A catalytic material for self-circulating photocatalytic Fenton and its preparation method

Abstract

The present invention discloses a catalytic material for self-circulating photocatalytic Fenton and a preparation method thereof, relating to the technical field of catalytic materials, the method comprising the following steps: adding thioacetamide to a manganese chloride solution and mixing, adding ammonia water with stirring, and then reacting at 180-200°C for 18-24h to obtain α-MnS; dispersing α-MnS in an ethanol solution, then adding thiourea and stirring to mix, then immersing foamed iron nickel in the mixed solution for ultrasonic treatment, and finally reacting at 120-140°C for 6-14h to obtain a catalytic material for self-circulating photocatalytic Fenton. The present invention also discloses a catalytic material for self-circulating photocatalytic Fenton obtained by the above method. The catalytic material has efficient self-circulating photo-Fenton performance and has great application value in pollutant degradation and wastewater treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic materials, and in particular to a catalytic material for self-circulating photocatalytic Fenton and a preparation method thereof. Background Art

[0002] Using Fenton reaction, H2O2 in Fe 2+ The method of generating hydroxyl radicals (·OH) with strong oxidizing ability under the presence of ions to effectively degrade organic pollutants has attracted much attention in the field of water pollution control and environmental remediation. However, the traditional Fenton reaction requires the addition of H2O2 and Fe 2+ A large amount of inorganic iron salts is usually used in the Fenton reaction process. The iron ions in the solution after the reaction are difficult to recycle, resulting in a large amount of iron-containing sludge. Therefore, it is still a huge challenge to study Fenton technology without adding H2O2 and inorganic iron salts at the same time and reduce the generation of iron sludge from the source without weakening the Fenton oxidation activity. Summary of the Invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a catalytic material for self-circulating photocatalytic Fenton and a preparation method thereof, which has high efficient self-circulating photo-Fenton performance and has great application value in pollutant degradation and wastewater treatment.

[0004] The present invention solves the above-mentioned technical problem with the following technical solution: a method for preparing a catalytic material for self-circulating photocatalytic Fenton is provided, comprising the following steps:

[0005] (1) Add thioacetamide to a manganese chloride solution, add ammonia water under stirring, react at 180-200°C for 18-24 hours, cool to room temperature, wash and dry to obtain α-MnS;

[0006] (2) The α-MnS obtained in step (1) is dispersed in an ethanol solution, and then thiourea is added and stirred. The foamed iron nickel is then immersed in the mixed solution and ultrasonically treated. Finally, the mixture is reacted at 120-140° C. for 6-14 hours. After the reaction is completed, the mixture is cooled to room temperature, washed, and dried to obtain a catalytic material for self-circulating photocatalytic Fenton.

[0007] Furthermore, in step (1), the concentration of the manganese chloride solution is 50-200 mmol / L.

[0008] Furthermore, in step (1), the amount of thioacetamide used is 60-100 mmol / L.

[0009] Furthermore, in step (1), the volume ratio of manganese chloride solution to ammonia water is 50 mL:0.5-0.8 mL.

[0010] Furthermore, in step (2), the molar volume ratio of α-MnS, ethanol solution and thiourea is 10-50 mmol:1 L:200-800 mmol.

[0011] Furthermore, in step (2), the mixture is stirred and mixed for 20-40 minutes.

[0012] Furthermore, in step (2), ultrasonic treatment is performed for 20-40 minutes.

[0013] Furthermore, in steps (1) and (2), ultrapure water and ethanol are used for washing; and the mixture is naturally dried.

[0014] Furthermore, in step (2), the foamed iron nickel is pre-treated as follows: the foamed iron nickel is ultrasonically cleaned in acetone, pure water and ethanol for 15 minutes respectively, and then naturally dried.

[0015] The invention also discloses a catalytic material for self-circulating photocatalytic Fenton prepared by the preparation method of the catalytic material for self-circulating photocatalytic Fenton.

[0016] The invention also discloses application of the catalytic material for self-circulating photocatalytic Fenton in wastewater treatment.

[0017] The present invention has the following beneficial effects:

[0018] 1. The present invention successfully prepared sulfur-defective α-MnS / Ni3S using a simple method. 2-x / NF, the material enhances sulfur vacancies through α-MnS, further improving the hydrogen peroxide production performance of Ni3S2. Without external addition of hydrogen peroxide and metal ions, α-MnS / Ni3S 2-x The / NF material exhibited an extremely high H2O2 yield under visible light irradiation, reaching 51.6 mM h -1 g -1 , which is 10-200 times higher than the photocatalytic self-Fenton system reported in the literature.

[0019] 2. The catalytic material of the present invention can be applied to the reduction of Cr(VI) and the oxidative degradation of oxytetracycline through a self-circulating photo-Fenton strategy. The corresponding degradation and reduction rates can reach 98%, which is much higher than the traditional Fenton reaction.

[0020] 3. Catalytic material α-MnS / Ni3S of the present invention 2-x / NF has good photothermal effect, and the water evaporation rate can reach 2.01 kg m -2 h -1 , also showed good performance in degrading fluorinated nitrobenzene wastewater and hospital wastewater, which will help to develop new functional nanostructures for use in environmental remediation and solar evaporation fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The catalytic material of the present invention is α-MnS / Ni3S 2-x / NF H2O2 yield measurement results;

[0022] Figure 2 The catalytic material of the present invention is α-MnS / Ni3S 2-x / NF degradation ability test results of Cr(VI) and oxytetracycline (OTC);

[0023] Figure 3 The catalytic material of the present invention is α-MnS / Ni3S 2-x / NF water evaporation capacity test results diagram. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. In the examples, where specific conditions are not specified, conventional conditions or manufacturer-recommended conditions were used. Reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially.

[0025] Example 1

[0026] A catalytic material for self-circulating photocatalytic Fenton, the preparation method of which comprises the following steps:

[0027] (1) To 50 mL of a 100 mmol / L manganese chloride solution, 80 mmol / L of thioacetamide was added, and 0.6 mL of aqueous ammonia was added under stirring. The mixture was reacted at 190°C for 20 h, cooled to room temperature, washed, and dried to obtain α-MnS.

[0028] (2) The α-MnS obtained in step (1) is dispersed in an ethanol solution, and then thiourea is added and stirred for 30 minutes. The foamed iron nickel is then immersed in the mixed solution and ultrasonically treated for 30 minutes. Finally, the mixture is reacted at 130° C. for 10 hours. After the reaction is completed, the mixture is cooled to room temperature, washed, and dried to obtain a catalytic material for self-circulating photocatalytic Fenton. The molar volume ratio of the α-MnS, ethanol solution, and thiourea is 30 mmol: 1 L: 500 mmol.

[0029] Example 2

[0030] A catalytic material for self-circulating photocatalytic Fenton, the preparation method of which comprises the following steps:

[0031] (1) Thioacetamide (60 mmol / L) was added to 50 mL of a 50 mmol / L manganese chloride solution, and 0.5 mL of aqueous ammonia was added under stirring. The mixture was reacted at 180°C for 18 h, cooled to room temperature, washed, and dried to obtain α-MnS.

[0032] (2) The α-MnS obtained in step (1) is dispersed in an ethanol solution, and then thiourea is added and stirred for 20 minutes. The foamed iron nickel is then immersed in the mixed solution and ultrasonically treated for 20 minutes. Finally, the mixture is reacted at 120° C. for 6 hours. After the reaction is completed, the mixture is cooled to room temperature, washed, and dried to obtain a catalytic material for self-circulating photocatalytic Fenton. The molar volume ratio of the α-MnS, ethanol solution, and thiourea is 10 mmol: 1 L: 200 mmol.

[0033] Example 3

[0034] A catalytic material for self-circulating photocatalytic Fenton, the preparation method of which comprises the following steps:

[0035] (1) Thioacetamide (100 mmol / L) was added to 50 mL of a 200 mmol / L manganese chloride solution, and 0.8 mL of aqueous ammonia was added under stirring. The mixture was reacted at 200°C for 24 h, cooled to room temperature, washed, and dried to obtain α-MnS.

[0036] (2) The α-MnS obtained in step (1) is dispersed in an ethanol solution, and then thiourea is added and stirred for 40 minutes. The foamed iron nickel is then immersed in the mixed solution and ultrasonically treated for 40 minutes. Finally, the mixture is reacted at 140°C for 14 hours. After the reaction is completed, the mixture is cooled to room temperature, washed and dried to obtain a catalytic material for self-circulating photocatalytic Fenton; wherein the molar volume ratio of α-MnS, ethanol solution and thiourea is 50 mmol: 1 L: 800 mmol.

[0037] Test Example 1

[0038] Referring to Example 1, α-MnS / Ni3S were prepared according to the α-MnS concentration of 10-50 mmol / L. 2-x / NF material, test H2O2 yield, the results are as follows Figure 1 As shown, a is a comparison of the photocatalytic synthesis of H2O2 by different materials, and b is a comparison of the performance of different amounts of 30α-MnS / Ni3S 2-x Comparison of visible light photocatalytic H2O2 synthesis performance of 30α-MnS / Ni3S / NF. c is the performance comparison of 30α-MnS / Ni3S / NF under different pH conditions. 2-x Comparison of visible light photocatalytic H2O2 synthesis performance of / NF.

[0039] Depend on Figure 1 It can be seen that 30α-MnS / Ni3S2-x The H2O2 yield of the / NF material is higher than that of other materials, reaching 51.6 mM g -1 At the same time, when the catalyst dosage was 50 mg and the pH was 5.2, the H2O2 yield was the highest.

[0040] Test Example 2

[0041] Comparative test of the degradation ability of different catalytic materials on Cr(VI) and oxytetracycline (OTC) under visible light irradiation. The results are as follows Figure 2 As shown, where ac are the residual amount of Cr(VI) degradation by different materials and the rate constant k app and cycle performance, de are the residual amount of oxytetracycline (OTC) degradation by different materials, rate constant k app and cycle performance.

[0042] Depend on Figure 2 It can be seen that in the absence of any photocatalyst, the pollutants were almost not degraded. Under light conditions, the degradation rates of Cr(VI) by NF, Ni3S2 and α-MnS were only 4.5%, 5.8% and 17% (within 60 min), respectively, while the degradation rates of Ni3S2 / NF and 30α-MnS / Ni3S 2-x The Cr(VI) degradation rates of 30α-MnS / Ni3S / NF were 81% and 98% respectively, indicating that the catalytic material 30α-MnS / Ni3S prepared by the method of the present invention is 2-x / NF significantly enhanced the photocatalytic reduction of Cr(VI), and the significant improvement in degradation efficiency can be attributed to the formation of sulfur vacancies. 2-x / NF has the highest reduction efficiency, with a rate constant K app 3.97h -1 , this value is approximately NF(0.217h -1 )、Ni3S2(0.036h -1 )、α-MnS(0.072h -1 ) and Ni3S2 / NF(3.01h -1 ) by 18.3, 110, 55 and 1.3 times. After three cycles, the catalytic material 30α-MnS / Ni3S 2-x / NF degradation rate still remains above 82%, indicating that it has good stability. 2-x / NF also showed good degradation performance in OTC degradation, with a degradation rate of 98% within 120 minutes. app 1.86h -1 , about NF(0.04h -1 )、Ni3S2(0.11h -1)、α-MnS(0.08h -1 ) and Ni3S2 / NF(0.9h -1 ) by 46.5 times, 17 times, 23 times and 2 times of that of the original. In addition, after three cycles, the degradation rate remained above 80%, indicating that it has good cyclic stability.

[0043] Test Example 3

[0044] In order to study the application of the new catalytic material of the present invention in solar-driven interfacial water evaporation, quantitative experiments were conducted. The results are as follows Figure 3 As shown, a is a schematic diagram of a small evaporator, b is the change in water evaporation mass, c is the evaporation efficiency, d is a photo of the microreactor, e is a comparison of nitrobenzene wastewater before and after solar evaporation, f is the change in chemical oxygen demand (COD) of OTC, Cr(VI) and nitrobenzene wastewater over time after solar evaporation, g and g are the wettability of the NF material surface, and h is the surface wettability of 30α-MnS / Ni3S 2-x / NF material surface wettability, i is 30α-MnS / Ni3S 2-x / NF temperature changes.

[0045] Depend on Figure 3 It can be seen that under a solar irradiation simulation condition, pure water, NF and 30α-MnS / Ni3S 2-x The evaporation rates of / NF were 0.71 kg·m -2 ·h -1 , 1.65kg·m -2 ·h -1 and 2.07 kg·m -2 ·h -1 And the results show that 30α-MnS / Ni3S 2-x / NF exhibits stronger hydrophilicity, allowing water molecules to be transported quickly within the material, resulting in better evaporation performance.

[0046] Under 1 times the sun irradiation condition, the experimental measurement of 30α-MnS / Ni3S 2-x The temperature of the evaporation system composed of 30α-MnS / Ni3S / NF gradually increased with time and reached 41.6 °C, which indicated that 2-x / NF absorbs the most heat energy in the evaporation system, and the absorbed energy is used for water evaporation, so 30α-MnS / Ni3S 2-x / NF evaporation system has the highest evaporation rate.

[0047] In summary, compared with the existing technology, the preparation method of the catalytic material of the present invention is simple, and the material is magnetic and easy to separate. It not only opens up a new path for the self-circulating photocatalytic Fenton system, but also has great application value in actual wastewater purification and various other fields.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a catalytic material for self-circulating photocatalytic Fenton, characterized in that: The following steps are involved: (1) Add thioacetamide to a manganese chloride solution, add ammonia water under stirring, react at 180-200°C for 18-24 hours, cool to room temperature, wash and dry to obtain α-MnS; (2) The α-MnS obtained in step (1) is dispersed in an ethanol solution, and then thiourea is added and stirred. The foamed iron nickel is then immersed in the mixed solution and ultrasonically treated. Finally, the mixture is reacted at 120-140° C. for 6-14 hours. After the reaction is completed, the mixture is cooled to room temperature, washed, and dried to obtain a catalytic material for self-circulating photocatalytic Fenton.

2. The method for preparing a catalytic material for self-circulating photocatalytic Fenton according to claim 1, characterized in that: In step (1), the concentration of the manganese chloride solution is 50-200 mmol / L.

3. The method for preparing a catalytic material for self-circulating photocatalytic Fenton according to claim 1, characterized in that: In step (1), the amount of thioacetamide used is 60-100 mmol / L.

4. The method for preparing a catalytic material for self-circulating photocatalytic Fenton according to claim 1, characterized in that: In step (1), the volume ratio of the manganese chloride solution to the ammonia water is 50 mL:0.5-0.8 mL.

5. The method for preparing a catalytic material for self-circulating photocatalytic Fenton as claimed in claim 1, characterized in that: In step (2), the molar volume ratio of the α-MnS, ethanol solution and thiourea is 10-50 mmol: 1 L: 200-800 mmol.

6. The method for preparing a catalytic material for self-circulating photocatalytic Fenton as claimed in claim 1, characterized in that: In step (2), the mixture is stirred and mixed for 20-40 minutes.

7. The method for preparing a catalytic material for self-circulating photocatalytic Fenton as claimed in claim 1, characterized in that: In step (2), ultrasonic treatment is performed for 20-40 min.

8. The method for preparing a catalytic material for self-circulating photocatalytic Fenton as claimed in claim 1, characterized in that: In steps (1) and (2), ultrapure water and ethanol are used for washing; and the mixture is naturally dried.

9. The catalytic material for self-circulating photocatalytic Fenton obtained by the method for preparing the catalytic material for self-circulating photocatalytic Fenton according to any one of claims 1 to 8.

10. Use of the catalytic material for self-circulating photocatalytic Fenton according to claim 9 in wastewater treatment.

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