A method for preparing an organic semiconductor photocatalyst, its products and applications

Abstract

This invention discloses a method for preparing an organic semiconductor photocatalyst, its product, and its application. The method selects water, thiourea dioxide, and hydrogen peroxide as solvent, reducing agent, and oxidizing agent, respectively, and treats reduced yellow GCN through a reduction-oxidation reaction to obtain an organic semiconductor photocatalyst with excellent photoelectric properties. This method has the advantages of high efficiency, simplicity, and economy.

Description

Technical Field

[0001] This invention belongs to the field of organic semiconductor photocatalyst technology, specifically relating to a method for preparing an organic semiconductor photocatalyst, its products, and applications. Background Technology

[0002] Semiconductor photocatalysis technology has opened up a new avenue for wastewater treatment. Compared to traditional water treatment methods, photocatalysis offers advantages such as mild operating conditions, simplicity, and high efficiency. However, common inorganic photocatalytic materials, such as TiO2, suffer from low visible light response levels, and the rapid recombination of photogenerated carriers in the bulk and surface of the catalyst during catalysis severely limit the actual efficiency of photocatalytic degradation of pollutants. Therefore, finding novel organic photocatalysts for efficient wastewater treatment remains a major challenge in the field of environmental remediation.

[0003] Photocatalyst research involves multiple disciplines such as catalysis, materials science, photochemistry, and the environment, making it quite challenging. Although significant progress has been made in improving the activity and stability of photocatalysts, practical application remains a long way off. Therefore, for photocatalysis and photocatalytic processes to be truly applied in real life, continued extensive research is needed to further enhance the activity and stability of catalysts. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments.

[0005] As one aspect of the present invention, the present invention provides a method for preparing an organic semiconductor photocatalyst, which comprises the following steps:

[0006] Sodium hydroxide was dissolved in water, and reduced yellow GCN was added. After stirring, thiourea dioxide was added and the mixture was heated to react. The mixture was filtered, and hydrogen peroxide was added and allowed to stand to oxidize and precipitate a yellow solid. The solid was washed and dried to obtain an organic semiconductor photocatalyst. The ratio of water, sodium hydroxide, thiourea dioxide, and reduced yellow GCN was 100-200 mL: 1.25-2.5 g: 2.5-5 g: 0.5-2 g.

[0007] As a preferred embodiment of the preparation method of the organic semiconductor photocatalyst of the present invention, the ratio of water, sodium hydroxide, thiourea dioxide, and reduced yellow GCN is 200mL:1.875g:3.75g:1.5g.

[0008] As a preferred embodiment of the preparation method of the organic semiconductor photocatalyst of the present invention, the temperature of the heating reaction is 50-70°C and the heating time is 20-50 min.

[0009] As a preferred embodiment of the preparation method of the organic semiconductor photocatalyst of the present invention, the heating reaction is carried out at a temperature of 60°C for a heating time of 30 min.

[0010] As a preferred embodiment of the preparation method of the organic semiconductor photocatalyst of the present invention, the volume ratio of hydrogen peroxide to water is 1:100 to 200.

[0011] As a preferred embodiment of the preparation method of the organic semiconductor photocatalyst of the present invention: the drying is carried out at a temperature of 45-60°C for a time of 5-8 hours.

[0012] As a preferred embodiment of the preparation method of the organic semiconductor photocatalyst of the present invention, the filter paper used for vacuum filtration has a pore size of 80-120 μm.

[0013] As a preferred embodiment of the preparation method of the organic semiconductor photocatalyst of the present invention, the stirring time is 10-20 min.

[0014] The beneficial effects of the present invention are as follows: The present invention relates to a method for preparing an organic semiconductor photocatalyst. The method selects water, thiourea dioxide and hydrogen peroxide as solvent, reducing agent and oxidizing agent respectively, and treats reduced yellow GCN through reduction-oxidation reaction to obtain an organic semiconductor photocatalyst with excellent photoelectric properties. The method has the advantages of high efficiency, simplicity and economy. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0016] Figure 1 The images are SEM images processed for Comparative Example 1 and Example 1.

[0017] Figure 2 To investigate the photocatalytic degradation rate of RhB solution by an organic semiconductor photocatalyst in Example 1 with the addition of different free radical scavengers.

[0018] Figure 3 The photocurrent response curves of the organic semiconductor photocatalysts prepared in Comparative Example 1, Comparative Example 2, and Example 1 are shown. Detailed Implementation

[0019] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0020] Test method:

[0021] Photocatalytic performance test: 0.1g of sample was dispersed in 100mL of 10mg / L RhB (Rhodamine B) solution and stirred in the dark for 30min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated sunlight (UV-Vis light) (300W xenon lamp). The liquid was centrifuged every 10min, and the absorbance of the supernatant was measured. The pollutant concentration degradation efficiency was calculated using the following equation:

[0022] η=(C0-C t ) / C0×100%

[0023] In the formula, η represents the removal rate (%) of pollutants;

[0024] CO - Initial concentration of pollutants (mg / L);

[0025] C t - The concentration of pollutants (mg / L) at time t during the reaction process.

[0026] Free radical capture experiment: In a typical photocatalytic degradation reaction, the main active components are ·O 2- Since free radicals such as OH- and h+ are present, detecting the dominant active species in the photocatalytic system is essential for elucidating the photocatalytic degradation mechanism. Different free radical quenchers were added to the photocatalytic degradation reaction mixture to study its main active components.

[0027] To investigate the photocatalytic mechanism of reduced yellow GCN photocatalyst and explore the photocatalytically active groups in the photocatalyst, an active group capture experiment was conducted. 1 mL of p-benzoquinone solution, disodium ethylenediaminetetraacetate solution, and tert-butanol solution were added to 0.1 g of reduced yellow GCN photocatalyst and 100 mL of a 10 mg / L RhB mixed solution. The mixture was then magnetically stirred for 30 min in the dark, followed by irradiation under simulated ultraviolet-visible light (300 W xenon lamp). After 60 min, the solution was collected, centrifuged, and the absorbance of the supernatant was measured and analyzed.

[0028] Photocurrent testing: Photocurrent was measured using a CHU660D electrochemical workstation from Shanghai Chenhua Co., Ltd. A three-electrode system was employed: the photocatalyst electrode as the working electrode, the Pt electrode as the counter electrode, and the Ag / AgCl electrode as the reference electrode. The initial potential was the open-circuit potential, and the light source was simulated ultraviolet-visible light (300W xenon lamp), with the lamp switched on and off every 20 seconds. The electrolyte was a 0.5M Na₂SO₄ solution. The transient photocurrent response intensity measurement can also provide valid evidence for demonstrating the charge separation capability of the photocatalyst.

[0029] The structural formula for reduced yellow GCN is as follows:

[0030]

[0031] Example 1:

[0032] First, 200 mL of deionized water was measured into a flask using a graduated cylinder. Then, 1.875 g of sodium hydroxide was weighed and added to the flask, stirred until dissolved. Next, 1.5 g of Reduced Yellow (GCN) was weighed and added to the flask while stirring, and the mixture was stirred for 10 min. Then, 3.75 g of thiourea dioxide was weighed and added to the flask, which was then immediately placed in an oil bath and heated at 60 °C for 30 min. After the reaction was complete, the solution was filtered using a Buchner funnel to remove impurities; the filter paper had a pore size of 100 μm. 2 mL of hydrogen peroxide was added to the treated solution, and the mixture was allowed to stand for 24 h for oxidation. The solution was collected using a centrifuge and washed several times with deionized water. Subsequently, the solution was dried in an oven at 50 °C for 5 h. The resulting sample is the Reduced Yellow (GCN) photocatalyst material.

[0033] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the degradation efficiency was calculated.

[0034] Example 2:

[0035] First, 200 mL of deionized water was added to a flask. Then, 1.875 g of sodium hydroxide was added to the flask and stirred until dissolved. Next, 1.5 g of Reduced Yellow GCN was added to the flask while stirring, and the mixture was stirred for 10 min. Then, 2.5 g of thiourea dioxide was added to the flask, and the flask was immediately placed in an oil bath and heated at 60 °C for 30 min. After the reaction was complete, the solution was filtered using a Buchner funnel to remove impurities. 2 mL of hydrogen peroxide was added to the treated solution, and the mixture was allowed to stand for 24 h for oxidation. The solution was collected using a centrifuge and washed several times with deionized water. Subsequently, the solution was dried in an oven at 50 °C for 5 h. The resulting sample is the Reduced Yellow GCN photocatalyst material.

[0036] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the degradation efficiency was calculated.

[0037] Example 3:

[0038] First, 200 mL of deionized water was added to a flask. Then, 1.875 g of sodium hydroxide was added to the flask and stirred until dissolved. Next, 1.5 g of Reduced Yellow (GCN) was added to the flask while stirring, and the mixture was stirred for 10 min. Then, 5 g of thiourea dioxide was added to the flask, and the flask was immediately placed in an oil bath and heated at 60°C for 30 min. After the reaction was complete, the solution was filtered using a Buchner funnel to remove impurities. 2 mL of hydrogen peroxide was added to the treated solution, and the mixture was allowed to stand for 24 h for oxidation. The solution was collected using a centrifuge and washed several times with deionized water. Subsequently, the solution was dried in an oven at 50°C for 5 h. The resulting sample is the Reduced Yellow (GCN) photocatalyst material.

[0039] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the degradation efficiency was calculated.

[0040] Example 4:

[0041] First, 200 mL of deionized water was added to a flask, followed by 1.25 g of sodium hydroxide. The mixture was stirred until dissolved. Then, 1.5 g of reduced yellow GCN was added to the flask while stirring, and the mixture was stirred for 10 min. Next, 3.75 g of thiourea dioxide was added to the flask, and the flask was immediately placed in an oil bath and heated at 60 °C for 30 min. After the reaction was complete, the solution was filtered using a Buchner funnel to remove impurities. 2 mL of hydrogen peroxide was added to the treated solution, and the mixture was allowed to stand for 24 h for oxidation. The solution was collected using a centrifuge and washed several times with deionized water. Subsequently, the solution was dried in an oven at 50 °C for 5 h. The resulting sample is the reduced yellow GCN photocatalyst material.

[0042] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the degradation efficiency was calculated.

[0043] Example 5:

[0044] First, 200 mL of deionized water was added to a flask, followed by 2.5 g of sodium hydroxide. The mixture was stirred until dissolved. Then, 1.5 g of Reduced Yellow (GCN) was added to the flask while stirring, and the mixture was stirred for 10 min. Next, 3.75 g of thiourea dioxide was added to the flask, and the flask was immediately placed in an oil bath and heated at 60 °C for 30 min. After the reaction was complete, the solution was filtered using a Buchner funnel to remove impurities. 2 mL of hydrogen peroxide was added to the treated solution, and the mixture was allowed to stand for 24 h for oxidation. The solution was collected using a centrifuge and washed several times with deionized water. Subsequently, the solution was dried in an oven at 50 °C for 5 h. The resulting sample is the Reduced Yellow (GCN) photocatalyst material.

[0045] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the degradation efficiency was calculated.

[0046] Compare with Example 1:

[0047] The purchased reduced yellow GCN material was washed several times with acetone solvent and deionized water to remove any impurities that might be present in the material. After centrifugation and drying, the resulting material was the standard reduced yellow GCN material. (All materials used in this invention's experiments were obtained using this method).

[0048] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the degradation efficiency was calculated.

[0049] Compare with Example 2:

[0050] First, measure 10 mL of concentrated sulfuric acid and add it to a beaker. Weigh 0.1 g of Reduced Yellow (GCN) and add it to the beaker, then sonicate until dissolved. Measure 100 mL of deionized water and add it to the beaker all at once; a solid precipitate will immediately form and remain suspended. Collect these solids by filtering them through a 0.45 μm membrane filter, wash them several times with deionized water, and then dry them in a 60°C oven for later use.

[0051] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the actual degradation efficiency was calculated.

[0052] Compare with Example 3:

[0053] First, add 50 mL of deionized water to a flask, then weigh 2.5 g of sodium hydroxide and add it to the flask, stirring until dissolved. Next, weigh 1.5 g of reduced yellow (GCN) and add it to the flask, stirring for 10 min. Then, weigh 5 g of sodium hydrosulfite and add it to the flask, immediately placing it in an oil bath and heating at 60°C for 30 min. After the reaction is complete, filter the solution through a 0.45 μm membrane filter, wash several times with deionized water, and then dry it in a 60°C oven for subsequent use.

[0054] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the actual degradation efficiency was calculated.

[0055] Compare with Example 4:

[0056] First, weigh 0.8g of Reduced Yellow GCN and add it to 120mL of water. Stir and mix well, then transfer it to a 150mL high-pressure reactor. After hydrothermal reaction at 120℃ for 2 hours, the product is washed with water and ethanol and dried for subsequent use.

[0057] 0.1 g of sample was dispersed in 100 mL of 10 mg / L RhB (Rhodamine B) solution and stirred in the dark for 30 min to reach adsorption-desorption equilibrium. Then, a photocatalytic degradation experiment was conducted under simulated UV-Vis light (300 W xenon lamp). Every 10 min, 5 mL of liquid was taken and centrifuged, and the absorbance of the supernatant was measured. The experiment was stopped after 120 min, and the degradation efficiency was calculated.

[0058] Table 1. Photocatalytic degradation rate of RhB solution by photocatalysts prepared by different treatments at 120 min.

[0059] Experimental protocol Example Degradation rate Between-group differences As is Compare with example (1) 0％ 0.036 Sulfuric acid treatment Compare with example (2) 70.66％ 0.01 Sodium hydrosulfite treatment Compare with example (3) 77.03％ 0.028 hydrothermal treatment Compare with example (4) 52.48％ 0.049 Thiourea dioxide treatment (3.75g) Example (1) 91.2％ 0.011 Thiourea dioxide treatment (2.5g) Example (2) 65.76％ 0.023 Thiourea dioxide treatment (5g) Example (3) 88.73％ 0.007 Thiourea dioxide treatment (3.75g) Example (4) 77.63％ 0.076 Thiourea dioxide treatment (3.75g) Example (5) 90.77％ 0.024

[0060] Figure 1The SEM images processed for Comparative Example 1 and Example 1 are shown below: (a) Comparative Example 1 × 10,000, (b) Comparative Example 1 × 50,000, (c) Example 1 × 60,000, and (d) Example 1 × 100,000.

[0061] like Figure 2 As shown, the addition of tert-butanol, benzoquinone, and disodium EDTA all reduced the photocatalytic degradation efficiency of reduced yellow GCN for pollutants to varying degrees. With the addition of benzoquinone and disodium EDTA, the photocatalytic degradation efficiency of reduced yellow GCN decreased sharply, indicating that... 2- and h + It is the main active component in this system. Meanwhile, the addition of tert-butanol also reduced the photodegradation rate of reduced yellow GCN, indicating that ·OH also plays a role in the photocatalytic degradation of pollutants by reduced yellow GCN.

[0062] Figure 3 The photocurrent response curves of the organic semiconductor photocatalysts are shown in the following figures: (a) Comparative Example 1, (b) Comparative Example 2, and (c) Example 1. Generally speaking, photocatalysts with higher photocurrent response intensity exhibit higher photogenerated carrier separation rates. Clearly, the modified catalyst samples have higher photocurrent response intensity than the original samples, with the catalyst obtained in Example 1 showing the highest photocurrent response intensity. These results indicate that the treatment method in Example 1 can effectively accelerate the separation of photogenerated carriers and improve photocatalytic activity.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. 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 be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. The application of an organic semiconductor photocatalyst in photocatalytic degradation reactions, characterized in that: The preparation method of the organic semiconductor photocatalyst consists of the following steps: Sodium hydroxide was dissolved in water, and reduced yellow GCN was added. After stirring, thiourea dioxide was added and the mixture was heated to react. The mixture was filtered, and hydrogen peroxide was added and allowed to stand to oxidize and precipitate a yellow solid. The solid was washed and dried to obtain an organic semiconductor photocatalyst. The ratio of water, sodium hydroxide, thiourea dioxide, and reduced yellow GCN was 200 mL: 1.875 g: 3.75 g: 1.5 g. The heating reaction is carried out at a temperature of 50~70℃ for 20~50 min.

2. The application according to claim 1, characterized in that: The heating reaction was carried out at a temperature of 60°C for 30 minutes.

3. The application according to claim 1 or 2, characterized in that: The volume ratio of hydrogen peroxide to water is 1:100~200.

4. The application according to claim 1 or 2, characterized in that: The drying process is carried out at a temperature of 45-60 ℃ for 5-8 h.

5. The application according to claim 1 or 2, characterized in that: The filter paper used for vacuum filtration has a pore size of 80~120 μm.

6. The application according to claim 1 or 2, characterized in that: The stirring time is 10-20 minutes.

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