Preparation of FeCoOnPm / g-C3N4 photo-activated PMS membrane material and application of FeCoOnPm / g-C3N4 photo-activated PMS membrane material in degradation of typical anti-cancer drug wastewater

Abstract

The invention relates to preparation of a FeCoOnPm / g-C3N4 photo-activated PMS membrane material and application of the FeCoOnPm / g-C3N4 photo-activated PMS membrane material to degradation of typical anti- The surface lattice and vacancy structure of the FeCo bimetallic oxide is regulated and controlled through P doping, the FeCo bimetallic oxide is compounded with N-defect g-C3N4, an effective interface electric field is constructed, directed migration of electrons is promoted, and the FeCoOnPm / g-C3N4 composite catalytic material is formed. After the particle size of the catalytic material is regulated and controlled, the catalytic material is blended with a cellulose acetate membrane casting solution, and the FCOP / CN catalytic membrane is obtained. In the PMS photoactivation process, under the synergistic effect of an interface electric field and an electron migration channel, photo-induced electrons generated on the surface of the FCOP / CN catalytic membrane are directionally transferred, so that the high-low valence cycle stability of Fe / Co double catalytic sites is maintained. And meanwhile, PMS is activated through double-site synergism of Fe and Co to promote the PMS to be converted into active oxide species. The removal rate of target pollutants can be maintained to be 99% or above when the catalytic membrane material is continuously operated.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental engineering, and relates to the preparation of a phosphorus-doped bimetallic oxide and N-deficient graphitic carbon nitride composite catalytic material, and also relates to the innovation of the method for applying the material loaded on the surface of a microfiltration membrane to activate persulfate (PMS) under visible light conditions to degrade the typical anticancer drug capecitabine. Background Art

[0002] Capecitabine (CAP) is a typical oral antimetabolic fluoropyrimidine carbamate anti-tumor drug. CAP has the advantages of convenient administration, relatively low price, high tumor selectivity, high stability, and low toxicity and side effects. Therefore, it is widely used in the treatment of cancers such as colorectal cancer, breast cancer, and gastric cancer in clinical practice. In recent years, anticancer drugs such as CAP have been widely detected in natural water bodies. Compared with drugs with large usage amounts such as antibiotics, antidepressants, and painkillers, the usage frequency of anticancer drugs by humans is relatively low, which has led to less attention from countries around the world to the environmental threats of anticancer drugs. However, these pollutants generally have strong biological immunotoxicity, teratogenicity, carcinogenicity and other characteristics, and have been recognized by the World Health Organization as one of the top ten public health threats. It is reported that the annual consumption of CAP in China is about 75 - 90 kg, and the main ways for it to enter the environment are hospital sewage discharge, domestic sewage discharge, etc. In addition, CAP can also spread through surface runoff and air, thus developing into a global pollutant. CAP that cannot be completely metabolized in the human body directly enters the municipal wastewater pipe network through excretion. Traditional sewage treatment processes cannot completely remove it, resulting in these drugs being discharged into surface water. It is detected that about 2.9% of CAP is discharged in its original form. Research on efficient removal methods for such pollutants has important practical significance for protecting water environment safety and human health.

[0003] The persulfate-based Fenton-like technology has the advantages of simple operation, low equipment cost, and fast degradation rate. However, the heterogeneous catalysts required for this type of technology generally have problems such as short service life and low catalytic stability. The essential reason for this phenomenon is that during the activation process of PMS, PMS takes electrons from the catalytic sites, resulting in the metal valence state of the catalytic sites showing a tendency to transform to a higher valence. When the catalytic sites are transformed into high valence states, they lose the ability to provide electrons, thus reducing the catalyst life and stability. Based on the above problems, a large number of related studies on improving the stability of PMS catalysts have emerged in previous research. The article "Building the confined CoS2 / MoS2 nanoreactor via interface electronic reconfiguration to synchronously enhance activity and stability of heterogeneous Fenton-like reactions" constructs a special vertical interface structure to regulate the interface electronic structure to promote the generation of reactive oxygen species; the article "High conductive polymer PANI link Bi2MoO6 and PBA to establish "tandem hybrid catalysis system" by coupling photocatalysis and PMS activation technology" uses Bi2MoO6 as a photocatalytic material, and utilizes photogenerated electrons to induce PMS activation through a Prussian blue analogue and a polyaniline complex to achieve efficient degradation of pollutants. Although the catalysts in the above articles can maintain the catalyst stability to a certain extent, with the continuous progress of the reaction, the stability of the reaction sites in the catalyst still shows an irreversible decay trend. In addition, the powdered catalyst cannot be quickly and effectively regenerated during the recycling process, and the catalyst needs to be collected by filtration. This process not only consumes energy and filter membranes, but also causes catalyst loss. Co, as a transition metal, its 3d orbitals can provide coordination vacancies. When the peroxy bond (O-O) of PMS approaches, the eg orbitals (dz 2+ of Co 2 , dx 2 -y 2 ) match the energy of the antibonding orbital (σ*) of O-O, prompting the d electrons of Co to transition to the antibonding orbital of O-O, resulting in the cleavage of the O-O bond and the generation of SO4 -· Free radicals. This process is accompanied by a large amount of Co ions forming stable complexes with organic substances in water, which will cause the inactivation of Co ions. The article "Almost 100% electron transfer regime over Fe-Co dual-atom catalyst toward pollutants removal: Regulation of peroxymonosulfate adsorption mode" constructs a Co-N-Fe structure through the incorporation of Fe 3+ , causing hybridization between the d orbitals of Co and Fe, and forming an effective electron transfer channel. This hybridization broadens the d electron energy band, enabling Co 2+ to have a better electron supply ability when activating PMS. However, this method still cannot fully meet the electron supply requirements of the system for the valence state cycle between +2 and +3 in the Co ion catalytic process. Therefore, it is necessary to develop a catalytic material with high activity and stability for activating PMS. At the same time, the catalyst has a stable carrier and does not require a regeneration process, increasing the practical application feasibility of the material. During the photocatalytic process, photogenerated electrons and holes are continuously generated. If a suitable photocatalytic material is combined with a PMS catalytic material and an effective electron migration channel is constructed between them, the tendency of catalytic sites to transform into higher valence states during the activation of PMS can be effectively inhibited, forming a stable valence state cycle process, thereby maintaining the stability and catalytic activity of catalytic sites.

[0004] Therefore, in this application, P doping is used to manipulate the lattice and vacancy structure of FeCo bimetallic oxide, regulate the d-band center position and local electronic structure of Fe and Co, construct an efficient electron migration channel, and at the same time increase the adsorption performance of Fe and Co dual sites for PMS. After the effective composite of P-doped FeCo bimetallic oxide and graphitic carbon nitride, under visible light, the photogenerated electrons generated on the surface of graphitic carbon nitride can effectively migrate to Fe and Co sites, thus stabilizing the valence state cycle process of catalytic sites (valence increase: PMS obtains electrons from Fe / Co sites; valence decrease: the photogenerated electrons on the surface of graphitic carbon nitride migrate to Fe / Co sites), forming catalytic sites that can continuously activate PMS. In order to further solve the problem that it is difficult to recycle and regenerate the powder catalyst, the present invention prepares the FeCoO n P m / g-C3N4 catalytic material into a film, and uses the porous structure on the film surface to maintain the catalytic reaction activity of the material while avoiding the problem of catalyst recycling and regeneration. Summary of the Invention

[0005] The present invention provides a preparation method of a P-doped bimetallic oxide and N-deficient graphitic carbon nitride (g-C3N4) composite catalytic material, which is applied to the photoactivation of PMS for the degradation of CAP. By doping P to regulate the surface lattice and vacancy structure of the FeCo bimetallic oxide, it is effectively compounded with N-deficient g-C3N4 to construct an effective interfacial electric field, promote the directional migration of electrons, and form FeCoO n P m / g-C3N4 composite catalytic material (FCOP / CN). After regulating the particle size of the catalytic material, it is blended with the cellulose acetate casting solution to prepare the FCOP / CN catalytic membrane material. Under visible light conditions, a large number of photogenerated electrons are generated on the surface of the FCOP / CN catalytic membrane. Under the synergistic action of the interfacial electric field and the electron migration channel, the directional transfer of electrons is realized, and the valence state cycle stability of the PMS catalytic site is maintained, thereby effectively improving the catalytic stability of PMS and achieving the goal of efficiently and continuously degrading CAP in water by photoactivating PMS.

[0006] The technical solution of the present invention:

[0007] A method for preparing an FeCoO n P m / g-C3N4 photoactivated PMS membrane material, the steps are as follows:

[0008] Step 1: Prepare the required N-deficient g-C3N4 material by referring to the method in the article "Novel dual-effective Z-scheme heterojunction with g-C3N4, Ti3C2MXene and black phosphorus for improving visible light-induced degradation of ciprofloxacin";

[0009] Step 2: Prepare the FeCo double hydroxide precursor (Fe1Co3-LDH) by referring to the method in the article "NiFe Layered-Double-Hydroxide-Derived NiO-NiFe2O4 / Reduced Graphene Oxide Architectures for Enhanced Electrocatalysis of Alkaline Water Splitting";

[0010] Step 3: Uniformly mix the Fe1Co3-LDH obtained in Step 2 and the N-defective g-C3N4 material obtained in Step 1, and grind them evenly using an agate mortar. The mass ratio of Fe1Co3-LDH to the N-defective g-C3N4 material is 1:50 - 1:10. Then, place the mixture of Fe1Co3-LDH and the N-defective g-C3N4 material in a tube furnace, and put sodium metaphosphate, which is the reaction precursor for generating PH3, in the air inlet direction. The dosage of sodium metaphosphate is 1 - 3 times the total mass of Fe1Co3-LDH and the N-defective g-C3N4 material. Under N2 protection, the reaction temperature is 350 °C, and the reaction time is 1 - 2 h. After phosphating and calcining in the tube furnace, FeCoO is obtained. n P m / g-C3N4 (FCOP / CN) photo-activated PMS membrane material.

[0011] A kind of FeCoO n P m Application of / g-C3N4 photo-activated PMS membrane material in degrading typical anticancer drug wastewater, the steps are as follows:

[0012] Step 1: Take cellulose acetate and N,N-dimethylformamide and stir them in a water bath at 60 - 90 °C for 5 - 10 h until the cellulose acetate is completely dissolved. Then add FeCoO n P m / g-C3N4 (FCOP / CN) photo-activated PMS membrane material. After ultrasonic treatment for 30 - 60 min, continue to heat and stir at 40 - 60 °C for 30 - 60 min, and then put it into a vacuum oven for vacuum degassing at room temperature for 50 - 60 min to obtain a casting solution. The mass ratio of cellulose acetate, N,N-dimethylformamide, and FeCoO n P m / g-C3N4 (FCOP / CN) photo-activated PMS membrane material added is 19:80:1 - 14:80:6. Pour the casting solution evenly onto one end of the glass plate of the film casting machine, set the gap between the film scraping knife and the glass plate to 200 - 300 μm, and the film scraping speed to 2 - 10 cm / s. After film scraping, quickly put the glass plate into a coagulation bath of deionized water and soak it for 24 h to obtain the FCOP / CN membrane material loaded.

[0013] Step 2: Use the FCOP / CN membrane material loaded obtained in Step 1 as a PMS catalyst to construct a flow-through photo-activated PMS degradation system. Under visible light conditions, the reaction temperature is 24 °C - 26 °C. Respectively use deionized water and the influent of the biological unit in a domestic sewage treatment plant to configure capecitabine (CAP) with a concentration of 0.1 - 10 mg / L as the target wastewater. The dosage of the PMS catalyst in the influent is 0.2 - 2 mmol / L, and continuous operation for 72 h can achieve a CAP degradation rate of over 99%.

[0014] Beneficial effects of the present invention: In the method of the present invention, a heterojunction material of layered double hydroxide and N-defective g-C3N4 is constructed, and the double hydroxide is etched in situ by P-chemical method to form a P-doped double metal oxide / N-defective g-C3N4 composite catalyst (FCOP / CN). In order to improve its applicability under actual working conditions, it is further prepared into a photoactivated PMS membrane material uniformly loaded with FCOP / CN, forming a degradation filtration system for photoactivated PMS under visible light conditions to efficiently and low-consumption remove the typical anticancer drug CAP in water. In step 1, a special structure is introduced into the traditional g-C3N4 precursor melamine structure by prepolymerization, and it is completely decomposed in the calcination stage at 550°C to produce CO2 and H2O, thereby inhibiting the large-scale polycondensation of melamine to form a large aggregated block structure. At the same time, it can also react with the N-containing functional groups in melamine during the decomposition process to form N defects in the g-C3N4 structure, which is conducive to capturing photogenerated electrons, inhibiting the recombination of photogenerated carriers, and improving the light utilization rate. Afterwards, the layered double hydroxide was used as a soft template precursor and composited with N-deficient g-C3N4, and a part of the -OH in the layered double hydroxide was etched away by in-situ phosphating. At the same time, P was introduced into the formed FeCo layered oxide structure to form an O vacancy and P doping structure. The above two special structures can effectively change the local electron configuration, reduce the band gap structure, and construct an effective electron migration path between the Fe and Co double reaction sites, thereby enhancing the electron migration ability of the system. The dpd hybrid orbital formed by the bridge between Fe and Co through O and P can cause the d-band center position of Co and Fe to move up and down, respectively, which is conducive to reducing the adsorption of small molecule ligands in water by the Co site and inhibiting its deactivation trend; at the same time, it is conducive to increasing the number of electrons filled in the eg orbital of the Fe site, enhancing its electron migration ability and increasing the catalytic activity. The effective conversion between the high and low valence states of the double site, that is, the low-valence state of the double site activation PMS process loses electrons, and after converting to the high-valence state, the pollutants can be directly oxidized to obtain electrons to restore to the low-valence state, thereby forming a stable catalytic system through reciprocating cycles. The high-valent metals formed in the process of activating PMS by traditional PMS catalytic materials are easy to form stable complexes with halogens and organic molecules in water. This process will make the activation process of the catalytic material irreversible and unable to continuously activate PMS. n P m The strong interaction with the g-C3N4 substrate can further reduce the energy barrier for the migration of photogenerated electrons from the substrate to the active sites, thereby maintaining the cyclic stability of the Fe and Co dual-site valence states and the utilization rate of photogenerated electrons during the catalytic process. After calcination, the FCOP / CN composite catalytic material was obtained, and the particle size of the material was controlled to sub-nanometer size by grinding. After that, it is evenly dispersed into the cellulose acetate casting solution to make a membrane material, increasing its application performance for continuous operation under actual working conditions, and can completely avoid the catalyst loss and additional energy consumption generated during the repeated recycling process of powder materials. Therefore, this material can achieve efficient degradation of pollutants by photoactivating PMS under visible light conditions. Description of the Drawings

[0015] Figure 1 is the TEM image of FCOP3 / CN 20

[0016] Figure 2 is the HRTEM image of FCOP3 / CN 20

[0017] Figure 3 is the EDS mapping image of FCOP3 / CN 20

[0018] Figure 4 is the XPS spectra of FCOP3 / CN 20 and CN, (a) is the survey spectrum, (b) is the C1s spectrum, (c) is the N 1s spectrum, (d) is the Fe2p spectrum, (e) is the Co 2p spectrum, (f) is the P 2p spectrum. Detailed Embodiments

[0019] The following describes the detailed embodiments of the present invention in conjunction with the technical solutions.

[0020] Example 1

[0021] Preparation of FCOP / CN catalytic material:

[0022] Disperse 3 g of melamine, 3 g of cyanuric acid, and 0.1 g of barbituric acid into 100 mL of deionized water and stir for 60 min. Then put it into a forced-air oven at 60 °C. After drying, the solid is ground and put into a crucible, and calcined under N2 protection. The reaction temperature is 530 °C and the reaction time is 3 h. After the reaction is completed, the solid is taken out, washed three times with deionized water and ethanol respectively, and dried in an oven at 60 °C to obtain a yellow solid of N-deficient g-C3N4.

[0023] Dissolve 10 mmol of iron nitrate and 30 mmol of cobalt nitrate in 60 mL of deionized water, add 9 mmol of urea, stir for 30 min, put it into a hydrothermal reaction kettle, react at 160 °C for 24 h, cool naturally, pour out the supernatant, disperse the residual solid with water and ethanol, and then centrifuge, repeating three times each. The obtained solid is put into an oven at 60 °C for drying to obtain a solid material of Fe1Co3-LDH.

[0024] ​​​Mix 10 mg of Fe1Co3-LDH and 200 mg of N-deficient g-C3N4 uniformly, grind them evenly with an agate mortar, then introduce both into 100 mL of ethanol solution, sonicate for 30 min, and place in an oven for drying. After that, put the dried solid into a crucible and calcine it by phosphorization in a tubular furnace. Place a crucible containing 630 mg of sodium metaphosphate at the air inlet. The reaction temperature is 350 °C, the reaction time is 2 h, and under N2 protection, (FCOP3 / CN 20 ) material is obtained.

[0025] FCOP3 / CN 20 has a large number of pore structures ( Figure 1 ), which provide more active sites for the photocatalytic reaction. In the HRTEM image ( Figure 2 ), the lattice spacings of 0.229 nm and 0.259 nm correspond to the (201) plane of Co2P and the (200) plane of Fe2P, respectively. The corresponding EDS mapping image ( Figure 3 ) shows that C, N, Fe, Co, and P are uniformly dispersed in the FCOP3 / CN 20 composite material. As shown in Figure 4 a, characteristic peaks corresponding to Fe2p, Co 2p, and P 2p appear in FCOP3 / CN 20 , proving that the iron-cobalt metal phosphide is successfully loaded on the substrate. Its C1s XPS spectrum ( Figure 4 b) contains three components, corresponding to standard carbon (284.7 eV), C-NH at the edge of the heptazine unit ( x )(286.8 eV), and N-C=N coordination in the framework CN (288.2 eV), respectively. The N 1s XPS spectrum ( Figure 4 c) is decomposed into three peaks located at 398.6, 400.4, and 401.0 eV, corresponding to the double-coordinated nitrogen (N2C), triple-coordinated nitrogen (N3C), and NH x group in the heptazine framework, respectively. Figure 4 d shows that the peak of Fe 2p 1 / 2 at 723.4 eV and the peak of Fe 2p 3 / 2 at 710.8 eV correspond to Fe δ+ (0 < δ < 3), and the peak of Fe2p 1 / 2 at 725.4 eV and the peak of Fe 2p 3 / 2 at 712.9 eV correspond to Fe 3+ . The peaks at 729.2 eV (2p 1 / 2 ) and 717.1 eV (2p 3 / 2 ) correspond to the satellite peaks. In the Co 2p spectrum ( Figure 4 e), the peaks at 798.0 eV (2p 1 / 2 ) and 782.1 eV (2p3 / 2 ) peaks correspond to Co in CoP δ+ (0 < δ < 3), while the peaks at 800.9 eV (2p 1 / 2 ) and 784.6 eV (2p 3 / 2 ) are attributed to Co 3+ . The peaks at 804.8 eV (2p 1 / 2 ) and 788.4 eV (2p 3 / 2 ) correspond to satellite peaks. The P 2p spectrum ( Figure 4 f), the peaks at 129.2, 130.2, 133.1 and 134.2 eV belong to Fe / Co-P 2P 3 / 2 , Fe / Co-P 2P 1 / 2 , P-N and P-O respectively.

[0026] Using the above method, the dosage ratios of Fe1Co3-LDH and N-deficient g-C3N4 were selected as 1:50, 1:40, 1:30, 1:10 respectively, and a series of FCOP / CN materials (named FCOP3 / CN 50 , FCOP3 / CN 40 , FCOP3 / CN 30 , FCOP3 / CN 10 ) were prepared for subsequent performance comparison tests. Comparison of high, medium, and low P doping amounts.

[0027] In addition, using the above method, the dosage ratio of Fe1Co3-LDH and N-deficient g-C3N4 was selected as 1:20, and the dosage ratios of sodium metaphosphate to the total mass of N-deficient g-C3N4 material were selected as 2:1 and 1:1 respectively, and a series of FCOP / CN materials (named FCOP1 / CN 20 , FCOP2 / CN 20 ) were prepared for subsequent performance comparison tests.

[0028] Example 2

[0029] Photocatalytic activation of PMS for CAP degradation:

[0030] Weigh 10 mg of FCOP / CN series catalytic materials separately and disperse them into a photocatalytic reactor containing 100 mL of 20 mg / L CAP aqueous solution (simulated wastewater prepared with deionized water). Before the degradation experiment, stir for 30 min under dark conditions to ensure that the catalytic materials adsorb CAP to saturation. Then, add 0.05 mmol of solid PMS to the solution, stir to dissolve it, and conduct the test for the degradation of CAP by photoactivating PMS under visible light. The reaction time is 15 min, the reaction temperature is 25 ± 1 °C, and the reaction solution is taken once every 2.5 min. After the taken reaction solution is filtered through a 0.22 μm water membrane, 1.5 mL is taken and put into a liquid-phase vial. Then, add 20 μL of methanol to quench the PMS degradation reaction. The sample vials are collected uniformly for testing the degradation performance. After the reaction is completed, take another 10 mL of the solution, filter it through a 0.22 μm water membrane, and use it to test the removal rate of TOC during the reaction process.

[0031] The CAP concentration is determined by ultra-high performance liquid chromatography. The test results show that the removal rate of CAP by the FCOP / CN series catalytic materials can reach over 99% after 15 min of reaction. Among them, the FCOP3 / CN 20 catalytic material can achieve a 99% removal rate of CAP in the solution at 5 min of reaction, which is better than other proportion catalytic materials. In addition, the comparison results of the mineralization rate also show that after 15 min of reaction, the FCOP3 / CN 20 has a TOC removal rate of 29% for the simulated wastewater, and the TOC removal rates of other catalytic materials in this series are all lower than 20%. Therefore, the FCOP3 / CN 20 is used as the performance test material for the subsequent membrane catalytic materials.

[0032] Example 3

[0033] Preparation of FCOP / CN catalytic membrane materials:

[0034] Use a ball mill to mill FCOP3 / CN 20 to make its average particle size ~1 μm. Take 16 g of cellulose acetate and 80 g of N,N-dimethylformamide to prepare a casting solution. Stir in a 90 °C water bath for 5 h until the cellulose acetate is completely dissolved. Then, add 4 g of the milled FCOP3 / CN 20 catalyst powder. After ultrasonic treatment for 60 min, continue to heat and stir at 60 °C for 60 min. Then, put it into a vacuum oven for vacuum degassing at room temperature for 60 min to obtain a casting solution. Pour the casting solution evenly onto one end of the glass plate of the film casting machine. Set the gap between the film casting knife and the glass plate to 300 μm and the film casting speed to 5 cm / s. After film casting, quickly put the glass plate into a coagulation bath (deionized water solution) and soak for 24 h to obtain the FCOP3 / CN 20 -4 catalytic membrane material.

[0035] Using the above method, a series of FCOP / CN catalytic membrane materials (named FCOP / CN 20 -1, FCOP / CN 20 -2, FCOP / CN 20 -3, FCOP / CN 20 -6) were prepared with the mass ratios of cellulose acetate, N,N-dimethylformamide and FCOP / CN catalyst powder being 19:80:1, 18:80:2, 17:80:3, and 14:80:6 respectively for subsequent performance comparison tests.

[0036] Example 4

[0037] Activation of PMS by FCOP / CN catalytic membrane materials for CAP degradation:

[0038] Pieces of 10×10 cm FCOP / CN series catalytic membrane materials were respectively cut and fixed at the bottom of the photocatalytic reactor. 100 mL of 20 mg / L CAP aqueous solution was introduced into the photocatalytic reactor. Before the degradation experiment, it was stirred for 30 min under dark conditions to make the catalytic material adsorb CAP to saturation. Then, 0.05 mmol of PMS solid was added to the solution, and after stirring and dissolving, the photocatalytic activation of PMS for CAP degradation was tested under visible light conditions. The reaction time was 15 min, the reaction temperature was 25±1°C, and the reaction solution was taken once every 2.5 min. After the taken reaction solution was filtered through a 0.22 μm water membrane, 1.5 mL was taken, put into a liquid phase vial, and 20 μL of methanol was added to quench the PMS degradation reaction. The sample bottles were collected uniformly for testing the degradation performance. After the reaction ended, another 10 mL of the solution was taken and filtered through a 0.22 μm water membrane for testing the TOC removal rate during the reaction process.

[0039] The CAP concentration was determined by ultra-high performance liquid chromatography. The test results showed that the removal rate of CAP by the series of FCOP / CN catalytic membrane materials could reach over 90% after 15 min of reaction. Among them, the FCOP3 / CN 20 -4 catalytic material could reach 99% for the removal rate of CAP in the solution at 10 min of reaction, which was better than other proportion catalytic membrane materials. In addition, the comparison results of the mineralization rate also showed that after 15 min of reaction, the TOC removal rate of FCOP / CN 20 for the simulated wastewater reached 23%, and the TOC removal rates of other catalytic materials in this series were all lower than 14%. Therefore, FCOP3 / CN 20 -4 was used as the catalytic membrane material for subsequent actual wastewater degradation performance tests.

[0040] Example 5

[0041] CAP degradation test in actual domestic wastewater:

[0042] The test method was the same as that of Example 4, except that the wastewater to be treated was domestic wastewater containing 20 mg / L CAP. The reaction time was 15 min, the reaction temperature was 25 ± 1 °C, and the reaction solution was taken once every 2.5 min. After the taken reaction solution was filtered through a 0.22 μm water membrane, 1.5 mL was taken and put into a liquid-phase vial, and then 20 μL of methanol was added thereto to quench the PMS degradation reaction. After the sample bottles were collected uniformly, they were used to test the degradation performance.

[0043] The CAP concentration was determined by ultra-high performance liquid chromatography. The test results showed that after 15 min of reaction, the degradation rate of CAP by the FCOP3 / CN 20 -4 catalytic membrane material could reach over 95%.

[0044] Example 6

[0045] Repeated performance test:

[0046] The test method and the target wastewater were the same as those of Example 5, and the degradation process was cycled 20 times.

[0047] The comparison of the repeated test results showed that the removal rate of CAP remained above 90% after 20 cycles, indicating that both the catalytic stability and catalytic activity of this catalytic material could meet its long-term operation requirements.

Claims

1. A kind of FeCoO n P m / g-C3N4 photo-activated PMS membrane material preparation method, which is characterized in that The steps are as follows: Step 1: Prepare N-defective g-C3N4 material; Step 2: Prepare FeCo double hydroxide precursor Fe1Co3-LDH; Step 3: Grind the Fe1Co3-LDH obtained in Step 2 and the N-deficient g-C3N4 material obtained in Step 1 evenly using an agate mortar; then place the mixture of the Fe1Co3-LDH and N-deficient g-C3N4 material in a tube furnace, and put sodium metaphosphate, the reaction precursor for generating PH3, at the air inlet direction; under N2 protection, the reaction temperature is 350 °C, and the reaction time is 1 - 2 h. Phosphating and calcining in the tube furnace to obtain FeCoO n P m / g-C3N4 photo-activated PMS membrane material.

2. The FeCoO according to claim 1 n P m Preparation method of P / g-C3N4 photo-activated PMS membrane material, characterized in that The mass ratio of the described Fe1Co3-LDH to the N-defective g-C3N4 material is 1:50 - 1:

10.

3. The FeCoO according to claim 1 n P m Preparation method of P / g-C3N4 photo-activated PMS membrane material, characterized in that The dosage of the sodium metaphosphate is 1 - 3 times the total mass of the Fe1Co3-LDH and the N-defective g-C3N4 material.

4. FeCoO obtained by the preparation method according to any one of claims 1-3 n P m Application of / g-C3N4 photo-activated PMS membrane material in degrading typical anti-cancer drug wastewater, characterized in that The steps are as follows: Step 1: Take cellulose acetate and N,N-dimethylformamide and stir them in a water bath at 60-90 °C for 5-10 h until the cellulose acetate is completely dissolved. Then add FeCoO n P m / g-C3N4 photoactivated PMS membrane material. After ultrasonic treatment for 30-60 min, continue to heat and stir at 40-60 °C for 30-60 min. Then put it into a vacuum oven and degas at room temperature for 50-60 min to obtain a casting solution. Pour the casting solution evenly onto one end of the glass plate of the film scraping machine. Set the gap between the film scraping knife and the glass plate to 200-300 μm and the film scraping speed to 2-10 cm / s. The glass plate after film scraping is quickly put into a coagulation bath of deionized water and soaked for 24 h to obtain the FCOP / CN membrane material loaded with Step 2: Use the FCOP / CN membrane material loaded obtained in Step 1 as a PMS catalyst to construct a flow-through photo-activated PMS degradation system; under visible light conditions, with a reaction temperature of 24°C - 26°C, configure anti-cancer drug wastewater with a concentration of 0.1 - 10 mg / L using deionized water and the influent of the biological unit in a domestic sewage treatment plant respectively. The dosage of the PMS catalyst in the influent is 0.2 - 2 mmol / L, and continuously operate for 72 h. The degradation rate of the anti-cancer drug wastewater can reach over 99%.

5. The application according to claim 4, wherein The cellulose acetate, N,N-dimethylformamide and FeCoO n P m The dosing mass ratio of the / g-C3N4 photo-activated PMS membrane material is 19:80:1 to 14:80:

6.

6. The application according to claim 4, characterized in that The anti-cancer drug described is capecitabine.

Images