Application of CoFe-PBA-at-MXenes nano confinement catalytic membrane

Abstract

The invention relates to application of a CoFe-PBA-coated MXenes nano confinement catalytic membrane, the CoFe-PBA-coated MXenes nano confinement catalytic membrane is combined with peroxymonosulfate to treat a polluted water body, and a pollutant of the polluted water body is bisphenol A. The CoFe-PBA-coated MXenes nano confinement catalytic membrane has the advantages that the CoFe-PBA-coated MXenes nano confinement catalytic membrane can be used for treating the polluted water body; according to the method disclosed by the invention, the bisphenol A in the water is removed by activating the peroxymonosulfate by using the CoFe-PBA-coated MXenes nano confinement catalytic membrane, and the method has the advantages of simplicity in operation, small secondary pollution and high removal rate.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and particularly to the application of a CoFe-PBA@MXenes nano-confined catalytic membrane. Background Art

[0002] With the rapid urbanization and industrialization processes in modern society, various new chemicals have been designed and produced. However, some refractory organic contaminants (ROCs), such as endocrine disrupting chemicals (EDCs) and pharmaceuticals and personal care products (PPCPs), pose a major challenge to the environment due to their complex and stable molecular structures, biodegradation resistance, and persistent toxicity in nature. Compared with traditional water treatment methods, membrane technology has been recognized as an efficient water treatment technology. Membrane filtration mainly achieves separation through size exclusion, so the filtration permeability and selectivity are crucial.

[0003] Sulfate radical-based advanced oxidation processes (SR-AOPs) have been widely used to degrade refractory organic contaminants due to their advantages. Currently, various common activation strategies for peroxymonosulfate have been adopted, including homogeneous or heterogeneous methods, such as heat treatment, ultrasound, ultraviolet light, radiation, alkalinity, transition metal, and carbon-based material activation. The reactive oxygen species generated by activating peroxymonosulfate include hydroxyl radicals (•OH), sulfate radicals (SO4 •− ), superoxide ions (O2 •− ), and non-radicals ( 1 O2) to destroy the pollutant structure. However, radical-based advanced oxidation processes are limited by a short propagation distance (less than 200 nm), an extremely short lifespan (10 -6 ~10 -9 s), and are easily affected by coexisting anions in complex water bodies. Therefore, the process dominated by non-radical 1 O2 has become a research hotspot, which can maintain high efficiency and a long lifespan in a wide pH range and exhibits excellent anti-interference ability in complex water bodies. Usually 1 The generation pathways of •−The role and the electron transfer between the catalyst and peroxymonosulfate. In most SR-AOPs, it is difficult to selectively generate a large amount of •− by enhancing the self-decomposition of peroxymonosulfate, the energy transfer of oxygen, and the role of 1 O2. Regarding the electron transfer between the catalyst and peroxymonosulfate, a feasible method is to confine the reaction within a nanoscale space, shortening the electron transfer migration distance while improving the utilization rate of active sites.

[0004] Preparing a catalytic membrane with nanochannels by loading a catalyst on the membrane is a feasible strategy to overcome the inherent limitations of SR-AOPs. Catalytic membranes based on two-dimensional materials include layered membranes (stacked two-dimensional nanosheets) and nanoporous membranes (stacked porous two-dimensional nanosheets or perforated two-dimensional nanosheets). Although the tight layered membrane effectively reduces the mass transfer resistance, it simultaneously limits the permeation flux of the layered membrane. By introducing additional catalytic components to stabilize or expand the layer spacing, it is possible to achieve SR-AOPs while increasing the permeation flux. According to previous literature, most catalytic membrane / peroxymonosulfate systems degrade pollutants by generating a large number of free radicals. Although the removal kinetics and removal efficiency of the catalytic membrane / peroxymonosulfate system can be improved by several orders of magnitude compared with the heterogeneous / peroxymonosulfate system, this system is still vulnerable to the interference of complex water bodies. Moreover, the existing catalytic membrane synthesis methods are not environmentally friendly, involving strong acids, strong bases, and complex redox processes. To solve the above problems and realize the application prospect of catalytic membranes in actual water bodies, the generation of non-free radicals by the catalytic membrane (room temperature synthesis) / peroxymonosulfate system under the nano-confinement effect has been studied in depth. Under nano-confinement conditions, the adsorption process, electronic state, reaction energy barrier, and surface potential of the catalytic material will all change. Research shows that the nano-confinement effect may change the electronic structure of the active sites on the catalyst surface and the electron transfer pathway between peroxymonosulfate and the catalyst, thereby selectively generating 1 O2. MOF / two-dimensional transition metal carbides (MXene) composites have been proven to be beneficial for the rapid transfer of charges through a strong synergistic effect in the fields of catalysts, electrocatalytic energy storage, and separation membranes. Therefore, catalytic membranes with nano-confinement are expected to generate a large amount of 1 O2 by improving electron transfer during the activation process of peroxymonosulfate. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide an application of a CoFe-PBA@MXenes nano-confined catalytic membrane in view of the above deficiencies in the prior art. It uses the CoFe-PBA@MXenes nano-confined catalytic membrane to activate peroxymonosulfate to remove bisphenol A in water, and has the advantages of simple operation, little secondary pollution, and high removal rate.

[0006] The above-mentioned object of the present invention is achieved by the following technical solutions: An application of a CoFe-PBA@MXenes nano-confined catalytic membrane, which combines the CoFe-PBA@MXenes nano-confined catalytic membrane with peroxymonosulfate to treat polluted water, and the pollutant in the polluted water is bisphenol A.

[0007] Furthermore, the preparation method of the CoFe-PBA@MXenes nano-confined catalytic membrane includes The process of preparing MXenes dispersion by reacting concentrated hydrochloric acid (12mol / L HCl), lithium fluoride (LiF) and aluminum carbonitride (Ti3A1C2); The process of preparing the first precursor solution by mixing MXenes dispersion, cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and deionized water; The process of preparing the second precursor solution by mixing potassium ferricyanide (K3Fe(CN)6), sodium citrate (C6H5Na3O7) and deionized water; And the process of preparing the CoFe-PBA@MXenes nano-confined catalytic membrane by reacting the first precursor solution and the second precursor solution.

[0008] Furthermore, in the process of preparing the MXenes dispersion, first add lithium fluoride to concentrated hydrochloric acid and stir until completely dissolved, then add aluminum carbonitride and stir and react at 30~50°C for 20~30h. After the etching reaction is completed, centrifuge at 3000~5000r / min for 4~6min to obtain a clay-like precipitate, then wash and centrifuge with pure water for several times until the pH = 5~7, and then perform ultrasonic treatment under the protection of inert gas and ice-water bath, centrifuge and retain the supernatant to obtain MXenes dispersion.

[0009] Most further, in the process of preparing the MXenes dispersion, control the molar ratio of hydrogen chloride, lithium fluoride and aluminum carbonitride in concentrated hydrochloric acid to be 45~50:12~18:1.

[0010] Furthermore, in the process of preparing the first precursor solution, control the ratio of MXenes, cobalt nitrate hexahydrate and deionized water in the MXenes dispersion to be 20~30mg:200~250mg:25mL.

[0011] Furthermore, in the process of preparing the second precursor solution, control the ratio of potassium ferricyanide, sodium citrate and deionized water to be 150~200mg:300~350mg:25mL.

[0012] Furthermore, in the process of preparing the CoFe-PBA@MXenes nanoconfined catalytic membrane, the first precursor solution and the second precursor solution are mixed and stirred at room temperature for 48 h. After the reaction, suction filtration is carried out through a water-based filter membrane to obtain a CoFe-PBA@MXene nanoconfined catalytic membrane with a mass of 0.6~2.2 mg / cm 2 2.

[0013] Further, after the peroxymonosulfate is added to the polluted water body, it passes through the CoFe-PBA@MXenes nanoconfined catalytic membrane by a peristaltic pump to remove the pollutants in the polluted water body.

[0014] Furthermore, the concentration of pollutants in the polluted water body is 1~10 mg / L.

[0015] Furthermore, the molar ratio of the pollutants in the polluted water body to peroxymonosulfate is 2.19~21.9:100.

[0016] In summary, the beneficial technical effects of the present invention are as follows: The present invention efficiently removes bisphenol A in water by constructing a CoFe-PBA@MXene catalytic membrane to activate the peroxymonosulfate system. It mainly utilizes the CoFe-PBA@MXene catalytic membrane, where CoFe mainly serves as the active site for activating peroxymonosulfate. The stacked structure of the CoFe-PBA / MXene nanoconfined channels not only enhances the adsorption of peroxymonosulfate but also effectively realizes the internal directional electron transfer of peroxymonosulfate to the active site. PMS molecules and the catalytic membrane can respectively serve as electron donors and "electron bridges" to transfer electrons to the active sites on the catalytic membrane, thereby selectively generating 1 O2 (PMS→PMS*→SO5 •− → 1 O2); The main active substance generated by the CoFe-PBA@MXene catalytic membrane of the present invention is 1 O2, which has strong anti-interference ability for complex water bodies, is simple to operate, easy to implement, has an extremely low concentration of metal ion dissolution, and extremely small secondary pollution. It can effectively remove bisphenol A, a pollutant in water, with a removal rate exceeding 99%; The present invention prepares the CoFe-PBA@MXenes nanoconfined catalytic membrane by in-situ synthesis. It can catalyze the degradation of bisphenol A, a pollutant in aqueous solution, by peroxymonosulfate and integrates the reaction and separation processes in one unit. It has good cyclic stability and reduces the operating cost. At the same time, the CoFe-PBA@MXenes nanoconfined catalytic membrane developed by the present invention exhibits excellent non-radical catalytic performance and water stability, can efficiently and rapidly remove bisphenol A in water, and realizes the safe control of pollutants. Brief Description of the Drawings

[0017] Figure 1 It is the schematic diagram of treating polluted water body in Embodiment 1 of the present invention.

[0018] Figure 2 It is the schematic diagram of the removal rate of bisphenol A in the polluted water body of Embodiment 3 and Comparative Examples 1 - 2 of the present invention. Detailed Embodiments

[0019] In order to make the technical means, creative features, achieved purposes and functions of the present invention clearer and easier to understand, the present invention will be further described below in conjunction with the drawings and specific embodiments.

[0020] Embodiment 1: It is an application of a CoFe - PBA@MXenes nano - confined catalytic membrane disclosed in the present invention. The CoFe - PBA@MXenes nano - confined catalytic membrane is combined with peroxymonosulfate to treat polluted water body, and the pollutant in the polluted water body is bisphenol A.

[0021] Specifically, in the application of the present invention, the mechanism of using the CoFe - PBA@MXenes nano - confined catalytic membrane to activate peroxymonosulfate to remove bisphenol A in water is as Figure 1 shown.

[0022] Embodiment 2: It is an application of a CoFe - PBA@MXenes nano - confined catalytic membrane disclosed in the present invention. The difference from Embodiment 1 is that the preparation method of the CoFe - PBA@MXenes nano - confined catalytic membrane includes S1 The process of preparing MXenes dispersion by reacting concentrated hydrochloric acid (HCl), lithium fluoride (LiF) and aluminum carbonitride (Ti3AlC2); Among them, in the process of preparing MXenes dispersion, first add lithium fluoride to concentrated hydrochloric acid and stir until completely dissolved, then add aluminum carbonitride, control the molar ratio of hydrogen chloride, lithium fluoride and aluminum carbonitride in concentrated hydrochloric acid to be 47:15:1, and stir and react at 40 °C for 24 h. After the reaction, centrifuge at 4000 r / min for 5 min to obtain a clay - like precipitate, then wash and centrifuge with pure water, repeat several times until pH = 6, and then perform ultrasonic treatment under the protection of inert gas and ice - water bath, centrifuge and retain the supernatant to obtain MXenes dispersion.

[0023] S2 The process of preparing the first precursor solution by mixing MXenes dispersion, cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and deionized water; Among them, control the ratio of MXenes, cobalt nitrate hexahydrate and deionized water in the MXenes dispersion to be 25 mg:218 mg:25 mL; Process S3 for preparing a second precursor solution by mixing potassium ferricyanide (K3Fe(CN)6), sodium citrate (C6H5Na3O7) and deionized water; Among them, the ratio of potassium ferricyanide, sodium citrate and deionized water is controlled to be 165 mg: 331 mg: 25 mL; Process S4 for preparing a CoFe-PBA@MXenes nanoconfined catalytic membrane by reacting a first precursor solution and a second precursor solution.

[0024] Among them, in the process of preparing the CoFe-PBA@MXenes nanoconfined catalytic membrane, the first precursor solution and the second precursor solution are mixed and stirred at room temperature for 48 h. After the reaction, suction filtration is carried out through a water-based filter membrane to obtain a CoFe-PBA@MXene nanoconfined catalytic membrane with a density of 1.8 mg / cm 2 of CoFe-PBA@MXene nanoconfined catalytic membrane.

[0025] Example 3: An application of a CoFe-PBA@MXenes nanoconfined catalytic membrane disclosed in the present invention. The difference from Example 2 is that after adding peroxymonosulfate (PMS) to the contaminated water body at 5 mg / L, the pollutant in the contaminated water body is bisphenol A, and the molar ratio of the pollutant in the contaminated water body to peroxymonosulfate is 2.19:100. Then, it passes through the CoFe-PBA@MXenes nanoconfined catalytic membrane by a peristaltic pump to remove the pollutants in the contaminated water body.

[0026] Examples 4 to 7: An application of a CoFe-PBA@MXenes nanoconfined catalytic membrane disclosed in the present invention. The difference from Example 3 is that the pollutant concentrations in the contaminated water body are 1, 3, 5, and 10 mg / L respectively.

[0027] Examples 8 to 11: An application of a CoFe-PBA@MXenes nanoconfined catalytic membrane disclosed in the present invention. The difference from Example 3 is that the grammage of the CoFe-PBA@MXene nanoconfined catalytic membrane is 0.6, 1.0, 1.5, and 2.2 mg / cm 2 .

[0028] Examples 12 to 15: An application of a CoFe-PBA@MXenes nanoconfined catalytic membrane disclosed in the present invention. The difference from Example 3 is that the molar ratios of the pollutant in the contaminated water body to peroxymonosulfate are 2.19, 6.57, 10.95, and 21.9:100 respectively.

[0029] Comparative Example 1: An application of the CoFe-PBA@MXenes nano-confined catalytic membrane disclosed in the present invention. The difference from Example 3 is that the CoFe-PBA@MXenes nano-confined catalytic membrane is not used.

[0030] Comparative Example 2: An application of the CoFe-PBA@MXenes nano-confined catalytic membrane disclosed in the present invention. The difference from Example 3 is that peroxymonosulfate is not used.

[0031] Test Example 1: The water bodies treated by the methods of Example 3 and Comparative Examples 1-2 were detected to compare the removal effects of bisphenol A under different application methods. Figure 2 It shows the removal of bisphenol A under different working conditions.

[0032] From Figure 2 It can be seen that the removal effect of bisphenol A by PMS alone is very limited, only 3.68% within 40 minutes; the CoFe-PBA@MXene nano-confined catalytic membrane alone can only adsorb 4.84% of bisphenol A at 40 minutes. When the CoFe-PBA@MXene nano-confined catalytic membrane is used in combination with PMS, the removal effect of bisphenol A in water is significant, and a high removal rate (>97.70%) is maintained in the first 40 minutes.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. Application of a CoFe-PBA@MXenes nanoconfined catalytic membrane, characterized in that: The CoFe-PBA@MXenes nano-confined catalytic membrane is combined with peroxymonosulfate to treat the contaminated water body, and the pollutant in the contaminated water body is bisphenol A.

2. Use of a CoFe-PBA@MXenes nano-confined catalytic membrane according to claim 1, characterized in that: The preparation method of the CoFe-PBA@MXenes nano-confined catalytic membrane includes The process of preparing the MXenes dispersion by reacting concentrated hydrochloric acid, lithium fluoride and aluminum carbonitride; The process of preparing the first precursor solution by mixing the MXenes dispersion, cobalt nitrate hexahydrate and deionized water; The process of preparing the second precursor solution by mixing potassium ferricyanide, sodium citrate and deionized water; And the process of preparing the CoFe-PBA@MXenes nano-confined catalytic membrane by reacting the first precursor solution and the second precursor solution.

3. Use of a CoFe-PBA@MXenes nano-confined catalytic membrane according to claim 2, characterized in that: In the process of preparing the MXenes dispersion, first add lithium fluoride to concentrated hydrochloric acid and stir until completely dissolved, then add aluminum carbonitride, and stir and react at 30-50 °C for 20-30 h. After the etching reaction is completed, centrifuge at 3000-5000 r / min for 4-6 min to obtain a clay-like precipitate, then wash and centrifuge with pure water, repeat several times until the pH = 5-7, and then perform ultrasonic treatment under the protection of inert gas and ice-water bath, centrifuge and retain the supernatant to obtain the MXenes dispersion.

4. Use of a CoFe-PBA@MXenes nanoconfined catalytic membrane according to claim 3, characterized in that: In the process of preparing the MXenes dispersion, control the molar ratio of hydrogen chloride, lithium fluoride and aluminum carbonitride in the concentrated hydrochloric acid to be 45-50:12-18:

1.

5. Use of a CoFe-PBA@MXenes nanoconfined catalytic membrane according to claim 2, characterized in that: In the process of preparing the first precursor solution, control the ratio of MXenes, cobalt nitrate hexahydrate and deionized water in the MXenes dispersion to be 20-30 mg:200-250 mg:25 mL.

6. The application of a CoFe-PBA@MXenes nano-confined catalytic membrane according to claim 2, characterized in that: In the process of preparing the second precursor solution, control the ratio of potassium ferricyanide, sodium citrate and deionized water to be 150-200 mg:300-350 mg:25 mL.

7. Use of a CoFe-PBA@MXenes nanoconfined catalytic membrane according to claim 2, characterized in that: In the process of preparing the CoFe-PBA@MXenes nano-confined catalytic membrane, the first precursor solution and the second precursor solution are mixed and stirred at room temperature for 48 h. After the reaction is completed, suction filtration is carried out through a water-based filter membrane to obtain a CoFe-PBA@MXene nano-confined catalytic membrane with a mass of 0.6~2.2 mg / cm 2 .

8. Use of a CoFe-PBA@MXenes nanoconfined catalytic membrane according to claim 1, characterized in that: After adding the peroxymonosulfate to the contaminated water body, pass it through the CoFe-PBA@MXenes nano-confined catalytic membrane by a peristaltic pump to remove the pollutants in the contaminated water body.

9. Use of a CoFe-PBA@MXenes nano-confined catalytic membrane according to claim 1, characterized in that: The concentration of pollutants in the contaminated water body is 1-10 mg / L.

10. Use of a CoFe-PBA@MXenes nano-confined catalytic membrane according to claim 1, characterized in that: The molar ratio of the pollutants in the contaminated water body and peroxymonosulfate is 2.19-21.9:100.

Images