Hydrophobic photocatalyst h-g-c3n4, and preparation method and application thereof

Abstract

The application provides a preparation method of a hydrophobic photocatalyst H-g-C3N4 and belongs to the technical field of new materials and photocatalytic wastewater treatment. ‑1 The method comprises the following steps: base material preparation: under an inert or air atmosphere, melamine is heated at a rate of 3-8°C·min ‑1 to 520-580°C and kept for 2-5 h, and after cooling, g-C3N4 powder is obtained by grinding; surface hydrophobic modification: g-C3N4 is dispersed in an inert organic solvent containing 3-aminopropyl triethoxysilane and a fluorine-containing olefin monomer to obtain a dispersion liquid; in the presence of a free radical initiator, amine-olefin Michael addition reaction is carried out, and after filtration, washing and drying, the hydrophobic photocatalyst H-g-C3N4 covalently grafted with organosilane-fluorine-containing olefin is obtained. The method has the advantages of simple preparation, low cost of raw materials and mild conditions, and the obtained material has high hydrophobicity, high stain resistance and high activity, and has a wide application prospect in photocatalytic treatment of wastewater containing antibiotic refractory organic matter, and in particular, has high efficiency and interference resistance in degradation of SMX under visible light.

Description

Technical Field

[0001] This invention relates to the fields of new materials and photocatalytic wastewater treatment technology, and in particular to a hydrophobic photocatalyst Hg-C3N4, its preparation method, and its application. Background Technology

[0002] Antibiotics are a class of therapeutic drugs used to prevent and treat diseases in humans and animals, characterized by large dosages and wide application. However, only a small portion of antibiotics used for treatment are absorbed and utilized in the body through metabolic processes such as hydroxylation; approximately 10-90% are excreted in urine or feces as parent structures or metabolites, subsequently entering the environment through direct discharge or wastewater collection systems. The main source of antibiotics in domestic sewage is the incomplete metabolism of antibiotics during the prevention and treatment of human diseases. This type of sewage, collected through municipal sewage networks, enters wastewater treatment plants, where various antibiotics can be detected in both the influent and effluent, with concentrations generally ranging from nanograms to micrograms.

[0003] Sulfonamide antibiotics are among the most frequently detected antibiotics in wastewater treatment plants. Sulfamethoxazole (SMX) is a typical example, with both high detection rates and concentrations in most wastewater treatment plants, ranging from 50.1 to 3263.01 ng / L. These antibiotics typically exhibit persistence and mobility in the aquatic environment, possessing chronic toxicity and sublethal effects on aquatic microorganisms and ecosystems, and adversely impacting plant photosynthesis. Furthermore, the long-term presence of antibiotics can promote the generation and spread of resistant bacteria and resistance genes, exacerbating antibiotic resistance problems and potentially posing long-term risks to human health through drinking water and agricultural irrigation.

[0004] SMX is highly polar and difficult to biodegrade, making it difficult to completely remove through conventional sedimentation or adsorption. Therefore, traditional wastewater treatment processes have limited removal efficiency for SMX, with significant fluctuations in removal rates. Although advanced treatment technologies such as membrane separation are effective in removing antibiotics, their high investment costs and energy consumption limit their large-scale application.

[0005] Photocatalysis, capable of efficiently degrading recalcitrant organic pollutants under ambient temperature and pressure, is considered a crucial approach to addressing environmental pollution and energy shortages, showing promise in treating wastewater containing antibiotics. Semiconductor photocatalytic materials, such as titanium dioxide (TiO2), have made significant progress in laboratory research. However, in real-world aquatic systems, photocatalysis still faces numerous challenges: firstly, some photocatalytic materials have limited visible light absorption range; secondly, naturally occurring organic compounds such as humic acid (HA) readily accumulate on the photocatalyst surface, forming complexes that occupy or cover active sites, thus masking the active sites and significantly reducing photocatalytic efficiency.

[0006] Inspired by the "lotus effect" in nature, researchers have begun to construct biomimetic materials that combine hydrophobicity and self-cleaning properties. Hydrophobic and even superhydrophobic materials can be widely used in antifouling, self-cleaning, and corrosion resistance. It is generally believed that forming a hydrophobic surface requires two conditions to be met simultaneously: first, reducing the free energy of the material surface; and second, constructing a rough surface with a geometric micro-nano-level hierarchical structure. Based on these construction principles, the common method for preparing hydrophobic photocatalytic materials mainly involves surface modification using low surface energy substances. Common low surface energy substances can be broadly classified into fluorine materials, silicon materials, and fluorosilicon materials. Among the many preparation methods, surface coating is widely used to construct hydrophobic or superhydrophobic surfaces due to its simplicity and low dependence on specialized equipment. However, when such coatings are directly applied to the surface of photocatalysts, improper control of the coating thickness can easily cover or block the photocatalytic active sites on the surface, leading to a decrease in the photocatalytic rate and affecting the actual application performance of the material.

[0007] Existing hydrophobic photocatalytic materials are mostly constructed using TiO2 as the main component, with hydrophobic modification achieved through processes such as the sol-gel method. However, TiO2 has a narrow light absorption range and low utilization efficiency for visible light, limiting its application under sunlight conditions. Therefore, how to achieve fouling-resistant hydrophobic modification of the photocatalyst surface while maintaining efficient visible light response performance and minimizing the masking and adhesion deactivation of active sites has become a pressing technical problem in this field. Therefore, it is necessary to design and construct an efficient hydrophobication preparation method for visible light-responsive photocatalytic materials (such as graphitic carbon nitride g-C3N4) to obtain fouling-resistant hydrophobic photocatalytic materials that possess both hydrophobic self-cleaning properties and excellent photocatalytic degradation performance, thereby achieving efficient treatment and removal of recalcitrant organic pollutants such as antibiotics from wastewater. Summary of the Invention

[0008] To overcome the problems of existing photocatalysts such as easy biofouling in actual water samples, sensitivity to humic substances, and limited degradation rates, this invention provides a hydrophobic photocatalyst Hg-C3N4, its preparation method, and its applications. The method described in this invention is simple to prepare, uses inexpensive raw materials, and operates under mild conditions. The resulting material possesses high hydrophobicity, high antifouling properties, and high activity, showing broad application prospects in the photocatalytic treatment of wastewater containing antibiotic-resistant organic matter, especially exhibiting high efficiency and interference resistance in the visible light degradation of SMX.

[0009] The technical solution of the present invention is as follows:

[0010] A method for preparing a hydrophobic photocatalyst Hg-C3N4 includes the following steps:

[0011] (1) Substrate preparation: Melamine is heated at 3-8°C·min under an inert or air atmosphere. -1 Heat to 520-580 °C and hold for 2-5 h, then cool and grind to obtain g-C3N4 powder;

[0012] (2) Surface hydrophobic modification: The g-C3N4 obtained in step (1) is dispersed in an inert organic solvent containing 3-aminopropyltriethoxysilane APTES and fluorinated olefin monomers to obtain a dispersion; an amine-olefin Michael addition reaction is carried out in the presence of a free radical initiator, filtered, washed and dried to obtain the hydrophobic photocatalyst g-C3N4 modified by organosilane-fluorinated olefin covalent grafting, namely Hg-C3N4.

[0013] Furthermore, the preferred process parameters for step (1) are: a heating rate of 4°C·min. -1 Heat to 550°C and keep warm for 4 hours.

[0014] Furthermore, the sieving in step (1) is sieving through a 100-200 mesh sieve.

[0015] Preferably, the fluorinated olefin monomer is dodecafluoroheptyl methacrylate C. 11 H8F 12 O2, or other perfluoroalkyl (meth)acrylates, wherein the inert organic solvent is dichloromethane, and the free radical initiator is the photoinitiator benzoin dimethyl ether (2,2-dimethoxy-2-phenylacetophenone) DMPA.

[0016] Preferably, the amount of APTES added is 2-4 wt% of the total mass of the dispersion; the amount of the fluorinated olefin monomer added is 0.1-1.0 wt% of the total mass of the dispersion.

[0017] Furthermore, the amount of APTES added is preferably 2 wt%, and the amount of the fluorinated olefin monomer added is preferably 0.4 wt%.

[0018] Preferably, the ratio of g-C3N4 to inert organic solvent is 1-2.5 g: 50 mL; the ratio of free radical initiator to inert organic solvent is 0.05-0.15 g: 50 mL.

[0019] Preferably, the amine-alkene Michael addition reaction takes 6-10 h and the reaction temperature is 30-45°C.

[0020] Preferably, the filtration, cleaning, and drying process involves washing with anhydrous ethanol 2-4 times and then vacuum drying at 70-90°C for 8-24 hours.

[0021] Furthermore, the surface of the Hg-C3N4 exhibits a rough, multi-layered structure with a static water contact angle ≥140°; in addition to C, N, and O elements, Si and F element signals are also present in the full spectrum, with a Si 2p characteristic peak at a binding energy of 100-105 eV and an F 1s characteristic peak at a binding energy of 685-690 eV.

[0022] Furthermore, compared to unmodified g-C3N4, biofilm growth was reduced by approximately 10-fold under the same culture conditions.

[0023] The present invention also provides the application of the hydrophobic photocatalyst Hg-C3N4 prepared by the method, namely, using Hg-C3N4 to degrade wastewater containing antibiotic organic pollutants under visible light irradiation.

[0024] Preferably, the antibiotic organic pollutant in the wastewater is sulfamethoxazole, with an initial concentration of 1-200 mg / L, a hydrophobic photocatalyst dosage of 0.04-1.2 g / 50 mL, and an average optical power density of 60-120 mW·cm⁻¹. -2 It can be completely degraded by light exposure for 90-180 minutes; the main active species in the degradation process of sulfamethoxazole are hydroxyl radicals and superoxide radicals.

[0025] Furthermore, when the wastewater containing antibiotic organic pollutants contains humic acid, the degradation efficiency of sulfamethoxazole is not affected.

[0026] Furthermore, the concentration of humic acid in wastewater containing antibiotic-containing organic pollutants can be no less than 25 mg / L.

[0027] The beneficial technical effects of this invention are as follows:

[0028] 1. This invention relates to a hydrophobic photocatalyst possessing both resistance to biofilm fouling and efficient visible light degradation of antibiotics, along with its preparation method. This method uses a visible light-responsive g-C3N4 photocatalyst as a substrate. Utilizing the abundant -NHx sites on its surface, silicon-fluorine segments are directly grafted onto the outermost layer of the material via an amine-ene Michael addition reaction, successfully preparing a novel material possessing both photocatalytic activity and hydrophobic properties. The obtained material, when pressed into tablets, exhibits a static water contact angle of approximately 144°. After culturing in a culture medium containing Chlorella for 3 days, the biofilm growth is reduced by approximately 10 times compared to the unmodified material, effectively delaying activity decay and reducing the frequency of cleaning.

[0029] 2. The hydrophobic photocatalyst prepared in this invention exhibits excellent degradation activity of sulfamethoxazole under visible light conditions, achieving complete removal within 90 minutes (sulfamethoxazole concentration 15 mg / L), and maintaining stable efficiency even in the presence of humic acid at 25 mg / L. Its humic acid resistance mechanism utilizes the enhanced electron-water interface formed by the hydrophobic reaction to introduce hydrogen bonds, thereby complexing humic acid through hydrogen bonds and altering its conformation, thus preventing humic acid from quenching holes. This effect demonstrates the good tolerance of the hydrophobic photocatalyst material prepared in this invention to natural organic matter.

[0030] 3. The method provided by this invention is simple and low-cost. First, graphitic carbon nitride (g-C3N4) is prepared by calcining melamine in a tube furnace as a substrate. Then, a low surface energy layer containing fluorinated silane is introduced onto its surface via click-type amine-alkene Michael addition, constructing a multi-level, rough, stacked layered micro / nano structure. This process can be completed without complex operations. This method not only provides a new approach to the hydrophobic modification of photocatalysts but also offers a promising new material for practical water treatment. Attached Figure Description

[0031] Figure 1 This is a scanning electron microscope (SEM) image of the hydrophobic photocatalytic material of the present invention;

[0032] Figure 2 The image shows the X-ray photoelectron spectroscopy (XPS) spectrum of the hydrophobic photocatalytic material of this invention.

[0033] Figure 3 This is a water contact angle test diagram of the hydrophobic photocatalytic material and the unmodified material of this invention;

[0034] Figure 4 This is a comparison diagram of the anti-biofilm effect of the hydrophobic photocatalytic material of this invention and the unmodified material in a culture medium containing Chlorella vulgaris.

[0035] Figure 5 This is a diagram illustrating the algae removal effect of the hydrophobic photocatalytic material of this invention.

[0036] Figure 6This is a comparison chart showing the SMX removal effect of the hydrophobic photocatalytic material of this invention and the unmodified material under visible light;

[0037] Figure 7 The image shows the electron paramagnetic resonance (EPR) test results of the photocatalytic system of the hydrophobic photocatalytic material and the unmodified material of this invention.

[0038] Figure 8 The graph shows the degradation effect of the hydrophobic photocatalyst Hg-C3N4 of this invention on different concentrations of SMX.

[0039] Figure 9 This is a comparison chart showing the effect of the photocatalyst of this invention on the degradation of 30 mg / L SMX under the influence of HA. Detailed Implementation

[0040] This invention provides a method for preparing a hydrophobic photocatalyst, a corresponding hydrophobic photocatalytic material, and its application in the removal of organic antibiotic wastewater. The hydrophobic photocatalytic material uses graphitic carbon nitride (g-C3N4) as a matrix. The matrix surface is hydrophobized and a multi-level micro / nano rough structure is constructed by introducing silane-containing bonding segments and fluorine-containing low surface energy segments to improve its antifouling properties and stability in complex water bodies.

[0041] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0042] Unless otherwise stated, all raw materials used in the examples were commercially available analytical grade; room temperature / normal temperature was 25±3 °C. The detection methods are as follows: contact angle was measured using a contact angle meter (pellet method); morphology was analyzed using SEM; surface elemental analysis was performed using XPS; and the target analyte (SMX) was quantified using HPLC.

[0043] Example 1: Preparation of hydrophobic photocatalyst Hg-C3N4

[0044] (1) Substrate preparation: Melamine was used as a precursor and placed in a covered alumina crucible in a tube furnace. The heating rate was controlled at 4°C·min under a nitrogen atmosphere. -1 The temperature was raised to a predetermined temperature of 550°C and held for 4 hours to allow condensation and carbonization reactions to occur. After natural cooling, grinding, and passing through a 100-mesh sieve, light yellow graphitic carbon nitride (g-C3N4) powder was obtained, denoted as CN.

[0045] (2) Hydrophobic modification: g-C3N4 powder is dispersed in an organic solvent at a certain solid-liquid ratio, and an amino-containing silane coupling agent and a fluorinated olefin monomer are introduced. An amine-olefin Michael addition reaction is carried out in the presence of a free radical initiator, so that the fluorinated low surface energy segments are fixed on the g-C3N4 surface through silane bonding to construct a hydrophobic surface with a multi-level rough structure. Then, solid-liquid separation, washing and drying are performed to obtain the hydrophobic photocatalyst Hg-C3N4.

[0046] The specific steps for hydrophobic modification are as follows:

[0047] Disperse 1.00 g of CN in 50 mL of dichloromethane by ultrasonication (10 min), then add 1 mL of APTES and 200 μL of C in sequence. 11 H8F 12 O2 and 0.1 g of DMPA were magnetically stirred and photoinitiated at 40 °C for 8 h; after filtration, the mixture was washed three times with anhydrous ethanol and dried at 80 °C for 24 h to obtain hydrophobically modified Hg-C3N4 powder.

[0048] The scanning electron microscopy results of Hg-C3N4 are as follows: Figure 1 As shown, the modified materials all exhibit a multi-layered structure, and the surface of Hg-C3N4 has a roughness.

[0049] XPS test results for Hg-C3N4 are as follows: Figure 2 As shown, characteristic peaks for C and N elements are present, and signals from Si and F species are detected, confirming the successful modification of the low surface energy fluorosilicon material onto the g-C3N4 surface. The high-resolution N1s spectrum exhibits three typical peaks. The main peak at 397.9 eV is attributed to the sp(triazine) ring. 2 Hybridized N (C=NC) is an important component of graphitic carbon nitride; the peak at 403.6 eV corresponds to sp 2 Hybridized pyridine nitride (NO) is often used as an intermediate to improve the separation and transport efficiency of electron-hole pairs. XPS results show that the g-C3N4 host structure remains stable during hydrophobic modification, and Si and F functional layers are successfully introduced onto the surface.

[0050] Test Example 1: Water Contact Angle Test

[0051] The static water contact angle of the g-C3N4 and Hg-C3N4 powders obtained in Example 1 was tested using a contact angle meter via a tablet compression method (room temperature 25±3℃, average of ≥3 different locations for each sample). The results are as follows: Figure 3As shown, the contact angle of Hg-C3N4 is approximately 144°, significantly higher than the 49° of unmodified g-C3N4. This comparison indicates that the low surface energy and micro / nano rough structure of the hydrophobic modified material work together to significantly improve hydrophobicity, effectively reducing the adhesion of aqueous pollutants to the surface and the risk of potential biofilm formation.

[0052] Test Example 2: Evaluation of Anti-biofilm Performance

[0053] The unmodified g-C3N4 and modified Hg-C3N4 powders obtained in Example 1 were loaded onto the surface of glass slides or inert substrates using binders to form catalyst support sheets with similar specific surface areas. These support sheets were placed in a culture medium containing Chlorella and cultured for 3 days under the same temperature and light conditions. After cultivation, the support sheets were removed and gently rinsed with distilled water to remove any unattached biomass. The amount of biofilm attached to the material surface was then quantified using crystal violet staining or weighing.

[0054] Test results are as follows Figure 4 As shown, the biofilm growth on the surface of the Hg-C3N4 carrier is about 1 / 10 of that on the unmodified g-C3N4, indicating that hydrophobic modification significantly inhibits the adhesion and growth of microorganisms on the material surface, demonstrating excellent antifouling and antibiofilm capabilities.

[0055] Test Example 3: Algae Removal Performance Evaluation

[0056] Take 0.04 g of Hg-C3N4 powder obtained in Example 1 and add it to 50 mL of Microcystis solution, where the algal density OD 680 =0.8. After 2 hours of illumination, the results are as follows: Figure 5 As shown, the number of algal cells decreased by 100%, indicating that the material has a good algae removal ability.

[0057] Application Example 1: Catalytic degradation of SMX by Hg-C3N4 under visible light

[0058] 50 mL of an initial SMX aqueous solution with a concentration of 15 mg / L was prepared, and 0.04 g each of g-C3N4 and Hg-C3N4 powder were added. The reaction solution was placed in a quartz reactor, and the photoreaction was carried out under magnetic stirring. The light source used was a xenon lamp equipped with a 400 nm visible light cutoff filter, with an average optical power density of 80 mW·cm⁻¹. -2 To simulate visible light illumination.

[0059] The reaction was carried out under stirring conditions, and samples were taken at regular intervals. After filtration (0.22 µm), the SMX concentration was monitored by HPLC as a function of reaction time. The reaction system temperature was maintained at 20-35°C, and a 30-minute dark adsorption equilibration was performed if necessary.

[0060] The results are as follows Figure 6 As shown, under the above conditions, Hg-C3N4 can achieve complete or near-complete removal of SMX within 90 min; while the maximum removal rate of SMX by unmodified g-C3N4 is 96% (120 min).

[0061] In the same experimental system, 25 mg / L humic acid was added to the SMX water sample, and the photocatalytic degradation experiment was repeated. Figure 6 The results show that the removal rate of SMX by g-C3N4 decreased to 84%, while the degradation rate and final removal rate of SMX in the Hg-C3N4 system showed almost no significant decrease compared to the system without the addition of humic acid. This indicates that Hg-C3N4 exhibits excellent photocatalytic activity in the degradation of antibiotics under visible light and has good tolerance to interference from natural organic matter, making it suitable for treating antibiotic-containing wastewater in complex aquatic environments.

[0062] Test Example 4: Identification of active species in the visible-photocatalytic degradation of Hg-C3N4

[0063] To investigate the reaction mechanism of Hg-C3N4 photocatalytic degradation of SMX, different types of free radical quenchers were added to the reaction solution in the same photocatalytic system as in Application Example 1, including p-benzoquinone (BQ) to capture superoxide radicals (•O2). - Isopropanol (IPA) is used to capture hydroxyl radicals (•OH); potassium iodide (KI) is used to capture photogenerated holes (h). + ).

[0064] The SMX degradation experiment was repeated after adding the above-mentioned quenchers, and compared with the blank control group. The results showed that the addition of any quencher inhibited the removal efficiency of SMX, and under certain conditions, it could significantly reduce the degradation rate, indicating that •OH and •O2... - Both photogenerated holes and photogenerated holes play important roles in the photocatalytic degradation of SMX by Hg-C3N4.

[0065] Furthermore, by using electron paramagnetic resonance (EPR) technology to capture transient free radicals with suitable spin trapping agents, •OH and •O2 can be detected under visible light illumination. - The characteristic signals and results are shown in [the table]. Figure 7 The results, corroborated by the quenching experiment, indicate that the main active species in the Hg-C3N4 photocatalytic system of this invention are hydroxyl radicals and superoxide radicals.

[0066] Application Example 2: Catalytic degradation of different concentrations of SMX by Hg-C3N4 under visible light

[0067] 50 mL of SMX aqueous solutions with initial concentrations of 20, 25, 30, 35, and 40 mg / L were prepared respectively, and 0.04 g of Hg-C3N4 powder was added to each solution. The reaction solutions were placed in a quartz reactor and subjected to photo-irradiation under magnetic stirring. The light source was a xenon lamp equipped with a 400 nm visible light cutoff filter, with an average optical power density of 100 mW·cm⁻¹. -2 To simulate visible light illumination.

[0068] The reaction was carried out under stirring conditions, and samples were taken periodically. After filtration (0.22 µm), the SMX concentration was monitored by HPLC as a function of reaction time. The reaction system temperature was maintained at 20–35 °C, and a 30-min dark adsorption equilibration was performed if necessary. The results are as follows: Figure 8 As shown, Hg-C3N4 has a good removal effect on SMX in the range of 20-40 mg / L, and can effectively remove high concentrations of SMX.

[0069] Furthermore, with an initial SMX concentration of 30 mg / L, 25 mg / L HA was added, and the photocatalytic degradation experiment was repeated, with the following results: Figure 9 As shown, without the addition of HA, Hg-C3N4 can completely remove SMX within 140 min, and with the addition of HA, Hg-C3N4 can still completely remove SMX within 180 min.

[0070] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, and for those of ordinary skill in the art, various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. Therefore, the present invention is not limited to the specific details without departing from the general concept defined by the claims and their equivalents.

Claims

1. A method for preparing a hydrophobic photocatalyst Hg-C3N4, characterized in that, Includes the following steps: (1) Substrate preparation: Melamine is heated at 3-8°C·min under an inert or air atmosphere. -1 Heat to 520-580 °C and hold for 2-5 h, then cool and grind to obtain g-C3N4 powder; (2) Surface hydrophobic modification: The g-C3N4 obtained in step (1) is dispersed in an inert organic solvent containing 3-aminopropyltriethoxysilane APTES and fluorinated olefin monomers to obtain a dispersion; an amine-olefin Michael addition reaction is carried out in the presence of a free radical initiator, filtered, washed and dried to obtain the hydrophobic photocatalyst g-C3N4 modified by organosilane-fluorinated olefin covalent grafting, namely Hg-C3N4.

2. The preparation method according to claim 1, characterized in that, The fluorinated olefin monomer is dodecafluoroheptyl methacrylate C. 11 H8F 12 O2, or other perfluoroalkyl (meth)acrylates, wherein the inert organic solvent is dichloromethane, and the free radical initiator is the photoinitiator benzoin dimethyl ether (2,2-dimethoxy-2-phenylacetophenone) DMPA.

3. The preparation method according to claim 1, characterized in that, The amount of APTES added is 2-4 wt% of the total mass of the dispersion; the amount of the fluorinated olefin monomer added is 0.1-1.0 wt% of the total mass of the dispersion.

4. The preparation method according to claim 1, characterized in that, The ratio of g-C3N4 to inert organic solvent is 1-2.5 g: 50 mL; the ratio of free radical initiator to inert organic solvent is 0.05-0.15 g: 50 mL.

5. The preparation method according to claim 1, characterized in that, The Michael addition reaction of the amine-ene takes 6-10 h and the reaction temperature is 30-45°C.

6. The preparation method according to claim 1, characterized in that, The filtration, cleaning, and drying process involves washing the product 2-4 times with anhydrous ethanol and then vacuum drying it at 70-90°C for 8-24 hours.

7. The preparation method according to claim 1, characterized in that, The surface of the Hg-C3N4 exhibits a rough, multi-layered structure with a static water contact angle ≥140°. In addition to C, N, and O elements, Si and F element signals are also present in the full spectrum. It has a Si 2p characteristic peak at a binding energy of 100-105 eV and an F 1s characteristic peak at a binding energy of 685-690 eV.

8. The application of the hydrophobic photocatalyst Hg-C3N4 prepared by the method according to any one of claims 1-7, characterized in that, The Hg-C3N4 was used to degrade antibiotic-containing organic pollutants in wastewater under visible light irradiation.

9. The application according to claim 8, characterized in that, The antibiotic organic pollutant in the wastewater is sulfamethoxazole, with an initial concentration of 1-200 mg / L. The hydrophobic photocatalyst dosage is 0.04-1.2 g / 50 mL, and the average optical power density is 60-120 mW·cm⁻¹. -2 It can be completely degraded by light exposure for 90-180 minutes; the main active species in the degradation process of sulfamethoxazole are hydroxyl radicals and superoxide radicals.

10. The application according to claim 8, characterized in that, The degradation efficiency of sulfamethoxazole is not affected when humic acid is present in wastewater containing antibiotic organic pollutants.

Images