An ultrasonic-visible light dual-energy driven bismuth ferrite-indium zinc sulfide-silver composite catalyst and a preparation method and application thereof

Abstract

The application relates to a bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by ultrasonic and visible light, and a preparation method and application thereof, wherein the preparation method comprises the following steps: S1. hollow bismuth ferrite core preparation: taking bismuth nitrate and iron nitrate as raw materials, adding a solvent, heating to obtain a precursor powder, calcining the precursor powder to obtain a crude product, and washing and drying the crude product to obtain the hollow bismuth ferrite core; S2. shell-core type bismuth ferrite-indium zinc sulfide heterojunction preparation: taking zinc chloride, indium chloride and thioacetamide as raw materials, adding a solvent, adding the hollow bismuth ferrite after mixing, dispersing, heating and reacting to obtain the shell-core type bismuth ferrite-indium zinc sulfide heterojunction; and S3. composite catalyst preparation: dispersing the heterojunction powder into a solvent, adding silver nitrate, mixing in the dark, heating and reacting, collecting the precipitate, washing and drying the precipitate, heating and stirring the precipitate in acetone, filtering, and drying to obtain the composite catalyst. The composite catalyst can form an inner core piezoelectric field, a heterojunction interface and an outer layer Mott-Schottky potential barrier, realizes ultrasonic and visible light dual-energy driving, activates persulfate and degrades organic pollutants.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of material science and catalysis, in particular to a BiFeO3-InZnS-Ag composite catalyst driven by ultrasonic and visible light, a preparation method and application thereof. BACKGROUND

[0002] Due to diet, drinking, smoking and other lifestyle factors, most Asian countries are high-risk areas for gastrointestinal cancer. In order to effectively relieve and cure gastrointestinal cancer, nizatidine (NTZ) drugs are synthesized and added as main components in omeprazole, lansoprazole, pantoprazole and other drugs. NTZ is the third generation of H2 receptor antagonists, which contains thiazole ring, secondary amine group and tertiary amine group in its structure, is a fully synthetic drug, has the effect of inhibiting gastric acid secretion, can reduce pepsin activity, inhibit gastric acid secretion, protect gastric mucosa, and treat gastric ulcer and duodenal ulcer gastric diseases. However, NTZ cannot be completely metabolized in the body after use, and will be excreted with urine and feces and finally enter the water environment, and can produce harmful N-nitrosodimethylamine (NDMA) after natural oxidation. NDMA in the environment shows cytotoxicity, genotoxicity and carcinogenicity, and has serious public health risks. Therefore, NDMA has been listed as a B2 hazardous compound by the US Environmental Protection Agency. In the face of the threat of nizatidine pollutants and derivatives in the environment to human health and ecological environment, it is necessary to select a high-efficiency, green and economical method to degrade nizatidine wastewater.

[0003] The persulfate-driven advanced oxidation technology can efficiently degrade organic pollutants containing nizatidine substances, but in general, persulfate is stable in nature and is difficult to generate active substances to degrade pollutants. Therefore, it is necessary to design a new type of high-efficiency catalyst to promote the persulfate advanced oxidation technology to treat nizatidine wastewater in a more efficient, green and economical way. SUMMARY

[0004] The present application provides a BiFeO3-InZnS-Ag composite catalyst driven by ultrasonic and visible light, a preparation method and application thereof, aiming to strengthen the persulfate advanced oxidation technology with the new type of high-efficiency catalyst to effectively degrade nizatidine organic pollutants.

[0005] The technical solution of the present application to solve the above technical problems is as follows: a preparation method of a BiFeO3-InZnS-Ag composite catalyst driven by ultrasonic and visible light, comprising the following steps:

[0006] S1. Hollow bismuth ferrite core preparation: Bi(NO3)3.5H2O and Fe(NO3)3.9H2O are mixed in an equimolar ratio, a mixed alcohol solvent is added, stirring at room temperature until the solution is clear, transferred to a reaction kettle, heated to fully react, cooled to room temperature after the reaction is completed, the precipitate is collected by centrifugation, washed and dried in vacuum to obtain bismuth ferrite precursor powder, then the precursor powder is transferred to a tube furnace and uniformly heated to 560℃, calcined for 1.5h or more, cooled to room temperature, washed and dried to obtain hollow bismuth ferrite powder with piezoelectric effect, ready for use;

[0007] S2. Shell-core type bismuth ferrite-indium zinc sulfide heterojunction preparation: ZnCl2, InCl3.4H2O and thioacetamide are added to a mixed solvent one composed of dimethylformamide, glycerol and deionized water in a molar ratio of 1:2:4, after fully stirring and mixing, the hollow bismuth ferrite powder prepared in S1 is added, fully stirred and ultrasonically dispersed at room temperature to obtain a dispersion liquid, the dispersion liquid is transferred to a reaction kettle for heating reaction, cooled to room temperature after the reaction is completed, filtered, washed and dried to obtain shell-core type bismuth ferrite-indium zinc sulfide heterojunction powder, ready for use;

[0008] S3. Preparation of composite catalyst: the shell-core type bismuth ferrite-indium zinc sulfide heterojunction powder prepared in S2 is dispersed in mixed solvent two of DMF and ethylene glycol, silver nitrate powder is added, mixed under room temperature and light shielding condition to obtain a mixed liquid, the mixed liquid is transferred to a reaction kettle, heated at 170-210℃ for 1.5-4h, then the precipitate is collected by centrifugation, washed and dried, the obtained solid powder is added to acetone, heated and stirred at 45-65℃ for 8-12h, then filtered and dried to obtain an ultrasonic visible light dual-energy driven bismuth ferrite-indium zinc sulfide-silver composite catalyst.

[0009] On the basis of the above technical solutions, the application can also be further specifically selected or more optimally selected as follows.

[0010] Preferably, the mixed alcohol solvent in S1 is glycerol, ethanol and isopropanol mixed in a volume ratio of 3:1:15-20, and the amount ratio of Bi(NO3)3.5H2O to the mixed alcohol solvent is 0.029mol:110-150mL.

[0011] Specifically, the solution in S1 is clear and the heating reaction after being transferred to the reaction kettle is under the condition that the reaction temperature is maintained at 215℃, static heating for 10h or more, the centrifugation speed is 5000rpm when the reaction is completed, the precipitate is washed with water and ethanol alternately for three times, vacuum dried at 60℃ for 12h to obtain the bismuth ferrite precursor powder, the heating rate of the precursor powder transferred to the tube furnace is controlled at 2℃ / min, and the specific operation of washing and drying the hollow bismuth ferrite crude product is to wash it with nitric acid and acetic acid alternately for three times, and finally wash it with deionized water to neutral.

[0012] Preferably, the mixed solvent one in S2 is dimethylformamide, glycerol and deionized water mixed in a ratio of 8:2:0.5-1, and the ratio of the amount of ZnCl2 to the mixed solvent is 0.001 mol:50-60 mL.

[0013] Preferably, the molar ratio of ZnCl2 to hollow bismuth ferrite powder in S2 is 1:0.5-2.

[0014] Specifically, after the S2 dispersion is transferred to the reaction kettle, the heating reaction condition is that the reaction temperature is maintained at 190 DEG C, and the reaction is carried out for 12 h or more, and after the reaction is completed and cooled to room temperature, the filter is washed with deionized water and ethanol alternately three times, and the filter solid is dried at 70 DEG C for 12 h.

[0015] Preferably, the mixed solvent two in S3 is DMF and ethylene glycol mixed in a volume ratio of 9:0.1-1, and the amount ratio of the core-shell type bismuth ferrite-zinc indium sulfide heterojunction powder to the mixed solvent two is 1g:50-100 mL.

[0016] Preferably, the mass ratio of the core-shell type bismuth ferrite-zinc indium sulfide heterojunction to silver nitrate in S3 is 1:0.005-0.1.

[0017] In addition, the application also provides a bismuth ferrite-zinc indium sulfide-silver composite catalyst driven by ultrasonic and visible light dual energy, which is prepared by the above method.

[0018] The application further provides the application of the above-mentioned bismuth ferrite-zinc indium sulfide-silver composite catalyst driven by ultrasonic and visible light dual energy in catalytic degradation of organic pollutants, specifically, activating persulfate to degrade organic pollutants by ultrasonic and visible light dual energy.

[0019] In the application, zinc indium sulfide (ZnIn2S4) is a multi-metal sulfide, which has a suitable energy band position, a tunable surface electronic configuration and a unique double-metal active site, and has developed rapidly in the field of catalysis. Compared with traditional metal oxides, ZnIn2S4 has a narrower band gap structure and excellent visible light absorption performance. Compared with other ternary metal sulfides such as CuInS4, CdI2S4 or CuCaS4, the synthesis and preparation method of ZnIn2S4 is also simple and flexible. However, the low carrier migration rate affects its large-scale practical application. The photo-corrosion behavior caused by the accumulation of holes on the surface of ZnIn2S4 leads to the weakening of the catalytic performance, and therefore, constructing a composite material is a feasible means to improve the photocatalytic performance.

[0020] Silver (Ag) nanoparticles have been widely and deeply studied in inorganic catalyst systems, and the surface plasmon resonance effect can effectively improve the catalytic efficiency of inorganic semiconductor photocatalysts under visible light. The improvement of catalytic activity mainly includes the following four processes: (1) enhancing light scattering; (2) increasing the absorption efficiency of the catalyst for visible light; (3) plasmonic energy transfer and rapid conduction of electrons; (4) forming a Mott-Schottky barrier to promote carrier separation. In the present application, the deposition of Ag nanoparticles on the surface of ZnIn2S4 can construct a Mott-Schottky barrier to improve its photocatalytic performance.

[0021] Bismuth ferrite (BiFeO3) not only has a narrow band gap (2.2eV) of visible light response, but also has spontaneous polarization characteristics as a ferroelectric material, showing typical piezoelectric effect. In addition, these ferroelectric materials can also generate built-in electric field to promote the separation of photo-generated electrons and holes without external pressure. However, due to the shielding effect of ferroelectric polarization, heterogeneous charges will gradually accumulate at the carrier separation interface under external light, forming an interface shielding layer, resulting in low charge separation efficiency and limiting the photocatalytic activity. When subjected to external mechanical force, the directional alignment of the internal dipole of this type of ferroelectric material is enhanced, forming a piezoelectric polarization electric field, which strengthens the separation of photo-generated electrons and holes, solves the disadvantage of easy recombination at the ferroelectric domain wall interface, and realizes the significant improvement of photocatalytic activity. In the present application, BiFeO3 particles with hollow structure are constructed as the inner core, which not only forms a heterojunction with ZnIn2S4 to promote the separation of photo-generated carriers, but also forms a built-in electric field under the action of external force represented by ultrasound to promote the directional separation of electron-hole pairs, thereby enhancing the catalytic performance of the composite catalyst. In addition, the hollow structure of BiFeO3 can enhance the piezoelectric effect and shorten the separation path of carriers.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] The BiFeO3-ZnIn2S4-Ag catalyst prepared in the present application ingeniously combines the narrow band gap structure and excellent visible light absorption performance of ZnIn2S4, the ability of Ag nanoparticles to increase light scattering absorption and form a Mott-Schottky barrier, and the ability of BiFeO3 particles to form a heterojunction with ZnIn2S4 to promote the separation of photo-generated carriers and to form a built-in electric field under the action of external force represented by ultrasound to promote the directional separation of electron-hole pairs. The advantages of BiFeO3-ZnIn2S4-Ag are synergistically enhanced, and the defects are overcome or supplemented. The prepared composite catalyst can form a core piezoelectric field, a heterojunction interface and an outer Mott-Schottky barrier, and has excellent catalytic performance. The composite catalyst can be driven by ultrasound and visible light to strongly activate persulfate, and can effectively degrade organic pollutants including nizatidine and its derivatives. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 XRD patterns of various samples, including the composite catalysts prepared in Examples 1 to 4, BiFeO3 / ZnIn2S4 heterojunction powder without silver loading, ZnIn2S4 powder without BiFeO3 addition, and BiFeO3 powder before and after acid washing;

[0025] Figure 2 FE-SEM patterns of various samples, where a represents the sample as hollow BiFeO3 powder, b represents the sample as pure ZnIn2S4 powder, c represents the sample as the composite catalyst prepared in Example 3, and d is a mapping pattern of the composite catalyst prepared in Example 3;

[0026] Figure 3 Nitrogen adsorption-desorption patterns of various samples, including pure ZnIn2S4 powder, pure hollow BiFeO3 powder, BiFeO3 / ZnIn2S4 heterojunction powder without silver loading, and the composite catalyst powder prepared in Example 3;

[0027] Figure 4 UV-Vis light absorption patterns and catalytic reaction rate patterns of the composite catalyst powder prepared in the application for catalytic degradation of nizatidine, Figure 4 a is a UV-Vis light absorption pattern of catalytic degradation of nizatidine using the composite catalyst prepared in Example 3 of the application as the sample, Figure 4 b is a catalytic reaction rate of catalytic degradation of nizatidine using the composite catalysts prepared in Examples 1 to 4 of the application, respectively, Figure 4 b, the catalytic reaction rate of samples including pure ZnIn2S4 powder, hollow BiFeO3 powder, and BiFeO3 / ZnIn2S4 heterojunction powder without silver loading was detected;

[0028] Figure 5 Catalytic reaction rate patterns of catalytic degradation of nizatidine using the composite catalyst powder prepared in Example 3 of the application under different conditions, Figure 5 a, the conditions are light, ultrasonic, and dual-energy driving of light and ultrasonic, Figure 5 b, the condition is no light and only the ultrasonic power is changed, Figure 5 c, the condition is dual-energy driving, and the ultrasonic power is changed under light conditions.

[0029] Figure 6 Cyclic catalytic activity of catalytic degradation of nizatidine using the composite catalyst powder prepared in Example 3 of the application (after each round of catalysis, the composite catalyst is centrifuged and washed clean, and then the next round of catalytic degradation reaction is performed). DETAILED DESCRIPTION

[0030] The application will be further described in conjunction with the accompanying drawings and specific embodiments, which are presented herein for illustration only, and should not be construed to limit the scope of the present application.

[0031] For the sake of brevity, conventional methods will not be described in detail herein. Unless otherwise specified, the methods used in the following examples are conventional methods in the art, and the drugs used are commercially available products.

[0032] Example 1

[0033] A method for preparing an ultrasonic-visible light dual-energy driven BiFeO3-In2Zn3SnS6-Ag composite catalyst, comprising the following steps:

[0034] S1. Preparation of hollow BiFeO3core: 1.40 g of Bi(NO3)3·5H2O and 1.16 g of Fe(NO3)3·9H2O powders were accurately weighed, and 18 mL of glycerol, 6 mL of ethanol and 120 mL of isopropyl alcohol were sequentially added to the above mixture in a volume ratio of 3:1:20. After stirring at room temperature for 2 hours, a clear solution was obtained. Then the clear solution was transferred to the inner liner of a high-pressure poly-p-phenylene reactor, and heated statically at 215°C for 10 hours. After cooling at room temperature, the precipitate was collected by centrifugation at 5000 rpm, washed with water and ethanol alternately for three times, and then vacuum dried at 60°C for 12 hours to obtain the precursor powder of BiFeO3. The precursor powder was then transferred to a tube furnace and calcined at 560°C for 1.5 hours under air atmosphere, with a heating rate of 2°C / min, to obtain BiFeO3powder containing a small amount of Bi 25 FeO 40 impurities. Finally, the pure-phase hollow BiFeO3powder with piezoelectric effect was obtained by washing with 2M nitric acid and 3M acetic acid alternately (single room temperature stirring for 15 minutes) for three times, and then washing with deionized water until neutral.

[0035] S2. Preparation of core-shell BiFe03-ZnIn2S4 heterojunction: 0.1363 g of ZnCl2, 0.5864 g of InCl3-4H2O and 0.3 g of thioacetamide were accurately weighed and dispersed into a mixture of 40 mL of dimethylformamide, 10 mL of glycerol and 5 mL of deionized water (a small amount of deionized water was added to make the ZnIn2S4 relatively loose and not dense, which can better combine BiFe03 and nano-silver later). Then 0.3128 g of the prepared hollow BiFe03 powder (ZnIn2S4 and BiFe03 molar ratio 1:1) was added to the above mixture. After stirring at room temperature for 1 h, ultrasonic dispersion was performed for 30 min. Then the dispersion was transferred to a polytetrafluoroethylene reaction kettle and heated at 190°C for 12 h. After cooling to room temperature, filtration, washing with deionized water and ethanol alternately for three times and drying at 70°C for 12 h, a BiFe03 / ZnIn2S4 heterojunction powder (denoted as BiFe03 / ZnIn2S4-1) was obtained.

[0036] S3. Preparation of ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst: 1 g of the above BiFe03-ZnIn2S4 heterojunction powder was dispersed in 50 mL of a mixture of DMF and ethylene glycol (volume ratio of DMF to ethylene glycol was 9:1), and then 0.1 g of silver nitrate was added. After stirring at room temperature for 10 h in the dark, the mixture was transferred to a polytetrafluoroethylene reaction kettle and heated at 210°C for 1.5 h. Then the precipitate was collected by centrifugation at 6000-6500 rpm, washed with DMF and ethanol alternately for three times, and then the solid powder was added to 50 mL of acetone and heated and stirred at 65°C for 8 h. Then the mixture was dried at 80°C for 24 h to obtain an ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst (denoted as BiFe03 / ZnIn2S4 / Ag-0.1).

[0037] Example 2

[0038] A method for preparing an ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst, comprising the following steps:

[0039] S1. Preparation of hollow BiFe03core: 1.40 g of Bi(N03)3.5H20 and 1.16 g of Fe(N03)3.9H20 powders were accurately weighed and added into the above mixture in the volume ratio of 3:1:20, respectively, 18 mL of glycerol, 6 mL of ethanol and 120 mL of isopropanol. After stirring at room temperature for 2 h, a clear solution was obtained. Subsequently, the clear solution was transferred into the inner liner of a high-pressure poly-p-phenylene reactor, and heated statically at 215 °C for 10 h. After cooling at room temperature, the precipitate was collected by centrifugation at 5000 rpm, washed with water and ethanol alternately for three times, and dried at 60 °C under vacuum for 12 h to obtain the precursor powder of BiFe03. The precursor powder was then transferred into a tube furnace and calcined at 560 °C for 1.5 h in air atmosphere with a heating rate of 2 °C / min to obtain BiFe03powder containing a small amount of Bi 25 FeO 40 impurities. Finally, the pure-phase hollow BiFe03powder with piezoelectric effect was obtained by washing with 2 M nitric acid and 3 M acetic acid alternately (single room temperature stirring for 15 min) for three times, and then washing with deionized water until neutral.

[0040] S2. Preparation of shell-core type BiFe03-ZnIn2S4heterojunction: 0.1363 g of ZnCl2, 0.5864 g of InCl3.4H20 and 0.3 g of thioacetamide were accurately weighed and dispersed into a mixture consisting of 40 mL of dimethylformamide, 10 mL of glycerol and 5 mL of deionized water, respectively. Then, 0.3128 g of the hollow BiFe03powder (ZnIn2S4and BiFe03molar ratio of 1:1) that had been prepared was added into the above mixture, and stirred at room temperature for 1 h and then ultrasonically dispersed for 30 min. Subsequently, the dispersion was transferred into a polytetrafluoroethylene reactor and heated at 190 °C for 12 h. After cooling to room temperature, the product was filtered, washed with deionized water and ethanol alternately for three times, and dried at 70 °C for 12 h to obtain the BiFe03 / ZnIn2S4heterojunction powder.

[0041] S3. Preparation of the ultrasonic-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst: 1 g of the above BiFeO3-ZnIn2S4 heterojunction powder was dispersed in 50 mL of a mixed solution of DMF and ethylene glycol (volume ratio of DMF to ethylene glycol was 9:1), and 0.02 g of silver nitrate was added. After stirring at room temperature for 9 h in the dark, the above mixture was transferred to a polytetrafluoroethylene reaction kettle and heated at 195 °C for 2.5 h. Then the precipitate was collected by centrifugation at 5500-6000 rpm, washed with DMF and ethanol alternately for 3 times, and then the solid powder was added to 50 mL of acetone and heated and stirred at 50 °C for 10 h. Subsequently, it was dried at 70 °C for 24 h to obtain the ultrasonic-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst (denoted as BiFeO3 / ZnIn2S4 / Ag-0.02).

[0042] Example 3

[0043] A method for preparing an ultrasonic-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst, comprising the following steps:

[0044] S1. Preparation of hollow BiFeO3 core: 1.40 g of Bi(NO3)3·5H2O and 1.16 g of Fe(NO3)3·9H2O powder were accurately weighed, and 18 mL of glycerol, 6 mL of ethanol and 120 mL of isopropyl alcohol were sequentially added to the mixture in a volume ratio of 3:1:20. After stirring at room temperature for 2 hours, a clear solution was obtained. Then the clear solution was transferred to the inner container of a high-pressure poly-p-phenylene reaction kettle, and heated statically at 215 °C for 10 hours. After cooling to room temperature, the precipitate was collected by centrifugation at 5000 rpm, washed with water and ethanol alternately for 3 times, and then dried at 60 °C under vacuum for 12 h to obtain the BiFeO3 precursor powder. The precursor powder was then transferred to a tube furnace and calcined at 560 °C for 1.5 h in air atmosphere at a heating rate of 2 °C / min to obtain BiFeO3 powder containing a small amount of Bi 25 FeO 40 impurities. Finally, the pure-phase hollow BiFeO3 powder with piezoelectric effect was obtained by washing with 2M nitric acid and 3M acetic acid alternately (single room temperature stirring for 15 min) for 3 times, and then washing with deionized water until neutral.

[0045] S2. Preparation of the core-shell BiFe03-ZnIn2S4 heterojunction: 0.1363 g of ZnCl2, 0.5864 g of InCl3-4H2O and 0.3 g of thioacetamide were accurately weighed and dispersed into a mixed solution composed of 40 mL of dimethylformamide, 10 mL of glycerol and 5 mL of deionized water, respectively. Then, 0.3128 g of the hollow BiFe03 powder prepared above (molar ratio of ZnIn2S4 to BiFe03 was 1:1) was added into the mixed solution. After stirring at room temperature for 1 h, the mixture was ultrasonically dispersed for 30 min. Subsequently, the dispersion was transferred into a polytetrafluoroethylene reactor and heated at 190 °C for 12 h. After cooling to room temperature, the product was filtered, washed with deionized water and ethanol alternately for three times and dried at 70 °C for 12 h to obtain the BiFe03-ZnIn2S4 heterojunction powder.

[0046] S3. Preparation of the ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst: 1 g of the BiFe03-ZnIn2S4 heterojunction powder above was dispersed in 50 mL of a mixed solution of DMF and ethylene glycol (volume ratio of DMF to ethylene glycol was 9:0.5), and 0.01 g of silver nitrate was added. After stirring at room temperature for 8 h in the dark, the mixture was transferred into a polytetrafluoroethylene reactor and heated at 170 °C for 4 h. Then, the precipitate was collected by centrifugation at 3500-4500 rpm, washed with DMF and ethanol alternately for three times, and then added into 50 mL of acetone. The mixture was heated and stirred at 45 °C for 12 h, and then dried at 50 °C for 24 h to obtain the ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst (denoted as BiFe03-ZnIn2S4 / Ag-0.01).

[0047] Example 4

[0048] A method for preparing an ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst, comprising the following steps:

[0049] S1. Preparation of hollow BiFe03core: 1.40 g of Bi(N03)3.5H20 and 1.16 g of Fe(N03)3.9H20 powders were accurately weighed and added into the above mixture in the volume ratio of 3:1:20, respectively, 18 mL of glycerol, 6 mL of ethanol and 120 mL of isopropanol. After stirring at room temperature for 2 h, a clear solution was obtained. Subsequently, the clear solution was transferred into the inner liner of a high-pressure poly-p-phenylene autoclave and heated statically at 215 °C for 10 h. After cooling at room temperature, the precipitate was collected by centrifugation at 5000 rpm, washed with water and ethanol alternately for three times, and dried at 60 °C under vacuum for 12 h to obtain the precursor powder of BiFe03. The precursor powder was then transferred into a tube furnace and calcined at 560 °C for 1.5 h in air atmosphere with a heating rate of 2 °C / min to obtain BiFe03powder containing a small amount of Bi 25 FeO 40 impurities. Finally, the pure-phase hollow BiFe03powder with piezoelectric effect was obtained by washing with 2 M nitric acid and 3 M acetic acid alternately (single room temperature stirring for 15 min) for three times, and then washing with deionized water until neutral.

[0050] S2. Preparation of shell-core type BiFe03-ZnIn2S4heterojunction: 0.1363 g of ZnCl2, 0.5864 g of InCl3.4H20 and 0.3 g of thioacetamide were accurately weighed and dispersed into a mixture consisting of 40 mL of dimethylformamide, 10 mL of glycerol and 5 mL of deionized water, respectively. Then, 0.3128 g of the hollow BiFe03powder (ZnIn2S4and BiFe03molar ratio of 1:1) that had been prepared was added into the above mixture, and stirred at room temperature for 1 h and then ultrasonically dispersed for 30 min. Subsequently, the dispersion was transferred into a polytetrafluoroethylene autoclave and heated at 190 °C for 12 h. After cooling to room temperature, the product was filtered, washed with deionized water and ethanol alternately for three times, and dried at 70 °C for 12 h to obtain the BiFe03 / ZnIn2S4heterojunction powder.

[0051] S3. Preparation of the ultrasonic-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst: 1 g of the above BiFeO3-ZnIn2S4 heterojunction powder was dispersed in 50 mL of a mixed solution of DMF and ethylene glycol (volume ratio of DMF to ethylene glycol was 9:0.5), 0.005 g of silver nitrate was added, and the mixture was stirred at room temperature for 8-10 h in the dark. Then the mixture was transferred to a polytetrafluoroethylene reactor and heated at 210°C for 1.5 h. The precipitate was collected by centrifugation at 6000-6500 rpm, washed with DMF and ethanol alternately for 3 times, and then the solid powder was added to 50 mL of acetone and heated and stirred at 45°C for 12 h. Then it was dried at 50°C for 24 h to obtain the ultrasonic-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst (denoted as BiFeO3 / ZnIn2S4 / Ag-0.005).

[0052] Example 5

[0053] A method for preparing an ultrasonic-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst, comprising the following steps:

[0054] S1. Preparation of hollow BiFeO3 core: 1.40 g of Bi(NO3)3·5H2O and 1.16 g of Fe(NO3)3·9H2O powder were accurately weighed, and 18 mL of glycerol, 6 mL of ethanol and 90 mL of isopropyl alcohol were added to the mixture in a volume ratio of 3:1:15. After stirring at room temperature for 2 hours, a clear solution was obtained. Then the clear solution was transferred to the inner container of a high-pressure poly-p-phenylene reactor, and heated statically at 215°C for 10 hours. After cooling to room temperature, the precipitate was collected by centrifugation at 5000 rpm, washed with water and ethanol alternately for 3 times, and then dried at 60°C under vacuum for 12 h to obtain the BiFeO3 precursor powder. The precursor powder was then transferred to a tube furnace and calcined at 560°C for 1.5 h in air atmosphere at a heating rate of 2°C / min to obtain BiFeO3 powder containing a small amount of Bi 25 FeO 40 impurities. Finally, the pure-phase hollow BiFeO3 powder with piezoelectric effect was obtained by washing with 2M nitric acid and 3M acetic acid alternately (single room temperature stirring for 15 minutes) for 3 times, and then washing with deionized water until neutral.

[0055] S2. Preparation of core-shell type BiFe03-ZnIn2S4 heterojunction: 0.1363 g of ZnCl2, 0.5864 g of InCl3-4H2O and 0.3 g of thioacetamide were accurately weighed and dispersed into a mixture of 40 mL of dimethylformamide, 10 mL of glycerol and 2.5 mL of deionized water, respectively. 0.1564 g of the hollow BiFe03 powder prepared above (molar ratio of ZnIn2S4 and BiFe03 is 1:0.5) was added to the mixture. After stirring at room temperature for 1 h, the mixture was ultrasonically dispersed for 30 min. The dispersion was then transferred into a polytetrafluoroethylene reactor and heated at 190 °C for 12 h. After cooling to room temperature, the product was filtered, washed with deionized water and ethanol alternately for three times and dried at 70 °C for 12 h to obtain the BiFe03 / ZnIn2S4 heterojunction powder.

[0056] S3. Preparation of ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst: 1 g of the BiFe03-ZnIn2S4 heterojunction powder above was dispersed in a mixture of 50 mL of DMF and ethylene glycol (volume ratio of DMF to ethylene glycol is 9:0.1), and 0.1 g of silver nitrate was added. After stirring at room temperature for 8-10 h in the dark, the mixture was transferred into a polytetrafluoroethylene reactor and heated at 190 °C for 3 h. The precipitate was then collected by centrifugation at 5000-5500 rpm, washed with DMF and ethanol alternately for three times, and then added into 50 mL of acetone. The mixture was heated and stirred at 55 °C for 12 h, and then dried at 65 °C for 24 h to obtain the ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst.

[0057] Example 6

[0058] A method for preparing an ultrasonic-visible light dual-energy driven BiFe03-ZnIn2S4-Ag composite catalyst, comprising the following steps:

[0059] S1. Preparation of hollow BiFe03 core: 1.40 g of Bi(NO3)3-5H2O and 1.16 g of Fe(NO3)3-9H2O powders were accurately weighed, and 18 mL of glycerol, 6 mL of ethanol and 90 mL of isopropyl alcohol were sequentially added to the mixture in a volume ratio of 3:1:15. After stirring at room temperature for 2 h, a clear solution was obtained. The clear solution was then transferred into the inner container of a polyphenyl high-pressure reactor and heated statically at 215 °C for 10 h. After cooling to room temperature, the precipitate was collected by centrifugation at 5000 rpm, washed with water and ethanol alternately for three times, and dried at 60 °C under vacuum for 12 h to obtain the BiFe03 precursor powder. The precursor powder was then transferred into a tube furnace and calcined at 560 °C for 1.5 h under air atmosphere at a heating rate of 2 °C / min to obtain the BiFe03 powder containing a small amount of Bi25 FeO 40 The impurities in the BiFeO3 powder were removed. Finally, the powder was washed three times alternately with 2M nitric acid and 3M acetic acid (stirred for 15 minutes at room temperature each time), and then washed with deionized water until neutral to obtain a pure phase hollow BiFeO3 powder with piezoelectric effect.

[0060] S2. Preparation of core-shell type bismuth ferrite-zinc indium sulfide (ZnIn2S4) heterojunction: Accurately weigh 0.1363 g of ZnCl2, 0.5864 g of InCl3·4H2O, and 0.3 g of thioacetamide, and redisperse them in a mixture consisting of 40 mL of dimethylformamide, 10 mL of glycerol, and 2.5 mL of deionized water. Then add 0.6256 g of the prepared hollow BiFeO3 powder (ZnIn2S4 to BiFeO3 molar ratio 1:2) to the above mixture, stir at room temperature for 1 h, and then ultrasonically disperse for 30 min. The dispersion is then transferred to a polytetrafluoroethylene reactor and heated at 190 °C for 12 h. After cooling to room temperature, filter, wash three times alternately with deionized water and ethanol, and dry at 70 °C for 12 h to obtain BiFeO3 / ZnIn2S4 heterojunction powder.

[0061] S3. Preparation of the ultrasound-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst: Weigh 1g of the above BiFeO3-ZnIn2S4 heterojunction powder and disperse it in 50ml of a mixture of DMF and ethylene glycol (DMF to ethylene glycol volume ratio of 9:0.1). Then add 0.1g of silver nitrate and stir at room temperature for 8-10h under light-protected conditions. Transfer the mixture to a polytetrafluoroethylene reactor and heat at 190℃ for 3h. Then collect the precipitate by centrifugation at 5000-5500rpm and wash it three times alternately with DMF and ethanol. Then add the solid powder to 50mL of acetone and heat and stir at 50℃ for 12h. Then dry at 70℃ for 24h to obtain the ultrasound-visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst.

[0062] Performance characterization:

[0063] First, the composite catalysts prepared in Examples 1 to 4 were used as samples for XRD analysis. Simultaneously, XRD analysis was also performed on BiFeO3 before acid washing, BiFeO3 after acid washing, BiFeO3 / ZnIn2S4 heterojunction powder without Ag nanoparticles, and pure ZnIn2S4 powder obtained during the preparation process. The pure ZnIn2S4 powder was prepared as follows: 0.1363 g of ZnCl2, 0.5864 g of InCl3·4H2O, and 0.3 g of thioacetamide were accurately weighed and redispersed in a mixture of 40 mL of dimethylformamide, 10 mL of glycerol, and 2.5 mL of deionized water. The mixture was stirred at room temperature for 1 h and then ultrasonically dispersed for 30 min. The dispersion was then transferred to a polytetrafluoroethylene reactor and heated at 190 °C for 12 h. After cooling to room temperature, the mixture was filtered, washed three times alternately with deionized water and ethanol, and dried at 70 °C for 12 h to obtain the final product. The XRD results for each sample are shown below. Figure 1 As shown in the figure, acid washing can significantly remove Bi generated during the self-assembly of hollow BiFeO3. 25 FeO 40 Impurities such as bismuth oxide are used to improve the piezoelectric properties of BiFeO3. Furthermore, both BiFeO3 / ZnIn2S4 and silver-loaded composite catalysts exhibit good crystal structure and good mechanical strength.

[0064] Subsequently, the corresponding samples were examined using field emission scanning electron microscopy (FE-SEM), and the results are as follows: Figure 2 As shown, from Figure 2 As can be seen from a, the prepared BiFeO3 is a self-assembled hollow structure, which is beneficial to its piezoelectric response, and the average particle size is about 1.2 μm. Figure 2 The ZnIn2S4 in b exhibits a self-assembled lamellar flower-like structure, and its porous structure is beneficial for the adsorption of pollutants by the composite catalyst. Figure 2 The excellent in-situ reduction and deposition of Ag nanoparticles on BiFeO3 / ZnIn2S4 indicates the successful preparation of the BiFeO3-ZnIn2S4-Ag composite catalyst. Furthermore, Figure 2 The elemental mapping diagram corresponding to d shows the uniform loading of Ag nanoparticles.

[0065] Then, nitrogen adsorption-desorption tests were conducted on the corresponding samples, and the results are as follows: Figure 3 As shown, hollow BiFeO3 has a large BET specific surface area, indicating that its cavity structure is favorable for the ultrasonic-driven cavitation enhancement effect during catalysis. Furthermore, the BiFeO3 / ZnIn2S4 / Ag-0.01 prepared in this invention has a large specific surface area, and the flower-like layer of the outer ZnIn2S4 sheets is conducive to adsorption.

[0066] Finally, the catalytic performance test was carried out: first, a nizatidine solution with a concentration of 40 mg / mL was prepared, 4 g of nizatidine powder was weighed and added to 100 mL of distilled water for later use. Then 5 mg of hollow BiFeO3 powder, ZnIn2S4 powder, BiFeO3 / ZnIn2S4-1 powder, BiFeO3 / ZnIn2S4 / Ag-0.1 powder, BiFeO3 / ZnIn2S4 / Ag-0.02 powder, BiFeO3 / ZnIn2S4 / Ag-0.01 powder and BiFeO3 / ZnIn2S4 / Ag-0.005 powder were taken in turn, each was mixed with 5 mL of deionized water and ultrasonically dispersed for 20 minutes, then 1 mL of each was added to a double-layer glass cup containing 25 mL of the prepared 40 mg / mL nizatidine solution, the circulating water was turned on to keep the reaction system temperature constant at 16°C, and the stirring speed was 200 rpm in the dark, then 1 mL of potassium persulfate solution (1 mg / mL) was added and an ultrasonic rod (output power 70 W) was inserted, and the light source (wavelength 400-800 nm) was turned on, every 10 minutes sample was taken for ultraviolet-visible light test at 230-370 nm wavelength, to characterize the degradation of nizatidine. Figure 4 a shows that the characteristic absorption peak of nizatidine is at 310 nm and BiFeO3 / ZnIn2S4 / Ag-0.01 can efficiently photocatalyze the degradation of nizatidine within 60 minutes. In Figure 4 b, BiFeO3 / ZnIn2S4 / Ag-0.01 showed the highest catalytic performance, i.e. it can efficiently activate persulfate to produce reactive oxygen species and catalyze the degradation of nizatidine under the driving of ultrasonic and visible light. In addition, as Figure 5 a shows that when using light and ultrasonic driving alone, BiFeO3 / ZnIn2S4 / Ag-0.01 has a lower first-order reaction fitting rate for catalyzing the degradation of nizatidine by persulfate, among which only the initial stage of the reaction driven by ultrasonic has good catalytic activity, and as the concentration of persulfate and pollutants decreases, the reaction rate will decrease greatly. When light and ultrasonic are used together, the reaction rate of BiFeO3 / ZnIn2S4 / Ag-0.01 for activating persulfate to degrade nizatidine is much greater than the sum of the rates of the two alone (where the rate of ultrasonic driving alone is also approximated as a first-order fitting rate). Figure 5 b also shows that as the ultrasonic power increases, the catalytic reaction rate will increase, but it is not obvious and the rate decreases rapidly, but Figure 5c indicates that under light conditions, increasing the ultrasonic power can significantly improve the reaction rate and the rate is fast and stable. This is because BiFeO3 / ZnIn2S4 / Ag-0.01 has a better visible light response, and when the photocatalytic activation of potassium persulfate is performed, the ultrasonic effect can promote the formation of built-in electric field in the BiFeO3 core to further promote the separation of carriers and improve the catalytic performance of the composite material, and a visible light-ultrasonic dual-energy driven reaction system is constructed.

[0067] In addition, in order to verify that the BiFeO3-ZnIn2S4-Ag composite catalyst prepared by the present application has stable catalytic activity and can be recycled, the present application carries out a cycle catalytic test: after the used BiFeO3 / ZnIn2S4 / Ag-0.01 catalyst is centrifuged, washed and dried, it is used as a catalyst again according to the above catalytic test steps to start 6 rounds of cycle catalytic test, and the test results are shown in Table 2. Figure 6 It can be seen that the product obtained by the present application has stable catalytic activity.

[0068] It should be noted that the ultrasonic visible light dual-energy driven BiFeO3-ZnIn2S4-Ag composite catalyst prepared in Examples 5 and 6 is also subjected to catalytic performance test, and it also has ultrasonic visible light dual-energy driven effect, but the effect is slightly worse than that of Examples 1 to 4, that is, the best ratio of BiFeO3 and ZnIn2S4 in the composite catalyst prepared by the present application is 1:1.

[0069] The above only describes the preferred embodiments of the present application and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by ultrasonic and visible light, characterized in that, Comprising the following steps: S1. Hollow bismuth ferrite core preparation: Bi(NO3)3·5H2O and Fe(NO3)3·9H2O are mixed in an equimolar ratio, a mixed alcohol solvent is added, stirring at room temperature until the solution is clear, transferred to a reaction kettle, heated to fully react, cooled to room temperature after reaction, centrifugal collection of precipitate, washed and vacuum dried to obtain bismuth ferrite precursor powder, then the precursor powder is transferred to a tube furnace and uniformly heated to 560℃, calcined for 1.5h or more, cooled to room temperature, washed and dried to obtain hollow bismuth ferrite powder with piezoelectric effect, ready for use; S2. Shell-core type bismuth ferrite-indium zinc sulfide heterojunction preparation: ZnCl2, InCl3·4H2O and thioacetamide are added to mixed solvent one composed of dimethylformamide, glycerol and deionized water in a molar ratio of 1:2:4, fully stirred and mixed, then the hollow bismuth ferrite powder prepared in S1 is added, fully stirred and ultrasonically dispersed at room temperature to obtain a dispersion, the dispersion is transferred to a reaction kettle and heated to react, cooled to room temperature after reaction, filtered, washed and dried to obtain shell-core type bismuth ferrite-indium zinc sulfide heterojunction powder, ready for use; S3. Preparation of composite catalyst: The shell-core type bismuth ferrite-indium zinc sulfide heterojunction powder prepared in S2 is dispersed in mixed solvent two of DMF and ethylene glycol, silver nitrate powder is added, mixed under room temperature and light shielding conditions to obtain a mixed solution, the mixed solution is transferred to a reaction kettle, heated at 170-210℃ for 1.5-4h, then the precipitate is collected by centrifugation, washed and dried, the obtained solid powder is added to acetone, heated and stirred at 45-65℃ for 8-12h, then filtered and dried to obtain an ultrasonic visible light dual-energy driven bismuth ferrite-indium zinc sulfide-silver composite catalyst.

2. The preparation method of the bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by ultrasonic and visible light according to claim 1, characterized in that, The mixed alcohol solvent in S1 is a mixture of glycerol, ethanol and isopropanol in a volume ratio of 3:1:15-20, and the amount of Bi(NO3)3·5H2O to mixed alcohol solvent is 0.029mol:110-150mL.

3. The preparation method of the bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by ultrasonic and visible light according to claim 1, characterized in that, In S1, the solution is clear and after being transferred to the reaction kettle, the reaction is heated at a temperature of 215℃ for 10h or more, the centrifugal speed is 5000rpm when the reaction is completed, the precipitate is collected, washed with water and ethanol three times alternately, vacuum dried at 60℃ for 12h to obtain bismuth ferrite precursor powder, the precursor powder is transferred to a tube furnace, the heating rate is controlled at 2℃ / min, the hollow bismuth ferrite crude product is washed with nitric acid and acetic acid three times alternately, and finally washed with deionized water to neutral.

4. The preparation method of the bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by dual energy of ultrasonic and visible light according to claim 1, characterized in that, In S2, the mixed solvent one is a mixture of dimethylformamide, glycerol and deionized water in a ratio of 8:2:0.5-1, and the amount of ZnCl2 to mixed solvent is 0.001mol:50-60mL.

5. The preparation method of a bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by dual energy of ultrasonic and visible light according to claim 1, characterized in that, In S2, the molar ratio of ZnCl2 to hollow bismuth ferrite powder is 1:0.5-2.

6. The preparation method of a bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by dual energy of ultrasonic and visible light according to claim 1, characterized in that, After the S2 dispersion is transferred to the reaction kettle, the reaction is heated at a reaction temperature of 190°C for 12 hours or more. After the reaction is completed and cooled to room temperature, the reaction product is filtered, washed with deionized water and ethanol three times alternately, and dried at 70°C for 12 hours.

7. The preparation method of a bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by dual energy of ultrasonic and visible light according to claim 1, characterized in that, The mixed solvent two in S3 is mixed by DMF and ethylene glycol according to a volume ratio of 9:0.1-1, and the amount ratio of the core-shell type BiFeO3-ZnIn2S4 heterojunction powder to the mixed solvent two is 1g:50-100mL.

8. A method for preparing a bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by dual energy of ultrasonic and visible light according to any one of claims 1 to 7, characterized in that, The mass ratio of the core-shell type BiFeO3-ZnIn2S4 heterojunction to silver nitrate in S3 is 1:0.005-0.

1.

9. A bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by ultrasonic and visible light, characterized in that, Prepared by the method of any one of claims 1 to 8.

10. Use of the bismuth ferrite-indium zinc sulfide-silver composite catalyst driven by dual energy of ultrasonic and visible light according to claim 9 for catalytic degradation of organic pollutants, characterized in that, The organic pollutants are degraded by activating persulfate through dual-energy driving of ultrasonic and visible light.

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