A molybdenum sulfide coupled biomass water purification catalyst, preparation method and application thereof

Abstract

The application belongs to the technical field of water treatment catalyst preparation, and specifically discloses a water purification catalyst of molybdenum sulfide coupled with biomass, a preparation method and application, and comprises the following steps: S1, dispersing a molybdenum source and a sulfur source in deionized water, stirring, and obtaining a mixed solution; S2, adding a nitrogen source into the mixed solution in proportion, stirring, adding biomass, stirring, pouring into a reaction kettle, and obtaining a reactant B; S3, performing hydrothermal treatment on the reaction kettle containing the reactant B, naturally cooling to room temperature, taking out a solid product, washing, drying, and obtaining a product A; and S4, placing the product A in a quartz capsule, performing calcination treatment, taking out a black solid, grinding, and obtaining a MoS2CNS Fenton catalyst. The water purification catalyst of molybdenum sulfide coupled with biomass, the preparation method and the application are used, effective utilization of resources is realized, the solid catalyst is convenient to separate from water, recycle and utilize, and a high organic matter removal effect is maintained.

Description

Technical Field

[0001] This invention relates to the field of water treatment catalyst preparation technology, and in particular to a molybdenum sulfide coupled biomass water purification catalyst, its preparation method, and its application. Background Technology

[0002] Freshwater resources in all regions are polluted to varying degrees, and some people still drink shallow water, river water, and deep well groundwater. The proportion of these types of water meeting the standards for high-quality, good, and relatively good water is low, and there are currently problems with water pollution and bacteria exceeding hygiene standards. In particular, the proportion of water contaminated with organic matter is increasing year by year, threatening people's health and safety.

[0003] Therefore, it is urgent to develop inexpensive and effective technologies and methods for removing such organic pollutants. Summary of the Invention

[0004] The purpose of this invention is to provide a molybdenum sulfide-coupled biomass water purification catalyst, its preparation method, and its application, so as to achieve effective utilization of resources. The solid catalyst is easy to separate from water, recycle, and maintain a high organic matter removal efficiency.

[0005] To achieve the above objectives, the present invention provides a method for preparing a molybdenum sulfide-coupled biomass water purification catalyst, comprising the following steps:

[0006] S1. Disperse the molybdenum source and sulfur source in deionized water according to the proportion, stir, and obtain a mixed solution;

[0007] S2. Add the nitrogen source to the mixture obtained in S1 according to the proportion, stir, then add biomass, stir, pour into the reactor, and obtain reactant B.

[0008] S3. The reaction vessel containing reactant B obtained in S2 is subjected to hydrothermal treatment, naturally cooled to room temperature, the solid product is taken out, washed, and dried to obtain product A.

[0009] S4. Place the product A obtained in S3 in a quartz jar and calcine it. Remove the black solid, grind it, and obtain the MoS2CNS Fenton catalyst.

[0010] Preferably, in S1, the molybdenum source is one or more of sodium molybdate, ammonium molybdate, and phosphomolybdic acid;

[0011] The sulfur source is one or more of thiourea, cyanuric acid, sodium sulfide, and elemental sulfur;

[0012] The ratio of the molybdenum source, the sulfur source, and the deionized water is 1 mM: 2~5 mM: 50 mL.

[0013] Preferably, the molybdenum source is sodium molybdate, and the sulfur source is thiourea, with a mass ratio of sodium molybdate:thiourea = 1:2~5.

[0014] Preferably, in S1, the stirring time is 15 minutes.

[0015] Preferably, in S2, the nitrogen source is one or more of urea, melamine, and thiourea;

[0016] The biomass is one or more of the following: silkworm excrement, corn cob, garlic stalks, and cow dung;

[0017] The mass ratio of the nitrogen source to the biomass is 2~6:1.

[0018] Preferably, the nitrogen source is urea, and the biomass is corn cob, with a mass ratio of urea:corn cob = 3~6:1.

[0019] Preferably, in S2, the stirring time is 30 minutes.

[0020] Preferably, in S3, the hydrothermal treatment specifically includes:

[0021] Heat in a forced-air drying oven at 150-300℃ for 6-30 hours.

[0022] Preferably, in step S3, the washing process specifically involves alternating between deionized water and ethanol three times.

[0023] Preferably, in step S3, the drying process uses a forced-air drying oven, with a drying time of 24 hours and a drying temperature of 60°C.

[0024] Preferably, in S4, the calcination treatment specifically includes:

[0025] Under the conditions of a tube furnace and nitrogen purging, the heating rate is 3-5℃ / min, the calcination temperature is 300-900℃, and the calcination time is 0.5-3h.

[0026] Preferably, the calcination treatment specifically includes:

[0027] Under the conditions of a tube furnace and nitrogen purging, the heating rate was 5℃ / min, the calcination temperature was 800℃, and the calcination time was 2h.

[0028] The present invention also provides a MoS2CNS Fenton catalyst.

[0029] This invention also provides an application of the MoS2CNS Fenton catalyst in the degradation of organic pollutants in water, comprising the following steps:

[0030] The MoS2CNS Fenton catalyst and hydrogen peroxide were dispersed evenly in water containing organic pollutants according to the specified ratio, and then reacted.

[0031] Preferably, the amount of MoS2CNS Fenton catalyst is 0.6 g / L, the amount of hydrogen peroxide is 5-20 mM, and the reaction time is 5-30 min.

[0032] Therefore, the present invention employs the above-mentioned molybdenum sulfide coupled biomass water purification catalyst, its preparation method, and its application, with the following beneficial effects:

[0033] The preparation method of this invention involves a two-step synthesis: first, a simple hydrothermal reaction, followed by calcination to obtain the catalyst. The process is simple and requires minimal equipment. It also utilizes biomass as a raw material, achieving effective utilization of waste resources and reducing environmental pollution.

[0034] The MoS2CNS Fenton catalyst prepared by this invention is a black solid powder. The catalyst's structure mainly consists of copper and graphene-like structures linked by Mo-NC, Mo-OC, and Mo-OC bonds, forming a cation-π system on the catalyst surface. By enhancing the directional transfer of interfacial electrons, it exhibits highly efficient EC degradation capabilities and excellent catalytic performance for the degradation of organic pollutants in water. It can rapidly remove organic pollutants such as bisphenol A (BPA), ciprofloxacin (CIP), sulfamethoxazole (SMX), atrazine (ATZ), dichlorophenol (2CP), and phenytoin (PHT) from water.

[0035] In wastewater degradation applications, the MoS2CNS Fenton catalyst reaction system of this invention does not require pH adjustment and can be carried out under neutral conditions; the MoS2CNS Fenton catalyst is a solid catalyst, which is easy to separate from water, recycle and reuse, and maintain a high removal efficiency.

[0036] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0037] Figure 1 This is the SEM spectrum of Embodiment 1 of the present invention;

[0038] Figure 2 This is the XRD pattern of Embodiment 1 of the present invention;

[0039] Figure 3 These are XPS spectra of Embodiment 1 of the present invention, wherein (a) is the XPS spectrum of C, (b) is the XPS spectrum of O, (c) is the XPS spectrum of N, and (d) is the XPS spectrum of S.

[0040] Figure 4 This is a C / C0 graph showing the catalytic degradation activity of the MoS2CNS Fenton catalyst of this invention for different organic pollutants.

[0041] Figure 5 This is a graph (C / C0) showing the activity evaluation of the MoS2CNS Fenton catalyst of the present invention in degrading BPA by initiating the Fenton reaction under different initial pH conditions.

[0042] Figure 6 This is an activity evaluation diagram of the MoS2CNS Fenton catalyst of the present invention for the repeated recycling of BPA degradation;

[0043] Figure 7 This is a graph showing the COD (Chemical Oxygen Demand) treatment effect of the MoS2CNS Fenton catalyst of this invention on actual pharmaceutical wastewater. Detailed Implementation

[0044] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0045] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0046] Example 1

[0047] A MoS2CNS Fenton catalyst, the preparation method of which includes the following steps:

[0048] (1) Disperse 1 mM sodium molybdate and 2 mM thiourea in 50 mL of deionized water and stir for 15 min to obtain a mixture;

[0049] (2) Add 8g of urea to the mixture obtained in step (1) and stir for 30 minutes;

[0050] (3) Add 2g of corn cob and stir for 30min, then pour into a polytetrafluoroethylene reactor;

[0051] (4) The polytetrafluoroethylene reactor was transferred to a forced-air drying oven at 230°C and heated for 24 hours. After cooling naturally to room temperature, it was washed three times with deionized water and ethanol alternately, and then dried in a forced-air drying oven at 60°C for 24 hours to obtain product A.

[0052] (5) Place the product A obtained in step (4) in a quartz cup and calcine it in a tube furnace under nitrogen conditions. The heating rate is 5℃ / min, the calcination temperature is 800℃, and the calcination time is 2h. A black solid is obtained and ground to obtain MoS2CNS Fenton catalyst.

[0053] Example 2

[0054] The application of the MoS2CNS Fenton catalyst prepared in Example 1 in the degradation of organic pollutants in water includes the following steps:

[0055] (1) 0.01g of the MoS2CNS Fenton catalyst prepared in Example 1 was added to 50mL of 20µM organic pollutant solution, and 50µL of hydrogen peroxide solution was added at the same time. The Fenton reaction was started by stirring continuously in a water bath at 35℃. The pollutant concentration was measured at different time points.

[0056] The organic pollutants in the solution were: bisphenol A (BPA), ciprofloxacin (CIP), sulfamethadiazole (SMZ), dichlorophenol (2CP), atrazine (ATZ), and phenytoin (PHT).

[0057] Example 3

[0058] The MoS2CNS Fenton catalyst prepared in Example 1 is applied to the degradation of actual pharmaceutical wastewater. The application method includes the following steps:

[0059] (1) 0.01g of the MoS2CNS Fenton catalyst prepared in Example 1 was added to 50mL of actual pharmaceutical wastewater, along with 50µL of hydrogen peroxide solution. The mixture was placed in a water bath at 35°C and stirred continuously to start the Fenton reaction. COD was measured at different time points.

[0060] Test

[0061] 1. The MoS2CNS Fenton catalyst prepared in Example 1 was characterized.

[0062] like Figure 1 As shown in the SEM image of the MoS2CNS Fenton catalyst prepared in Example 1, it can be observed that it has a typical molybdenum sulfide flower-like structure of porous materials.

[0063] like Figure 2 As shown, the XRD pattern of the MoS2CNS Fenton catalyst prepared in Example 1 is consistent with the characteristic diffraction peaks of MoS2 when compared with the standard card.

[0064] like Figure 3 As shown in the XPS spectrum of the MoS2CNS Fenton catalyst prepared in Example 1, it can be seen that Mo-NC, Mo-OC and Mo-SC structures were formed on the catalyst surface.

[0065] 2. The degradation effect of the application in Example 2 was measured, and the degradation rate test results are as follows: Figure 4 As shown.

[0066] Depend on Figure 4It can be seen that the degradation curves of MoS2CNS Fenton catalyst for BPA, CIP, SMZ, 2CP, ATZ and PHT show that at 15 min, the removal rates of BPA, CIP, ATZ, 2CP and SMZ all exceeded 80%, and the removal rate of PHT was about 60%.

[0067] 3. The pH of the reaction system in Example 2 was investigated. The investigation method included the following steps:

[0068] The initial pH of the solution was adjusted using sodium hydroxide and hydrochloric acid. After adjusting to a specific pH, 0.01 g of the MoS2CNS Fenton catalyst prepared in Example 1 was added to 50 mL of actual pharmaceutical wastewater, along with 50 µL of hydrogen peroxide solution. The solution was then placed in a water bath at 35 °C with continuous stirring to initiate the Fenton reaction, and the concentration of pollutants was tested.

[0069] Test results, such as Figure 5 As shown.

[0070] Depend on Figure 5 It can be seen that the MoS2CNS Fenton catalyst reaction system does not require pH adjustment and can be carried out under neutral conditions.

[0071] 4. A stability study was conducted on Example 2. The study method included the following steps:

[0072] (1) Add 0.01g of the MoS2CNS Fenton catalyst prepared in Example 1 to 50 mL of 20μM BPA solution, and add 50μL of hydrogen peroxide solution at the same time. Place the mixture in a water bath at 35°C and stir continuously to start the Fenton reaction.

[0073] (2) After reacting for 60 minutes, samples were taken at different time points to detect the concentration of BPA;

[0074] (3) After reacting for 60 min in step (2), the MoS2CNS Fenton catalyst is separated and dried. The dried MoS2CNS Fenton catalyst is then used to repeat steps (1) to (3).

[0075] The results of the investigation, such as Figure 6 As shown.

[0076] Depend on Figure 6 It can be observed that the degradation effect of the prepared MoS2CNS Fenton catalyst on BPA did not decrease significantly after continuous cyclic reaction. In 6 repeated experiments, the removal effect reached more than 95%.

[0077] 5. The degradation effect of the application in Example 3 was measured, and the degradation rate test results are as follows: Figure 7 As shown.

[0078] Depend on Figure 7It can be seen that after 60 minutes of reaction, COD was reduced from 280 mg / L to 28.8 mg / L, with a removal rate of about 90%.

[0079] Therefore, the present invention employs the above-mentioned molybdenum sulfide coupled biomass water purification catalyst, its preparation method, and its application to achieve effective resource utilization. The solid catalyst is easy to separate from water, recycle, and maintain a high organic matter removal efficiency.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. The application of a molybdenum sulfide-coupled biomass MoS2CNS Fenton catalyst in the degradation of organic pollutants in water, characterized in that, MoS2CNS Fenton catalyst and hydrogen peroxide were evenly dispersed in water containing organic pollutants and reacted. The preparation method of the MoS2CNS Fenton catalyst includes the following steps: S1. Disperse the molybdenum source and sulfur source in deionized water according to the proportion, stir, and obtain a mixed solution; The molybdenum source is sodium molybdate, and the sulfur source is thiourea, with a mass ratio of sodium molybdate:thiourea = 1:2~5; S2. Add the nitrogen source to the mixture obtained in S1 according to the proportion, stir, then add biomass, stir, pour into the reactor, and obtain reactant B. S3. The reaction vessel containing reactant B obtained in S2 is subjected to hydrothermal treatment, naturally cooled to room temperature, the solid product is taken out, washed, and dried to obtain product A. S4. Place the product A obtained in S3 in a quartz jar, calcine it, remove the black solid, grind it, and obtain the MoS2CNS Fenton catalyst. In S2, the nitrogen source is urea, and the biomass is corn cob, with a mass ratio of urea:corn cob = 3~6:

1.

2. The application according to claim 1, characterized in that, In S3, the hydrothermal treatment specifically includes: Heat in a forced-air drying oven at 150-300℃ for 6-30 hours.

3. The application according to claim 1, characterized in that, In S4, the calcination treatment specifically includes: Under the conditions of a tube furnace and nitrogen purging, the heating rate is 3-5℃ / min, the calcination temperature is 300-900℃, and the calcination time is 0.5-3h.

4. The application according to claim 1, characterized in that, The amount of MoS2CNS Fenton catalyst used is 0.6 g / L, the amount of hydrogen peroxide used is 5~20 mM, and the reaction time is 5-30 min.

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