Molybdenum sulfide coupled biomass water purification catalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of water treatment catalyst preparation, and particularly discloses a molybdenum sulfide coupled biomass water purification catalyst and a preparation method and application thereof, the preparation method comprises the following steps: S1, dispersing a molybdenum source and a sulfur source in deionized water, and stirring to obtain a mixed solution; s2, proportionally adding a nitrogen source into the mixed solution, stirring, adding biomass, stirring, and pouring into a reaction kettle to obtain a reactant B; s3, carrying out hydrothermal treatment on the reaction kettle containing the reactant B, naturally cooling to room temperature, taking out a solid product, washing and drying to obtain a product A; and S4, putting the product A into a quartz cup, carrying out calcination treatment, taking out a black solid, and grinding to obtain the MoS2CNS Fenton catalyst. According to the molybdenum sulfide coupled biomass water purification catalyst and the preparation method and application thereof, effective utilization of resources is achieved, the solid catalyst is conveniently separated from water and recycled, and the high organic matter removal effect is kept.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment catalyst preparation, and in particular to a molybdenum sulfide coupled biomass water purification catalyst, a preparation method and an application thereof. Background Art

[0002] Freshwater resources in all regions are polluted to varying degrees, and some people still drink shallow, river, and deep well water. The proportion of this type of water that meets the criteria of high-quality, good, and relatively good quality is relatively low, and there are currently problems with water quality being contaminated and bacteria exceeding sanitary standards. In particular, the proportion of water contaminated by organic matter is increasing year by year, posing a threat to public health and safety.

[0003] Therefore, it is urgent to develop low-cost and effective technologies and methods to remove such organic pollutants. Summary of the Invention

[0004] The purpose of the present invention is to provide a molybdenum sulfide-coupled biomass water purification catalyst and its preparation method and application, so as to achieve efficient utilization of resources. The solid catalyst is easy to separate from water, be recycled and reused, and maintain a high organic matter removal effect.

[0005] To achieve the above object, the present invention provides a method for preparing a molybdenum sulfide-coupled biomass water purification catalyst, comprising the following steps: S1. Disperse the molybdenum source and the sulfur source in deionized water according to proportion and stir to obtain a mixed solution; S2. Add the nitrogen source to the mixed solution obtained in S1 according to the proportion, stir, then add the biomass, stir, and pour into the reactor to obtain reactant B; S3, hydrothermally treating the reactor containing reactant B obtained in S2, cooling it naturally to room temperature, taking out the solid product, washing it, and drying it to obtain product A; S4. Place the product A obtained in S3 in a quartz cup and calcine it. Take out the black solid and grind it to obtain the MoS2CNS Fenton catalyst.

[0006] Preferably, in S1, the molybdenum source is one or more of sodium molybdate, ammonium molybdate, and phosphomolybdic acid; The sulfur source is one or more of thiourea, cyanuric acid, sodium sulfide, and elemental sulfur; The usage ratio of the molybdenum source, the sulfur source and the deionized water is 1 mM: 2-5 mM: 50 mL.

[0007] Preferably, the molybdenum source is sodium molybdate, and the sulfur source is thiourea, and the mass ratio thereof is sodium molybdate:thiourea=1:2-5.

[0008] Preferably, in S1, the stirring time is 15 minutes.

[0009] Preferably, in S2, the nitrogen source is one or more of urea, melamine, and thiourea; The biomass is one or more of silkworm litter, corn cobs, garlic straw, and cow dung; The mass ratio of the nitrogen source to the biomass is 2-6:1.

[0010] Preferably, the nitrogen source is urea, the biomass is corn cob, and the mass ratio thereof is urea:corn cob=3~6:1.

[0011] Preferably, in S2, the stirring time is 30 min.

[0012] Preferably, in S3, the hydrothermal treatment is specifically: Heat in a forced air drying oven at 150-300°C for 6-30h.

[0013] Preferably, in S3, the washing is performed by alternating deionized water and ethanol for 3 times.

[0014] Preferably, in S3, the drying is carried out in a blast drying oven, the drying time is 24 hours, and the drying temperature is 60°C.

[0015] Preferably, in S4, the calcination treatment is specifically: In a tubular furnace under nitrogen conditions, the heating rate is 3-5°C / min, the calcination temperature is 300-900°C, and the calcination time is 0.5-3h.

[0016] Preferably, the calcination treatment is specifically: In a tubular furnace with nitrogen, the heating rate was 5°C / min, the calcination temperature was 800°C, and the calcination time was 2h.

[0017] The present invention also provides a MoS2CNS Fenton catalyst.

[0018] The present invention also provides an application of a MoS2CNS Fenton catalyst in degrading organic pollutants in water, comprising the following steps: The MoS2CNS Fenton catalyst and hydrogen peroxide are uniformly dispersed in proportion in water containing organic pollutants and reacted.

[0019] Preferably, the amount of the 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.

[0020] Therefore, the present invention adopts the above-mentioned molybdenum sulfide coupled biomass water purification catalyst and its preparation method and application, and the beneficial effects are as follows: The preparation method of the present invention is a two-step synthesis, firstly through a simple hydrothermal reaction, and then by a calcination method to prepare the catalyst, the process is simple and the equipment requirements are low; the use of biomass as a raw material realizes the effective utilization of waste resources and reduces environmental pollution.

[0021] The MoS2CNS Fenton catalyst prepared by the present invention is a black solid powder. The structural composition of the catalyst is mainly copper and a graphene-like structure connected 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 efficient ECs degradation ability and has excellent catalytic performance for the degradation of organic pollutants in water. It can quickly remove organic pollutants such as bisphenol A (BPA), ciprofloxacin (CIP), sulfamethizole (SMX), atrazine (ATZ), dichlorophenol (2CP) and phenytoin (PHT) in water.

[0022] In the wastewater degradation application of the present invention, the MoS2CNS Fenton catalyst reaction system 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 effect.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the SEM spectrum of Example 1 of the present invention; Figure 2 is the XRD spectrum of Example 1 of the present invention; Figure 3 1 is the XPS spectrum of Example 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; Figure 4 This is a graph showing the evaluation of the catalytic degradation activity (C / C0) of the MoS2CNS Fenton catalyst of the present invention for different organic pollutants; Figure 5 3. This is a graph showing the activity evaluation (C / C0) of the MoS2CNS Fenton catalyst of the present invention for degradation of BPA by initiating Fenton reaction under different initial pH conditions; Figure 6 This is a diagram for evaluating the recycling activity of the MoS2CNS Fenton catalyst for BPA degradation; Figure 7 This is a diagram showing the treatment effect (COD) of the MoS2CNS Fenton catalyst of the present invention on actual pharmaceutical wastewater. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0026] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0027] Example 1 A MoS2CNS Fenton catalyst, the preparation method of which comprises the following steps: (1) Disperse 1 mM sodium molybdate and 2 mM thiourea in 50 mL of deionized water and stir for 15 min to obtain a mixed solution; (2) Add 8 g of urea to the mixture obtained in step (1) and stir for 30 min; (3) Add 2 g of corn cob and stir for 30 min, then pour into a polytetrafluoroethylene reactor; (4) The polytetrafluoroethylene reactor was transferred to a 230°C forced air drying oven and heated for 24 h. The mixture was naturally cooled to room temperature, washed alternately with deionized water and ethanol for three times, and dried in a 60°C forced air drying oven for 24 h to obtain product A.

[0028] (5) The product A obtained in step (4) was placed in a quartz cup and calcined in a tubular furnace under nitrogen conditions at a heating rate of 5°C / min, a calcination temperature of 800°C, and a calcination time of 2 h to obtain a black solid, which was ground to obtain MoS2CNS Fenton catalyst.

[0029] Example 2 The MoS2CNS Fenton catalyst prepared in Example 1 is used to degrade organic pollutants in water, and the application method includes the following steps: (1) 0.01 g of the MoS2CNS Fenton catalyst prepared in Example 1 was added to 50 mL of a 20 μM organic pollutant solution. 50 μL of hydrogen peroxide solution was added at the same time. The mixture was placed in a water bath at 35 °C and stirred continuously to initiate the Fenton reaction. Samples were taken at different time points to determine the pollutant concentration.

[0030] The organic pollutants in the organic pollutant solution are: bisphenol A (BPA), ciprofloxacin (CIP), sulfamethizole (SMZ), dichlorophenol (2CP), atrazine (ATZ), and phenytoin (PHT).

[0031] Example 3 The MoS2CNS Fenton catalyst prepared in Example 1 is used to degrade actual pharmaceutical wastewater, and the application method includes the following steps: (1) 0.01 g of the MoS2CNS Fenton catalyst prepared in Example 1 was added to 50 mL of actual pharmaceutical wastewater, and 50 μL of hydrogen peroxide solution was added at the same time. The mixture was placed in a water bath at 35 °C and stirred continuously to initiate the Fenton reaction. Samples were taken at different time points to determine the COD.

[0032] Experimental testing 1. The MoS2CNS Fenton catalyst prepared in Example 1 was characterized.

[0033] like Figure 1 As shown in the SEM spectrum 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.

[0034] like Figure 2 As shown, the XRD spectrum of the MoS2CNS Fenton catalyst prepared in Example 1 is consistent with the characteristic diffraction peaks of MoS2 when compared with the standard card.

[0035] like Figure 3 As shown in the XPS spectrum of the MoS2CNS Fenton catalyst prepared in Example 1, it can be obtained that Mo-NC, Mo-OC and Mo-SC structures are formed on the catalyst surface.

[0036] 2. The degradation effect of the application of Example 2 was measured, and the degradation rate test results were as follows: Figure 4 shown.

[0037] Depend on Figure 4 It can be seen that the degradation curves of MoS2CNS Fenton catalyst for BPA, CIP, SMZ, 2CP, ATZ and PHT show that at 15 minutes, the removal rates of BPA, CIP, ATZ, 2CP and SMZ all exceed 80%, and the removal rate of PHT is also about 60%.

[0038] 3. The pH of the reaction system was investigated in Example 2. The investigation method included the following steps: 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. At the same time, 50 µL of hydrogen peroxide solution was added. The mixture was placed in a water bath at 35°C with continuous stirring to initiate the Fenton reaction and test the concentration of the pollutants.

[0039] Test results, such as Figure 5 shown.

[0040] 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.

[0041] 4. A stability study was conducted on Example 2, and the study method included the following steps: (1) 0.01 g of the MoS2CNS Fenton catalyst prepared in Example 1 was added to 50 mL of 20 μM BPA solution, and 50 μL of hydrogen peroxide solution was added at 35°C in a water bath with continuous stirring to initiate the Fenton reaction.

[0042] (2) After 60 min of reaction, samples were taken at different time points to detect the concentration of BPA; (3) Separate and dry the MoS2CNS Fenton catalyst after 60 min of reaction in step (2), and repeat steps (1) to (3) with the dried MoS2CNS Fenton catalyst.

[0043] The results of the study, such as Figure 6 shown.

[0044] Depend on Figure 6 It can be seen that the effect of the prepared MoS2CNS Fenton catalyst in degrading BPA did not decrease significantly after continuous cyclic reaction. In 6 repeated experiments, the removal effect could reach more than 95%.

[0045] 5. The degradation effect of the application of Example 3 was measured, and the degradation rate test results were as follows: Figure 7 shown.

[0046] Depend on Figure 7 It can be seen that after 60 minutes of reaction, COD was removed from 280 mg / L to 28.8 mg / L, and the removal rate reached about 90%.

[0047] Therefore, the present invention adopts the above-mentioned molybdenum sulfide coupled biomass water purification catalyst and its preparation method and application to achieve effective utilization of resources. The solid catalyst is easy to separate from water, recycle and reuse, and maintain a high organic matter removal effect.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a molybdenum sulfide coupled biomass water purification catalyst, characterized in that: The following steps are involved: S1. Disperse the molybdenum source and the sulfur source in deionized water according to proportion and stir to obtain a mixed solution; S2. Add the nitrogen source to the mixed solution obtained in S1 according to the proportion, stir, then add the biomass, stir, and pour into the reactor to obtain reactant B; S3, hydrothermally treating the reactor containing reactant B obtained in S2, cooling it naturally to room temperature, taking out the solid product, washing it, and drying it to obtain product A; S4. Place the product A obtained in S3 in a quartz cup and calcine it. Take out the black solid and grind it to obtain the MoS2CNS Fenton catalyst.

2. The method for preparing a molybdenum sulfide coupled biomass water purification catalyst according to claim 1, characterized in that: In S1, the molybdenum source is one or more of sodium molybdate, ammonium molybdate, and phosphomolybdic acid; The sulfur source is one or more of thiourea, cyanuric acid, sodium sulfide, and elemental sulfur; The usage ratio of the molybdenum source, the sulfur source and the deionized water is 1 mM: 2-5 mM: 50 mL.

3. The method for preparing a molybdenum sulfide coupled biomass water purification catalyst according to claim 2, characterized in that: The molybdenum source is sodium molybdate, and the sulfur source is thiourea, and the mass ratio thereof is sodium molybdate:thiourea=1:2-5.

4. The method for preparing a molybdenum sulfide coupled biomass water purification catalyst according to claim 1, characterized in that: In S2, the nitrogen source is one or more of urea, melamine, and thiourea; The biomass is one or more of silkworm litter, corn cobs, garlic straw, and cow dung; The mass ratio of the nitrogen source to the biomass is 2-6:

1.

5. The method for preparing a molybdenum sulfide coupled biomass water purification catalyst according to claim 4, characterized in that: The nitrogen source is urea, and the biomass is corn cob, and the mass ratio of urea is: Corn cob = 3~6:

1.

6. The method for preparing a molybdenum sulfide coupled biomass water purification catalyst according to claim 1, characterized in that: In S3, the hydrothermal treatment is specifically: Heat in a forced air drying oven at 150-300°C for 6-30h.

7. The method for preparing a molybdenum sulfide coupled biomass water purification catalyst according to claim 1, characterized in that: In S4, the calcination treatment is specifically: In a tubular furnace under nitrogen conditions, the heating rate is 3-5°C / min, the calcination temperature is 300-900°C, and the calcination time is 0.5-3h.

8. A MoS2CNS Fenton catalyst prepared by the method for preparing a molybdenum sulfide-coupled biomass water purification catalyst according to any one of claims 1 to 7.

9. Use of the MoS2CNS Fenton catalyst according to claim 8 in degrading organic pollutants in water, characterized in that: The following steps are involved: The MoS2CNS Fenton catalyst and hydrogen peroxide are uniformly dispersed in proportion in water containing organic pollutants and reacted.

10. The use according to claim 9, characterized in that The dosage of the MoS2CNS Fenton catalyst is 0.6 g / L, the dosage of the hydrogen peroxide is 5-20 mM, and the reaction time is 5-30 min.

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