A polypyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst, a preparation method and application thereof

Abstract

The application belongs to the field of advanced catalytic oxidation technology for water treatment, and particularly relates to a polypyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst, a preparation method and application thereof. The application uses a nitrogen-rich compound as a precursor to pyrolyze g-C3N4, and then polypyrrole is in-situ polymerized to modify g-C3N4 to obtain polypyrrole modified Z-type heterojunction PPy / g-C3N4. The catalyst has good degradation capacity for different organic matters such as antibiotics and phenols, and has good anti-interference ability and stability, and provides a new type of efficient catalyst for a synergistic system of photocatalysis / PMS-AOPs.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of advanced catalytic oxidation technology for water treatment, and particularly relates to a polypyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst, a preparation method and application thereof. BACKGROUND

[0002] New pollutants antibiotics have biological toxicity, environmental persistence, biological accumulation and other characteristics, and these substances have great risks to the ecological environment or human health. According to the latest article and related report of WHO, antibiotic resistance can cause 10 million deaths per year by 2050. In order to solve this problem, it is urgent to develop advanced treatment technology to effectively remove antibiotics.

[0003] Combining photocatalytic technology with persulfate advanced oxidation process technology is an ideal and feasible strategy, which can overcome the shortcomings of single catalytic system, and it is very crucial to build a suitable heterojunction catalyst for realizing the synergistic effect of photocatalysis / PMS-AOP. Graphite-like carbon nitride (g-C3N4) has the advantages of low cost, good stability, high abundance, simple preparation, suitable band gap (2.7 eV), visible light response and other advantages, and has unique optical and electronic properties, which is an ideal coupling material.

[0004] However, g-C3N4 also has the same shortcomings as most semiconductor materials, such as rapid recombination of photo-induced electrons and holes (charged carriers), poor visible light absorption (λ<460 nm), small specific surface area, and loss of photocatalytic reactivity caused by photo-corrosion effect, which limits the practical application of g-C3N4. Polypyrrole (PPy) has high thermal stability and chemical stability, and has considerable electrical conductivity, outstanding and perfect carrier channel, which acts as a hole transport and electron donor under visible light, and can effectively improve the electron-hole separation efficiency. In recent years, various research groups have tried to design coupling structures between organic conductive polymers and semiconductor nanomaterials to be widely applied in photocatalytic processes, but there are still few applications in photocatalytic / PMS-AOP synergistic systems.

[0005] Based on the existing catalysts, the following problems still exist: (1) metal-containing catalysts have good effects, but there is a risk of metal leaching and secondary pollution; (2) the light absorption utilization ability is limited, and the electron-hole pair separation ability is poor; (3) the recycling effect is poor, and the regeneration energy consumption is complex; (4) the raw material cost is high, and the preparation process is complex, which greatly limits their application in practice.

[0006] Therefore, there is currently a need for a solution to solve the technical problems in the prior art. The present application fully plays the synergistic effect by reasonably designing a Z-type heterojunction based on g-C3N4 and PPy for photocatalytic / PMS-AOP synergistic technology. SUMMARY

[0007] The application provides a MCN / PPy Z-type heterojunction catalyst with simple preparation process, controllable structure, high catalytic efficiency, strong anti-interference and recycling, a preparation method thereof and application of the catalyst in a photocatalytic / PMS-AOP system.

[0008] To achieve the object of the application, the g-C3N4 is obtained by pyrolysis of nitrogen-rich compounds, and then the PPy / g-C3N4 Z-type heterojunction is obtained by in-situ polymerization of polyaniline on the g-C3N4.

[0009] To solve the above technical problems, according to one aspect of the application, the application provides the following technical scheme:

[0010] The application provides a polypyrrole-modified graphite-like carbon nitride Z-type heterojunction catalyst, wherein the catalyst is obtained by in-situ polymerization of graphite-like carbon nitride g-C3N4 and polypyrrole PPy.

[0011] As a preferred scheme of the polypyrrole-modified graphite-like carbon nitride Z-type heterojunction catalyst, the graphite-like carbon nitride g-C3N4 is obtained by pyrolysis of nitrogen-rich compounds under oxygen-deficient conditions.

[0012] As a preferred scheme of the polypyrrole-modified graphite-like carbon nitride Z-type heterojunction catalyst, the nitrogen-rich compound is one or more of urea, dicyan diamine and melamine.

[0013] To solve the above technical problems, according to another aspect of the application, the application provides the following technical scheme:

[0014] The application provides a preparation method of the polypyrrole-modified graphite-like carbon nitride Z-type heterojunction catalyst, and the preparation method comprises the following steps:

[0015] (1) a certain amount of nitrogen-rich compound is placed in a double-crust double-crucible double-cover, the loaded crucible is placed in a muffle furnace for sintering reaction treatment, after the sintering reaction is completed, the product is cooled and ball milled to obtain a powder-like graphite-like silicon nitride g-C3N4;

[0016] (2) the graphite-like silicon nitride g-C3N4 is uniformly ultrasonically dispersed in water, then is transferred to a magnetic stirrer at room temperature for a period of time, sodium dodecyl sulfate SDS is added, pyrrole is added after the sodium dodecyl sulfate SDS is completely dissolved, high-speed magnetic stirring is performed until the pyrrole is completely dissolved, then a previously prepared FeCl3 aqueous solution is added drop by drop under the condition of high-speed magnetic stirring, and the reaction is performed at room temperature, after the reaction is completed, filtration separation is performed, the filter cake is washed with water and ethanol, and the product PPy / g-C3N4 is obtained after vacuum drying.

[0017] As a preferred scheme of the preparation method of the poly-pyrrole modified graphite-like phase carbon nitride Z-type heterojunction catalyst, in step (1), the sintering reaction treatment temperature is 500-600 DEG C, and the time is 2-6 h.

[0018] As a preferred scheme of the preparation method of the poly-pyrrole modified graphite-like phase carbon nitride Z-type heterojunction catalyst, in step (1), the particle size of the powdered graphite-like phase silicon nitride g-C3N4 obtained by ball milling is controlled to be below 1.5 μm.

[0019] As a preferred scheme of the preparation method of the poly-pyrrole modified graphite-like phase carbon nitride Z-type heterojunction catalyst, in step (2), the addition amount of pyrrole is 0.1%-5% of the mass of the graphite-like phase silicon nitride g-C3N4, the molar ratio of pyrrole to sodium dodecyl sulfate SDS is 1:(0.5-2), and the molar ratio of pyrrole to FeCl3·6H2O is 1:(2-3).

[0020] As a preferred scheme of the preparation method of the poly-pyrrole modified graphite-like phase carbon nitride Z-type heterojunction catalyst, in step (2), the reaction temperature is 25-35 DEG C, and the reaction time is 10-24 h.

[0021] As a preferred scheme of the preparation method of the poly-pyrrole modified graphite-like phase carbon nitride Z-type heterojunction catalyst, in the washing of the filter cake, first, water is used for magnetic stirring washing of the filter cake, then filtration is performed, and the process is repeated until the filtrate is free of bubbles and smooth feeling, finally, ethanol is used for magnetic stirring washing of the filter cake, then filtration is performed, and the process is repeated at least twice.

[0022] To solve the above technical problems, according to another aspect of the present application, the present application provides the following technical scheme:

[0023] The poly-pyrrole modified graphite-like phase carbon nitride Z-type heterojunction catalyst is applied to the activation of a photocatalysis / PMS-AOP coupling system for degrading antibiotics and / or phenols.

[0024] The Z-type heterojunction PPy / g-C3N4 catalytic material prepared above is applied in the field of water treatment. The PPy / g-C3N4 is used as a catalyst for degrading antibiotic and phenolic pollutants in a photocatalytic / PMS-AOP synergistic system, including antibiotic PPy / g-C3N4 such as sulfamethazine (SMT), tetracycline hydrochloride (TC) and oxytetracycline (OTC), and phenol such as phenol, 2,4-dichlorophenol, bisphenol A and the like simulated wastewater. The system has strong anti-interference ability, and the common anions, cations or coexisting natural organic matters in the reaction solution have little effect on it, and individual ions Cl - , HCO3 - , Ca 2+ , Mg 2+ even have a promoting effect, and it is applicable in a wide pH (3-11), and has excellent reusability and stability. The removal efficiency is still as high as 100% in the actual water body (such as lake water and effluent from a sewage treatment plant). In the application, first, the Z-type heterojunction mechanism is followed, and the e - generated by the CB light of MCN under light irradiation is transferred to the contact interface, and recombines with h + in the HOMO of PPy. Therefore, the photo-generated carriers on the LUMO of PPy and the VB of MCN are effectively separated and quickly transferred to the surface of the catalyst. The e - on the LUMO of PPy and the h + on the VB of MCN have strong redox ability, which helps to activate PMS and O2 molecules to generate active substances such as ·O2 - , 1 O2, ·OH and SO4·, which will participate in the degradation of pollutants together with h + . PPy with high conductivity can quickly transfer electrons, further avoiding the recombination of photo-generated carriers. In addition, PMS can act as both an electron acceptor and an electron donor. It can capture photo-generated electrons (e - ), trigger a self-activation process, produce reactive oxygen species (ROS) such as hydroxyl radicals (·OH), sulfate radicals (SO4 ·- ) and superoxide radicals (O2 ·- ), PMS can also be oxidized by holes (h + ) to produce SO5 ·- and 1O2. The consumption of e - or h + by PMS can promote the charge separation in the photocatalyst and improve the photocatalytic activity, thereby showing the synergistic effect of photocatalytic / PMS-AOPs.

[0025] The beneficial effects of the application are as follows:

[0026] (1) The preparation method of the catalyst is simple and easy to operate, which can be carried out in an aqueous solution at room temperature, and a Z-type heterojunction is successfully constructed by precise control, which can promote light absorption, while maintaining the strong reducing property and strong oxidizing property of the semiconductor. In addition, the rapid charge transfer rate of the Z-type heterojunction system significantly inhibits the recombination of photo-induced electron-hole pairs, improves the separation efficiency of effective carriers, and thus improves the photocatalytic performance. The negatively charged g-C3N4 in the inner layer and the positively charged PPy in the outer layer are combined by van der Waals force and stably exist, and the loading amount of PPy can be fine-tuned to achieve the best photocatalytic performance under visible light irradiation, providing a new type of high-efficiency catalyst for the synergistic system of photocatalysis / PMS-AOPs.

[0027] (2) The catalyst has strong anti-interference ability and high catalytic activity in a wide pH range of 3-11. In particular, it is almost not affected by various coexisting anions and cations and humic acid, and the removal rate of ciprofloxacin is still as high as 100% in the actual water body (such as lake water and effluent from a sewage treatment plant), which has excellent reusability and stability.

[0028] (3) The Z-type heterojunction PPy / g-C3N4 material prepared by the application has excellent catalytic effect on photocatalysis / PMS-AOPs, and has good degradation ability for different organic matters such as antibiotics and phenols. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0030] Figure 1 Catalytic degradation of CIP in different systems for catalysts with different PPy / g-C3N4 ratios (a) catalyst / PMS, (b) catalyst / LED, (c) catalyst / LED / PMS, (d) corresponding degradation reaction rate constant;

[0031] Figure 2 UV-Vis diffuse reflectance absorption spectrum of the catalyst of Example 4;

[0032] Figure 3 Influence of coexisting ions, natural organic matter and different actual water backgrounds on removal of CIP in 0.5% PPy / MCN / LED / PMS system of Example 4 (a) Cl - , (b) HCO3 - , (c) PO43- (d) NO3 - (e) Ca 2+ (f) Mg 2+ (g) HA, lake water, tap water

[0033] Figure 4 Removal of different pollutants (a) Phe, 2,4-DCP, BPA and CT, (b) SMT, TC, OTC in 0.5% PPy / MCN / white light / PMS system of catalyst of Example 4

[0034] Figure 5 Cyclic use of catalyst of Example 4

[0035] The objectives, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments will be described below clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0037] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings). If the certain posture changes, the directional indications also change accordingly.

[0038] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.

[0039] The application provides a MCN / PPy Z-type heterojunction catalyst with simple preparation process, controllable structure, high catalytic efficiency, strong anti-interference and recycling, a preparation method thereof and application of the catalyst in a photocatalysis / PMS-AOP system.

[0040] A polypyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst is obtained by in-situ polymerization of graphite-like carbon nitride g-C3N4 and polypyrrole PPy.

[0041] Preferably, the graphite-like carbon nitride g-C3N4 is obtained by pyrolysis of a nitrogen-rich compound under oxygen-deficient conditions.

[0042] Preferably, the nitrogen-rich compound is one or more of urea, dicyan diamine and melamine.

[0043] A preparation method of the above polypyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst, wherein the method comprises the following steps:

[0044] (1) a certain amount of nitrogen-rich compound is placed in a double-crust double-crucible double-cover, the loaded crucible is placed in a muffle furnace for sintering reaction treatment, after the sintering reaction is completed, the product is cooled and ball milled to obtain a powder-like graphite-like carbon nitride g-C3N4;

[0045] (2) the graphite-like carbon nitride g-C3N4 is uniformly dispersed in water by ultrasonic dispersion, then is transferred to a magnetic stirring at room temperature for a period of time, sodium dodecyl sulfate SDS is added, pyrrole is added after the sodium dodecyl sulfate SDS is completely dissolved, high-speed magnetic stirring is performed until the pyrrole is completely dissolved, then a previously prepared FeCl3 aqueous solution is added dropwise under the condition of high-speed magnetic stirring, and the reaction is carried out at room temperature, after the reaction is completed, filtration separation is performed, the filter cake is washed with water and ethanol, and the product PPy / g-C3N4 is obtained after vacuum drying.

[0046] Preferably, the temperature of the sintering reaction treatment in step (1) is 500-600 DEG C, and the time is 2-6 h.

[0047] Preferably, the particle size of the powder-like graphite-like carbon nitride g-C3N4 obtained by ball milling in step (1) is controlled to be below 1.5 microns.

[0048] Preferably, in step (2), the addition amount of pyrrole is 0.1%-5% of the mass of the graphite-like carbon nitride g-C3N4, the molar ratio of pyrrole to sodium dodecyl sulfate SDS is 1:(0.5-2), and the molar ratio of pyrrole to ferric chloride hexahydrate is 1:(2-3).

[0049] Preferably, the molar ratio of pyrrole, sodium dodecyl sulfate SDS and FeCl3 in step (2) is 1:1:2.

[0050] Preferably, the reaction temperature of step (2) is 25-35℃, and the reaction time is 10-24h.

[0051] Preferably, the filter cake washing is first magnetic stirring washing of the filter cake with water, then filtering, repeating the process until the filtrate is no foam and no smooth feeling, and finally the filter cake is magnetic stirring washed with ethanol, then filtering, and the process is repeated at least twice.

[0052] The application of a poly-pyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst, wherein the catalytic material is used for activating a photocatalysis / PMS-AOP coupling system to degrade antibiotics and / or phenols.

[0053] Example 1

[0054] (1) Preparation of graphite-like carbon nitride g-C3N4

[0055] 10g of nitrogen-rich compound melamine was added to a 25mL quartz crucible, and the melamine accounted for about 2 / 3 of the volume of the crucible, then covered with a lid, and then a 100mL quartz crucible was set outside and covered. Put the assembled crucible in the muffle furnace, the heating rate is 5℃ / min, the reaction temperature is 550℃, the reaction time is 2h, after the reaction, the obtained one-piece hard block product is cooled and ground into powder with particle size less than 1.5μm by ball mill, and graphite-like carbon nitride g-C3N4 is obtained, which is ready for use.

[0056] (2) Preparation of poly-pyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst PPy / g-C3N4

[0057] 0.5 g of product graphite-like carbon nitride g-C3N4 was dispersed in 50 mL of water, and after ultrasonic dispersion for 30 min, it was transferred to a room temperature magnetic stirring for 10 min, then 0.1075 g of sodium dodecyl sulfate SDS was added, and after it was completely dissolved, 2.5 mL of pyrrole with a concentration of 10 g / L was added, and it was completely dissolved under high-speed magnetic stirring for about 20 min. 4 mL of 50 g / L FeCl3·6H2O aqueous solution was diluted to 20 mL and mixed uniformly, and then transferred to a 60 mL constant pressure low liquid funnel, and added dropwise at a speed of 1 drop / s under high-speed magnetic stirring. After the addition was completed, it was reacted at room temperature 25℃ for 20 h, and after the reaction was completed, it was filtered and separated. The filter cake was first washed with water under magnetic stirring for 30 min, then filtered, and the process was repeated until the filtrate was smooth and no foam. Finally, the filter cake was washed with ethanol under magnetic stirring for 30 min and then filtered, and the process was repeated twice. After drying in a vacuum environment at a temperature of 40℃, the product PPy / g-C3N4 was obtained, where the amount of pyrrole added was 5% of the mass of g-C3N4, and was denoted as 5% PPy / g-C3N4. The molar ratio between pyrrole, sodium dodecyl sulfate SDS, and FeCl3 was: pyrrole: FeCl3 = 1:2, pyrrole: SDS = 1:1.

[0058] Example 2

[0059] This example is the same as the process of Example 1, except that the amount of pyrrole added is 2% of the mass of g-C3N4, denoted as 2% PPy / g-C3N4.

[0060] Example 3

[0061] This example is the same as the process of Example 1, except that the amount of pyrrole added is 1% of the mass of g-C3N4, denoted as 1% PPy / g-C3N4.

[0062] Example 4

[0063] This example is the same as the process of Example 1, except that the amount of pyrrole added is 0.5% of the mass of g-C3N4, denoted as 0.5% PPy / g-C3N4.

[0064] Example 5

[0065] This example is the same as the process of Example 1, except that the amount of pyrrole added is 0.1% of the mass of g-C3N4, denoted as 0.1% PPy / g-C3N4.

[0066] Application Example 1

[0067] The performance of Z-type heterojunction PPy / g-C3N4 catalyst for photocatalytic / PMS-AOPs synergistic system to degrade pollutants was evaluated: the target pollutant was ciprofloxacin (CIP), and the experimental conditions were: CIP 10 mg / L, peroxymonosulfate (PMS) 0.5 mM, and catalyst 0.2 g / L. First, static adsorption experiments were performed on PPy / g-C3N4, then a certain amount of previously dissolved PMS was added, and the LED light source was turned on and PMS was added at the same time. At several preset time intervals, samples were taken and filtered to monitor the concentration change of the pollutants. The concentration of CIP was analyzed by high performance liquid chromatography (HPLC), and the detection wavelength was 360 nm.

[0068] The results are shown in Figure 1 a-1d. Within 30 min, the adsorption of the catalyst on the pollutants can be ignored, indicating that the physical adsorption effect of the material is very limited in the degradation process of the pollutants. In the photocatalytic / PMS-AOPs synergistic system, the best 0.5% PPy / g-C3N4 can remove almost 100% of CIP within 60 min, which is more effective than single PMS-AOPs or photocatalysis. The reaction kinetic constant K value of 0.5% PPy / g-C3N4 / LED / PMS system (0.0643 min -1 ) is the highest, which is 2.91 times that of g-C3N4 / LED / PMS (0.0221 min -1 ). Further increasing the PPy content to 5% will cover the active sites of g-C3N4, and thus reduce the CIP removal rate to below 70%, even lower than g-C3N4. Therefore, the PPy content should be carefully controlled during the synthesis process to ensure the best performance.

[0069] Semiconductors have effective light trapping ability to generate electrons and holes, and effective separation of electrons and holes can realize their redox effect. As shown in Figure 2 a, the UV-Vis diffuse reflectance absorption spectrum of the catalyst shows that the absorption edge of g-C3N4 is between 200-450 nm, which confirms its strong absorption in the ultraviolet and part of the visible light region. In contrast, the absorption of 0.5% PPy / g-C3N4 after PPy modification is expanded to the full spectrum light region. In the transient photocurrent response experiment Figure 2 b, it can be seen that the photocurrent density of 0.5% PPy / g-C3N4 is significantly higher than that of g-C3N4, indicating that the recombination efficiency of electron-hole pairs is reduced, and PPy significantly improves the charge transfer dynamics of the photocatalyst.

[0070] Application Example 2

[0071] Real water coexisting anions, cations and dissolved organic matter (DOM) can affect the reaction efficiency by scavenging the generated free radicals or affecting the electron transfer, thus hindering its practical application. The experimental procedure is the same as that of Comparative Example 1, except that different concentrations and different types of coexisting ions are added in each group of experiments. As shown in Figure 3 Figure 2 shows the effect of common anions, cations and DOM in the LED / PMS coupling system on the degradation of CIP. Overall, most of the coexisting components have obvious enhancing effect on the removal of CIP. Among them, HCO3 - has the strongest enhancing ability. When the concentration of HCO3 - increases from 0 to 0.2 mM, 1 mM and 5 mM, the time required for complete degradation of CIP is shortened to 60 min, 15 min and 10 min, respectively. In contrast, NO3 - and HA have no obvious effect on the removal of CIP, and PO4 3- has a slight inhibitory effect. In addition, in order to verify the practicability of the 0.5% PPy / MCN / white light / PMS system, the removal rate of CIP has reached 100% at 10 min when tap water and lake water are used as the background. In summary, the 0.5% PPy / MCN / LED / PMS system has strong environmental anti-interference ability and has potential for application in actual water bodies.

[0072] Application Example 3

[0073] The 0.5% PPy / g-C3N4 catalyst is used in the synergistic system of photocatalysis / PMS-AOPs to degrade phenolic pollutants such as phenol (Phe), 2.4-dichlorophenol (2,4-DCP), bisphenol A (BPA) and catechol (CT) and other antibiotics such as sulfamethoxazole (SMT), tetracycline hydrochloride (TC) and oxytetracycline (OTC) and the like. The experimental conditions are: the concentration of phenols is 0.1 mM, the concentration of antibiotics is 10 mg / L, PMS is 1 mM, and the catalyst is 0.2 g / L. The experimental procedure is the same as that of Comparative Example 1. As shown in Figure 4 Figure 3, all target pollutants are degraded to a certain extent, but due to the different structures and properties of the pollutants, the removal efficiency is also different. For phenolic pollutants, CT is the easiest to degrade and can be completely removed within 15 min of reaction. BPA, 2,4-DCP and Phe show similar degradation kinetics and the removal rate is about 80% at 60 min. In contrast, the degradation kinetics of antibiotics is relatively fast, especially for TC and OTC, which can be completely degraded within 10 min. In summary, in the 0.5% PPy / g-C3N4 / LED / PMS system, various pollutants have good degradation efficiency and are universal.

[0074] Application Example 4

[0075] The reusability and stability of the catalyst are very important for the application of the treatment technology in practice. Therefore, in order to verify the reusability and stability of 0.5% PPy / g-C3N4, the synergistic white light activated PMS degradation CIP experiment was repeated for 5 times in succession, and the specific experimental steps were the same as those in application example 1. The results are shown in Table 2. Figure 5 As shown in Table 2, when 0.5% PPy / g-C3N4 CIP was recycled for the 5th time, the removal efficiency of CIP still remained above 97%, indicating that 0.5% PPy / g-C3N4 had significant reusability for the white light synergistic PMS system.

[0076] The catalyst of the present application has good application prospect when applied to the treatment of actual wastewater.

[0077] The above description is only the preferred embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made by using the content of the present application, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. Use of a polypyrole-modified graphitic-phase carbon nitride Z-type heterojunction catalyst, characterized in that: The catalytic material is used for activating a photocatalysis / PMS-AOP coupling system to degrade antibiotics or phenols; The preparation method of the polypyrrole modified graphite-like carbon nitride Z-type heterojunction catalyst comprises the following steps: (1) A certain amount of nitrogen-rich compound is placed in a double-covering double-crucible double-covering, and the loaded crucible is placed in a muffle furnace for sintering reaction treatment. After the sintering reaction is completed, the product is cooled and ball milled to obtain a powder-like graphite-like carbon nitride g-C3N4. The graphite-like carbon nitride g-C3N4 is obtained by pyrolysis of the nitrogen-rich compound under oxygen-deficient conditions. The nitrogen-rich compound is one or more of urea, dicyan diamine and melamine. The sintering reaction treatment temperature is 500-600 DEG C, and the time is 2-6 h. The particle size of the powder-like graphite-like carbon nitride g-C3N4 obtained by ball milling is controlled to be below 1.5 μm; (2) The graphite-like carbon nitride g-C3N4 is uniformly dispersed in water by ultrasonic dispersion, then transferred to room temperature and magnetically stirred for a period of time, then sodium dodecyl sulfate SDS is added, then pyrrole is added after the sodium dodecyl sulfate SDS is completely dissolved, then high-speed magnetic stirring is performed until the pyrrole is completely dissolved, then a previously prepared FeCl3·6H2O aqueous solution is added dropwise under high-speed magnetic stirring, and the reaction is carried out at room temperature. After the reaction is completed, filtration separation is performed, the filter cake is washed with water and ethanol, and the product PPy / g-C3N4 is obtained after vacuum drying. The addition amount of pyrrole is 0.1%-5% of the mass of the graphite-like carbon nitride g-C3N4, the molar ratio of pyrrole to sodium dodecyl sulfate SDS is 1:(0.5-2), the molar ratio of pyrrole to FeCl3·6H2O is 1:(2-3), the reaction temperature is 25-35 DEG C, and the reaction time is 10-24 h.

2. The use of a polypyrole-modified graphite-like carbon nitride Z-type heterojunction catalyst according to claim 1, characterized in that: The filter cake washing first uses water to magnetically stir the filter cake, then filters, repeats the process until the filtrate is free of foam and smooth feeling, and finally the filter cake is washed with ethanol by magnetic stirring, then filtered, and the process is repeated at least twice.

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