Carbon-doped bimetallic sulfide catalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of catalysts, and particularly provides a carbon-doped bimetallic sulfide catalyst which comprises a carbon carrier, and carbon-doped molybdenum disulfide and ferrous disulfide loaded on the carbon carrier, the structure of molybdenum disulfide loaded on the carbon carrier is a mixed phase of a 1T phase and a 2H phase. The catalyst disclosed by the invention has the beneficial effects that the catalyst disclosed by the invention is high in catalytic efficiency, good in stability and good in environmental protection property, and the preparation method is simple; the catalyst has better catalytic performance, can further promote wide-range application of a persulfate advanced oxidation technology in the field of treatment of refractory organic wastewater, and is huge in market and considerable in prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a carbon-doped bimetallic sulfide catalyst and a preparation method and application thereof. Background Art

[0002] Organic matter exists widely in water bodies such as urban sewage treatment plants and hospital wastewater in natural forms or as metabolites. Organic pollutants have poor biodegradability, strong persistence and biological toxicity, and can induce the production of drug-resistant bacteria. Since organic matter mainly comes from industries such as human medical care and animal husbandry, it cannot be effectively removed during large-scale discharge.

[0003] The commonly used technology for removing organic pollutants from water bodies is advanced oxidation, which mainly generates free radicals to attack the corresponding chemical bonds in organic pollutants, decompose or directly carbonize organic pollutants in water, thereby eliminating their toxicity. Commonly used advanced oxidation technologies include Fenton reaction and Fenton-like reaction, photocatalytic oxidation, ozone catalytic oxidation, persulfate catalytic oxidation, etc.

[0004] The persulfate oxidant system has a higher redox potential and a longer half-life than other oxidation systems. However, the catalysts currently used in the persulfate oxidant system are carbon and carbon-like materials that meet the requirements of sustainable development and low cost. The types of surface functional groups of such catalysts are limited, the anti-interference ability is weak, and the catalytic performance is poor. The heterogeneous reaction that relies on the active sites on the catalyst to trigger the decomposition of persulfate (PMS) and form reactive oxygen species (ROS) is inexpensive and effective, but the precipitate produced during the reaction will be deposited on the carrier surface, reducing the catalytic activity of the catalyst and causing Fe 2+ / Fe 3+ Therefore, there is a need for a persulfate oxidation system catalyst that is simple to prepare, more environmentally friendly, highly efficient, stable, and low in price. Summary of the invention

[0005] The present application provides a carbon-doped bimetallic sulfide catalyst and a preparation method and application thereof, aiming to solve the problems of the existing advanced oxidation technology in that the catalysts are expensive, have a narrow scope of application, poor reusability, low catalytic efficiency, and pollute the environment.

[0006] In a first aspect, the present application provides a carbon-doped bimetallic sulfide catalyst, which includes a carbon carrier, carbon-doped molybdenum disulfide and ferrous disulfide loaded on the carbon carrier; the structure of the molybdenum disulfide loaded on the carbon carrier is a mixed phase of 1T phase and 2H phase.

[0007] The technical effects and advantages of the carbon-doped bimetallic sulfide catalyst of the embodiment of the present application are as follows: the structure of the molybdenum disulfide is a mixed phase of 1T phase and 2H phase, and carbon doping replaces part of the S position in the molybdenum disulfide, causing the molybdenum disulfide to transform from the hexahedral 2H phase to the octahedral 1T phase, thereby improving the electron transfer ability as a whole and improving the catalytic efficiency of the catalyst.

[0008] The catalyst described in the present application can be reused, and its catalytic capacity remains basically unchanged as the number of uses increases.

[0009] The catalyst described in the present application can continuously activate the oxidant to produce two oxidizing species, free radicals and strongly oxidizing non-free radicals, and the two pathways can degrade organic pollutants in the water to the maximum extent.

[0010] According to some embodiments of the carbon-doped bimetallic sulfide catalyst described in the present application, the mass ratio of the carbon element in the carbon carrier to the molybdenum element in the molybdenum disulfide is (0.04-0.08):1.

[0011] According to some embodiments of the carbon-doped bimetallic sulfide catalyst described in the present application, the mass ratio of the carbon element in the carbon carrier to the iron element in the ferrous disulfide is (0.04-0.08):1.

[0012] According to some embodiments of the carbon-doped bimetallic sulfide catalyst described in the present application, the microscopic morphology of the carbon-doped bimetallic sulfide catalyst presents a flaky nanoflower structure.

[0013] The second aspect of the present application provides a composition for preparing the carbon-doped bimetallic sulfide catalyst of the first aspect of the present application, comprising ammonium molybdate tetrahydrate, thiourea, sodium thiosulfate pentahydrate, ferrous sulfate heptahydrate, sulfur powder and a carbon source.

[0014] According to some embodiments of the composition described herein, the carbon source includes glucose and / or ethylene glycol.

[0015] The third aspect of the present application provides a method for preparing a carbon-doped bimetallic sulfide catalyst, which is prepared using the composition described in the second aspect of the present application.

[0016] The preparation method described in the present application has a simple operation process, and no other operations are required after the hydrothermal treatment is completed.

[0017] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the method comprises the following steps: mixing ammonium molybdate tetrahydrate, thiourea, sodium thiosulfate pentahydrate, ferrous sulfate heptahydrate, sulfur powder, a carbon source and water to obtain a reaction solution, and reacting the reaction solution to obtain the carbon-doped bimetallic sulfide catalyst.

[0018] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the concentration of the ammonium molybdate tetrahydrate in the reaction solution is 48-55 g / L.

[0019] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the concentration of the thiourea in the reaction solution is 90-98 g / L.

[0020] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the concentration of the sodium thiosulfate pentahydrate in the reaction solution is 120-128 g / L.

[0021] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the concentration of the ferrous sulfate heptahydrate in the reaction solution is 130-145 g / L.

[0022] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the reaction temperature is 180-220° C., and the reaction time is 20-28 hours.

[0023] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the preparation method further comprises a cleaning treatment and a drying treatment. Preferably, the cleaning treatment is to sequentially clean the reaction product with water and ethanol.

[0024] According to some embodiments of the method for preparing the carbon-doped bimetallic sulfide catalyst described in the present application, the preparation method further comprises grinding and screening the reaction product.

[0025] The fourth aspect of the present application provides a method for removing organic matter from sewage, wherein the method is implemented under the action of the catalyst described in the first aspect of the present application or the catalyst obtained by the preparation method described in the third aspect of the present application.

[0026] The catalyst described in the present application has more active sites, can accelerate the circulation of divalent iron ions and trivalent iron ions, has high catalytic efficiency, is reusable, and is environmentally friendly.

[0027] According to some embodiments of the method for removing organic matter from sewage described in the present application, the following steps are included: mixing the catalyst, oxidant and sewage for treatment.

[0028] According to some embodiments of the method for removing organic matter in sewage described in the present application, the oxidant includes one or more of potassium persulfate, potassium peroxydisulfate and hydrogen peroxide.

[0029] According to some embodiments of the method for removing organic matter from sewage described in the present application, the amount of the catalyst added per liter of sewage is 0.05-0.4 g, preferably 0.2-0.3 g.

[0030] According to some embodiments of the method for removing organic matter from sewage described in the present application, the amount of the oxidant added per liter of sewage is 0.5-4 mmol, preferably 2-4 mmol.

[0031] According to some embodiments of the method for removing organic matter in sewage described in the present application, the initial concentration of organic matter in the sewage is 10-30 mg / L.

[0032] According to some embodiments of the method for removing organic matter from sewage described in the present application, the pH of the sewage is 3-11, preferably the pH is 3-5.

[0033] According to some embodiments of the method for removing organic matter from sewage described in the present application, the treatment temperature is 20-30° C.; the treatment time is 5-60 min.

[0034] According to some embodiments of the method for removing organic matter in sewage described in the present application, the organic matter includes one or more of ciprofloxacin, bisphenol A, rhodamine B, sulfadiazine and ofloxacin. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a SEM image of the carbon-doped bimetallic sulfide catalyst prepared in Example 1 of the present application;

[0036] Figure 2 This is the Raman spectrum of molybdenum disulfide, an active ingredient in the carbon-doped bimetallic sulfide catalyst prepared in Example 1 of the present application;

[0037] Figure 3 This is a curve diagram showing the degradation effect of potassium persulfate activated by the catalysts described in Examples 1-3 and Comparative Example 1 of the present application on organic matter in sewage;

[0038] Figure 4 This is a curve diagram showing the degradation effect of different amounts of potassium persulfate on the organic matter in sewage when the catalyst prepared in Example 1 of the present application is activated;

[0039] Figure 5 The curve diagram is a graph showing the degradation effect of different amounts of potassium persulfate activated by the catalyst obtained in Example 1 of the present application on organic matter in sewage;

[0040] Figure 6 The curve diagram is a graph showing the degradation effect of the catalyst prepared in Example 1 of the present application on the organic matter in the sewage by catalytic activation of potassium persulfate under different pH conditions;

[0041] Figure 7 This is a curve chart showing the recycling effect of the catalyst prepared in Example 1 of the present application;

[0042] Figure 8 This is a curve diagram of the degradation effect of different organic matter in sewage by catalytic activation of potassium persulfate prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0043] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0044] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0045] The embodiment of the present application provides a carbon-doped bimetallic sulfide catalyst, the catalyst comprising a carbon carrier, carbon-doped molybdenum disulfide and ferrous disulfide supported on the carbon carrier;

[0046] The structure of molybdenum disulfide supported on the carbon support is a mixed phase of 1T phase and 2H phase.

[0047] The structure of the molybdenum disulfide described in the present application is a mixed phase of 1T phase and 2H phase. When molybdenum disulfide is loaded on a carbon carrier, carbon replaces part of the S position in molybdenum disulfide, causing the molybdenum disulfide to transform from the hexahedral 2H phase to the octahedral 1T phase, thereby improving the electron transfer ability and the catalytic efficiency of the catalyst as a whole.

[0048] In some embodiments of the present application, the mass ratio of the carbon element in the carbon carrier to the molybdenum element in the molybdenum disulfide is (0.04-0.08):1; for example, 0.04:1, 0.06:1, 0.07:1, 0.08:1, etc.

[0049] In some embodiments of the present application, the mass ratio of the carbon element in the carbon carrier to the iron element in the ferrous disulfide is (0.04-0.08):1; for example, 0.04:1, 0.06:1, 0.07:1, 0.08:1, etc.

[0050] In some embodiments of the present application, the microscopic morphology of the carbon bimetallic sulfide catalyst presents a flaky nanoflower structure. Because the catalyst of the present application has a flaky nanoflower structure, it has a larger specific surface area, can provide more active sites, can adsorb more oxidants and pollutants on the catalyst surface to react, and accelerate the Fe 2+ and Fe 3+ cycle to improve catalytic efficiency.

[0051] The present application also provides a composition for preparing the carbon-doped bimetallic sulfide catalyst described in the first aspect of the present application, comprising ammonium molybdate tetrahydrate, thiourea, sodium thiosulfate pentahydrate, ferrous sulfate heptahydrate, sulfur powder and a carbon source. The preparation method described in the present application has a simple operation process, and no other operation is required after the hydrothermal process is completed.

[0052] In some embodiments of the present application, the carbon source includes glucose and / or ethylene glycol.

[0053] The present application also provides a method for preparing a carbon-doped bimetallic sulfide catalyst, which is prepared using the composition described in the second aspect of the present application.

[0054] In some embodiments of the present application, the method for preparing the carbon-doped bimetallic sulfide catalyst comprises the following steps: mixing ammonium molybdate tetrahydrate, thiourea, sodium thiosulfate pentahydrate, ferrous sulfate heptahydrate, sulfur powder, a carbon source and water to obtain a reaction solution, and reacting the reaction solution to obtain the carbon-doped bimetallic sulfide catalyst.

[0055] In some embodiments of the present application, the concentration of the ammonium molybdate tetrahydrate in the reaction solution is 48-55 g / L; for example, 48 g / L, 50 g / L, 52 g / L, 53 g / L, 55 g / L, etc.

[0056] In some embodiments of the present application, the concentration of thiourea in the reaction solution is 90-98 g / L; for example, 90 g / L, 92 g / L, 95 g / L, 97 g / L, 98 g / L, etc.

[0057] In some embodiments of the present application, the concentration of the sodium thiosulfate pentahydrate in the reaction solution is 120-128 g / L; for example, 120 g / L, 122 g / L, 125 g / L, 126 g / L, 128 g / L, etc.

[0058] In some embodiments of the present application, the concentration of ferrous sulfate heptahydrate in the reaction solution is 130-145 g / L; for example, 130 g / L, 132 g / L, 135 g / L, 138 g / L, 140 g / L, 143 g / L, 145 g / L, etc.

[0059] In some embodiments of the present application, the reaction temperature is 180-220°C, such as 180°C, 200°C, 210°C, 220°C, etc., and the reaction time is 20-28h, such as 20h, 22h, 23h, 26h, 28h, etc. Different synthesis temperatures have a greater impact on the material. The present application adopts 180-220°C, which can make the carbon element well doped with molybdenum disulfide and promote the transformation of 1T phase to 2H phase.

[0060] In some embodiments of the present application, the preparation method further includes a cleaning process and a drying process.

[0061] In some embodiments of the present application, the cleaning process is to sequentially use water and ethanol to clean the reaction product;

[0062] In some embodiments of the present application, the temperature of the drying treatment is 50-70°C, for example, 50°C, 55°C, 60°C, 65°C, 68°C, 70°C.

[0063] In some embodiments of the present application, the preparation method further comprises grinding and sieving the reaction product.

[0064] An embodiment of the present application also provides a method for removing organic matter from sewage, wherein the method is implemented under the action of the catalyst described in the first aspect of the present application or the catalyst obtained by the preparation method described in the second aspect of the present application.

[0065] The catalyst described in the present application has more active sites, can accelerate the circulation of divalent iron ions and trivalent iron ions, has high catalytic efficiency, is reusable, and is environmentally friendly.

[0066] In some embodiments of the present application, the method for removing organic matter from sewage comprises the following steps: mixing the catalyst, oxidant and sewage for treatment.

[0067] In some embodiments of the present application, the oxidant includes one or more of potassium persulfate, potassium peroxydisulfate and hydrogen peroxide.

[0068] In some embodiments of the present application, the amount of the catalyst added per liter of sewage is 0.05-0.4g, such as 0.05g, 0.08g, 0.10g, 0.12g, 0.15g, 0.18g, 0.20g, 0.25g, 0.30g, 0.36g, 0.4g. If the amount of the catalyst is too little, the reaction active sites are limited and insufficient to fully activate the oxidant to degrade organic matter. If the amount of the catalyst is too much, the iron and molybdenum in the catalyst may dissolve in the water and pollute the water.

[0069] In some embodiments of the present application, the amount of the catalyst added per liter of sewage is 0.2-0.3 g.

[0070] In some embodiments of the present application, the amount of the oxidant added per liter of sewage is 0.5-4mmol, such as 0.5mmol, 0.8mmol, 1.0mmol, 1.6mmol, 1.9mmol, 2.0mmol, 2.3mmol, 2.6mmol, 2.9mmol, 3.1mmol, 3.8mmol, 4mmol. If the amount is too little, the organic pollutants cannot be fully degraded, and if the amount is too much, it will cause a waste of resources.

[0071] In some embodiments of the present application, the amount of the oxidant added per liter of sewage is 2-4 mmol.

[0072] In some embodiments of the present application, the initial concentration of organic matter in the sewage is 10-30 mg / L, for example, 10 mg / L, 15 mg / L, 18 mg / L, 20 mg / L, 26 mg / L, 29 mg / L, 30 mg / L, etc.

[0073] In some embodiments of the present application, the pH of the sewage is 3-11, for example, pH 3, pH 5, pH 6, pH 7, pH 9, pH 11, etc., preferably pH 3-5.

[0074] In some embodiments of the present application, the treatment temperature is 20-30°C, for example, 20°C, 22°C, 25°C, 28°C, 30°C, etc., and the treatment time is 5-60min, for example, 5min, 8min, 10min, 16min, 20min, 25min, 28min, 30min, 36min, 40min, 46min, 50min, 52min, 58min, 60min, etc.

[0075] In some embodiments of the present application, the organic matter includes one or more of ciprofloxacin, bisphenol A, rhodamine B, sulfadiazine and ofloxacin.

[0076] The technical solution of the present application is described in detail below in conjunction with specific embodiments and drawings.

[0077] Example 1

[0078] A method for preparing a carbon-doped bimetallic sulfide catalyst comprises the following steps:

[0079] 1.023 g of ammonium molybdate tetrahydrate and 1.886 g of thiourea were dissolved in 20 g of ultrapure water to obtain solution A; 2.4818 g of sodium thiosulfate pentahydrate, 2.7802 g of ferrous sulfate heptahydrate and 0.3207 g of sulfur powder were dissolved in 20 g of ultrapure water to obtain solution B; solution A, solution B and 0.08367 g of glucose were mixed to obtain a mixed solution; the mixed solution was added into a reactor, reacted at a reaction temperature of 200° C. for 24 hours, and the reaction product was washed with ultrapure water and ethanol in turn, and the washed reaction product was vacuum dried at a drying temperature of 60° C. to obtain a carbon-doped bimetallic sulfide catalyst.

[0080] The SEM image of the carbon-doped bimetallic sulfide catalyst prepared in Example 1 is as follows: Figure 1 shown.

[0081] from Figure 1 It can be seen that the microscopic morphology of the carbon-doped bimetallic sulfide catalyst described in Example 1 of the present application presents a flaky nanoflower structure.

[0082] The Raman spectrum of the active ingredient molybdenum disulfide in the catalyst prepared in Example 1 is as follows: Figure 2 As shown:

[0083] from Figure 2 It can be seen that the molybdenum disulfide in the catalyst includes 1T phase and 2H phase.

[0084] Example 2

[0085] The difference between Example 2 and Example 1 is that the amount of glucose added is different.

[0086] The specific operations are:

[0087] A method for preparing a carbon-doped bimetallic sulfide catalyst comprises the following steps:

[0088] 1.023 g of ammonium molybdate tetrahydrate and 1.886 g of thiourea were dissolved in 20 g of ultrapure water to obtain solution A; 2.4818 g of sodium thiosulfate pentahydrate, 2.7802 g of ferrous sulfate heptahydrate and 0.3207 g of sulfur powder were dissolved in 20 g of ultrapure water to obtain solution B; solution A, solution B and 0.09075 g of glucose were mixed to obtain a mixed solution; the mixed solution was added into a reactor, reacted at a reaction temperature of 200° C. for 24 hours, and the reaction product was washed with ultrapure water and ethanol in turn, and the washed reaction product was vacuum dried at a drying temperature of 60° C. to obtain a carbon-doped bimetallic sulfide catalyst.

[0089] Example 3

[0090] The difference between Example 3 and Example 1 is that the amount of glucose added is different.

[0091] The specific operations are:

[0092] A method for preparing a carbon-doped bimetallic sulfide catalyst comprises the following steps:

[0093] 1.023 g of ammonium molybdate tetrahydrate and 1.886 g of thiourea were dissolved in 20 g of ultrapure water to obtain solution A; 2.4818 g of sodium thiosulfate pentahydrate, 2.7802 g of ferrous sulfate heptahydrate and 0.3207 g of sulfur powder were dissolved in 20 g of ultrapure water to obtain solution B; solution A, solution B and 0.11156 g of glucose were mixed to obtain a mixed solution; the mixed solution was added into a reactor, reacted at a reaction temperature of 200° C. for 24 hours, and the reaction product was washed with ultrapure water and ethanol in turn, and the washed reaction product was vacuum dried at a drying temperature of 60° C. to obtain a carbon-doped bimetallic sulfide catalyst.

[0094] Comparative Example 1

[0095] The only difference between Comparative Example 1 and Example 1 is that no glucose is added to the preparation raw materials.

[0096] The specific operations are:

[0097] A method for preparing a bimetallic sulfide catalyst comprises the following steps:

[0098] 1.023 g of ammonium molybdate tetrahydrate and 1.886 g of thiourea were dissolved in 20 g of ultrapure water to obtain solution A; 2.4818 g of sodium thiosulfate pentahydrate, 2.7802 g of ferrous sulfate heptahydrate and 0.3207 g of sulfur powder were dissolved in 20 g of ultrapure water to obtain solution B; solution A and solution B were mixed to obtain a mixed solution; the mixed solution was added into a reactor, reacted at a reaction temperature of 200° C. for 24 hours, and then the reaction product was washed with ultrapure water and ethanol in turn, and the washed reaction product was vacuum dried at a drying temperature of 60° C. to obtain a bimetallic sulfide catalyst.

[0099] 1. Study on the catalytic performance of the catalysts described in Examples 1-3 and Comparative Example 1 of the present application:

[0100] Experimental method: The catalysts described in Examples 1-3 of the present application and the catalyst described in Comparative Example 1 were added to the same sewage with a pH value of 6.5 and an initial concentration of organic pollutants of 30 mg / L (calculated as ciprofloxacin organic pollutants) with potassium persulfate, and the organic pollutants were degraded at a temperature of 25°C, stirred at a stirring speed of 150 r / min for 0-60 min, and the concentration of organic pollutants (calculated as ciprofloxacin organic pollutants) in each sewage was detected using a high performance liquid chromatograph (Shimadzu LC-20A, Japan); the amount of catalyst added to each liter of sewage was 0.2 g, and the amount of potassium persulfate added to each liter of sewage was 3 mmol. The test results are as follows: Figure 3 shown.

[0101] Figure 3 The Ct / C0 on the vertical axis is the ratio of the residual concentration of organic pollutants in the sewage to the original concentration.

[0102] from Figure 3 It can be seen that the catalyst prepared in the example of the present application has a better catalytic effect and a higher catalytic efficiency than the catalyst prepared in comparative example 1. The catalyst prepared in the example of the present application catalytically activated persulfate reduced the concentration of ciprofloxacin in sewage from 30 mg / L to 0 mg / L within 30 minutes, while the catalyst prepared in comparative example 1 catalytically activated persulfate reduced the concentration of ciprofloxacin in sewage from 30 mg / L to only 15.6 mg / L within 60 minutes.

[0103] 2. Effect of different amounts of persulfate added on the catalytic degradation of ciprofloxacin in wastewater:

[0104] Experimental method: The catalyst described in Example 1 of the present application and different amounts of potassium persulfate were added to the same sewage with a pH value of 6.5 and an initial concentration of organic pollutants of 30 mg / L (calculated as ciprofloxacin organic pollutants), and the organic pollutants were degraded at a temperature of 25°C, stirred at a stirring speed of 150 r / min for 0-60 min, and the concentration of organic pollutants (calculated as ciprofloxacin organic pollutants) in each sewage was detected using a high performance liquid chromatograph; the amount of catalyst added to each liter of sewage was 0.2 g, and the amount of potassium persulfate added to each liter of sewage was 0.5 mmol, 1 mmol, 2 mmol, 3 mmol, and 4 mmol, respectively. The test results are as follows: Figure 4 shown.

[0105] Remark: Figure 4 The Ct / C0 on the vertical axis is the ratio of the residual concentration of organic pollutants in the sewage to the original concentration.

[0106] from Figure 4It can be seen that: when the addition amount of potassium persulfate is 0.5mmol / L-4mmol / L, the catalyst described in Example 1 of the present application can effectively activate the potassium persulfate oxidant to degrade the target pollutant, and the more potassium persulfate is added, the higher the activation efficiency is. However, when the addition amount of potassium persulfate reaches 3mmol / L, the activation effect remains basically unchanged even if the addition amount of the oxidant is increased.

[0107] 3. Effects of different amounts of the catalyst added on the catalytic activation of potassium persulfate to degrade ciprofloxacin in wastewater:

[0108] Experimental method: Different amounts of the catalyst described in Example 1 of the present application and potassium persulfate were added to the same sewage with a pH value of 6.5 and an initial concentration of organic pollutants of 30 mg / L (calculated as ciprofloxacin organic pollutants). The organic pollutants were degraded at 25°C, and after stirring at a stirring speed of 150 r / min for 0-60 min, the concentration of organic pollutants (calculated as ciprofloxacin organic pollutants) in each sewage was detected using a high performance liquid chromatograph; the amount of catalyst added per liter of sewage was 0.05 g, 0.1 g, 0.2 g, 0.3 g, and 0.4 g, respectively, and the amount of potassium persulfate added per liter of sewage was 3 mmol. The test results are as follows: Figure 5 shown.

[0109] from Figure 5 It can be seen that when the addition amount of the catalyst is 0.05-0.4 g / L, the catalyst described in Example 1 of the present application can effectively activate the potassium persulfate oxidant to degrade the target pollutants, and the activation efficiency increases with the increase in the addition amount. Considering factors such as cost and activation efficiency, it can be seen that the performance is best when the addition amount of the catalyst is 0.2 g / L.

[0110] 4. Effect of pH on the catalytic activation of potassium persulfate to degrade ciprofloxacin in sewage:

[0111] Experimental method: The catalyst and potassium persulfate described in Example 1 of the present application were added to sewage with pH values ​​of 3, 5, 6.5, 9, and 11, respectively, and an initial concentration of organic pollutants of 30 mg / L (calculated as ciprofloxacin organic pollutants), and the organic pollutants were degraded at 25° C., stirred at a stirring speed of 150 r / min for 0-60 min, and the concentration of organic pollutants (calculated as ciprofloxacin organic pollutants) in each sewage was detected by high performance liquid chromatography; the test results are as follows: Figure 6 shown.

[0112] Figure 6 The Ct / C0 on the vertical axis is the ratio of the residual concentration of organic pollutants in the sewage to the original concentration.

[0113] from Figure 6It can be seen that within the pH range of 3-11, the catalyst described in Example 1 of the present application can effectively activate potassium persulfate oxidant to degrade the target pollutant, and the pH value has a certain influence on the activation efficiency of the catalyst. The degradation efficiency of the system on the target pollutant can be enhanced in an acidic environment, but there will be a certain inhibitory effect under overacid conditions, and from Figure 6 It can be seen that the degradation effect is better when pH = 5.

[0114] 5. Study on the Cyclic Performance of the Catalyst Described in the Application:

[0115] Experimental method: The catalyst and potassium persulfate described in Example 1 of the present application are added to sewage with a pH value of 6.5 and an initial concentration of organic pollutants of 30 mg / L (calculated as ciprofloxacin organic pollutants), and the organic pollutants are degraded at 25°C, stirred at a stirring speed of 150 r / min for 0-60 min, and the concentration of organic pollutants in the sewage (calculated as ciprofloxacin organic pollutants) is detected using a high performance liquid chromatograph (the result is recorded as 1st), and the catalyst is recovered, and the recovered catalyst is repeated with the above-mentioned catalytic activation of potassium persulfate to degrade organic matter in the sewage, and the concentration of organic pollutants in the sewage after degradation is detected (the result is recorded as 2nd), and the catalyst is recovered and repeated with the above-mentioned operation, and the concentration of organic pollutants in the sewage after degradation is detected (the result is recorded as 3rd); the test results are statistically shown as follows Figure 7 shown.

[0116] Figure 7 The Ct / C0 on the vertical axis is the ratio of the residual concentration of organic pollutants in the sewage to the original concentration.

[0117] from Figure 7 It can be seen that: with the increase in the number of times the catalyst is recycled, the reuse effect of the catalyst is sometimes better than that of the first use. With the increase in the number of times the catalyst is recycled, the catalytic activation performance of the catalyst does not show a significant decrease. After being reused 3 times, the catalyst still has good catalytic activation efficiency, that is, the catalyst described in this application has good recyclability.

[0118] 6. Study on the efficiency of the catalyst described in this application in catalyzing the activation of potassium persulfate to degrade different organic pollutants in sewage:

[0119] Experimental method: The catalyst and potassium persulfate described in Example 1 of the present application were added to sewage with a pH value of 6.5 and an initial concentration of organic pollutants of 30 mg / L, and the organic pollutants were degraded at 25°C. After stirring at a stirring speed of 150 r / min for 0-60 min, the concentrations of ciprofloxacin, ofloxacin and sulfadiazine were detected using a high performance liquid chromatograph (Shimadzu LC-20A, Japan), and the concentration of rhodamine B was detected using an ultraviolet spectrophotometer (TU-1901) at a wavelength of 554 nm. The test results are as follows: Figure 8 shown.

[0120] Figure 8 The Ct / C0 on the vertical axis is the ratio of the residual concentration of organic pollutants in the sewage to the original concentration.

[0121] from Figure 8 It can be seen that the catalyst described in the present application can catalyze and activate persulfate to degrade different types of organic pollutants (such as ciprofloxacin, rhodamine B, sulfadiazine and ofloxacin), and the removal rate of each pollutant is more than 94%.

[0122] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A carbon-doped bimetallic sulfide catalyst, characterized in that: The catalyst comprises a carbon carrier, carbon-doped molybdenum disulfide and ferrous disulfide supported on the carbon carrier; The structure of molybdenum disulfide supported on the carbon support is a mixed phase of 1T phase and 2H phase.

2. The carbon-doped bimetallic sulfide catalyst according to claim 1, characterized in that: The mass ratio of the carbon element in the carbon carrier to the molybdenum element in the molybdenum disulfide is (0.04-0.08): 1; And / or, the mass ratio of the carbon element in the carbon carrier to the iron element in the ferrous disulfide is (0.04-0.08):1; And / or, the microscopic morphology of the carbon-doped bimetallic sulfide catalyst presents a flaky nanoflower structure.

3. A composition for preparing the carbon-doped bimetallic sulfide catalyst according to claim 1 or 2, characterized in that: The invention comprises ammonium molybdate tetrahydrate, thiourea, sodium thiosulfate pentahydrate, ferrous sulfate heptahydrate, sulfur powder and a carbon source; And / or, the carbon source comprises glucose and / or ethylene glycol.

4. A method for preparing a carbon-doped bimetallic sulfide catalyst, characterized in that: The composition according to claim 3 is used for preparation.

5. The method for preparing the carbon-doped bimetallic sulfide catalyst according to claim 4, characterized in that: The following steps are involved: ammonium molybdate tetrahydrate, thiourea, sodium thiosulfate pentahydrate, ferrous sulfate heptahydrate, sulfur powder, a carbon source and water are mixed to obtain a reaction solution, and the reaction solution is reacted to obtain the carbon-doped bimetallic sulfide catalyst; Preferably, the concentration of the ammonium molybdate tetrahydrate in the reaction solution is 48-55 g / L; Preferably, the concentration of thiourea in the reaction solution is 90-98 g / L; Preferably, the concentration of the sodium thiosulfate pentahydrate in the reaction solution is 120-128 g / L; Preferably, the concentration of the ferrous sulfate heptahydrate in the reaction solution is 130-145 g / L.

6. The method for preparing the carbon-doped bimetallic sulfide catalyst according to claim 4 or 5, characterized in that: The reaction temperature is 180-220°C, and the reaction time is 20-28h; And / or, the preparation method further comprises a cleaning process and a drying process, preferably, the cleaning process is to sequentially clean the reaction product with water and ethanol; And / or, the preparation method further comprises grinding and sieving the reaction product.

7. A method for removing organic matter from sewage, characterized in that: The method is carried out under the action of the catalyst described in any one of claims 1 to 2 of the present application or the catalyst obtained by the preparation method described in any one of claims 4 to 6.

8. The method for removing organic matter from sewage according to claim 7, characterized in that: The method comprises the following steps: mixing the catalyst, oxidant and sewage for treatment; Preferably, the oxidant comprises one or more of potassium persulfate, potassium peroxydisulfate and hydrogen peroxide; Preferably, the amount of the catalyst added per liter of sewage is 0.05-0.4 g, preferably 0.2-0.3 g; Preferably, the amount of the oxidant added per liter of sewage is 0.5-4 mmol, preferably 2-4 mmol.

9. The method for removing organic matter from sewage according to claim 7 or 8, characterized in that: The initial concentration of organic matter in the sewage is 10-30 mg / L; And / or, the pH of the sewage is 3-11, preferably 3-5; And / or, the treatment temperature is 20-30°C; the treatment time is 5-60min.

10. The method for removing organic matter from sewage according to claim 7 or 8, characterized in that: The organic matter includes one or more of ciprofloxacin, bisphenol A, rhodamine B, sulfadiazine and ofloxacin.

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