A Co-doped C3N4 composite material, its preparation method and application

Abstract

This invention relates to the fields of composite material synthesis and water treatment technology, and discloses a Co-doped C3N4 composite material, its preparation method, and its application. The method includes: (1) dissolving cobalt salt and urea in ultrapure water, stirring, and sonicating for 10-15 min to obtain solution I; (2) adding melamine to ultrapure water, stirring, to obtain solution II; (3) adding solution I to solution II, stirring, and transferring to a reaction vessel, heating at 178-182℃ for 24-24.5 h, allowing the reaction vessel to cool naturally, and collecting the precipitate; (4) washing the precipitate sequentially with anhydrous ethanol and deionized water, centrifuging, and collecting the solid; (5) drying the solid at 68-72℃ until its mass no longer changes; (6) placing the solid in a crucible, heating at 550℃ for 2 h to obtain the composite material. The method of this invention can effectively degrade antibiotic resistance genes and is used to treat wastewater containing antibiotic resistance genes.

Description

Technical Field

[0001] This invention relates to the fields of composite material synthesis and water treatment technology, specifically to a Co-doped C3N4 composite material, its preparation method, and its application. Background Technology

[0002] The widespread use of antibiotics has led to the emergence of antibiotic-resistant bacteria in the environment. These bacteria carry antibiotic resistance genes, which have become a new type of pollutant. Advanced oxidation methods can effectively remove antibiotic resistance genes from water bodies, ensuring water safety and human health.

[0003] C3N4 is a non-metallic material with good thermal and water stability. However, C3N4 has a small specific surface area, and its effect on pollutant treatment is not good when used alone. C3N4 can be modified by metal ion doping, vacancy defects, etc., to increase the material's reaction sites and improve its adsorption and catalytic degradation performance of pollutants.

[0004] Co, as a transition metal, exhibits high catalytic efficiency for PMS. When Co compounds are used to activate PMS, Co is present... 2+ The issue of leaching leads to secondary pollution while degrading pollutants. C3N4 is a non-metallic material lacking metal catalytic active sites. Doping C3N4 with Co allows it to serve as a metal element support, leveraging Co's ability to activate PMS for efficient pollutant degradation. Simultaneously, Co can be anchored to the C3N4 support, reducing metal ion leaching during PMS activation.

[0005] By doping Co onto C3N4, the unique properties of Co can increase the number of reactive metal sites, improve the catalytic performance of the material, and increase the reaction rate.

[0006] Therefore, how to load Co into C3N4 to prepare composite materials and study their removal performance of typical antibiotic resistance genes in water is a technical problem worth studying. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and solve the problem of poor tetracycline removal effect using existing C3N4 materials. This invention provides a Co-doped C3N4 composite material and its preparation method, and applies it to the removal of wastewater containing antibiotic resistance genes.

[0008] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a Co-doped C3N4 composite material, the method comprising the following steps:

[0009] (1) Dissolve cobalt salt and urea in ultrapure water, stir, and sonicate for 10-15 min to obtain solution I;

[0010] (2) Melamine was added to ultrapure water and stirred to obtain solution II;

[0011] (3) Add solution I to solution II, stir, and transfer to a reaction vessel. Heat at 178-182°C for 24-24.5 h, and allow the reaction vessel to cool naturally. Take the precipitate.

[0012] (4) Wash the precipitate with anhydrous ethanol and deionized water in sequence, centrifuge to separate the solid;

[0013] (5) Place the solid at 68-72°C and bake until its mass no longer changes;

[0014] (6) Place the solid in a crucible and heat at 550°C for 2 hours to obtain the composite material.

[0015] Preferably, in step (1), the cobalt salt is hydrated cobalt chloride, and more preferably, the cobalt salt is CoCl2·6H2O.

[0016] More preferably, in step (1), the amount of cobalt salt used is 1 to 20 mg.

[0017] Preferably, in step (1), the amount of urea used is 8g.

[0018] In a preferred embodiment, in step (1), the amount of ultrapure water used is 35 mL.

[0019] Preferably, in step (1), the stirring conditions are: room temperature, a rotation speed of 380-420 rpm, and a stirring time of 10-15 min.

[0020] More preferably, in step (1), the conditions for ultrasound also include: the ultrasound frequency is 40KHz.

[0021] Preferably, in step (2), the amount of melamine used is 6g.

[0022] Preferably, in step (2), the amount of ultrapure water used is 35 mL.

[0023] Preferably, in step (2), the stirring conditions are: a rotation speed of 400 rpm and a time of 15 min.

[0024] Preferably, in step (3), the stirring conditions are: time 30 min.

[0025] A second aspect of the present invention provides a Co-doped C3N4 composite material prepared by the method described in the first aspect of the present invention.

[0026] A third aspect of the present invention provides the application of the Co-doped C3N4 composite material described in the second aspect of the present invention in the treatment of wastewater containing antibiotic resistance genes.

[0027] The composite material provided by this invention also has at least the following beneficial effects:

[0028] (1) The composite material provided by the present invention can achieve efficient removal of antibiotic resistance genes, an emerging pollutant, from water bodies.

[0029] (2) The composite material provided by the present invention can achieve efficient removal of resistance genes of different types of antibiotics in water. Attached Figure Description

[0030] Figure 1 These are graphs showing the degradation effect of composite materials with different amounts of CoCl2·6H2O on tetW;

[0031] Figure 2 This is a graph showing the degradation effect of Co0.02 / C3N4 on different antibiotic resistance genes. Detailed Implementation

[0032] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0033] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, the raw materials are all commercially available products.

[0034] Example 1

[0035] A method for preparing a Co-doped C3N4 composite material, the method comprising the following steps:

[0036] (1) Weigh 8g of urea and dissolve it in 35mL of ultrapure water. Then add 20mg of CoCl2·6H2O, stir and dissolve at room temperature, and then place it in an ultrasonic cleaner and sonicate at 40KHz for 10min to obtain solution I.

[0037] (2) Weigh 6g of melamine into 35mL of ultrapure water and stir magnetically at 400rpm for 15min to obtain solution II;

[0038] (3) Add solution I to solution II, stir for 30 min, transfer to a 100 mL reaction vessel, heat at 180 °C for 24 h, allow the reaction vessel to cool naturally, and take the precipitate;

[0039] (4) Wash the precipitate with anhydrous ethanol and deionized water in sequence, centrifuge to separate the solid;

[0040] (5) The solid is dried at 70°C until its mass no longer changes, to obtain solid powder;

[0041] (6) The solid was placed in a crucible and heated at 550°C for 2 hours to obtain the composite material, which was denoted as Co0.02 / C3N4.

[0042] Example 2

[0043] (1) Weigh 8g of urea and dissolve it in 35mL of ultrapure water, then add 1mg of CoCl2·6H2O, stir and dissolve at room temperature, then place it in an ultrasonic cleaner and sonicate at 40KHz for 10min to obtain solution I;

[0044] (2) Weigh 6g of melamine into 35mL of ultrapure water and stir magnetically at 400rpm for 15min to obtain solution II;

[0045] (3) Add solution I to solution II, stir for 30 min, transfer to a 100 mL reaction vessel, heat at 180 °C for 24 h, allow the reaction vessel to cool naturally, and take the precipitate;

[0046] (4) Wash the precipitate with anhydrous ethanol and deionized water in sequence, centrifuge to separate the solid;

[0047] (5) The solid is dried at 70°C until its mass no longer changes, to obtain solid powder;

[0048] (6) The solid was placed in a crucible and heated at 550°C for 2 hours to obtain the composite material, which was denoted as Co0.001 / C3N4.

[0049] Example 3

[0050] (1) Weigh 8g of urea and dissolve it in 35mL of ultrapure water, then add 5mg of CoCl2·6H2O, stir and dissolve at room temperature, then place it in an ultrasonic cleaner and sonicate at 40KHz for 10min to obtain solution I.

[0051] (2) Weigh 6g of melamine into 35mL of ultrapure water and stir magnetically at 400rpm for 15min to obtain solution II;

[0052] (3) Add solution I to solution II, stir for 30 min, transfer to a 100 mL reaction vessel, heat at 180 °C for 24 h, allow the reaction vessel to cool naturally, and take the precipitate;

[0053] (4) Wash the precipitate with anhydrous ethanol and deionized water in sequence, centrifuge to separate the solid;

[0054] (5) The solid is dried at 70°C until its mass no longer changes, to obtain solid powder;

[0055] (6) The solid was placed in a crucible and heated at 550°C for 2 hours to obtain the composite material, which was denoted as Co0.005 / C3N4.

[0056] Example 4

[0057] (1) Weigh 8g of urea and dissolve it in 35mL of ultrapure water, then add 10mg of CoCl2·6H2O, stir and dissolve at room temperature, then place it in an ultrasonic cleaner and sonicate at 40KHz for 10min to obtain solution I;

[0058] (2) Weigh 6g of melamine into 35mL of ultrapure water and stir magnetically at 400rpm for 15min to obtain solution II;

[0059] (3) Add solution I to solution II, stir for 30 min, transfer to a 100 mL reaction vessel, heat at 180 °C for 24 h, allow the reaction vessel to cool naturally, and take the precipitate;

[0060] (4) Wash the precipitate with anhydrous ethanol and deionized water in sequence, centrifuge to separate the solid;

[0061] (5) The solid is dried at 70°C until its mass no longer changes, to obtain solid powder;

[0062] (6) The solid was placed in a crucible and heated at 550°C for 2 hours to obtain the composite material, which was denoted as Co0.01 / C3N4.

[0063] Example 5

[0064] (1) Weigh 8g of urea and dissolve it in 35mL of ultrapure water. Then add 15mg of CoCl2·6H2O, stir and dissolve at room temperature, and then place it in an ultrasonic cleaner and sonicate at 40KHz for 10min to obtain solution I.

[0065] (2) Weigh 6g of melamine into 35mL of ultrapure water and stir magnetically at 400rpm for 15min to obtain solution II;

[0066] (3) Add solution I to solution II, stir for 30 min, transfer to a 100 mL reaction vessel, heat at 180 °C for 24 h, allow the reaction vessel to cool naturally, and take the precipitate;

[0067] (4) Wash the precipitate with anhydrous ethanol and deionized water in sequence, centrifuge to separate the solid;

[0068] (5) The solid is dried at 70°C until its mass no longer changes, to obtain solid powder;

[0069] (6) The solid was placed in a crucible and heated at 550°C for 2 hours to obtain the composite material, which was denoted as Co0.015 / C3N4.

[0070] Comparative Example 1

[0071] A method for preparing C3N4 material includes the following steps:

[0072] (1) Weigh 8g of urea and dissolve it in 35mL of ultrapure water. Stir to dissolve, then place it in an ultrasonic cleaner and sonicate for 10min to obtain solution I.

[0073] (2) Weigh 6g of melamine into 35mL of ultrapure water and stir magnetically at 400rpm for 15min to obtain solution II;

[0074] (3) Transfer the solutions I and II to a 100 mL reactor, heat at 180 °C for 24 h, and allow the reactor to cool naturally. Take the precipitate, wash it with anhydrous ethanol and deionized water in sequence, centrifuge it, and place the obtained solid at 70 °C until its mass no longer changes to obtain solid powder.

[0075] (6) The solid was placed in a crucible and heated at 550°C for 2 hours to obtain C3N4.

[0076] Application Example 1

[0077] The Co-doped C3N4 composite materials obtained in Comparative Example 1 and the embodiments of the present invention were used to degrade antibiotic resistance genes to obtain... Figure 1 and Figure 2 The results are shown.

[0078] Specifically, first prepare a solution with a concentration of ~10. 10The antibiotic resistance gene solution was prepared in copies / mL. 5 mL of the antibiotic resistance gene solution was placed in a 25 mL beaker, and 2.5 mg of C3N4 or the Co-doped C3N4 composite material obtained in this invention was added. The beaker was then transferred to a magnetic stirrer and stirred at room temperature and 400 rpm for 30 min. 1 mmol / L PMS was then added, and 200 μL of the solution was taken at regular intervals and transferred to centrifuge tubes. 7 μL of 20 g / L Na2S2O3 solution (quencher) was added, and the concentration of the antibiotic resistance gene was determined using real-time quantitative PCR.

[0079] Depend on Figure 1 It can be seen that for ~10 10 With increasing Co doping concentration, the antibiotic resistance gene treatment effect of the resulting composite material improved. Specifically, the removal efficiencies of C3N4, Co0.001 / C3N4, Co0.005 / C3N4, Co0.01 / C3N4, Co0.015 / C3N4, and Co0.02 / C3N4 for tetW were 2.41 log, 2.56 log, 2.94 log, 2.98 log, 3.24 log, and 6.67 log, respectively.

[0080] Depend on Figure 2 It can be seen that the Co0.02 / C3N4 obtained in the embodiments of the present invention has a high removal efficiency for antibiotic resistance genes sul1, TEM-1, qnrS, and tetW.

[0081] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a Co-doped C3N4 composite material for treating wastewater containing antibiotic resistance genes, characterized in that, The method includes the following steps: (1) Dissolve cobalt salt and urea in ultrapure water, stir, and sonicate for 10-15 min to obtain solution I; (2) Melamine was added to ultrapure water and stirred to obtain solution II; (3) Add solution I to solution II, stir, and transfer to a reaction vessel. Heat at 178~182℃ for 24~24.5h, and allow the reaction vessel to cool naturally. Take the precipitate. (4) Wash the precipitate with anhydrous ethanol and deionized water in sequence, centrifuge to separate the solid; (5) Place the solid at 68~72℃ and bake until its mass no longer changes; (6) Place the solid in a crucible and heat at 550°C for 2 hours to obtain the composite material; The cobalt salt is CoCl2 •6H2O; And / or, in step (1), the amount of the cobalt salt used is 1~20 mg; In step (1), the amount of urea used is 8g; And / or, in step (1), the amount of ultrapure water used is 35 mL; In step (2), the amount of melamine used is 6g; And / or, in step (2), the amount of ultrapure water used is 35 mL; The application of the Co-doped C3N4 composite material in the treatment of wastewater containing antibiotic resistance genes.

2. The method according to claim 1, characterized in that, In step (1), the stirring conditions are: room temperature, a rotation speed of 380~420 rpm, and a time of 10~15 min.

3. The method according to claim 1 or 2, characterized in that, In step (1), the conditions for ultrasound also include: the ultrasound frequency is 40KHz.

4. The method according to claim 1 or 2, characterized in that, In step (2), the stirring conditions are: a rotation speed of 400 rpm and a time of 15 min.

5. The method according to claim 1 or 2, characterized in that, In step (3), the stirring conditions are satisfied: time 30 min.

6. The Co-doped C3N4 composite material prepared by the method according to any one of claims 1-5.

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