Preparation of flexible perovskite quantum dot composite photoanode material and application thereof in photoelectrocatalytic antibiosis

Abstract

The application discloses a kind of preparation of flexible perovskite quantum dot composite photoanode material and its application in photoelectrocatalytic antibiosis.The flexible perovskite quantum dot composite photoanode material is obtained by using flexible conductive material as substrate, preparing perovskite quantum dots by room temperature anti-solvent method, and then depositing them on the flexible conductive substrate by electrodeposition method.The flexible perovskite quantum dot composite photoanode material obtained by the application has excellent bactericidal effect and recycling performance, can effectively and quickly kill bacteria, and can be directly washed and recycled by deionized water after use for reuse, overcoming the shortcomings of traditional perovskite quantum dots that are easily decomposed in water and traditional photocatalytic nanomaterials that cannot be recycled.Compared with ordinary photocatalytic nanomaterials, it is more green and environmentally friendly.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of photoelectrocatalysis, and particularly relates to a preparation of a flexible perovskite quantum dot composite photoanode material and application thereof in photoelectrocatalytic antibiosis. BACKGROUND

[0002] Drinking water safety is an important issue worldwide, and the existence of pathogenic microorganisms in water bodies has led to the spread of many diseases. In recent years, photocatalytic antibacterial technology has attracted widespread attention from researchers due to its advantages of few side effects, high antibacterial efficiency, no obvious drug resistance, etc. However, photocatalytic materials are mostly in the form of powder materials, which cannot be recycled and reused after entering the water body. Moreover, the photo-generated electron-hole pairs generated by photocatalysis are prone to recombination in a short time, reducing the catalytic efficiency. Photoelectrocatalytic sterilization technology is favored due to its ability to utilize a weak external voltage to significantly improve photocatalytic effect and efficiently solve environmental pollution problems. Meanwhile, since the catalyst is fixed on the conductive substrate, the catalyst material can be effectively recycled and reused, and this technology has the advantages of stronger disinfection capacity, green environmental protection, secondary recycling, no toxic by-products, and system self-cleaning, as well as low energy consumption, mild reaction conditions, wide application range, and reduced secondary pollution.

[0003] As a quantum dot nanomaterial with a perovskite crystal structure, perovskite quantum dots have high quantum yield, high photo-generated carrier mobility, long carrier lifetime, and other characteristics. When the external incident energy is higher than the band gap of the perovskite quantum dots, the electrons on the valence band are excited to jump from the valence band to the conduction band, generating photo-generated holes and photo-generated electrons. The photo-generated carriers undergo oxidation-reduction reactions with water and oxygen in the water body to generate superoxide free radicals with strong oxidizing properties, which can effectively kill Escherichia coli in the water body. However, in practical applications, perovskite quantum dots are prone to decomposition in the presence of water and air, affecting their performance. SUMMARY

[0004] Based on the deficiencies of the prior art, the present application provides a preparation of a flexible perovskite quantum dot composite photoanode material and application thereof in photoelectrocatalytic antibiosis. The FAPbX3 quantum dots modified by SiO2 coating are deposited onto the ITO conductive substrate by electrodeposition, and the perovskite quantum dot film is packaged with a self-adhesive graphite heat pad to prepare a photoanode catalytic material with good light response under standard sunlight and indoor light conditions.

[0005] The preparation method of the flexible perovskite quantum dot composite photoanode material of the present application comprises the following steps:

[0006] Step 1: The conductive substrate is sequentially placed in a cleaning agent, deionized water, isopropyl alcohol, and anhydrous ethanol, and is ultrasonically treated, dried in an oven at 60°C, and then placed in a UV-ozone device for treatment to improve the surface wettability of the glass substrate and reduce defects.

[0007] In Step 1, the conductive substrate is selected from one of the following transparent conductive substrates: PET, PEN, polyimide (PI), polycarbonate (PC), polydimethylsiloxane (PDMS), and thermoplastic polyurethane (TPU), but is not limited to the above.

[0008] In Step 1, the ultrasonic treatment time is 15-20 minutes.

[0009] In Step 1, the UV-ozone treatment time is 50-60 minutes.

[0010] Step 2: An electron transport layer is prepared using a spin coating method. Prepare the transport layer mother liquor by taking 1 mL of SnO2·2H2O, uniformly mixing it with 5 mL of deionized water, and diluting it to prepare the electron transport layer mother liquor. Place the conductive substrate treated in Step 1 on a spin coater and spin coat the electron transport layer mother liquor at a speed of 5000 rpm / s for 20 seconds. After spin coating, anneal on a 150°C hot plate for 30 minutes to obtain a SnO2 electron transport layer, which is placed in a desiccator for storage.

[0011] Step 3: Add formamidinium halide (FAX) and lead halide (PbX2) in a molar ratio of 1:1 to N,N-dimethylformamide (DMF) in a three-necked flask and stir for 20 minutes; add a mixture of oleic acid (OA) and oleylamine (OAM) in a volume ratio of 2:1 to the solution system and continue stirring for 10 minutes to complete the reaction; after the reaction is completed, a precursor solution is obtained. X represents halogen, selected from Cl, Br, or I.

[0012] Step 4: Add 100 μL of the precursor solution to 5 mL of toluene, stir for 10 minutes, then add 1 mL of tetramethyl orthosilicate (TMOS), and continue stirring for 10 minutes to obtain a SiO2@FAPbX3 quantum dot crude solution.

[0013] Step 5: Place the flexible conductive substrate with a deposited SnO2 electron transport layer prepared in Step 2 in a 0.5M sodium chloride solution containing 1 mg / mL of polydiallyldimethylammonium chloride (PDDA) and soak for 15 minutes to enrich the surface with a layer of positive charges, then rinse with deionized water and dry; another piece of zinc sheet with a size comparable to the flexible conductive substrate is cleaned with deionized water and dried.

[0014] Step 6: Take 2.5 mL of the SiO2@FAPbX3 quantum dot crude solution obtained in step 4, add 0.5 mL of an ascorbic acid aqueous solution with a concentration of 5 mg / mL, and adjust the pH value to 7.8 with 0.1M NaOH.

[0015] Step 7: Introduce argon into the solution obtained in step 6 for 10 minutes to sufficiently remove dissolved oxygen in the water, immerse the cleaned flexible conductive substrate and zinc sheet in the solution in parallel opposition, connect the flexible conductive substrate to the positive electrode of the direct current power supply, connect the zinc sheet to the negative electrode of the power supply, set the voltage to 2.8V, and deposit for 10 minutes to obtain a SiO2@FAPbX3 quantum dot film on the flexible conductive substrate.

[0016] Step 8: After taking out the device with the SiO2@FAPbX3 film deposited in step 7, blow dry it with nitrogen, and package it with a self-adhesive graphite heat-conducting gasket to obtain a flexible perovskite quantum dot composite photoanode material.

[0017] Application of the flexible perovskite quantum dot composite photoanode material in photoelectrocatalytic antibacterial applications.

[0018] The application scenario of the flexible perovskite quantum dot composite photoanode material is outdoor water bodies and indoor water body environments, and the main components of the antibacterial system include a photoanode antibacterial material, a counter electrode (platinum electrode), a direct current power supply, a PBS phosphate buffer, and target microorganisms.

[0019] The present application generates superoxide radicals with strong oxidizing properties through photoelectrocatalytic technology, which oxidizes bacteria through superoxide radicals, ultimately causing the lysis and death of bacteria.

[0020] The present application uses photoelectrocatalytic technology, which has spectral antibacterial properties and does not have bacterial species selectivity in terms of inactivation effect on bacteria.

[0021] The present application uses photoelectrocatalytic technology, which has the advantages of being green and environmentally friendly, recyclable, non-toxic and non-hazardous byproducts, and self-cleaning system, and has low energy consumption, mild reaction conditions, wide application range, and reduced secondary pollution.

[0022] In the invention patent of the previous application of the team, a perovskite solar cell driven photoelectrocatalytic system (CN118579888A), a photovoltaic self-driven antibacterial system is constructed, which uses a perovskite solar cell device as a photovoltaic driving module, WO3@WSe2 as a photoanode material, and platinum as a counter electrode, and good antibacterial effect is achieved. However, in this work, the perovskite solar cell as a driving module has a fixed voltage and current. However, in actual application scenarios, the intensity of sunlight may change, and the bias voltage can be flexibly changed with the light intensity, which can improve the photoelectric synergistic catalytic effect. In the present invention, a direct current power source is used as a photovoltaic driving module, and perovskite quantum dots are deposited on a flexible substrate as a photoanode material. The flexible substrate is more flexible in environmental applications, and the direct current power source can accurately and real-time control the output voltage and current value, achieving significant improvement in photoelectrocatalytic antibacterial efficiency.

[0023] The photoanode material SiO2@FAPbX3 light absorption layer used in the present invention generates separation of photo-generated electron-hole pairs under visible light excitation. In traditional perovskite quantum dot materials, electrons and holes will quickly recombine in a very short time, which limits the further application of perovskite quantum dot materials in the field of sterilization. In the present invention, under visible light irradiation, the separation of photo-generated electron-hole pairs inside the perovskite quantum dots is excited, and the photo-generated electrons are transferred to the Pt electrode as the counter electrode by an external direct current power source, achieving effective separation of photo-generated electron-hole pairs. This application method of photo / electricity synergistic catalytic sterilization solves the limitation of traditional photocatalytic materials due to the rapid recombination of photo-generated electron-hole pairs on their sterilization performance. Moreover, the photoanode material of the present invention can be directly washed and recycled for reuse after use.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibacterial application has a simple preparation method, good visible light utilization rate, and is easy to repeat and synthesize on a large scale.

[0026] 2. The flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibacterial application has multiple application scenarios and good antibacterial effect under AM 1.5G sunlight and indoor weak light environment.

[0027] 3. The flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibacterial application can effectively produce reactive oxygen free radicals and effectively kill E. coli in water within a short time. Compared with traditional photocatalysts, which achieve sterilization within 2-3 hours, the present invention can achieve efficient sterilization within 30 minutes.

[0028] 4、The application is used for the flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibiosis, the material has high flexibility, and the catalyst is fixed on the conductive substrate, which is easy to recycle and can be reused multiple times, and has the characteristics of green environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibiosis.

[0030] Figure 2 It is an XRD comparison diagram of Example 1 and Comparative Example 1 of the application.

[0031] Figure 3 It is a steady-state photoluminescence (PL) absorption spectrum diagram of Example 1, Example 2, Example 3, Comparative Example 1 of the application.

[0032] Figure 4 It is a photoelectrocatalytic antibiosis efficiency diagram of Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 of the application under AM 1.5G (a) and 5500K, 1000LUX (b).

[0033] Figure 5 It is a photoelectrocatalytic antibiosis efficiency diagram of Example 1, Comparative Example 1 of the application.

[0034] Figure 6 It is a bacterial scanning morphology diagram before and after photoelectrocatalytic antibiosis of Example 1 of the application. DETAILED DESCRIPTION

[0035] The embodiments of the application will be described in detail below, and the embodiments are implemented on the premise of the technical scheme of the application, and detailed implementation modes and specific operation processes are given, but the protection scope of the application is not limited to the following embodiments.

[0036] Example 1:

[0037] Step 1: Select polyethylene terephthalate (PET film) as the flexible perovskite quantum dot composite photoanode material substrate.

[0038] Step 2: Put the conductive glass substrate into the detergent, deionized water, isopropanol, and anhydrous ethanol in sequence and ultrasonically treat for 15-20 minutes, dry in a 60°C oven, and then place the cleaned conductive glass substrate in a UV-ozone device for 50-60 minutes to improve the surface wettability of the glass substrate and reduce defects.

[0039] Step 3: Prepare the electron transport layer by using the spin coating method. Prepare the transport layer mother liquor: take 1 mL of SnO2·2H2O, uniformly mix with 5 mL of deionized water, and dilute to prepare the electron transport layer mother liquor.

[0040] Step 4: The cleaned and dried PET conductive substrate was placed on a spin coater and spin-coated at a speed of 5000 rpm / s for 20 seconds. After spin-coating, the SnO2 electron transport layer was annealed on a 150°C hot plate for 30 minutes and placed in a desiccator for later use.

[0041] Step 5: 24 mg (2 mmol) of formamidinium bromide (FABr) and 72 mg (2 mmol) of lead bromide (PbBr2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-necked flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and stirring was continued for 10 minutes to complete the reaction. After the reaction was completed, a precursor solution was obtained.

[0042] Step 6: 100 μL of the precursor solution was added to 5 mL of toluene, and after stirring for 10 minutes, 1 mL of tetramethyl orthosilicate (TMOS) was added. After continuous stirring for 10 minutes, a SiO2@FAPbBr3 quantum dot crude solution was obtained.

[0043] Step 7: The flexible conductive substrate with SnO2 deposited as prepared above was immersed in a 0.5 M sodium chloride solution containing 1 mg / mL of polydiallyldimethylammonium chloride (PDDA) for 15 minutes to enrich the surface with a layer of positive charges, then rinsed with deionized water and dried. Another piece of zinc sheet with a size comparable to the flexible conductive substrate was cleaned with deionized water and dried.

[0044] Step 8: 2.5 mL of SiO2@FAPbBr3 quantum dot crude solution was taken, 0.5 mL of ascorbic acid aqueous solution with a concentration of 5 mg / mL was added, and the pH value was adjusted to 7.8 with 0.1 M NaOH.

[0045] Step 9: In the above solution, argon was bubbled for 10 minutes to remove dissolved oxygen in water. The cleaned flexible conductive substrate and zinc sheet were immersed in the solution in parallel. The flexible conductive substrate was connected to the positive electrode of a direct current power supply, and the zinc sheet was connected to the negative electrode of the power supply. The voltage was set to 2.8 V, and the deposition time was 10 minutes. SiO2@FAPbBr3 quantum dot thin film was obtained on the flexible conductive substrate.

[0046] Step 10: After the device with SiO2@FAPbBr3 thin film deposited in step 9 was taken out, it was dried with nitrogen and packaged with a self-adhesive graphite heat-conducting gasket. A flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibacterial was prepared.

[0047] Example 2:

[0048] Step 1: Select polyethylene terephthalate (PET film) as the flexible perovskite quantum dot composite photoanode material substrate.

[0049] Step 2: Place the conductive glass substrate in a detergent, deionized water, isopropanol, and anhydrous ethanol in sequence and ultrasonically treat for 15-20 minutes each. Dry in a 60°C oven, then place the cleaned conductive glass substrate in a UV-ozone device for 50-60 minutes to improve the surface wettability of the glass substrate and reduce defects.

[0050] Step 3: Use the spin coating method to prepare the electron transport layer. Prepare the transport layer stock solution: take 1 mL of SnO2·2H2O, mix it evenly with 5 mL of deionized water, and dilute it to prepare the electron transport layer stock solution.

[0051] Step 4: Place the cleaned and dried PET conductive substrate on a spin coater and spin coat it at a speed of 5000 rpm / s for 20 seconds. After spin coating, anneal it on a 150°C hot plate for 30 minutes to obtain the SnO2 electron transport layer, which is then placed in a desiccator for storage.

[0052] Step 5: Add 24 mg (2 mmol) of formamidinium chloride (FACl) and 72 mg (2 mmol) of lead chloride (PbCl2) to 2 mL of N,N-dimethylformamide (DMF) in a three-necked flask and stir for 20 minutes. Add 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) to the solution and continue stirring for 10 minutes to complete the reaction. After the reaction is complete, a precursor solution is obtained.

[0053] Step 6: Add 100 μL of the precursor solution to 5 mL of toluene and stir for 10 minutes. Then add 1 mL of tetramethyl orthosilicate (TMOS) and continue stirring for 10 minutes to obtain a SiO2@FAPbCl3 quantum dot crude solution.

[0054] Step 7: Place the flexible conductive substrate with SnO2 deposited on it into a 0.5M sodium chloride solution containing 1 mg / mL of polydiallyldimethylammonium chloride (PDDA) and soak it for 15 minutes to enrich the surface with a layer of positive charges. Then rinse it with deionized water and dry it. Also, wash a piece of zinc sheet with deionized water and dry it.

[0055] Step 8: Take 2.5 mL of the SiO2@FAPbCl3 quantum dot crude solution and add 0.5 mL of a 5 mg / mL aqueous ascorbic acid solution. Adjust the pH value to 7.8 with 0.1M NaOH.

[0056] Step 9: The above solution was bubbled with argon for 10 minutes to remove the dissolved oxygen in water, and a clean flexible conductive substrate was immersed in the solution in parallel with a zinc plate. The flexible conductive substrate was connected to the positive electrode of the DC power supply, and the zinc plate was connected to the negative electrode of the power supply. The voltage was set to 2.8V, and the deposition time was 10 minutes. SiO2@FAPbCl3 quantum dot film was obtained on the flexible conductive substrate.

[0057] Step 10: After the device with SiO2@FAPbBr3 thin film deposited in step 9 was taken out, it was dried with nitrogen, and a self-adhesive graphite heat-conducting pad was used for packaging. A flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibacterial was prepared.

[0058] Example 3:

[0059] Step 1: Select a conductive substrate. The transparent conductive substrate can be PET, PEN, polyimide (PI), polycarbonate (PC), polydimethylsiloxane (PDMS), and thermoplastic polyurethane (TPU), but is not limited to the above.

[0060] Step 2: The conductive glass substrate was sequentially placed in a detergent, deionized water, isopropanol, and anhydrous ethanol, and was ultrasonically treated for 15-20 minutes. It was then placed in a 60°C oven for drying, and then was placed in a UV-ozone device for 50-60 minutes to improve the surface wettability of the glass substrate and reduce defects.

[0061] Step 3: An electron transport layer was prepared by spin coating. A transport layer stock solution was prepared by diluting 1 mL of SnO2·2H2O with 5 mL of deionized water.

[0062] Step 4: The cleaned and dried PET conductive substrate was placed on a spin coater and was spin-coated at a speed of 5000 rpm / s for 20 seconds. After spin coating, the SnO2 electron transport layer was annealed on a 150°C hot plate for 30 minutes, and was then placed in a desiccator for storage.

[0063] Step 5: 24 mg (2 mmol) of formamidinium iodide (FAI) and 72 mg (2 mmol) of lead chloride (PbI2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-necked flask and were stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution, and the stirring was continued for 10 minutes to complete the reaction. After the reaction was completed, a precursor solution was obtained.

[0064] Step 6: 100 μL of precursor solution was added into 5 mL of toluene, after stirring for 10 minutes, 1 mL of tetramethyl orthosilicate (TMOS) was added, and the SiO2@FAPbI3 quantum dot crude solution was obtained after stirring for 10 minutes.

[0065] Step 7: The flexible conductive substrate deposited with SnO2 prepared in the previous step was immersed in a 0.5 M sodium chloride solution containing 1 mg / mL polydiallyldimethylammonium chloride (PDDA) for 15 minutes to enrich the surface with a layer of positive charges, and then washed with deionized water and dried. Another piece of zinc sheet with a size comparable to the flexible conductive substrate was cleaned with deionized water and dried.

[0066] Step 8: 2.5 mL of SiO2@FAPbI3 quantum dot crude solution was taken, 0.5 mL of ascorbic acid aqueous solution with a concentration of 5 mg / mL was added, and the pH value was adjusted to 7.8 with 0.1 M NaOH.

[0067] Step 9: In the above solution, argon was bubbled for 10 minutes to remove dissolved oxygen in water, and the cleaned flexible conductive substrate and zinc sheet were immersed in the solution in parallel. The flexible conductive substrate was connected to the positive electrode of the direct current power supply, and the zinc sheet was connected to the negative electrode of the power supply. The voltage was set to 2.8 V, and the deposition time was 10 minutes. SiO2@FAPbI3 quantum dot film was obtained on the flexible conductive substrate.

[0068] Step 10: After the device with SiO2@FAPbBr3 thin film deposited in step 9 was taken out, it was dried with nitrogen, and packaged with self-adhesive graphite heat-conducting pads. A flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibacterial was prepared.

[0069] Comparative Example 1:

[0070] Step 1: Polyethylene terephthalate (PET film) was selected as the flexible perovskite quantum dot composite photoanode material substrate.

[0071] Step 2: The conductive glass substrate was sequentially immersed in a detergent, deionized water, isopropanol, and anhydrous ethanol for 15-20 minutes of ultrasonic treatment each, dried in a 60°C oven, and then placed in a UV-ozone device for 50-60 minutes of treatment to improve the surface wettability of the glass substrate and reduce defects.

[0072] Step 3: The electron transport layer was prepared by spin coating. The transport layer mother liquor was prepared by diluting 1 mL of SnO2·2H2O with 5 mL of deionized water.

[0073] Step 4: The cleaned and dried PET conductive substrate was placed on a spin coater and spin coated at a speed of 5000 rpm / s for 20 seconds. After spin coating, the SnO2 electron transport layer was annealed on a 150°C hot plate for 30 minutes and placed in a desiccator for later use.

[0074] Step 5: 24 mg (2 mmol) of formamidinium bromide (FABr) and 72 mg (2 mmol) of lead bromide (PbBr2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-necked flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and stirring was continued for 10 minutes to complete the reaction. After the reaction was completed, a precursor solution was obtained.

[0075] Step 6: 100 μL of the precursor solution was added to 5 mL of toluene, and after stirring for 10 minutes, a crude FAPbBr3 quantum dot solution was obtained.

[0076] Step 7: The flexible conductive substrate with SnO2 deposited thereon was placed in a 0.5 M sodium chloride solution containing 1 mg / mL of polydiallyldimethylammonium chloride (PDDA) for 15 minutes to enrich the surface with a layer of positive charges, then rinsed with deionized water and dried. Another piece of zinc sheet with a size comparable to the flexible conductive substrate was cleaned with deionized water and dried.

[0077] Step 8: 2.5 mL of FAPbBr3 quantum dot crude solution was taken and 0.5 mL of ascorbic acid aqueous solution with a concentration of 5 mg / mL was added. The pH value was adjusted to 7.8 with 0.1 M NaOH.

[0078] Step 9: Argon was bubbled into the above solution for 10 minutes to remove dissolved oxygen in the water. The cleaned flexible conductive substrate and zinc sheet were immersed in the solution in parallel, with the flexible conductive substrate connected to the positive electrode of the direct current power supply and the zinc sheet connected to the negative electrode of the power supply. The voltage was set to 2.8 V and the deposition time was 10 minutes, resulting in a FAPbBr3 quantum dot film on the flexible conductive substrate.

[0079] Step 10: After the device with FAPbBr3 film deposited in step 9 was taken out, it was dried with nitrogen and packaged with a self-adhesive graphite heat-conducting gasket. A flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibacterial was prepared.

[0080] Comparative Example 2:

[0081] Step 1: 24 mg (2 mmol) of formamidinium bromide (FABr) and 72 mg (2 mmol) of lead bromide (PbBr2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-neck flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and the reaction was completed by continuing to stir for 10 minutes. After the reaction was completed, a precursor solution was obtained.

[0082] Step 2: 100 μL of the precursor solution was added to 5 mL of toluene, and after stirring for 10 minutes, 1 mL of tetramethyl orthosilicate (TMOS) was added. After stirring for 10 minutes, a crude SiO2@FAPbBr3 quantum dot solution was obtained.

[0083] Step 3: The crude SiO2@FAPbBr3 quantum dot solution synthesized was centrifuged at a speed of 7000 rpm / minute for 10 minutes to separate the quantum dots from the residual ligand solution. Next, the supernatant was removed, and the precipitate was dissolved in 2 mL of n-hexane and 6 mL of ethyl acetate. After drying, a SiO2@FAPbBr3 quantum dot powder was obtained.

[0084] Comparative Example 3:

[0085] Step 1: 24 mg (2 mmol) of formamidinium chloride (FACl) and 72 mg (2 mmol) of lead chloride (PbCl2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-neck flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and the reaction was completed by continuing to stir for 10 minutes. After the reaction was completed, a precursor solution was obtained.

[0086] Step 2: 100 μL of the precursor solution was added to 5 mL of toluene, and after stirring for 10 minutes, 1 mL of tetramethyl orthosilicate (TMOS) was added. After stirring for 10 minutes, a crude SiO2@FAPbCl3 quantum dot solution was obtained.

[0087] Step 3: The crude SiO2@FAPbCl3 quantum dot solution synthesized was centrifuged at a speed of 7000 rpm / minute for 10 minutes to separate the quantum dots from the residual ligand solution. Next, the supernatant was removed, and the precipitate was dissolved in 2 mL of n-hexane and 6 mL of ethyl acetate. After drying, a SiO2@FAPbCl3 quantum dot powder was obtained.

[0088] Comparative Example 4:

[0089] Step 1: 24 mg (2 mmol) of formamidinium chloride amine (FAI) and 72 mg (2 mmol) of lead chloride (PbI2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-neck flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and the reaction was completed by continuing to stir for 10 minutes. After the reaction was completed, a precursor solution was obtained.

[0090] Step 2: 100 μL of the precursor solution was added to 5 mL of toluene, and after stirring for 10 minutes, 1 mL of tetramethyl orthosilicate (TMOS) was added. After stirring for 10 minutes, a SiO2@FAPbI3 quantum dot crude solution was obtained.

[0091] Step 3: The synthesized SiO2@FAPbI3 quantum dot crude solution was centrifuged at a speed of 7000 rpm / minute for 10 minutes to separate the quantum dots from the residual ligand solution. Next, the supernatant was removed, and the precipitate was dissolved in 2 mL of n-hexane and 6 mL of ethyl acetate. After drying, SiO2@FAPbI3 quantum dot powder was obtained.

[0092] Comparative Example 5:

[0093] Step 1: 24 mg (2 mmol) of formamidinium bromide (FABr) and 72 mg (2 mmol) of lead bromide (PbBr2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-neck flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and the reaction was completed by continuing to stir for 10 minutes. After the reaction was completed, a precursor solution was obtained.

[0094] Step 2: 100 μL of the precursor solution was added to 5 mL of toluene, and after stirring for 10 minutes, a FAPbBr3 quantum dot crude solution was obtained.

[0095] Step 3: The synthesized FAPbBr3 quantum dot crude solution was centrifuged at a speed of 7000 rpm / minute for 10 minutes to separate the quantum dots from the residual ligand solution. Next, the supernatant was removed, and the precipitate was dissolved in 2 mL of n-hexane and 6 mL of ethyl acetate. After drying, FAPbBr3 quantum dot powder was obtained.

[0096] Comparative Example 6:

[0097] Step 1: 24 mg (2 mmol) of formamidinium chloride (FACl) and 72 mg (2 mmol) of lead chloride (PbCl2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-neck flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and the reaction was completed by stirring for another 10 minutes. After the reaction was completed, a precursor solution was obtained.

[0098] Step 2: 100 μL of the precursor solution was added to 5 mL of toluene, and a crude FAPbCl3 quantum dot solution was obtained after stirring for 10 minutes.

[0099] Step 3: The crude FAPbCl3 quantum dot solution synthesized was centrifuged at a speed of 7000 rpm / minute for 10 minutes to separate the quantum dots from the residual ligand solution. Then the supernatant was removed, and the precipitate was dissolved in 2 mL of n-hexane and 6 mL of ethyl acetate. After drying, FAPbCl3 quantum dot powder was obtained.

[0100] Comparative Example 7:

[0101] Step 1: 24 mg (2 mmol) of formamidinium chloride (FACl) and 72 mg (2 mmol) of lead chloride (PbCl2) were added to 2 mL of N,N-dimethylformamide (DMF) in a three-neck flask and stirred for 20 minutes. 100 μL of oleic acid (OA) and 50 μL of oleylamine (OAM) were added to the solution and the reaction was completed by stirring for another 10 minutes. After the reaction was completed, a precursor solution was obtained.

[0102] Step 2: 100 μL of the precursor solution was added to 5 mL of toluene, and a crude FAPbCl3 quantum dot solution was obtained after stirring for 10 minutes.

[0103] Step 3: The crude FAPbCl3 quantum dot solution synthesized was centrifuged at a speed of 7000 rpm / minute for 10 minutes to separate the quantum dots from the residual ligand solution. Then the supernatant was removed, and the precipitate was dissolved in 2 mL of n-hexane and 6 mL of ethyl acetate. After drying, FAPbCl3 quantum dot powder was obtained.

[0104] The bactericidal effect of the samples obtained in the above examples and comparative examples was tested as follows:

[0105] a. Preparation before experiment: several 15 mL glass test tubes, several 5 mL glass test tubes, several 1.5 mL centrifuge tubes, lactose bile salt fermentation medium (LB), lactose bile salt agar fermentation solid medium, PBS buffer were prepared, all were sterilized by high pressure steam (121℃, 40 minutes), standby, the lactose bile salt agar fermentation solid medium was cooled to 60℃, poured into plates, and waited for solidification to form solid culture plates.

[0106] b. Shake the bacteria: Take 15 mL glass test tubes, add 10-12 mL of lactose salt fermentation medium (LB), inoculate E. coli, and then place in a constant temperature shaker at 37°C, 160 rpm for 18-20 hours, so that the colony count reaches about 5 x 10 8 CFU / mL.

[0107] c. Use a pipette to take 3 μL of the bacterial solution obtained in step b and add it to 4 mL of deionized water, and shake until uniform.

[0108] d. Take 70 μL of the bacterial suspension obtained in step c and mix it in 70 mL of PBS buffer to obtain a mixture; under the light intensity and power selection conditions specified in each of the comparative examples and examples, use E. coli as the target microorganism to detect the antibacterial effect of each example and comparative example.

[0109] e. In the photoelectrocatalytic reaction box, adjust the xenon lamp to irradiate the photoelectrocatalytic reaction system in step d at an intensity of AM 1.5G or AM 0.75G, every 5 minutes use a pipette to take 50 μL of the bacterial solution from the solution, spread the plate, and place the culture dish in a constant temperature incubator for incubation (incubation temperature is 30-37°C, incubation time is 24-36 hours), and count.

[0110] f. After the experiment is completed, recover the used photoanode material sample, wash the surface of the sample with deionized water, and repeat the above experimental steps after the sample is naturally air dried, and record the number of colonies. The results of the bactericidal performance tests of the samples obtained in each example against E. coli and Staphylococcus aureus are shown in Tables 1 and 2.

[0111] Table 1 (target microorganism is E. coli)

[0112]

[0113]

[0114] Table 2 (target microorganism is Staphylococcus aureus)

[0115]

[0116] From the above table, the flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibiosis has spectral antibiosis, and can achieve effective antibiosis for both gram-negative bacteria and gram-positive bacteria. However, the antibiosis effect on gram-negative bacteria is better than that on gram-positive bacteria, because gram-positive bacteria have a thick peptidoglycan layer cell membrane and an external lipid membrane, while the cell wall of gram-negative bacteria is thin. The active oxygen free radicals generated by the flexible perovskite quantum dot composite photoanode material under the action of photoelectrocatalysis can more easily penetrate the cell membrane of gram-negative bacteria, causing damage to the cell membrane of bacteria, and ultimately leading to the death of bacteria.

[0117] Figure 1 The structure of the flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibiosis and the antibiosis system formed by the structure are shown in the schematic diagram.

[0118] Figure 2 The XRD comparison diagram of Example 1 and Comparative Example 1 is shown in the figure, and there are obvious characteristic peaks at the FAPbBr3 characteristic peak positions (100), (110), and Example 1 has an obvious peak position at the silicon oxide (101), which confirms the successful preparation of the SiO2@FAPbBr3 quantum dot film.

[0119] Figure 3 The steady-state photoluminescence spectrum (PL) of Examples 1-3 and Comparative Example 1 is shown in the figure, which is used to study the separation and transmission efficiency of carriers. Examples 1 and Comparative Example 1 emit light at a wavelength of 480-550 nm. Comparative Example 1 produces a stronger PL peak than Example 1, indicating that the SiO2@FAPbBr3 film has weaker non-radiative recombination than the SiO2@FAPbBr3 quantum dot photoelectrocatalyst. Reducing harmful non-radiative recombination can accelerate the effective transport rate of photo-generated carriers.

[0120] Figure 4 The photoelectrocatalytic antibiosis efficiency diagram of Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2 under AM 1.5G and 5500K1000LUX is shown in the figure, according to Table 1 and Figure 4The antibacterial efficiency can be seen. Examples 1-3 all show 100% antibacterial efficiency within 30 minutes, thanks to the effective absorption of visible light by the perovskite quantum dot film and the effective separation of photo-generated electron-hole pairs under an applied bias. The FAPbBr3 film prepared in Comparative Example 1 has low antibacterial efficiency because it is easily decomposed in the water environment due to the lack of SiO2 coating protection. The perovskite quantum dot powders coated with SiO2 prepared in Comparative Examples 2-4 do not show good antibacterial effect within 30 minutes because the photo-generated electron-hole pairs are quickly recombined, and the perovskite quantum dot powders without SiO2 coating prepared in Comparative Examples 5-7 are easily decomposed after entering the water body, and cannot achieve effective antibacterial within 30 minutes.

[0121] Figure 5 To observe the decrease in the number of bacteria in the same dose of culture solution as the photoelectrocatalysis process progresses, the bacterial plate coating photos of samples taken every 5 minutes during the 25-minute photoelectrocatalysis treatment of Example 1 of the present application are shown. It can be seen from the photos that the number of bacterial coating decreases sharply, proving that the content of active bacteria in the system decreases.

[0122] Figure 6 To observe the death of bacteria, the bacterial morphology scanning photos before and after the photoelectrocatalysis treatment of Example 1 of the present application are shown. It can be seen from the photos that the bacteria treated by the photoelectrocatalysis system driven by the perovskite solar photovoltaic cell designed in the present application have damaged morphology, ruptured structure, and lost bacterial body integrity, proving that the bacteria have died.

[0123] Obviously, the above examples are merely examples for clarity and do not limit the embodiments. Any person skilled in the art can modify or reform the above disclosed technology content into equivalent examples with equivalent changes. However, any simple modification, equivalent change and modification made to the above examples without departing from the technical solution of the present application and according to the technical essence of the present application still belongs to the protection scope of the technical solution of the present application.

Claims

1. A method for preparing a flexible perovskite quantum dot composite photoanode material for photoelectrocatalytic antibiosis, characterized in that The method comprises the following steps: (1) adding formamidinium halide and lead halide into N,N-dimethylformamide and stirring to disperse uniformly; adding oleic acid and oleylamine into the obtained solution system to obtain a precursor solution; adding the precursor solution into toluene, and then adding tetraoxymethylsilane to obtain a SiO2@FAPbX3 quantum dot crude solution; wherein X represents halogen selected from Cl, Br or I; (2) placing a flexible conductive substrate on which an SnO2 electron transport layer is deposited into a sodium chloride solution containing polydiallyldimethylammonium chloride to soak, so that a layer of positive charges is enriched on the surface of the flexible conductive substrate, and then washing with deionized water and blowing dry; another zinc sheet with a size comparable to that of the flexible conductive substrate is cleaned with deionized water and blown dry; (3) taking the SiO2@FAPbX3 quantum dot crude solution obtained in step (1), adding an ascorbic acid aqueous solution, and adjusting the pH value to 7.8 with a NaOH solution; then, argon is introduced into the obtained solution to remove dissolved oxygen in water; then, the flexible conductive substrate treated in step (2) and the zinc sheet are parallelly and oppositely immersed into the solution, the flexible conductive substrate is connected to the positive electrode of a direct current power supply, and the zinc sheet is connected to the negative electrode of the power supply, so that a SiO2@FAPbX3 quantum dot film is obtained on the flexible conductive substrate by electrodeposition; after blowing dry and packaging, a composite photoanode material is obtained.

2. The preparation method according to claim 1, characterized in that: in step (1), the oleic acid and the oleylamine are mixed at a volume ratio of 2:

1.

3. The preparation method according to claim 1, characterized in that: in step (1), the molar ratio of the formamidinium halide and the lead halide is 1:1; and the addition amount of the tetraoxymethylsilane is 0.5 mL / mmol FAPbX3.

4. The preparation method according to claim 1, characterized in that: in step (2), in the sodium chloride solution containing polydiallyldimethylammonium chloride, the concentration of the polydiallyldimethylammonium chloride is 1 mg / mL, and the concentration of the sodium chloride is 0.5 M.

5. The preparation method according to claim 1, characterized in that: in step (3), during the electrodeposition, the voltage is 2.8 V, and the deposition time is 10 minutes.

6. A photoelectrocatalytic antibacterial system, characterized in that: the photoelectrocatalytic antibacterial system comprises a flexible perovskite quantum dot composite photoanode prepared by the preparation method in any one of claims 1-5, a platinum counter electrode, a direct current power supply, a PBS phosphate buffer, and target microorganisms.

7. The photoelectrocatalytic antibacterial system according to claim 6, characterized in that: the target microorganisms include one or more of gram-negative bacteria and gram-positive bacteria.

8. The photoelectrocatalytic antibacterial system according to claim 7, characterized in that: the target microorganisms include Escherichia coli and / or Staphylococcus aureus.

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