Preparation method of polythiophene / FeOCl composite photocatalyst

Abstract

The invention relates to a preparation method of a polythiophene / FeOCl composite photocatalyst, and aims to solve the problems that the process conditions of the existing preparation method of an oxyferric chloride photocatalyst are harsh and ferric oxide impurities are easy to generate. The preparation method comprises the following steps: 1, dissolving a thiophene monomer in a dichloromethane or acetonitrile solvent; 2, dissolving anhydrous FeCl3 in an acetonitrile solvent; 3, under the stirring condition, dropwise adding the acetonitrile solution of FeCl3 into the thiophene solution, and after dropwise adding is completed, continuing stirring reaction to obtain a mixed reaction solution; and 4, pouring the mixed reaction solution into absolute ethyl alcohol for precipitation treatment, carrying out suction filtration and water washing on a solid-phase reactant, and drying to obtain the polythiophene / FeOCl composite photocatalyst. The polythiophene / FeOCl composite photocatalyst is prepared by adopting a one-step method, FeOCl is a 2D lamellar single crystal, polythiophene is nanoparticles and is uniformly attached to the surface of FeOCl, and polythiophene / FeOCl phase compounding has good photocatalytic performance.

Description

Technical Field

[0001] The invention relates to a method for preparing a polythiophene / FeOCl composite photocatalyst. Background Art

[0002] As a two-dimensional semiconductor photocatalyst, ferric chloride (FeOCl) has potential advantages such as a narrow band gap (~1.59 eV), a suitable energy level position, and good visible light response. It is an efficient photocatalytic material for degrading organic pollutants (Adv. Mater. 2022, 34, 2108847; Angew. Chem. Int. Ed. 2024, e202401972). Pyrolysis and chemical vapor transport are the two most commonly used methods for preparing FeOCl photocatalysts. The pyrolysis method is based on FeCl 3 6H 2 O is a precursor, heated at about 220 ° C, and the high temperature induces FeCl 3 and H 2 O reacts with HCl to form FeOCl photocatalyst. However, the chemical vapor transport law requires more stringent conditions to convert α-Fe 2 O 3 With anhydrous FeCl 3 Mix in a sealed glass container at a molar ratio of 1:1.3, and then heat at 380°C for 40h or 1 week (Current Pollution Reports 2023,9:143–164). In addition, FeOCl can also be prepared by other methods, such as liquid laser ablation (Phys.Rev.B.2000,62(21):57–63), hydrothermal method (J.Am.Chem.Soc.1995,117(36):9229–9242), etc. However, these methods require relatively harsh experimental conditions, such as high temperature, hydrothermal, negative pressure, etc., and iron oxide impurities will still exist in the prepared products. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the process conditions of the existing oxyferric chloride photocatalyst preparation method are relatively harsh and iron oxide impurities are easily generated, and to provide a method for preparing a polythiophene / FeOCl composite photocatalyst.

[0004] The preparation method of the polythiophene / FeOCl composite photocatalyst of the present invention is achieved by the following steps:

[0005] 1. dissolving thiophene monomer in dichloromethane or acetonitrile solvent to obtain thiophene solution;

[0006] 2. Anhydrous FeCl 3 Dissolve in acetonitrile solvent to obtain FeCl 3of acetonitrile solution;

[0007] 3. Under stirring conditions, FeCl 3 The acetonitrile solution is added dropwise to the thiophene solution, and after the addition is completed, the stirring reaction is continued for 6 to 48 hours to obtain a mixed reaction solution;

[0008] Fourth, pouring the mixed reaction liquid into anhydrous ethanol for precipitation treatment, filtering the solid phase reactant, washing with water, and drying to obtain a polythiophene / FeOCl composite photocatalyst;

[0009] In step 3, anhydrous FeCl 3 The molar ratio of thiophene monomer to thiophene monomer is (1-6):1.

[0010] The present invention directly prepares a polythiophene / FeOCl composite photocatalyst, wherein anhydrous FeCl 3 As an oxidant, it can initiate the polymerization of thiophene monomers to obtain polythiophene, and at the same time obtain FeOCl two-dimensional semiconductor photocatalyst. 3 The acetonitrile solution needs to be added slowly to the thiophene solution at a controlled dropping speed. If it is added too quickly, only polythiophene can be obtained, and the polythiophene / FeOCl composite photocatalyst cannot be obtained.

[0011] The preparation method of the polythiophene / FeOCl composite photocatalyst of the present invention has the following beneficial effects:

[0012] 1. The reaction can be carried out at room temperature and pressure without the need for high temperature, hydrothermal, negative pressure and other conditions. Traditional FeOCl preparation generally requires high temperature (above 200°C).

[0013] 2. The preparation of polythiophene / FeOCl composite photocatalyst is completed in one step, and the process is simple.

[0014] 3. The prepared FeOCl is a 2D lamellar single crystal, polythiophene is a nanoparticle and is evenly attached to the surface of FeOCl with good dispersion, and the polythiophene / FeOCl composite has good photocatalytic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The infrared spectrum of the polythiophene / FeOCl composite photocatalyst prepared in Example;

[0016] Figure 2 The XRD pattern of the polythiophene / FeOCl composite photocatalyst prepared in Example;

[0017] Figure 3 The SEM spectrum of the polythiophene / FeOCl composite photocatalyst prepared in Example;

[0018] Figure 4HAADF and EDS spectra of the polythiophene / FeOCl composite photocatalyst prepared in Example;

[0019] Figure 5 These are test graphs of the catalytic performance of the polythiophene / FeOCl composite photocatalyst prepared in the example, wherein the left graph is a test graph of the removal rate of Rhodamine B, and the right graph is a UV spectrum of Rhodamine B during the degradation process. DETAILED DESCRIPTION

[0020] Specific implementation method 1: The preparation method of the polythiophene / FeOCl composite photocatalyst of this implementation method is implemented according to the following steps:

[0021] 1. dissolving thiophene monomer in dichloromethane or acetonitrile solvent to obtain thiophene solution;

[0022] 2. Anhydrous FeCl 3 Dissolve in acetonitrile solvent to obtain FeCl 3 of acetonitrile solution;

[0023] 3. Under stirring conditions, FeCl 3 The acetonitrile solution is added dropwise to the thiophene solution, and after the addition is completed, the stirring reaction is continued for 6 to 48 hours to obtain a mixed reaction solution;

[0024] Fourth, pouring the mixed reaction liquid into anhydrous ethanol for precipitation treatment, filtering the solid phase reactant, washing with water, and drying to obtain a polythiophene / FeOCl composite photocatalyst;

[0025] In step 3, anhydrous FeCl 3 The molar ratio of thiophene monomer to thiophene monomer is (1-6):1.

[0026] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the molecular formula of the thiophene monomer in step 1 is C 4 H 4 S, structural formula is

[0027] Specific implementation method three: This implementation method is different from specific implementation method one or two in that the concentration of thiophene monomer in the thiophene solution in step one is 80 mmol / L to 200 mmol / L.

[0028] Specific embodiment 4: This embodiment is different from the specific embodiments 1 to 3 in that step 2 FeCl 3 FeCl in acetonitrile solution 3 The concentration is 500mmol / L~750mmol / L.

[0029] Specific embodiment 5: This embodiment is different from specific embodiments 1 to 4 in that the temperature of the stirring reaction in step 3 is 20-30°C.

[0030] Specific embodiment 6: This embodiment is different from the specific embodiments 1 to 5 in that the anhydrous FeCl 3 The molar ratio of thiophene monomer to thiophene monomer is (2-4):1.

[0031] Specific embodiment 7: This embodiment is different from the specific embodiments 1 to 6 in that the control of FeCl in step 3 3 The dropping speed of the acetonitrile solution is 0.2-0.3 mL / min.

[0032] This embodiment requires controlling FeCl 3 The acetonitrile solution is added dropwise to the thiophene solution at a rate of 1:1.

[0033] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that the stirring reaction is continued for 20 to 30 hours after the dropwise addition is completed in step three.

[0034] Specific embodiment 9: This embodiment is different from specific embodiments 1 to 8 in that the precipitation treatment time in step 4 is 18 to 26 hours.

[0035] Specific embodiment ten: This embodiment is different from any one of specific embodiments one to nine in that the drying temperature in step four is 50-70°C.

[0036] Embodiment: The preparation method of the polythiophene / FeOCl composite photocatalyst of this embodiment is implemented according to the following steps:

[0037] 1. Dissolve 12 mmol of thiophene monomer (1-thia-2,4-cyclopentadiene) in 100 mL of acetonitrile solvent to obtain a thiophene solution;

[0038] 2. 36 mmol of anhydrous FeCl 3 Dissolve in 50 mL of acetonitrile solvent to obtain FeCl 3 of acetonitrile solution;

[0039] 3. Under stirring at room temperature, FeCl 3 The acetonitrile solution was slowly added dropwise to the thiophene solution for 3 hours. After the addition was completed, the stirring reaction was continued for 24 hours to obtain a mixed reaction solution.

[0040] Fourth, the mixed reaction liquid was poured into anhydrous ethanol for precipitation treatment for 24 hours, the solid phase reactant was filtered and washed with water, and dried at 60°C to obtain a polythiophene / FeOCl composite photocatalyst.

[0041] Depend on Figure 1 It can be seen that 788cm -1 and 3078cm -1 Corresponding to the CH vibration mode of the thiophene ring in polythiophene, 486 cm -1 and 690cm -1 They correspond to the Fe-O symmetric and antisymmetric stretching vibrations in FeOCl, respectively, indicating that the preparation of polythiophene / FeOCl composite photocatalyst was completed in one step.

[0042] Depend on Figure 2 It can be seen that the XRD pattern of the polythiophene / FeOCl composite photocatalyst is well consistent with that of PDF#72-0619 (FeOCl), and the diffraction peak near 2θ=24° is attributed to the π-π stacking of the amorphous polythiophene main chain (J.Am.Chem.Soc.2009,131,17315-17320). This indicates that the one-step method is used to prepare the polythiophene / FeOCl composite photocatalyst.

[0043] Depend on Figure 3 It can be seen that in the prepared polythiophene / FeOCl composite photocatalyst, FeOCl is a 2D lamellar single crystal, and polythiophene is a nanoparticle and is uniformly attached to the surface of FeOCl, indicating that the preparation of the polythiophene / FeOCl composite photocatalyst was completed by a one-step method.

[0044] Depend on Figure 4 It can be seen from the HAADF and EDS characterization that the distribution of C and S elements is consistent, indicating that the prepared composite photocatalyst contains polythiophene; the distribution of Fe, O and Cl elements is consistent, indicating that the prepared composite photocatalyst contains FeOCl. Combined with the HAADF diagram, it can be seen that FeOCl is a 2D lamellar structure, and polythiophene is a nanoparticle and is uniformly attached to the surface of FeOCl, which is consistent with the previous other characterization results, indicating that the preparation of polythiophene / FeOCl composite photocatalyst was completed in one step.

[0045] The process of photocatalytic experiment using the polythiophene / FeOCl composite photocatalyst of this embodiment is as follows:

[0046] 10 mg of polythiophene / FeOCl composite photocatalyst powder was evenly dispersed in 50 ml of deionized water and ultrasonicated for 15 min. Then 250 μL of rhodium B solution was added and 1 ml of hydrogen peroxide (H 2 O 2), stir in the dark for 30 minutes (500r / min). After stirring in the dark, irradiate vertically with a 300W xenon lamp equipped with a 420nm filter, connect 25℃ condensed water to keep the reactor temperature stable, and carry out photocatalytic degradation experiments under continuous stirring (500r / min). During the reaction, take a sample every 1 minute, take out the sample, seal it and place it in a dark place. After the photocatalytic degradation experiment is completed, the taken sample will continue to stand in the dark for 24 hours. After the placement is completed, take the supernatant and detect it with a UV spectrophotometer.

[0047] In this example, rhodamine B (RhB, Chinese name: 9-(2-carboxyphenyl)-3,6-bis(diethylamino)xanthine chloride, molecular formula: C 28 H 31 C1N 2 O 3 ) was used as the target pollutant, and the catalytic performance of the prepared polythiophene / FeOCl composite photocatalyst was investigated. The results are shown in the attached figure. Figure 5 As shown. After 5 minutes of photocatalytic degradation, the removal rate of RhB can reach 90%. From the UV spectrum of RhB during the degradation process, it can be seen that with the extension of light irradiation time, the intensity of the characteristic peak of RhB (at ~553nm) gradually decreases. The experimental results show that the prepared catalyst has excellent photocatalytic degradation activity.

Claims

1. A method for preparing a polythiophene / FeOCl composite photocatalyst, characterized in that The preparation method is achieved by the following steps:

1. dissolving thiophene monomer in dichloromethane or acetonitrile solvent to obtain thiophene solution; 2. dissolving anhydrous FeCl3 in acetonitrile solvent to obtain an acetonitrile solution of FeCl3; 3. Under stirring conditions, add the acetonitrile solution of FeCl3 dropwise to the thiophene solution, and continue stirring and reacting for 6 to 48 hours after the addition is completed to obtain a mixed reaction solution; Fourth, pouring the mixed reaction liquid into anhydrous ethanol for precipitation treatment, filtering the solid phase reactant, washing with water, and drying to obtain a polythiophene / FeOCl composite photocatalyst; In step 3, the molar ratio of anhydrous FeCl3 and thiophene monomer is controlled to be (1-6):

1.

2. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that The molecular formula of the thiophene monomer described in step 1 is C4H4S, and the structural formula is 3. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that In step 1, the concentration of thiophene monomer in the thiophene solution is 80 mmol / L to 200 mmol / L.

4. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that Step 2: The concentration of FeCl3 in the acetonitrile solution of FeCl3 is 500mmol / L to 750mmol / L.

5. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that The temperature of the stirring reaction in step 3 is 20-30°C.

6. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that In step 3, the molar ratio of anhydrous FeCl3 and thiophene monomer is controlled to be (2-4):

1.

7. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that In step 3, the dropping speed of the acetonitrile solution of FeCl3 is controlled to be 0.2-0.3 mL / min.

8. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that After the dropwise addition in step 3 is completed, the reaction is continued with stirring for 20 to 30 hours.

9. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that The precipitation treatment time in step 4 is 18 to 26 hours.

10. The method for preparing the polythiophene / FeOCl composite photocatalyst according to claim 1, characterized in that The drying temperature in step 4 is 50-70°C.

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