Preparation of a cobalt phosphide-based catalyst and its application in the activation of persulfate degradation of antibiotics in wastewater

Abstract

This invention discloses the preparation of a cobalt phosphide-based catalyst and its application in the degradation of antibiotics in wastewater by activated persulfate. A porous, carbon-defined cobalt phosphide catalyst is used to activate persulfate to treat antibiotic wastewater. The porous, carbon-defined cobalt phosphide catalyst comprises a graphitized carbon matrix and cobalt phosphide nanoparticles. In this invention, the activation efficiency of persulfate is improved by adjusting the activity of the porous, carbon-defined cobalt phosphide catalyst, thereby degrading various types of antibiotic wastewater. This process has advantages such as simple operation, no byproduct generation, fast reaction rate, good degradation effect, and economic and environmental benefits. Furthermore, it can achieve rapid degradation of antibiotics in complex water conditions, and can completely remove antibiotics from wastewater containing high concentrations of salt and complex actual water bodies. Simultaneously, the catalyst exhibits excellent stress resistance, showing great promise for industrial wastewater treatment and practical applications.

Description

Technical Field

[0001] This invention belongs to the field of water treatment, specifically relating to the preparation of a cobalt phosphide-based catalyst and its application in the degradation of antibiotics in activated persulfate wastewater. Background Technology

[0002] With social development and progress, the use of various antibiotics has increased, leading to higher antibiotic levels in natural water bodies and causing significant damage to the ecological environment and aquatic life. Taking sulfamethoxazole pharmaceutical wastewater as an example, its pollutant concentration is high, with COD values ​​reaching tens or hundreds of thousands of milligrams per liter. Simultaneously, the wastewater contains large amounts of salts, greatly inhibiting traditional biological treatment methods. In recent years, advanced persulfate-based oxidation processes have demonstrated excellent practical performance in treating high-concentration organic wastewater. Compared to the limited hydroxyl radical oxidation capacity and large amounts of iron sludge generated in the traditional Fenton process, the advanced persulfate-based oxidation process can achieve efficient removal of organic matter from wastewater without generating other byproducts. However, the persulfate process is mainly limited by its activation efficiency. Traditional methods such as ultrasound, heating, and ultraviolet irradiation cannot promote high-level activation. While transition metal catalysts can achieve efficient activation of persulfate, their easy leaching can harm the aquatic environment. Therefore, constructing efficient and stable transition metal catalysts is key to the activation of persulfate technology.

[0003] Meanwhile, the transition metal phosphides formed after phosphating can further improve catalytic performance. In recent years, cobalt phosphide has attracted much attention due to its high catalytic performance; however, its practical application is limited by factors such as metal ion leaching and the composition of wastewater. Therefore, synthesizing stable cobalt phosphide that can maintain good catalytic performance under high-salt and high-organic conditions is a necessary measure to improve its application. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a green, environmentally friendly, efficient, effective, and salt-tolerant method for treating antibiotic wastewater by activating a porous carbon-limited cobalt phosphide catalyst with controlled activity through phosphorus content regulation.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for activating a porous carbon-defined cobalt phosphide catalyst to degrade antibiotics in high-salt wastewater by controlling the activity of phosphorus content involves in-situ doping of a zeolite imidazole ester framework precursor, followed by carbonization at high temperature, then low-temperature oxidation, and finally phosphorus doping at low temperature, thus forming a carbonization-oxidation-phosphating process. The method includes the following steps:

[0007] S1. A stable cobalt tetroxide and carbon material composite precursor is synthesized through primary calcination, secondary calcination and acid washing.

[0008] S2. Cobalt phosphide catalysts defined by porous carbon matrix were synthesized under low temperature conditions by doping with different amounts of phosphorus source.

[0009] In a further improvement to the above method, step S1 of the method for preparing the cobalt and carbon material composite precursor includes the following steps:

[0010] (1) Dissolve 2.87 g of cobalt nitrate in 80–100 mL of methanol solution, which is called solution 1. Dissolve 6.52 g of 2-methylimidazole in 200–220 mL of methanol solution, which is called solution 2. Then quickly pour solution 1 into solution 2 and stir vigorously at room temperature (20–30 °C). After 12–14 h, collect the purple product by high-speed centrifugation, wash the purple product three times or more with ultrapure methanol, place it in a vacuum drying oven, and dry it at 60–80 °C for 8–10 h to obtain a blocky purple product.

[0011] (2) The lumpy purple product from step (1) is ground into powder, and then placed in a tube furnace for calcination under an argon atmosphere to obtain a black powder product. The argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate during the first calcination process is 2℃ / min to 5℃ / min; the calcination temperature is 800℃ to 1000℃; and the calcination time is 3 to 5 h.

[0012] (3) The black powder product from step (2) is washed with 0.5 mol / L solution to remove unstable cobalt from the material surface. The product is then washed multiple times until the solution is neutral. The product is then placed in a vacuum drying oven and dried at 60℃~80℃ for 12~16 h. The ratio of sulfuric acid to black powder product during the pickling process is 100 mL:1 g; the temperature during the pickling process is 70℃~80℃; and the pickling time is 12~14 h.

[0013] (4) The product of step (3) is placed in a tube furnace and calcined a second time in an air atmosphere to obtain carbon material-cobalt tetroxide nanoparticles, called Co3O4 / NC. The heating rate during the second calcination process is 2℃ / min to 5℃ / min; the calcination temperature is 350℃ to 400℃; and the calcination time is 4 to 6 h.

[0014] In a further improvement to the above method, step S2, the synthesis of the carbon-matrix-defined cobalt phosphide catalyst includes: placing a phosphorus source upstream of a quartz boat, then placing Co3O4 / NC downstream of the quartz boat, subsequently placing the quartz boat in a tube furnace, and reacting under an argon atmosphere to obtain CoP / NC. The mass ratio of Co3O4 / NC to sodium hypophosphite is 1:1 to 100; the phosphorus source is sodium hypophosphite monohydrate and other reagents capable of generating gaseous phosphine; the argon atmosphere is a mixture of argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate during the reaction is 2℃ / min to 5℃ / min; the reaction temperature is 300℃ to 350℃; and the reaction time is 2 to 4 h.

[0015] A further improvement to the above method involves using a porous carbon-defined cobalt phosphide catalyst with controlled phosphorus content to activate persulfate degradation for treating antibiotics in high-salt wastewater. This includes the following steps: mixing the CoP / NC catalyst with the antibiotic wastewater and conducting a degradation reaction at 20℃–50℃ to degrade the antibiotics in the wastewater; the amount of CoP / NC catalyst added is 10–100 mg per liter of antibiotic wastewater; the antibiotic wastewater is either antibiotic wastewater containing various high concentrations of salts or surface water containing antibiotics from different sources; the initial concentration of antibiotics in the antibiotic wastewater is 1–100 mg / L, and the initial concentration of various salts in the wastewater is 0.05–0.6 mg / L. mM; the persulfate is one or both of permonosulfate and perdisulfate; the concentration of the persulfate is 0.01-3.0 mM; the pH of the reaction system is 3-11; the antibiotic in the antibiotic wastewater is at least one of sulfamethoxazole, sulfadiazine, tetracycline, oxytetracycline, penicillin, and bisphenols.

[0016] The principle of this invention is as follows: using ZIF-67, produced by the reaction of cobalt nitrate and zeolite imidazole ester skeleton, as a precursor, different types of CoP / NC catalysts are obtained through step-by-step modification and adjustment of the phosphorus ratio in the material. Therefore, this invention achieves high-catalytic-performance CoP / NC by controlling the phosphorus content in the catalyst. The high catalytic performance of CoP is utilized to activate persulfate, promoting the generation of sulfate radicals and singlet oxygen, thereby treating antibiotics in wastewater.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] (1) This invention provides a method for degrading antibiotics in high-salt wastewater by activating cobalt phosphide persulfate using a porous carbon-defined cobalt phosphide catalyst whose activity can be controlled by adjusting the phosphorus content. The method involves degrading antibiotics in wastewater by activating persulfate with CoP / NC. The synthesized CoP / NC has high catalytic performance, and its activity can be adjusted by regulating the phosphorus content. It can achieve the degradation of antibiotics in a short time when in contact with persulfate. At the same time, it is a green and environmentally friendly catalyst with low metal ion leaching and no harm to the environment.

[0019] (2) The process used in this invention produces no byproducts and does not require secondary processing, providing an economical, energy-saving, and environmentally friendly process. This process degrades antibiotics under high-salt and high-concentration organic conditions. Furthermore, the pH level has minimal impact on the process, allowing for antibiotic degradation over a wide range.

[0020] (3) In this invention, the catalyst synthesis method is safe, simple, easy to operate, has low requirements for preparation conditions and equipment, low cost, high yield, green and pollution-free, and can form a chain production, which is easy to produce on a large scale.

[0021] (4) In this invention, the catalyst is resistant to interference from natural organic matter in the water body and has shown high efficiency in the removal of antibiotics in actual natural water bodies, and has practical application potential. Attached Figure Description

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0023] Figure 1 The graph shows the degradation effect of cobalt phosphide catalyst with porous carbon controlled by different phosphorus contents on sulfamethoxazole under different time conditions in Example 1.

[0024] Figure 2 The graph shows the degradation effect of the porous carbon-defined cobalt phosphide catalyst on sulfamethoxazole under different concentrations of chloride salts in Example 2.

[0025] Figure 3 The graph shows the yield of free chlorine in the porous carbon-defined cobalt phosphide catalyst of Example 2 under different concentrations of chloride salts.

[0026] Figure 4 The graph shows the degradation effect of the porous carbon-defined cobalt phosphide catalyst on sulfamethoxazole under different sulfate concentrations in Example 2.

[0027] Figure 5 The graph shows the degradation effect of the porous carbon-defined cobalt phosphide catalyst on sulfamethoxazole under different time conditions at different temperatures in Example 3.

[0028] Figure 6 The graphs show the degradation effects of porous carbon-defined cobalt phosphide catalysts on sulfamethoxazole in actual water bodies under different time conditions in Example 4. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention. Example 1

[0030] A method for activating persulfate degradation of sulfamethoxazole using a porous carbon-defined cobalt phosphide catalyst with controlled phosphorus content, specifically involving the treatment of sulfamethoxazole wastewater using a porous carbon-defined cobalt phosphide catalyst, comprising the following steps:

[0031] Weigh out the porous carbon-defined cobalt phosphide catalysts (CoP / NC-1, CoP / NC-5, CoP / NC-10, CoP / NC-30 and CoP / NC-50), the carbon material and the cobalt tetroxide composite catalyst (Co3O4). 4 / 4 mg of each of the 0.1 mM persulfate and catalyst were added to 100 mL of a 5 mg / L sulfamethoxazole solution, and then the reaction was started on a water bath shaker. All reactions were carried out in 250 mL Erlenmeyer flasks; the pH of all solutions was 7.5; the water bath shaker speed was 150 rpm; and the water bath shaker temperature was 30 °C.

[0032] Blank group: No catalyst added, all other conditions are the same.

[0033] During the reaction, 1.0 mL samples were collected at 1, 2, 3, 4, 5, and 7 min and immediately mixed with excess sodium thiosulfate solution. The concentration of residual sulfamethoxazole was measured by high-performance liquid chromatography (HPLC). The degradation of sulfamethoxazole by persulfate activated by the porous carbon-defined cobalt phosphide catalyst at different time points was calculated. The results are as follows: Figure 1 As shown.

[0034] Figure 1 This is a graph showing the degradation effect of cobalt phosphide catalysts with porous carbon defined by different phosphorus contents on sulfamethoxazole under different time conditions in Example 1. Figure 1It is evident that, in the absence of a catalyst, unactivated persulfate is almost incapable of degrading sulfamethoxazole. With the addition of a catalyst, sulfamethoxazole is virtually completely degraded. It can be observed that CoP / NC-1, CoP / NC-5, and CoP / NC-10 exhibit better degradation effects on sulfamethoxazole than the precursor Co3O4 / NC, while CoP / NC-30 and CoP / NC-50 show worse degradation effects than Co3O4 / NC. This result reflects the regulatory effect of different phosphorus doping amounts on catalyst activity. Simultaneously, from... Figure 1 It can be seen that CoP / NC-5 exhibits the best catalytic activity, achieving almost 100% removal of sulfamethoxazole in 1 minute, while other catalysts can achieve removal within 7 minutes.

[0035] In this embodiment, a method for preparing a porous carbon-defined cobalt phosphide catalyst (CoP / NC-5) includes the following steps:

[0036] (1) Dissolve 2.87 g of cobalt nitrate in 80 mL of methanol solution, which is called solution 1. Dissolve 6.52 g of 2-methylimidazole in 200 mL of methanol solution, which is called solution 2. Then quickly pour solution 1 into solution 2 and stir vigorously at room temperature (25°C). After 12 h, collect the purple product by high-speed centrifugation, wash the purple product three times or more with ultrapure methanol, place it in a vacuum drying oven, and dry it at 60°C for 8 h to obtain a blocky purple product.

[0037] (2) The lumpy purple product from step (1) is ground into powder, and then placed in a tube furnace for calcination under an argon atmosphere to obtain a black powder product. The argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate during the first calcination process is 2 ℃ / min; the calcination temperature is 900℃; and the calcination time is 3 h.

[0038] (3) The black powder product from step (2) was washed with 0.5 mol / L solution to remove unstable cobalt from the material surface. The solution was then washed multiple times until it was neutral. The solution was then placed in a vacuum drying oven and dried at 60°C for 12 h. The ratio of sulfuric acid to black powder product during the pickling process was 100 mL: 1 g; the temperature during the pickling process was 80°C; and the pickling time was 12 h.

[0039] (4) The product of step (3) is placed in a tube furnace and calcined a second time in an air atmosphere to obtain carbon material-cobalt tetroxide nanoparticles, called Co3O4 / NC. The heating rate during the second calcination process is 2 °C / min; the calcination temperature is 350 °C; and the calcination time is 4 h.

[0040] (5) In step (4), the method for synthesizing the carbon-matrix-defined cobalt phosphide catalyst includes: placing sodium hypophosphite upstream of a quartz boat, then placing Co3O4 / NC downstream of the quartz boat, and subsequently placing the quartz boat in a tube furnace for reaction under an argon atmosphere to obtain CoP / NC-5. The ratio of Co3O4 / NC to sodium hypophosphite is 1:5; the argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate during the reaction is 2 °C / min; the reaction temperature is 300 °C; and the reaction time is 2 h. Example 2

[0041] A method for activating sulfamethoxazole in high-salt wastewater by persulfate degradation using a porous carbon-defined cobalt phosphide catalyst with controlled phosphorus content is essentially the same as in Example 1, except that in Example 2, different concentrations of chloride and sulfate were added to the sulfamethoxazole wastewater solution, at concentrations of 0, 50, 100, and 600 mM. The catalyst used was CoP / NC-5 from Example 1.

[0042] Figure 2 This is a graph showing the degradation effect of the porous carbon-defined cobalt phosphide catalyst on sulfamethoxazole under different chloride salt concentrations in Example 2 of the present invention. Figure 2 It can be seen that the degradation rate of sulfamethoxazole is significantly accelerated in the chloride system, and the higher the concentration, the faster the degradation rate, reflecting that sulfamethoxazole can achieve efficient degradation in high-chlorine wastewater. Subsequently, through analysis of the active substances in the high-chlorine system, Figure 3 It is known that the free chlorine produced in the reaction promotes the degradation of sulfamethoxazole. When there is no CoP / NC-5 catalyst in the system, chloride ions react with persulfate to produce free chlorine, and the yield of free chlorine increases with the increase of chloride ion concentration. When the CoP / NC-5 catalyst is added to the system, the yield of free chlorine is further increased, and some of the free chlorine participates in the degradation of sulfamethoxazole.

[0043] Figure 4 This is a graph showing the degradation effect of the porous carbon-defined cobalt phosphide catalyst on sulfamethoxazole under different sulfate concentrations in Example 2 of the present invention. Figure 4 It can be seen that the degradation of sulfamethoxazole was inhibited to some extent under the high sulfate system, and the inhibitory effect was stronger with the increase of concentration. 50 mM sulfate ions showed a slight inhibitory effect, while 300 and 600 mM sulfate ions showed stronger inhibitory effects. However, high concentrations of sulfate only inhibited the degradation rate of sulfamethoxazole but did not inhibit the degradation effect. Its degradation effect could still reach 100% removal within 7 minutes. Example 3

[0044] A method for activating sulfamethoxazole in persulfate degradation wastewater by controlling the activity of a porous carbon-defined cobalt phosphide catalyst through adjusting phosphorus content, specifically involving the treatment of sulfamethoxazole wastewater using a porous carbon-defined cobalt phosphide catalyst, comprising the following steps:

[0045] Weigh 4 mg of each of the four CoP / NC-5 catalysts from Example 1 and add them to 100 mL of a 5 mg / L sulfamethoxazole solution (0.1 mM persulfate was added to the solution simultaneously with the catalyst). Then, start the reaction on a water bath shaker, using the shaker for temperature control. The reaction temperatures for the four groups were 20°C, 30°C, 40°C, and 50°C, respectively. All reactions were carried out in 250 mL Erlenmeyer flasks; the pH of all solutions was 7.5; and the water bath shaker speed was 150 rpm.

[0046] During the reaction, 1.0 mL samples were collected at 0.5, 1, 2, 3, 4, 5, and 7 min and immediately mixed with excess sodium thiosulfate solution. The concentration of residual sulfamethoxazole was measured by high-performance liquid chromatography (HPLC). The degradation of sulfamethoxazole by persulfate activated by the porous carbon-defined cobalt phosphide catalyst at different time points was calculated. The results are as follows: Figure 5 As shown.

[0047] Figure 5 The graph shows the degradation efficiency of sulfamethoxazole using a porous carbon-defined cobalt phosphide catalyst at different temperatures and time periods in Example 3. As can be seen from the graph, temperature has a significant impact on the degradation of sulfamethoxazole. When the reaction temperature is 20°C, the reaction rate is significantly slower than in the other groups. At this temperature, the activation rate of persulfate is slower. However, the low temperature only affects the reaction process; the final degradation efficiency still reaches 100%. Although the temperatures of the other three groups differ considerably, the differences are small. Within 1 minute, the reaction rate increases with increasing temperature. In all three temperature groups, the degradation efficiency of sulfamethoxazole reaches 100% within 1 minute. Example 4

[0048] A method for activating a porous carbon-defined cobalt phosphide catalyst to degrade sulfamethoxazole in actual water bodies by controlling the activity of phosphorus content, specifically involving the treatment of sulfamethoxazole wastewater using a porous carbon-defined cobalt phosphide catalyst, comprising the following steps:

[0049] Weigh 4 mg of each of the four CoP / NC-5 catalysts from Example 1 and add them to 100 mL of actual water samples containing 1 mg / L sulfamethoxazole (0.1 mM persulfate was added to the solution simultaneously with the catalyst). Then, start the reaction in a water bath shaker. All reactions were carried out in 250 mL Erlenmeyer flasks; the pH of all solutions was 7.5; the water bath shaker speed was 150 rpm; and the water bath shaker temperature was 30℃. The actual water samples were from the Xiangjiang River and Houhu Lake. During the reaction, at 1, 2, 3, 4, 5, and 7 min, 1.0 mL of sample was collected and immediately mixed with excess sodium thiosulfate solution. The concentration of residual sulfamethoxazole was measured by high-performance liquid chromatography (HPLC). The degradation of sulfamethoxazole by the porous carbon-defined cobalt phosphide catalyst activated by persulfate at different time points was calculated. The results are as follows: Figure 6 As shown.

[0050] Figure 6 This is a graph showing the degradation effect of four porous carbon-defined cobalt phosphide catalysts on sulfamethoxazole in actual water bodies under different time conditions in Example 4. Figure 6 It can be seen that in the two actual water bodies, the degradation rate of sulfamethoxazole was lower than that in the ultrapure water system in Example 1. This is attributed to the presence of a large amount of free organic matter in the actual water body and the fact that some organic matter consumed the active substances produced by the reaction. Although the reaction rate was inhibited to some extent in the actual water body, the removal efficiency of sulfamethoxazole could still reach 100% within 3 minutes. This indicates that the porous carbon-defined cobalt phosphide catalyst has practical application prospects in the activation of persulfate to remove antibiotics from actual water bodies.

Claims

1. The application of a porous carbon-defined cobalt phosphide catalyst with activity controlled by adjusting phosphorus content in the activation of antibiotics in persulfate-degrading wastewater, characterized in that, A porous carbon-defined cobalt phosphide catalyst with controlled phosphorus content is used to oxidize antibiotics in wastewater. The porous carbon-defined cobalt phosphide catalyst comprises a graphitized carbon matrix containing cobalt phosphide nanoparticles. The antibiotic is sulfamethoxazole. The preparation method of the porous carbon-defined cobalt phosphide catalyst with controlled phosphorus content includes the following steps: S1. A stable cobalt tetroxide and carbon material composite precursor is synthesized through a first calcination, acid washing, and a second calcination. S2. A porous carbon-defined cobalt phosphide catalyst was synthesized under low-temperature conditions by doping with different amounts of phosphorus source. In step S1, the preparation of the cobalt tetroxide and carbon material composite precursor includes the following steps: (1) Dissolve 2.87 g of cobalt nitrate in 80-100 mL of methanol solution, which is called solution 1. Dissolve 6.52 g of 2-methylimidazole in 200-220 mL of methanol solution, which is called solution 2. Then quickly pour solution 1 into solution 2. After stirring vigorously at room temperature (20℃-30℃) for 12-14 h, collect the purple product by high-speed centrifugation. Wash the purple product with ultrapure water and methanol three times or more. Place it in a vacuum drying oven and dry it at 60℃-80℃ for 8-10 h to obtain a blocky purple product. (2) The blocky purple product in step (1) is ground into powder, and then placed in a tube furnace and calcined once under an argon atmosphere to obtain a black powder product; the argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate during the first calcination process is 2℃ / min~5℃ / min; the calcination temperature is 800℃~1000℃; the calcination time is 3~5 h; (3) Wash the black powder product from step (2) with 0.5 mol / L sulfuric acid to remove unstable cobalt from the surface of the material. Then wash it multiple times until the solution is neutral. Then place it in a vacuum drying oven and dry it at 60℃~80℃ for 12~16 h. The ratio of sulfuric acid to black powder product during the pickling process is 100 mL: 1 g. The temperature during the pickling process is 70℃~80℃. The pickling time is 12~14 h. (4) The product of step (3) is placed in a tube furnace and calcined twice in an air atmosphere to obtain a cobalt tetroxide and carbon material composite precursor, called Co3O4 / NC; the heating rate during the second calcination process is 2℃ / min~5℃ / min; the calcination temperature is 350℃~400℃; and the calcination time is 4~6 h. In step S2, the synthesis of porous carbon-defined cobalt phosphide catalyst includes: placing sodium hypophosphite upstream of a quartz boat, placing Co3O4 / NC downstream of the quartz boat, and then placing the quartz boat in a tube furnace for reaction under an argon atmosphere to obtain porous carbon-defined cobalt phosphide catalyst CoP / NC; the mass ratio of Co3O4 / NC to sodium hypophosphite is 1:1 to 100; the argon atmosphere is a mixed atmosphere containing argon and air; the volume fraction of argon in the argon atmosphere is 5%; the heating rate during the reaction is 2℃ / min to 5℃ / min; the reaction temperature is 300℃ to 350℃; and the reaction time is 2 to 4 h.

2. The application according to claim 1, characterized in that, The specific surface area of ​​the Co3O4 / NC is 400–500 m². 2 ·g -1 The pore size is 2–4 nm, and the particle size is 200–270 nm; the specific surface area of ​​the CoP / NC is 190–250 m². 2 ·g -1 The pore size is 2.5–5 nm, and the particle size is 210–280 nm.

3. The application according to any one of claims 1 to 2, characterized in that, The oxidation treatment of antibiotics in wastewater using a porous carbon-defined cobalt phosphide catalyst includes the following steps: mixing the porous carbon-defined cobalt phosphide catalyst with antibiotic wastewater, adding persulfate to carry out a catalytic oxidation reaction, thereby degrading the antibiotics in the wastewater.

4. The application according to claim 3, characterized in that, The amount of porous carbon-defined cobalt phosphide catalyst added is 10-100 mg per liter of antibiotic wastewater; the antibiotic wastewater is antibiotic wastewater containing high concentrations of salt or surface water containing antibiotics from different sources; the persulfate is one or both of permonosulfate and perdisulfate; the pH of the reaction system is 3-11.

5. The application according to claim 4, characterized in that, The initial concentration of antibiotics in the antibiotic wastewater is 1–100 mg / L, and the initial concentration of various salts in the wastewater is 50–600 mM; the concentration of persulfate is 0.01–3.0 mM; and the reaction temperature is 20℃–50℃.

Images