A Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst and its preparation method and application

Abstract

The invention discloses a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst and its preparation method and application, belonging to the field of water treatment. The present invention first crushes a certain amount of styrene-butadiene rubber and uniformly dissolves it in dichloromethane, and also dissolves a certain amount of ferric acetylacetonate, pyridine, zinc chloride, and anhydrous sodium sulfate in methanol in sequence, mixes each solution and ultrasonically disperses it, and obtains a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst after evaporation and programmed temperature calcination and carbonization under inert gas protection. The Fenton-like catalyst prepared by the present invention can rapidly degrade acetaminophen in water by activating potassium persulfate, with surface-mediated electron transfer and singlet oxygen path, with high catalytic efficiency, high oxidant utilization rate, low cost, and good industrial benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and relates to an advanced oxidation catalyst capable of repairing acetaminophen-contaminated wastewater, and specifically relates to a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst, and a preparation method and application thereof. Background Art

[0002] Acetaminophen has a long history in human society. As an antipyretic and analgesic, it was used clinically in 1893. However, as one of the most commonly detected drugs in rivers, acetaminophen can cause teratogenicity in fish embryos and larvae and produce neurotoxicity and cardiotoxicity. Excessive presence in the human body can interfere with the endocrine system, invade the nerve center, and weaken the immune function. Acetaminophen in the environment mainly comes from improper process treatment of pharmaceutical wastewater, and secondarily from discharge after medication. As a difficult-to-degrade organic matter, acetaminophen is suitable for advanced oxidation degradation. The advanced oxidation catalysts currently used are restricted by factors such as high cost, low catalytic efficiency, poor stability, and few active sites. Therefore, it is crucial to develop a low-cost, multi-metal atomic-level dispersed Fenton-like catalyst that can efficiently degrade acetaminophen. Summary of the invention

[0003] One of the purposes of the present invention is to provide a method for preparing a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst, which is convenient to synthesize and low in cost.

[0004] The second object of the present invention is to provide a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst prepared by the above method, which rapidly degrades acetaminophen in water by surface-mediated electron transfer and singlet oxygen pathways.

[0005] The third object of the present invention is to provide the application of the above-mentioned Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst, which can efficiently degrade acetaminophen in water, has strong stability and fast reaction rate.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst, comprising the following steps:

[0008] (1) Weighing styrene-butadiene rubber, cutting it into pieces, and placing it into a dichloromethane solution, stirring and dissolving it to obtain a solution a;

[0009] (2) weighing iron acetylacetonate and dissolving it in methanol, then adding pyridine and zinc chloride respectively, and performing ultrasonic dispersion to obtain solution b;

[0010] (3) weighing anhydrous sodium sulfate and dissolving it in methanol aqueous solution and ultrasonically dispersing solution c;

[0011] (4) Under stirring conditions, the solution b obtained in step (2) and the solution c obtained in step (3) are simultaneously added dropwise to the solution a obtained in step (1), and stirred at a constant temperature until the liquid evaporates to obtain a reddish-brown precursor, and programmed temperature carbonization is performed under the protection of an inert atmosphere to obtain a black solid; after washing and drying, a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst is obtained.

[0012] Preferably, in step (1), the mass volume of styrene-butadiene rubber and dichloromethane is 3 g:200 mL.

[0013] Preferably, in step (2), the concentration of the ferric acetylacetonate is 0.08-0.09 mol / L, and the concentration of the zinc chloride is 0.5-0.6 mol / L.

[0014] Preferably, the concentration of anhydrous sodium sulfate in step (3) is 0.95-1 mol / L, and the volume ratio of water to methanol in the methanol aqueous solution is 1:4.

[0015] Preferably, the constant temperature stirring temperature in step (4) is 60°C; the carbonization temperature rising program is: heating from room temperature to 600°C at a heating rate of 5°C / min and maintaining for 2h, then heating to 800°C at a heating rate of 5°C / min, maintaining for 2h and then cooling with the furnace; the washing step is washing with dilute hydrochloric acid and water respectively; the drying temperature is 100°C and the drying time is 2 hours.

[0016] In a second aspect, the present invention also provides a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst prepared by the above preparation method.

[0017] The catalyst comprises a carbonized styrene-butadiene rubber catalyst skeleton and Fe2Zn3S5 crystal active sites loaded on the surface and inside of the catalyst skeleton.

[0018] In a third aspect, the present invention also provides the use of the above-mentioned Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst in catalytic degradation of acetaminophen.

[0019] Specifically, the catalyst is added to the acetaminophen-containing wastewater to be treated, and then the potassium persulfate solution is added, and the reaction is stirred at room temperature for 60-120 minutes. The concentration of acetaminophen in the system is 10 mg / L, the amount of the catalyst added is 0.1-0.2 g / L, and the concentration of potassium persulfate in the system is 5 mmol / L.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The catalyst of the present invention uses styrene-butadiene rubber as a carrier, which is low-cost and easy to synthesize. In addition, the metal is dispersed at the atomic level by dissolving the styrene-butadiene rubber during the synthesis process, and has more catalytic active sites.

[0022] 2. The catalyst of the present invention can activate potassium persulfate and rapidly degrade acetaminophen in water through surface-mediated electron transfer and singlet oxygen pathways, and has strong adaptability to the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a scanning electron microscope photograph of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton-type catalyst prepared in Example 1 of the present invention;

[0024] Figure 2 The scanning electron microscope and energy spectrum of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton-type catalyst prepared in Example 1 of the present invention;

[0025] Figure 3 The X-ray diffraction pattern of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton-type catalyst prepared in Example 1 of the present invention;

[0026] Figure 4 The electron paramagnetic resonance spectrum of singlet oxygen generation and direct electron transfer reaction in the process of potassium persulfate activation of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton-type catalyst prepared in Example 1 of the present invention;

[0027] Figure 5 This is the degradation curve of acetaminophen degraded by potassium persulfate activated by the Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] (1) Weigh 3 g of styrene-butadiene rubber, cut it into pieces and put it into 200 mL of dichloromethane solution to dissolve it with magnetic stirring to obtain solution a. Weigh 570 mg of ferric acetylacetonate and dissolve it in 20 mL of methanol. Then add 522 μL of pyridine and 1.5 g of zinc chloride and disperse them ultrasonically to obtain solution b. Weigh 684 mg of anhydrous sodium sulfate and dissolve it in 5 mL of methanol aqueous solution (V 水 / V 甲醇=1:4) and ultrasonically dispersed to obtain solution c, and solutions b and c were simultaneously added dropwise to solution a, and magnetic stirring was performed at a constant temperature of 60°C. After the liquid was volatilized, a reddish-brown precursor was obtained. Under nitrogen protection, the temperature was increased from room temperature to 600°C at a heating rate of 5°C / min and maintained for 2h, and then increased to 800°C at a heating rate of 5°C / min, maintained for 2h, and then cooled with the furnace to obtain a black solid, which was washed with 0.1mol / L dilute hydrochloric acid and deionized water for 10min and then dried at 100°C for 2h to obtain a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst.

[0031] Figure 1 The scanning electron microscope photograph of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst prepared in Example 1 of the present invention; Figure 1 It can be seen that the catalyst surface has a rich pore structure with a stable structure. Most of the pores are less than 5 microns in size and have good permeability.

[0032] Figure 2 The scanning electron microscope and energy spectrum of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst prepared in Example 1 of the present invention; Figure 2 It can be seen that the catalyst is a carbon-based material, and the evenly loaded elements such as Fe, Zn, S, etc. are distributed on the catalyst surface in the form of crystals.

[0033] Figure 3 The X-ray diffraction pattern of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst prepared in Example 1 of the present invention; Figure 3 It can be seen that the crystals on the surface of this catalyst are Fe2Zn3S5.

[0034] Example 2

[0035] 1 mg of the catalyst prepared in Example 1 was added to 10 mL of wastewater having an acetaminophen concentration of 10 mg / L, and then 31 mg of potassium persulfate was added, and the mixture was stirred at room temperature for 120 minutes.

[0036] Figure 4 The degradation curve of acetaminophen degraded by Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst activated potassium persulfate was measured in this embodiment. Figure 4 It can be seen that the degradation rate of acetaminophen within 120 minutes is 95.88%. The composite catalyst can quickly degrade acetaminophen in water by activating potassium persulfate, and has high catalytic efficiency.

[0037] Figure 5 The electron paramagnetic resonance spectrum of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst activated with potassium persulfate to generate singlet oxygen and direct electron transfer reaction prepared in Example 1 of the present invention is shown in FIG. Figure 5It can be seen that the catalyst generates singlet oxygen during the activation of potassium persulfate and participates in the oxidation reaction through direct surface electron mediation, which can degrade acetaminophen more efficiently.

[0038] Example 3

[0039] 2 mg of the catalyst prepared in Example 1 was added into 10 mL of wastewater with a paracetamol concentration of 10 mg / L, and then 31 mg of potassium persulfate was added, and the mixture was stirred at room temperature for 60 minutes. The degradation rate of paracetamol was measured to be 95.21%.

Claims

1. A method for preparing a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst, characterized in that: The following steps are involved: (1) Weighing styrene-butadiene rubber, cutting it into pieces, and placing it into a dichloromethane solution, stirring and dissolving it to obtain a solution a; (2) weighing iron acetylacetonate and dissolving it in methanol, then adding pyridine and zinc chloride respectively, and performing ultrasonic dispersion to obtain solution b; (3) weighing anhydrous sodium sulfate, dissolving it in a methanol aqueous solution and ultrasonically dispersing it to obtain a solution c; (4) Under stirring conditions, the solution b obtained in step (2) and the solution c obtained in step (3) are simultaneously added dropwise to the solution a obtained in step (1), and stirred at a constant temperature until the liquid evaporates to obtain a reddish-brown precursor, and programmed temperature carbonization is performed under the protection of an inert atmosphere to obtain a black solid; after washing and drying, a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst is obtained.

2. The method for preparing a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst according to claim 1, characterized in that: In step (1), the mass volume of styrene-butadiene rubber and dichloromethane is 3 g:200 mL.

3. The method for preparing a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst according to claim 1, characterized in that: In step (2), the concentration of the ferric acetylacetonate is 0.08-0.09 mol / L, and the concentration of the zinc chloride is 0.5-0.6 mol / L.

4. The method for preparing a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst according to claim 1, characterized in that: The concentration of anhydrous sodium sulfate in step (3) is 0.95-1 mol / L, and the volume ratio of water to methanol in the methanol aqueous solution is 1:

4.

5. The method for preparing a Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst according to claim 1, characterized in that: The constant temperature magnetic stirring temperature in step (4) is 60°C; the carbonization temperature rising program is: heating from room temperature to 600°C at a heating rate of 5°C / min and maintaining for 2h, then heating to 800°C at a heating rate of 5°C / min, maintaining for 2h and then cooling with the furnace; the washing step is washing with dilute hydrochloric acid and water respectively; the drying temperature is 100°C and the drying time is 2 hours.

6. The Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the Fe2Zn3S5-styrene-butadiene rubber composite Fenton catalyst according to claim 6 in catalytic degradation of acetaminophen.

8. The use according to claim 7, characterized in that: The catalyst was added to the acetaminophen-contaminated water, followed by the addition of potassium persulfate solution, and the reaction was stirred at room temperature for 60-120 minutes.

9. The use according to claim 8, characterized in that: The concentration of acetaminophen in the system is 10 mg / L, the amount of catalyst added is 0.1-0.2 g / L, and the concentration of potassium persulfate in the system is 5 mmol / L.

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