeatedly with water until the pH value of the supernatant reaches 6, and then wash it 3 times with ethanol and water respectively; Disperse the washed product in water, ultrasonically treat it in an N2 environment, then centrifuge to collect the precipitate, and obtain few-layer MXene through freeze-drying treatment.

4. The preparation method of an anion dye adsorption and degradation material according to claim 1, characterized in that, The step of dispersing the MXene in an ethylenediamine solution, then adding Zn(NO3)2·6H2O and thiourea, and reacting at 140 - 160 °C, washing and drying the obtained product to obtain an MXene / ZnS composite specifically includes: Uniformly disperse the MXene in a 40.7% ethylenediamine solution, where the mass concentration of the MXene is 0.18%. Then add Zn(NO3)2·6H2O and thiourea, react at 140 - 160 °C for 10 h. After cooling, wash the product 3 times with water and ethanol respectively, and obtain the MXene / ZnS composite through freeze-drying.

5. The preparation method of an anion dye adsorption and degradation material according to claim 1, characterized in that, Adding cellulose and chitosan into a lithium bromide solution to obtain a mixed solution, and adding the MXene / ZnS suspension into the mixed solution, and fully dissolving to obtain an MXene / ZnS / cellulose-chitosan composite material, specifically including: Dissolving lithium bromide in water to obtain a lithium bromide solution, adding cellulose and chitosan into the lithium bromide solution, then adding the MXene / ZnS suspension, fully stirring to obtain a mixed system, stirring the mixed system at 110 °C to fully dissolve cellulose and chitosan, and then cooling to obtain an MXene / ZnS / cellulose-chitosan composite material.

6. The preparation method of an anion dye adsorption and degradation material according to claim 1, wherein, Washing the MXene / ZnS / cellulose-chitosan composite material, and then successively soaking it in water, ethanol and tert-butanol, and drying to obtain an anion dye adsorption and degradation material, specifically including: Repeatedly washing the MXene / ZnS / cellulose-chitosan composite material with water to remove lithium bromide, then successively soaking it in water, ethanol and tert-butanol, and freeze-drying to obtain an anion dye adsorption and degradation material.

7. The preparation method of an anion dye adsorption and degradation material according to claim 6, characterized in that, The subsequent successive soaking treatment in water, ethanol and tert-butanol specifically includes: Subsequently successively soaking it in solvent water, ethanol and tert-butanol, wherein each solvent is soaked 3 times, and each soaking time is 2 h.

8. An anion dye adsorption and degradation material, characterized in that, The anion dye adsorption and degradation material is prepared by the preparation method of an anion dye adsorption and degradation material according to any one of claims 1-7.

9. Use of an anion dye adsorption and degradation material according to claim 8 in treating sewage containing anionic dyes.

10. The use according to claim 9, characterized in that, The anionic dye includes at least one of methyl blue, chrome black T and acid blue 80.

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