Preparation method of narrow-band-gap organic semiconductor carbon composite photocatalyst for degrading ciprofloxacin

Abstract

The invention discloses a preparation method of a narrow-band-gap organic semiconductor carbon composite photocatalyst for degrading ciprofloxacin, which comprises the following operation steps: A, drying waste coconut shells to constant weight to obtain crude carbon; b, mechanically crushing the crude charcoal, calcining in a tubular furnace, heating from room temperature to 700 DEG C, and preserving heat for 1-2 hours to obtain coconut shell charcoal particles; c, crushing the coconut shell charcoal particles in a crusher, cleaning the crushed coconut shell charcoal particles in a 60-mesh screen, and drying the cleaned coconut shell charcoal particles to obtain a coconut shell charcoal carrier; d, mixing an organic photovoltaic material and chloroform according to the following weight ratio to prepare an organic semiconductor mixed solution: 0.003-0.006 g of the organic photovoltaic material and 10-20 mL of chloroform, wherein the organic photovoltaic material is PM6: Y6 or PM6: ITCPTC or PM6: Y6: ITCPTC; and E, uniformly coating a coconut shell charcoal carrier with the organic semiconductor mixed solution obtained in the step D, heating to 50-60 DEG C, and preserving heat for 18-24 hours to obtain the narrow-band-gap organic semiconductor carbon composite photocatalyst for degrading ciprofloxacin. The method provided by the invention has the advantages of simple process, low cost, greenness, stability and reusability, and the obtained catalyst has good photocatalytic performance and can effectively remove organic pollutants such as antibiotic ciprofloxacin and the like in medical wastewater.

Description

Technical Field

[0001] The invention relates to the technical field of functional material preparation, in particular to a method for preparing a photocatalyst for degrading ciprofloxacin using a narrow-bandgap organic semiconductor-carbon composite material. Background Art

[0002] Antibiotics have been widely and long-term used in modern medicine, but their overuse and delayed metabolism have adverse effects on the ecosystem and create a source of pollution that is difficult to resolve. As an emerging organic pollutant, even at low concentrations, it may lead to the proliferation of drug-resistant bacteria, seriously threatening human health. Ciprofloxacin is a commonly used broad-spectrum antibiotic for the treatment of various bacterial infections. Ciprofloxacin residues have been found in water sources, agriculture and domestic waste. At present, the concentration in some medical wastewater has reached 20μg / L, and the concentration in its production wastewater is as high as 5mg / L. This pollutant is bioaccumulative and non-biodegradable, and its removal is of great significance to environmental remediation.

[0003] As an advanced oxidation process (AOPs), visible light-driven photocatalysis has a good application prospect in pollutant degradation. 3 N 4 The multiphase photocatalysis of traditional semiconductors has been proven to have a certain effect on the degradation of antibiotics. However, there are still some key scientific and technological problems in its photocatalytic technology, which has certain limitations in its widespread industrial application and is not conducive to the treatment of organic pollutants in medical wastewater. The main problems are:

[0004] (1) Most metal-based catalysts, such as Bi-based, TiO 2 , ferrite, etc., have a narrow light response range, an absorption band edge of about 300-400nm, can only be driven by ultraviolet light, and are insensitive to visible light absorption. Studies have shown that organic semiconductors are usually composed of polymers or small molecules with conjugated structures. Their efficient and rapid carrier dissociation, adjustable energy levels, and wide absorption range are conducive to photocatalysis in the visible light region, which can make up for the shortcomings of metal-based photocatalysts and have made progress in wastewater treatment. Therefore, the development of organic photocatalysts with high efficiency under visible light is conducive to achieving a breakthrough in the application of photocatalysts in industrial wastewater.

[0005] (2) In current research, most photocatalysts exist in the form of free powders, which have the disadvantages of small specific surface area and poor recyclability. Therefore, the loading process and recycling of photocatalysts are currently difficult problems that need to be solved urgently, and are also the key to the materialization and commercialization of photocatalytic technology.

[0006] Therefore, there is an urgent need to develop a method for preparing a photocatalyst that is reusable, has good photocatalytic performance, and can effectively treat medical wastewater containing antibiotics such as ciprofloxacin and its production wastewater. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a method for preparing a photocatalyst for degrading ciprofloxacin using a narrow-bandgap organic semiconductor-carbon composite material. The photocatalyst obtained by the method can overcome the shortcomings of poor recyclability, low reuse rate, narrow light absorption range and only being able to be driven by ultraviolet light, etc. of photocatalytic materials under existing technical conditions, thereby achieving long-term and effective use of the photocatalyst and effectively treating medical wastewater and production wastewater containing antibiotics such as ciprofloxacin.

[0008] The present invention solves the above technical problems with the following technical solutions:

[0009] The present invention provides a method for preparing a photocatalyst for degrading ciprofloxacin using a narrow-bandgap organic semiconductor carbon composite material, comprising the following steps:

[0010] A. Dry the waste coconut shell to constant weight to obtain crude charcoal;

[0011] B. Mechanically crush the crude charcoal and then put it into a tubular furnace for calcination, heating it from room temperature to 700°C and then keeping it at that temperature for 1h to 2h to obtain coconut shell charcoal particles;

[0012] C. Put the coconut shell charcoal particles into a pulverizer for pulverization, then put them into a 60-mesh sieve for cleaning, take the sieved coconut shell charcoal particles and dry them to obtain a coconut shell charcoal carrier;

[0013] D. preparing an organic semiconductor mixed solution by mixing an organic photovoltaic material and an organic solvent in the following weight ratio: 0.003-0.006 g of organic photovoltaic material: 10-20 mL of organic solvent, wherein the organic photovoltaic material is PM6:Y6 or PM6:ITCPTC or PM6:Y6:ITCPTC, PM6:Y6 and PM6:ITCPTC are mixed in a mass ratio of 1:1, and PM6:Y6:ITCPTC is mixed in a mass ratio of 1-2:1:1; and the organic solvent is chloroform;

[0014] E. The organic semiconductor mixed solution obtained in step D is uniformly coated on the coconut shell carbon carrier, and then heated to 50-60° C. and kept warm for 18 h to 24 h to obtain a narrow-bandgap organic semiconductor / carbon composite material photocatalyst for degrading ciprofloxacin.

[0015] In step A of the present invention, the drying process is to place the waste coconut shells in a forced air drying oven at 120-180° C. for drying.

[0016] In step B of the present invention, the calcining atmosphere of the tubular furnace is N2 atmosphere, and the heating rate was 5°C / min.

[0017] In step C of the present invention, the cleaning operation is: first rinse with tap water for 10 minutes and then soak with deionized water for 5 minutes, and then wash with deionized water for 5 times after soaking.

[0018] In step C of the present invention, the drying treatment is to place the washed coconut shell charcoal particles in an oven at 60° C. and dry them for 6-8 hours.

[0019] In step E of the present invention, the organic semiconductor mixed solution and the coconut shell carbon carrier are configured in a mass ratio of 1:1000 to 1:1500, coated on the coconut shell carbon carrier and heated until the organic solvent is completely volatilized.

[0020] The method of the present invention has the following beneficial effects:

[0021] (1) The present invention utilizes the photocatalyst obtained by compounding organic photovoltaic materials PM6, Y6, ITCPTC with carbon. The visible light absorption range of the organic photovoltaic material is 500-800nm ​​as measured by ultraviolet-visible diffuse reflectance spectroscopy, and the sunlight can be effectively utilized. Under the irradiation of simulated AM 1.5G sunlight, the organic photovoltaic material generates photogenerated electron-hole pairs, activates its catalytic activity, and photodegrades the fluoroquinolone antibiotic ciprofloxacin. Under the irradiation of visible light, the photogenerated electron-hole pairs react with water and oxygen to obtain active oxygen species such as superoxide free radicals, hydroxyl free radicals, holes, etc., which rapidly degrade ciprofloxacin and convert it into small molecular substances or carbon dioxide and water. The catalyst obtained by the method of the present invention has good photocatalytic performance and can effectively remove organic pollutants such as antibiotic ciprofloxacin in medical wastewater.

[0022] (2) The inherent porous structure and economy of the coconut shell charcoal used in the present invention enable it to function as a fixed photocatalyst carrier, that is, the coconut shell charcoal has many excellent properties such as being green and environmentally friendly, having a high porosity and a large specific surface area. Using coconut shell charcoal to load photocatalytic materials is beneficial to improving the overall photocatalytic performance.

[0023] (3) The preparation method of the present invention has the advantages of simple process, low cost, greenness, stability and reusability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a stability test chart of photocatalyst degradation of ciprofloxacin obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0026] Example 1

[0027] The method for preparing the photocatalyst for degrading ciprofloxacin by using the narrow bandgap organic semiconductor carbon composite material of the present invention comprises the following steps:

[0028] A. 50g of waste coconut shells were placed in an electric blast drying oven at 160°C for drying. After 3 days, the weight was weighed and dried to a constant weight, yielding about 22g of crude charcoal.

[0029] B. Put the crude charcoal obtained in step A into a wall-breaking machine for mechanical crushing for 2 minutes to obtain coconut shell charcoal particles, and then put the coconut shell charcoal particles into a tubular furnace for calcination at N 2 Under the atmosphere, the temperature was raised from the current room temperature to 700 °C at a rate of 5 °C / min and kept at that temperature for 1 h to obtain about 15 g of pure coconut shell charcoal particles;

[0030] C. Put the coconut shell charcoal particles obtained in step B into a wall breaking machine for mechanical crushing for 2 minutes, then put the crushed coconut shell charcoal into a 60-mesh sieve, take the sieved coconut shell charcoal particles, rinse them with tap water for 10 minutes and then soak them in deionized water for 5 minutes, wash them with deionized water 5 times after soaking, and then dry them in a 60°C oven for 8 hours to obtain 12g of coconut shell charcoal carrier;

[0031] D. mixing 0.006 g of the organic photovoltaic material PM6:Y6 with 20 ml of chloroform to obtain an organic semiconductor mixed solution, wherein the organic photovoltaic material PM6:Y6 is obtained by mixing PM6 and Y6 in a mass ratio of 1:1;

[0032] E. The organic semiconductor mixed solution obtained in step D is uniformly coated on the coconut shell carbon carrier, and then dried at 50° C. for 24 hours to obtain the narrow-bandgap organic semiconductor / carbon composite material photocatalyst for degrading ciprofloxacin of the present invention, wherein the organic semiconductor mixed solution and the coconut shell carbon carrier are configured in a mass ratio of 1:1000.

[0033] The narrow bandgap organic semiconductor carbon composite material photocatalyst for degrading ciprofloxacin prepared in this example was used to degrade ciprofloxacin, and the degradation rate of ciprofloxacin reached 95% in 60 minutes. Figure 1 As shown, after the cycle number reaches 25 times, the degradation rate of ciprofloxacin is still above 90%, indicating that the composite material has good stability and reusability.

[0034] Example 2

[0035] The method for preparing the photocatalyst for degrading ciprofloxacin by using the narrow bandgap organic semiconductor carbon composite material of the present invention comprises the following steps:

[0036] A. 50g of waste coconut shells were placed in an electric blast drying oven at 120°C for drying. After 4 days, the weight was weighed and dried to a constant weight, yielding about 24g of crude charcoal.

[0037] B. Put the crude charcoal obtained in step A into a wall-breaking machine for mechanical crushing for 2 minutes to obtain coconut shell charcoal particles, and then put the coconut shell charcoal particles into a tubular furnace for calcination at N 2 Under the atmosphere, the temperature was raised from the current room temperature to 700 °C at a rate of 5 °C / min and kept at this temperature for 2 h to obtain about 15 g of pure coconut shell charcoal particles;

[0038] C. Put the coconut shell charcoal particles obtained in step B into a wall breaking machine for mechanical crushing for 2 minutes, then put the crushed coconut shell charcoal into a 60-mesh sieve, take the sieved coconut shell charcoal particles, rinse them with tap water for 10 minutes and then soak them in deionized water for 5 minutes. After the soaking, wash them with deionized water for 5 times, and then dry them in a 60°C oven for 8 hours to obtain about 12g of coconut shell charcoal carrier;

[0039] D. mixing 0.006 g of an organic photovoltaic material PM6:ITCPTC with 20 ml of chloroform to obtain an organic semiconductor mixed solution, wherein the organic photovoltaic material PM6:ITCPTC is obtained by mixing PM6 and ITCPTC in a mass ratio of 1:1;

[0040] E. The organic semiconductor mixed solution obtained in step D is uniformly coated on the coconut shell carbon carrier, and then dried at 55° C. for 18 hours to obtain the narrow band gap organic semiconductor / carbon composite material photocatalyst for degrading ciprofloxacin of the present invention, wherein the organic semiconductor mixed solution and the coconut shell carbon carrier are configured in a mass ratio of 1:1500.

[0041] The narrow-bandgap organic semiconductor carbon composite material photocatalyst for degrading ciprofloxacin prepared in this example was used for the degradation of ciprofloxacin, and the degradation rate of ciprofloxacin reached 92.1% in 60 minutes.

[0042] Example 3

[0043] The method for preparing the photocatalyst for degrading ciprofloxacin by using the narrow bandgap organic semiconductor carbon composite material of the present invention comprises the following steps:

[0044] A. 50g of waste coconut shells were placed in an electric hot air drying oven at 180°C for drying. After 3 days, the weight was weighed and dried to a constant weight, yielding about 22g of crude charcoal.

[0045] B. Put the crude charcoal obtained in step A into a wall-breaking machine for mechanical crushing for 2 minutes to obtain coconut shell charcoal particles, and then put the coconut shell charcoal particles into a tubular furnace for calcination at N 2 Under the atmosphere, the temperature was raised from the current room temperature to 700 °C at a rate of 5 °C / min and kept at this temperature for 2 h to obtain about 15 g of pure coconut shell charcoal particles;

[0046] C. Put the coconut shell charcoal particles obtained in step B into a wall breaking machine for mechanical crushing for 2 minutes, then put the crushed coconut shell charcoal into a 60-mesh sieve, take the sieved coconut shell charcoal particles, rinse them with tap water for 10 minutes and then soak them in deionized water for 5 minutes, wash them with deionized water 5 times after soaking, and dry them in a 60°C oven for 8 hours to obtain the desired coconut shell charcoal carrier of about 12g;

[0047] D. mixing 0.004 g of an organic photovoltaic material PM6:Y6:ITCPTC with 10 ml of chloroform to obtain an organic semiconductor mixed solution, wherein the organic photovoltaic material PM6:Y6:ITCPTC is obtained by mixing PM6, Y6, and ITCPTC in a mass ratio of 2:1:1;

[0048] E. The organic semiconductor mixed solution obtained in step D is uniformly coated on the coconut shell carbon carrier, and then dried at 60° C. for 24 hours to obtain the narrow-bandgap organic semiconductor / carbon composite material photocatalyst for degrading ciprofloxacin of the present invention, wherein the organic semiconductor mixed solution and the coconut shell carbon carrier are configured in a mass ratio of 1:1000.

[0049] The narrow-bandgap organic semiconductor carbon composite material photocatalyst for degrading ciprofloxacin prepared in this example was used for degrading ciprofloxacin, and the degradation rate of ciprofloxacin reached 99% in 60 minutes.

[0050] Example 4

[0051] The method for preparing the photocatalyst for degrading ciprofloxacin by using the narrow bandgap organic semiconductor carbon composite material of the present invention comprises the following steps:

[0052] A. 50g of waste coconut shells were placed in an electric hot air drying oven at 150℃ for drying. After 3 days, the weight was weighed and dried to a constant weight, yielding about 22g of crude charcoal.

[0053] B. Put the crude charcoal obtained in step A into a wall-breaking machine for mechanical crushing for 2 minutes to obtain coconut shell charcoal particles, and then put the coconut shell charcoal particles into a tubular furnace for calcination at N 2 Under the atmosphere, the temperature was raised from the current room temperature to 700 °C at a rate of 5 °C / min and kept at that temperature for 1 h to obtain about 15 g of pure coconut shell charcoal particles;

[0054] C. Put the coconut shell charcoal particles obtained in step B into a wall breaking machine for mechanical crushing for 2 minutes, then put the crushed coconut shell charcoal into a 60-mesh sieve, take the sieved coconut shell charcoal particles, rinse them with tap water for 10 minutes and then soak them in deionized water for 5 minutes, wash them with deionized water 5 times after soaking, and dry them in a 60°C oven for 6 hours to obtain the desired coconut shell charcoal carrier of about 12g;

[0055] D. mixing 0.004 g of the organic photovoltaic material PM6:Y6 with 20 ml of chloroform to obtain an organic semiconductor mixed solution, wherein the organic photovoltaic material PM6:Y6 is obtained by mixing PM6 and Y6 in a mass ratio of 1:1;

[0056] E. The organic semiconductor mixed solution obtained in step D is uniformly coated on the coconut shell carbon carrier, and then dried at 50° C. for 20 h to obtain the narrow band gap organic semiconductor / carbon composite material photocatalyst for degrading ciprofloxacin of the present invention, wherein the organic semiconductor mixed solution and the coconut shell carbon carrier are configured in a mass ratio of 1:1500.

[0057] The narrow-bandgap organic semiconductor carbon composite material photocatalyst for degrading ciprofloxacin prepared in this example was used for degrading ciprofloxacin, and the degradation rate of ciprofloxacin reached 89% in 60 minutes.

[0058] Example 5

[0059] The method for preparing the photocatalyst for degrading ciprofloxacin by using the narrow bandgap organic semiconductor carbon composite material of the present invention comprises the following steps:

[0060] A. 50g of waste coconut shells were placed in an electric hot air drying oven at 120°C for drying. After 3 days, the weight was weighed and dried to a constant weight, yielding about 23g of crude charcoal.

[0061] B. Put the crude charcoal obtained in step A into a wall-breaking machine for mechanical crushing for 2 minutes to obtain coconut shell charcoal particles, and then put the coconut shell charcoal particles into a tubular furnace for calcination at N 2 Under the atmosphere, the temperature was raised from the current room temperature to 700 °C at a rate of 5 °C / min and kept at that temperature for 1 h to obtain about 15 g of pure coconut shell charcoal particles;

[0062] C. Put the coconut shell charcoal particles obtained in step B into a wall breaking machine for mechanical crushing for 2 minutes, then put the crushed coconut shell charcoal into a 60-mesh sieve, take the sieved coconut shell charcoal particles, rinse them with tap water for 10 minutes and then soak them in deionized water for 5 minutes, wash them with deionized water 5 times after soaking, and dry them in a 60°C oven for 6 hours to obtain the desired coconut shell charcoal carrier of about 12g;

[0063] D. mixing 0.004 g of an organic photovoltaic material PM6:ITCPTC with 20 ml of chloroform to obtain an organic semiconductor mixed solution, wherein the organic photovoltaic material PM6:ITCPTC is obtained by mixing PM6 and ITCPTC in a mass ratio of 1:1;

[0064] E. The organic semiconductor mixed solution obtained in step D is uniformly coated on the coconut shell carbon carrier, and then dried at 50° C. for 18 h to obtain the narrow-bandgap organic semiconductor carbon composite material of the present invention for degrading ciprofloxacin. The organic semiconductor mixed solution and the coconut shell carbon carrier are configured in a mass ratio of 1:1500.

[0065] The narrow-bandgap organic semiconductor carbon composite material photocatalyst for degrading ciprofloxacin prepared in this example was used for degrading ciprofloxacin, and the degradation rate of ciprofloxacin reached 87% in 60 minutes.

[0066] Example 6

[0067] The method for preparing the photocatalyst for degrading ciprofloxacin by using the narrow bandgap organic semiconductor carbon composite material of the present invention comprises the following steps:

[0068] A. 50g of waste coconut shells were placed in a 160℃ electric heating blast drying oven for drying. After 4 days, the weight was weighed and dried to a constant weight, yielding about 22g of crude charcoal.

[0069] B. Put the crude charcoal obtained in step A into a wall-breaking machine for mechanical crushing for 2 minutes to obtain coconut shell charcoal particles, and then put the coconut shell charcoal particles into a tubular furnace for calcination at N 2 Under the atmosphere, the temperature was raised from the current room temperature to 700 °C at a rate of 5 °C / min and kept at that temperature for 1 h to obtain about 15 g of pure coconut shell charcoal particles;

[0070] C. Put the coconut shell charcoal particles obtained in step B into a wall breaking machine for mechanical crushing for 2 minutes, then put the crushed coconut shell charcoal into a 60-mesh sieve, take the sieved coconut shell charcoal particles, rinse them with tap water for 10 minutes and then soak them in deionized water for 5 minutes, wash them with deionized water 5 times after soaking, and dry them in a 60°C oven for 8 hours to obtain about 12g of the required coconut shell charcoal carrier;

[0071] D. mixing 0.003 g of an organic photovoltaic material PM6:Y6:ITCPTC with 10 ml of chloroform to obtain an organic semiconductor mixed solution, wherein the organic photovoltaic material PM6:Y6:ITCPTC is obtained by mixing PM6, Y6, and ITCPTC in a mass ratio of 1:1:1;

[0072] E. The organic semiconductor mixed solution obtained in step D is uniformly coated on the coconut shell carbon carrier, and then dried at 50° C. for 20 h to obtain the narrow-bandgap organic semiconductor carbon composite material of the present invention for degrading ciprofloxacin. The organic semiconductor mixed solution and the coconut shell carbon carrier are configured in a mass ratio of 1:1000.

[0073] The narrow-bandgap organic semiconductor carbon composite material photocatalyst for degrading ciprofloxacin prepared in this example was used for degrading ciprofloxacin, and the degradation rate of ciprofloxacin reached 93% in 60 minutes.

Claims

1. A method for preparing a photocatalyst for the degradation of ciprofloxacin by a narrow-bandgap organic semiconductor carbon composite material, characterized in that: The method includes the following steps: A. Dry the waste coconut shells to constant weight to obtain crude charcoal; B. Mechanically crushing the crude charcoal and then calcining it in a tubular furnace, heating it from room temperature to 700°C and then keeping it at that temperature for 1 to 2 hours to obtain coconut shell charcoal particles; C. putting the coconut shell charcoal particles into a grinder for pulverization, then placing them on a 60-mesh sieve for cleaning, taking the sieved coconut shell charcoal particles, and drying them to obtain a coconut shell charcoal carrier; D. preparing an organic semiconductor mixed solution by mixing an organic photovoltaic material and chloroform in the following weight ratio: 0.003-0.006 g of organic photovoltaic material: 10-20 mL of chloroform, wherein the organic photovoltaic material is PM6:Y6 or PM6:ITCPTC or PM6:Y6:ITCPTC, wherein the PM6:Y6 and PM6:ITCPTC are mixed in a mass ratio of 1:1, and the PM6:Y6:ITCPTC is mixed in a mass ratio of 1-2:1:1; E. The organic semiconductor mixture obtained in step D is evenly coated on a coconut shell carbon support, and then heated to 50-60° C. and kept warm for 18-24 hours to obtain a narrow-bandgap organic semiconductor / carbon composite material photocatalyst for degrading ciprofloxacin.

2. The method for preparing a photocatalyst for degrading ciprofloxacin by using a narrow-bandgap organic semiconductor carbon composite material according to claim 1, characterized in that: In step A, the drying process is to place the waste coconut shells in a forced air drying oven at 120-180° C. for drying.

3. The method for preparing a photocatalyst for degrading ciprofloxacin by using a narrow-bandgap organic semiconductor carbon composite material according to claim 1 or 2, characterized in that: In step B, the calcination atmosphere of the tubular furnace is N2 atmosphere, and the heating rate is 5°C / min.

4. The method for preparing a photocatalyst for degrading ciprofloxacin by using a narrow-bandgap organic semiconductor carbon composite material according to claim 1 or 2, characterized in that: In step C, the cleaning operation is: first rinse with tap water for 10 minutes and then soak with deionized water for 5 minutes, and then wash with deionized water 5 times after soaking.

5. The method for preparing a photocatalyst for degrading ciprofloxacin by using a narrow-bandgap organic semiconductor carbon composite material according to claim 1 or 2, characterized in that: In step C, the drying process is to place the washed coconut shell charcoal particles in an oven at 60° C. and dry them for 6-8 hours.

6. The method for preparing a photocatalyst for degrading ciprofloxacin using a narrow-bandgap organic semiconductor carbon composite material according to claim 1 or 2, characterized in that: In step E, the organic semiconductor mixed solution and the coconut shell carbon support are prepared in a mass ratio of 1:1000 to 1:1500, coated on the coconut shell carbon support, and then heated until the organic solvent is completely volatilized.

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