AMX2 type ferroelectric semiconductor composite catalytic composition, its application, and methods for degrading organic pollutants.

Abstract

This invention relates to the field of catalysis, specifically to an AMX2-type ferroelectric semiconductor composite catalytic composition, its application, and a method for degrading organic pollutants. The AMX2 ferroelectric semiconductor in the composite catalytic composition provided by this invention acts like a fuse for a projectile, responding to visible light, force, heat, and magnetism, and effectively performing electron-hole separation. This overcomes the limitation of its own redox potential, allowing excitons to excite catalysts with long lifetimes and higher oxidation or reduction potentials, resulting in an order-of-magnitude enhancement of the catalytic reaction. The composite catalytic composition provided by this invention is particularly suitable for degrading recalcitrant organic pollutants in water. Under existing experimental conditions, this invention, using CuGaO2 ferroelectric semiconductor and persulfate (PMS) in combination to degrade organic pollutants, achieves a degradation rate increase of nearly 100 times.

Description

Technical Field

[0001] This invention relates to the field of catalysis, specifically to AMX2 type ferroelectric semiconductor composite catalytic compositions, their applications, and methods for degrading organic pollutants. Background Technology

[0002] Photovoltaic conversion devices, utilizing the green and inexhaustible solar energy, are considered the ultimate means for modern human society to solve energy and environmental problems. They can directly convert light into electrical energy for storage and utilization, or utilize the generated photogenerated carriers for catalytic reactions, thus giving rise to another important branch of the field—photocatalysis. After half a century of development, the practical applications of photocatalysis have expanded to a considerable range: from the degradation of organic pollutants or antibiotics, to fuel production (obtaining hydrocarbons and hydrogen fuels through carbon dioxide reduction and water splitting), to organic synthesis such as nitrogen fixation and methane activation, and the production of fine chemicals. These reactions are essentially catalytic reactions.

[0003] To fully utilize the visible and infrared portions of sunlight that reach the Earth's surface, the development of semiconductor photocatalysis technology has become a natural choice. Since Japanese scientists Fujishima and Honda reported the splitting of water to produce hydrogen on the surface of a TiO2 photoelectrode in 1972, semiconductor photocatalysis technology has experienced rapid development. Currently, photocatalysis technology is widely used in fields such as photocatalytic water splitting for hydrogen production, degradation of organic pollutants, reduction of heavy metal ions, reduction of carbon dioxide, and synthesis of organic compounds.

[0004] like Figure 1 As shown, Figure 1 This is a schematic diagram of the photocatalytic reaction mechanism. The photocatalytic reaction can be roughly divided into the following steps: First, the semiconductor catalyst absorbs photons exceeding its band gap (hν>E). g The first step is to enable electrons in the valence band of a semiconductor to jump to the conduction band, leaving holes in the valence band. The second step is for the generated electron-hole pairs to migrate to the surface of the material. The third step is for the electrons and holes that migrate to the surface to initiate corresponding reduction or oxidation reactions on the surface, provided that the redox potential requirements are met. It can be seen that the determining factors for photocatalytic reactions are (1) the efficiency of light absorption, achieving full-spectrum absorption of visible light is the first determining factor for making full use of sunlight; (2) the effective separation of electron-hole pairs, constructing a built-in electric field to suppress electron-hole recombination and promote their rapid separation is the second determining factor; (3) the redox potential that the material itself can achieve ultimately determines the type of catalytic reaction it can participate in; (4) the material surface is in contact with sufficient reactants.

[0005] Ferroelectric semiconductors have emerged to address this need. Firstly, their semiconductor properties allow for full-spectrum absorption, especially for materials with small band gaps, enabling absorption even in indoor lighting sources. Secondly, the built-in electric field generated by the spontaneous polarization inherent in ferroelectricity ensures effective electron-hole exciton separation, which is superior to the built-in electric field generated by heterojunction technology. Heterojunctions are prone to introducing defects, creating exciton annihilation sites, and their complex fabrication processes hinder widespread application. Finally, ferroelectrics promote the accumulation of electrons and holes on the surface, generating an electrode potential that can exceed the material's inherent band gap limitations, further enhancing its redox potential.

[0006] Currently, there are some strong redox catalysts, such as some peroxymonosulfate (HSO5). - PMS and persulfate (S2O8) 2- PS), whose sulfate radicals (SO4) participate in the oxidation reaction ·- The advantages of ) are (1) a very high oxidation potential (E) 0 (SO4 ·- SO4 2- = 2.5~3.1V NHE Compared to E 0 (HO · / OH - = 1.9~2.7V NHE (2) Longer lifespan (SO4) ·- The half-life is 30–40 μs, which is the HO... · (3) It can exist stably for a long time and is easy to store and transport. However, its limitation is that it requires relatively harsh conditions to be excited, such as ultraviolet light, ozone, etc., which greatly limits its practical application.

[0007] Chinese Patent 201610482121.3 discloses a method for remediating organic polluted water using a ferrous oxalate-activated persulfate system. This method involves adding ferrous oxalate and persulfate to the organic polluted water to remediate it. Chinese Patent 202311024319.3 discloses a method for preparing a highly efficient composite photocatalyst for treating high-concentration dye wastewater. This method uses an in-situ acid etching strategy with a sacrificial metal-organic framework (MOF) to prepare a 2-aminoterephthalic acid-modified TiO2 photocatalyst (NH2BDC). x -TiO2), and then YCQDs / (NH2BDC) loaded with carbon quantum dots were deposited by solvent deposition. xThe TiO2 composite catalyst exhibits beneficial visible light response and enhanced adsorption capacity, effectively improving photogenerated electron-hole separation and demonstrating good removal efficiency when treating high-concentration RhB solutions.

[0008] Although the existing technologies mentioned above can all degrade pollutants, they have the following drawbacks: (1) Existing composites are simple and only suitable for the two materials mentioned. There are insufficient material options and composite matching cases; or the preparation technology of composite materials is complicated, making it difficult to achieve large-scale preparation technology and resulting in poor economic benefits. (2) The catalytic reaction efficiency of the samples prepared by existing technologies is low. For example, the degradation reaction of tetracycline by ferrous oxalate-activated persulfate can only reach 27% after 30 minutes. (3) Existing technologies provide energy to ferroelectric materials through light. Summary of the Invention

[0009] In view of this, the technical problem to be solved by the present invention is to provide an AMX2 type ferroelectric semiconductor composite catalytic composition, its application and a method for degrading organic pollutants. The composite catalytic composition provided by the present invention can achieve an order-of-magnitude enhancement of the redox catalytic reaction rate and has full-spectrum absorption characteristics; when applied to pollutant degradation, it can achieve complete degradation of high concentrations of organic pollutants within minutes.

[0010] This invention provides an AMX2 type ferroelectric semiconductor composite catalytic composition, comprising:

[0011] AMX2 type ferroelectric semiconductor and strong oxidizing and reducing agent;

[0012] The A is Li, Na, K, Rb, Cs, Cu, Ag, Au, Pd, or Tl;

[0013] The M is B, Al, Ga, In, P, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or Fe;

[0014] X is O, S, or Se;

[0015] The strong oxidizing and reducing agent is selected from persulfate, hydrogen peroxide, persulfate, borate or iodate.

[0016] Specifically, the composite catalytic composition of the present invention comprises an AMX2 type ferroelectric semiconductor and a strong oxidizing and reducing agent in a concentration ratio of 0.2-2.0 g / L: 0.5-5.0 mmol / L.

[0017] The inventors of this application have creatively discovered that by utilizing the multi-source response of AMX2 type ferroelectric semiconductors, especially the broadened light absorption range and the electron-hole separation and rapid migration characteristics promoted by the built-in electric field as exciton initiators, it is possible to further initiate strong redox agents with longer lifetimes and better stability, thereby achieving an order-of-magnitude enhancement of the existing redox catalytic reaction rate.

[0018] The strong oxidizing or reducing agent described in this invention is a catalyst with strong oxidizing or reducing properties, specifically selected from persulfate, hydrogen peroxide, persulfate, sulfite, borate, or iodate. Persulfate and persulfate can be activated by AXM2 to promote the excitation of sulfate radicals, thereby improving catalytic efficiency; hydrogen peroxide can be activated by AXM2 to promote the excitation of hydroxyl radicals, thereby improving catalytic efficiency; while sulfite, borate, or iodate are catalytic materials based on electron reduction reactions. In some embodiments of this invention, the radical-type oxidizing or reducing agent includes potassium hydrogen persulfate, potassium persulfate, ammonium persulfate, sodium persulfate, or hydrogen peroxide. This invention utilizes a composite of an AMX2-type ferroelectric semiconductor and a strong oxidizing or reducing agent, or a composite of multiple AMX2-type ferroelectric semiconductors, to achieve orders-of-magnitude improvements in the corresponding catalytic reactions. Only the stability, radical lifetime, and corresponding potential need to be considered, allowing for a wide range of material selection.

[0019] The AMX2 type ferroelectric semiconductor of the present invention has a non-centrosymmetric zincite structure (space group Pna21). In the composition of AMX2, A is a monovalent metal, specifically Li, Na, K, Rb, Cs, Cu, Ag, Au, Pd or Tl; M is a trivalent element, specifically B, Al, Ga, In, P, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or Fe; X is O, S or Se, preferably O.

[0020] The AMX2 type ferroelectric semiconductor described in this invention is a stable lead-zinc ore phase β-type AMO2 type ferroelectric. In some embodiments of the present invention, A is Li, and M is B, Al, Ga, In, P, As, Sb, Bi, Sc, Y, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Lu, or Fe; or, A is Na, and M is B, Al, Ga, In, P, As, Sb, Sc, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb, Lu, or Fe; or, A is K, and M is Al, Ga, In, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Fe; or, A is Rb, and M is Al, In, P, Sc, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, b, Lu, or Fe; or, A is Cs, and M is Sc, Y, Ce, Nd, Sm, Tb, Dy, Er, Tm, Yb, or Lu; or, A is Cu, and M is B, Al, Ga, In, Y, Pr, Nd, Eu, Dy, Ho, Er, Tm, Yb, Lu, or Fe; or, A is Ag, and M is B, Al, Ga, In, Bi, Sc, La, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or Fe; or, A is Au, and M is Al, In, As, Sb, Sc, Er, Tm, Yb, Lu, or Fe; or, A is Pd, and M is Al, Ga, As, Nd, or Fe; or, A is Tl, and M is B, Al, Ga, Bi, Sc, Y, Ce, Pr, Tb, or Fe.

[0021] Furthermore, the AMX2 type ferroelectric semiconductor described in this invention is at least one of CuGaO2 ferroelectric semiconductor or AgFeO2 ferroelectric semiconductor catalyst.

[0022] This invention also provides applications of the above-mentioned catalytic composition in antibacterial, air purification, water pollution control, CO2 reduction, hydrogen production from water splitting, or nitrogen fixation reactions. The catalytic composition provided by this invention achieves full-spectrum absorption and rapid exciton separation by combining inorganic ferroelectric semiconductor nanoparticles and a strong oxidizing-reducing agent. Under suitable surface redox potentials, it excites catalysts with longer lifetimes and more stable strong oxidizing or reducing properties. The combined use of these two agents significantly improves degradation efficiency by two orders of magnitude. When the strong oxidizing-reducing agent in the above-mentioned catalytic composition is a catalyst with strong oxidizing properties, it can significantly increase the reaction rate in oxidation-related directions, such as antibacterial, sterilization, air purification, deodorization, and water pollution control. When the strong oxidizing-reducing agent in the above-mentioned catalytic composition is a catalyst with strong reducing properties, it can significantly improve reduction-related directions, such as CO2 reduction, hydrogen production from water splitting, and nitrogen fixation reactions in the energy field.

[0023] This invention provides a method for degrading organic pollutants, comprising:

[0024] The catalyst and organic pollutants are mixed to provide energy to initiate the degradation reaction;

[0025] The catalyst is the aforementioned AMX2 type ferroelectric semiconductor composite catalytic composition.

[0026] The present invention first mixes the catalyst and the organic pollutant; specifically, it first mixes the AMX2 type ferroelectric semiconductor, the strong oxidizing and reducing agent, and the organic pollutant; more specifically, it first mixes the AMX2 type ferroelectric semiconductor and the organic pollutant, and then adds the strong oxidizing and reducing agent thereto. In some embodiments of the present invention, the mixing time of the AMX2 type ferroelectric semiconductor and the organic pollutant is 0.5 to 2.5 hours.

[0027] This invention involves mixing the catalyst with organic pollutants and then providing energy to initiate the degradation reaction; the energy source includes light, force, heat, or magnetism. This invention employs an AMX2-type ferroelectric semiconductor composite catalytic composition to degrade organic pollutants. This AMX2-type ferroelectric semiconductor composite catalytic composition can respond not only in the visible light range but also when exposed to visible light in daily activities, resulting in low application cost and high efficiency. Furthermore, external fields such as force, heat, and magnetism can also serve as energy sources. In some embodiments of this invention, providing energy specifically involves irradiating the reaction system with sunlight or visible light.

[0028] The organic pollutants described in this invention include at least one of tetracycline pollutants, penicillin pollutants, β-lactam pollutants, organophosphorus pollutants, carbamate pollutants, azo pollutants, thiazide pollutants, triphenylmethane pollutants, or phenolic pollutants; wherein tetracycline pollutants, penicillin pollutants, and β-lactam pollutants belong to antibiotic pollutants; organophosphorus pollutants and carbamate pollutants belong to pesticide pollutants; azo pollutants such as methyl orange, thiazide pollutants such as methylene blue, and triphenylmethane pollutants such as rhodamine B belong to dye pollutants; and phenolic pollutants such as phenol belong to organic solvent pollutants. In some embodiments of this invention, the method of this invention achieves 100% efficiency in degrading antibiotics such as tetracycline hydrochloride in just 4 minutes.

[0029] This invention provides an AMX2-type ferroelectric semiconductor composite catalytic composition, its application, and a method for degrading organic pollutants. The AMX2-type ferroelectric semiconductor in the composite catalytic composition acts like a fuse, responding to visible light, force, heat, and magnetism, and effectively performing electron-hole separation. This overcomes the limitation of its own redox potential, allowing excitons to excite catalysts with long lifetimes and higher oxidation or reduction potentials, resulting in an order-of-magnitude enhancement of the catalytic reaction. The composite catalytic composition provided by this invention is particularly suitable for degrading recalcitrant organic pollutants in water. Under existing experimental conditions, this invention, using CuGaO2 ferroelectric semiconductor and persulfate (PMS) in combination to degrade organic pollutants, achieves a 97-fold increase in degradation rate. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the photocatalytic reaction mechanism;

[0031] Figure 2 Separating charge carriers and exciting SO4 under visible light for CuGaO2 ·- Degradation of TC at different initial concentrations and its pseudo-first-order kinetics;

[0032] Figure 3 The degradation of TC at different initial concentrations by 1 mM PMS under UV-Vis light and its pseudo-first-order kinetics are shown.

[0033] Figure 4 The degradation of RhB with different initial concentrations by AgFeO2 under visible light and SO4·- and its pseudo-first-order kinetics are shown.

[0034] Figure 5 Separating charge carriers and exciting SO4 under visible light for CuGaO2 · Degradation of RhB at different initial concentrations and its pseudo-first-order kinetics;

[0035] Figure 6 The degradation of different RhBs and their pseudo-first-order kinetics under UV-Vis light by 1mM PMS;

[0036] Figure 7 To separate charge carriers and excite SO4 under visible light for different amounts of PMS and CGO recombination. ·- Degradation diagram of RhB;

[0037] Figure 8 To separate charge carriers and excite SO4 under visible light for different amounts of PMS and CGO recombination. ·- The pseudo-first-order kinetics of RhB;

[0038] Figure 9 To separate charge carriers and excite SO4 under visible light by compositing different amounts of ferroelectric semiconductor CuGaO2 with PMS. ·- Degradation diagram of RhB;

[0039] Figure 10 To separate charge carriers and excite SO4 under visible light by compositing different amounts of ferroelectric semiconductor CuGaO2 with PMS. ·- The pseudo-first-order kinetics of RhB;

[0040] Figure 11 To add h + Scavengers and SO4 ·- The trapping agent separates charge carriers from CuGaO2 and excites SO4. ·- Degradation diagram of RhB degradation ability;

[0041] Figure 12 Add h to + Scavengers and SO4 ·- The trapping agent separates charge carriers from CuGaO2 and excites SO4. ·- The pseudo-first-order kinetics of RhB degradation;

[0042] Figure 13 Separating charge carriers and exciting SO42 under an LED light source for CuGaO2 ·- Degradation of RhB and its pseudo-first-order kinetics. Detailed Implementation

[0043] This invention discloses an AMX2-type ferroelectric semiconductor composite catalytic composition, its application, and a method for degrading organic pollutants. Those skilled in the art can refer to this document and appropriately modify the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0044] The method of easily and efficiently separating photogenerated carriers and exciting sulfate radicals based on a spontaneously polarized built-in electric field, which greatly improves the efficiency of photocatalytic oxidation, has been experimentally verified. In a specific example, the designed photocatalytic oxidation reaction is for the degradation of organic pollutants, and the pollutant concentration is analyzed by ultraviolet-visible spectrophotometry to determine the reaction progress.

[0045] The ferroelectric semiconductor material used is a narrow bandgap ferroelectric semiconductor, wurtzite-type CuGaO2 (β-CuGaO2, CGO). Details of its synthesis method have been disclosed in patent CN 112397642 A, "A Narrow Bandgap Ferroelectric Semiconductor Nanoparticle, Its Preparation Method and Application," with a suitable dosage of 0.5–1.0 g / L. -1 .

[0046] Considering that heterogeneous catalysts require sufficient contact to participate in the reaction, the mixture was stirred in the dark for 1 hour before the experiment began. The selected organic pollutants were Rhodamine B (RhB) and tetracycline hydrochloride (TC), both purchased from Maclean's at concentrations of 10, 20, and 30 mg / L. -1 Sulfate free radicals (SO4) ·- The source of ) is persulfate (HSO5) - PMS), specifically the drug used is potassium hydrogen persulfate (KHSO5, Maclean), with a concentration of 1 mmol / L. -1 (1mM).

[0047] The light sources used include xenon lamps and LEDs. The xenon lamp system is a PLS-SXE300+ (Pofilai) lamp with a UVCUT420 filter (wavelength 420–780 nm). The LED system is a PCX-50C Discover multi-channel photocatalytic reaction system (Pofilai). The bulbs are 10W*9 LEDs simulating the solar spectrum (wavelength 420–760 nm, radiant intensity 140 mW / cm²). 2 ).

[0048] During the reaction, samples were taken at regular intervals. To accurately determine the pollutant concentration at each moment, each sample was quenched with a certain amount of methanol (MeOH) to remove HO. · and SO4 ·- The reaction was terminated by free radicals, and the reaction was then analyzed using a UV-Vis spectrophotometer to determine the reaction progress. Methanol was spectroscopic grade (HPL C / ACS, 99.9%) and purchased from Energie.

[0049] The present invention will be further described below with reference to the embodiments:

[0050] Example 1

[0051] Configure 10, 20, 30 mg L -1 Tetracycline hydrochloride solution was prepared in a brown 1000mL volumetric flask. 50mL of the solution was then transferred to separate quartz flasks, and 50mg of CuGaO2 powder was weighed and added. The flasks were then magnetically stirred in the dark for 1 hour to ensure sufficient contact between the powder and the contaminant. A 1.25mol / L solution was prepared. -1 Potassium hydrogen peroxide solution (1.25M PMS): Pipette 40 μL of 1.25M PMS into 50 mL of the solution; this adds 1 mM PMS to the reaction system. Simultaneously, turn on the xenon lamp and start the timer. The xenon lamp is fitted with a UVCUT420 filter, thus filtering out ultraviolet light; the irradiated light is only in the visible light band.

[0052] Samples were taken every 1 minute throughout the reaction. Each time, 1 mL of sample was quickly transferred into a centrifuge tube containing 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1 After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 358 nm, and the concentration was calculated. If necessary, the centrifugation step was repeated 2–3 times with the supernatant, and the absorbance was measured again. This yielded concentrations of 10, 20, and 30 mg / L. -1 The curve showing the change in tetracycline hydrochloride concentration over time, i.e., the separation of charge carriers and excitation of SO4 by the ferroelectric semiconductor CGO under visible light. ·- Degradation capacity for different initial concentrations of TC, such as Figure 2 As shown, the inset in the upper right corner is a kinetic graph calculated and linearly fitted based on a pseudo-first-order kinetic reaction model, with its slope being the apparent rate constant k.

[0053] Comparative Example 1

[0054] Configure 10, 20, 30 mg L -1 Tetracycline hydrochloride solution was prepared in a brown 1000 mL volumetric flask. 50 mL of the solution was then transferred to separate quartz flasks and magnetically stirred in the dark. This prepared 1.25 mol / L solution...-1 Potassium hydrogen peroxide solution (1.25 M PMS): Transfer 40 μL of 1.25 M PMS to 50 mL of solution; this adds 1 mM PMS to the reaction system. Simultaneously turn on the xenon lamp and start the timer. Because SO42- under visible light... ·- Almost no excitation was achieved, and the degradation of pollutants was barely observable under pure visible light. Therefore, the UVCUT420 filter was omitted in this comparative example, and the ultraviolet light band of the xenon lamp was retained.

[0055] Samples were taken every 10 minutes for the first hour of the reaction, and then every 30 minutes thereafter. Each time, 1 mL of sample was quickly transferred into a centrifuge tube pre-filled with 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1 After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 358 nm, and the concentration was calculated. This yielded concentrations of 10, 20, and 30 mg / L. -1 The curve showing the change in tetracycline hydrochloride concentration over time is shown; this is a curve of SO4 excited by 1 mM MPMS under UV-Vis light. ·- Degradation capacity for different initial concentrations of TC, such as Figure 3 As shown, the inset in the upper right corner is a kinetic graph calculated and linearly fitted based on a pseudo-first-order kinetic reaction model, with its slope being the apparent rate constant k.

[0056] From Example 1 Figure 2 The experimental data show that, in Example 1, 1g L -1 CGO drives 1 mMMPMS SO4 excitation under visible light ·- For 10, 20, 30 mg L -1 TC exhibits excellent degradation effects. From Figure 3 The experimental data from Comparative Example 1 show that 1 mM PMS has a limited effect on the degradation of high concentrations of TC, especially after one hour of degradation, the degradation effect significantly declines or even stops. Therefore... Figure 2 Although the degradation experiments with added CuGaO2 were effective for 20 and 30 mg L... -1 The degradation of TC is not as good as that of 10 mg L -1 TC exhibits remarkable degradation performance, showing a significant improvement compared to the degradation experiment in Comparative Example 1 without the addition of CuGaO2, demonstrating the effectiveness of the strategy employed in this invention. For 10 mg L... -1 TC and CGO separate charge carriers and drive 1mM PMS to excite SO4. ·- The idea demonstrated its powerful effect, achieving 100% degradation in just 4 minutes, with the rate constant k increasing by 97 times.

[0057] Example 2

[0058] Configure 10, 20, 30 mg L -1 Rhodamine B solution was prepared in a 1000 mL volumetric flask. 50 mL of the solution was then transferred to separate quartz flasks, and 50 mg of AgFeO2 powder was weighed and added. The flasks were then magnetically stirred in the dark for 0.5 h to ensure sufficient contact between the powder and the contaminant. A 1.25 mol / L solution was prepared. -1 Potassium hydrogen peroxide solution (1.25 M PMS): Pipette 40 μL of 1.25 M PMS into 50 mL of the solution; this adds 1 mM PMS to the reaction system. Simultaneously, turn on the xenon lamp and start the timer. The xenon lamp is fitted with a UVCUT420 filter, thus filtering out ultraviolet light; the irradiated light is only in the visible light band.

[0059] Samples were taken every 1 minute throughout the reaction. Each time, 1 mL of sample was quickly transferred into a centrifuge tube containing 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1 After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 556 nm, and the concentration was calculated. If necessary, the centrifugation step was repeated 2–3 times with the supernatant, and the absorbance was measured again. This yielded concentrations of 10, 20, and 30 mg / L. -1 The curve showing the change in Rhodamine B concentration over time, i.e., the degradation ability of the ferroelectric semiconductor AFO under visible light by separating charge carriers and exciting SO4·- to different initial concentrations of RhB, such as... Figure 4 As shown, the inset in the upper right corner is a kinetic graph calculated and linearly fitted based on a pseudo-first-order kinetic reaction model, with its slope being the apparent rate constant k.

[0060] Example 3

[0061] Configure 10, 20, 30 mg L -1 Rhodamine B solution was prepared in a 1000 mL volumetric flask. 50 mL of the solution was then measured into separate quartz flasks, and 50 mg of CuGaO2 powder was weighed and added. The flasks were then magnetically stirred in the dark for 1 hour to ensure sufficient contact between the powder and the contaminant. A 1.25 mol / L solution was prepared. -1 Potassium hydrogen peroxide solution (1.25 M PMS): Transfer 40 μL of 1.25 M PMS to 50 mL of solution; this adds 1 mM PMS to the reaction system. Simultaneously turn on the xenon lamp light source and start timing. The xenon lamp light source is equipped with a UVCUT420 filter, which filters out ultraviolet light; the irradiated light is only in the visible light band.

[0062] Samples were taken every 0.5 minutes throughout the reaction. Each time, 1 mL of sample was quickly transferred into a centrifuge tube containing 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1 After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 556 nm, and the concentration was calculated. If necessary, the centrifugation step was repeated 2–3 times with the supernatant, and the absorbance was measured again. This yielded concentrations of 10, 20, and 30 mg / L. -1 The curve showing the change in Rhodamine B concentration over time, i.e., the separation of charge carriers and excitation of SO4 by CuGaO2 under visible light. ·- Degradation capacity for different initial concentrations of RhB, such as Figure 5 As shown, the inset in the upper right corner is a kinetic graph calculated and linearly fitted based on a pseudo-first-order kinetic reaction model, with its slope being the apparent rate constant k.

[0063] Comparative Example 2

[0064] Configure 10, 20, 30 mg L -1 Prepare a 1000 mL volumetric flask containing Rhodamine B solution. Measure 50 mL of the solution into separate quartz flasks and stir magnetically in the dark. Prepare a 1.25 mol / L solution. -1 Potassium hydrogen peroxide solution (1.25M PMS): Pipette 40 μL of 1.25M PMS into 50 mL of the solution; this adds 1 mM PMS to the reaction system. Simultaneously turn on the xenon lamp and start the timer. Because SO42- under visible light... ·- Almost no excitation was achieved, and the degradation of pollutants was barely observable under pure visible light. Therefore, the UVCUT420 filter was omitted in this comparative example, and the ultraviolet light band of the xenon lamp was retained.

[0065] Samples were taken every 10 minutes for the first hour of the reaction, and then every 30 minutes thereafter. Each time, 1 mL of sample was quickly transferred into a centrifuge tube pre-filled with 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1 After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 556 nm, and the concentration was calculated. This yielded concentrations of 10, 20, and 30 mg / L. -1 The curve showing the change in Rhodamine B concentration over time is shown; this is a curve of SO4 excited by 1 mM PMS under UV-Vis light. ·- Degradation capacity for different initial concentrations of RhB, such as Figure 6 As shown, the inset in the upper right corner is a kinetic graph calculated and linearly fitted based on a pseudo-first-order kinetic reaction model, with its slope being the apparent rate constant k.

[0066] In Example 2, 1g L -1 AFO drives 1mM PMS to excite SO4 under visible light. ·- For 10, 20, 30 mg L -1 RhB exhibited excellent degradation effects. In Example 3, 1 g L -1 CGO drives 1mM PMS to excite SO4 under visible light. ·- For 10, 20, 30 mg L -1 RhB exhibited excellent degradation effects. Compared to the degradation experiments in Comparative Example 2 without the addition of AgFeO2 or CuGaO2 under UV conditions, it significantly improved the degradation efficiency. Specifically, for 10 mg L... -1 RhB and AFO separate charge carriers and drive 1mM PMS to excite SO4. ·- It achieved 100% degradation in just 5 minutes, a 30-fold reduction in time and a 24-fold increase in rate. For 10 mg L... -1 RhB and CGO separate charge carriers and drive 1mM PMS to excite SO4. ·- It achieved 100% degradation in just 2 minutes, a 75-fold reduction in time and a 65-fold increase in rate.

[0067] Example 4:

[0068] Prepare 20mg L -1 Rhodamine B solution was prepared in a 1000 mL volumetric flask. Four 50 mL aliquots of the solution were measured into quartz flasks, each weighed, and 50 mg of CuGaO2 powder was added to each. The flasks were then magnetically stirred in the dark for 1 hour to ensure sufficient contact between the powder and the contaminant. A 1.25 mol / L solution was prepared. -1 Potassium hydrogen peroxide solution (1.25 M PMS): 20, 40, 80, and 120 μL of 1.25 M PMS were pipetted into four 50 mL aliquots, respectively, adding 0.5, 1, 2, and 3 mM PMS to each reaction system. Simultaneously, the xenon lamp light source was turned on and the timer started. The xenon lamp light source was fitted with a UVCUT420 filter, thus filtering out ultraviolet light; the irradiated light was only in the visible light band.

[0069] Samples were taken every 0.5 minutes throughout the reaction. Each time, 1 mL of sample was quickly transferred into a centrifuge tube containing 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 556 nm, and the concentration was calculated. If necessary, the centrifugation step was repeated 2-3 times with the supernatant, and the absorbance was measured again. This yielded the Rhodamine B concentration versus time curve, demonstrating how the ferroelectric semiconductor CuGaO2 separates charge carriers and excites SO42 under visible light when the PMS dosage is adjusted. ·- The ability to degrade RhB, such as Figure 7 As shown. To express its degradation rate, a kinetic graph was plotted based on a pseudo-first-order kinetic model and linear fitting, with the slope representing the apparent rate constant k, as shown. Figure 8 As shown.

[0070] By changing the experimental parameters, the effects of each parameter can be clearly observed, confirming the ideas proposed in this invention. In Example 3, the amount of PMS was changed, i.e., the SO4 content was adjusted. ·- The number of activated SO42- and the degradation rate showed significant changes, confirming that SO42- induced by PMS was significantly affected. ·- It primarily participates in photocatalytic oxidation reactions. In particular, even with very small amounts of PMS, the ferroelectric semiconductor CGO is sufficient to rapidly generate enough SO42-. ·- It degrades in a short time.

[0071] Example 5

[0072] Prepare 10mg L -1 Rhodamine B solution was prepared in a 1000 mL volumetric flask. Four 50 mL aliquots of the solution were placed in quartz flasks, and 12.5, 25, 50, and 100 mg of CuGaO2 powder were added to each flask. The flasks were then magnetically stirred in the dark for 1 hour to ensure sufficient contact between the powder and the contaminant (the amounts of CuGaO2 added were 0.25, 0.5, 1.0, and 2.0 g / L, respectively). -1 ). Prepare 1.25 mol L. -1 Potassium hydrogen peroxide solution (1.25M PMS): Pipette 40 μL of 1.25M PMS into 50 mL of the solution; this adds 1 mM PMS to the reaction system. Simultaneously, turn on the xenon lamp and start the timer. The xenon lamp is fitted with a UVCUT420 filter, thus filtering out ultraviolet light; the irradiated light is only in the visible light band.

[0073] Samples were taken every 0.5 minutes for the first 5 minutes of the reaction, and then every 1 minute thereafter. Each time, 1 mL of sample was quickly transferred into a centrifuge tube pre-filled with 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 556 nm, and the concentration was calculated. If necessary, the centrifugation step was repeated 2-3 times with the supernatant, and the absorbance was measured again. This yielded the Rhodamine B concentration versus time curve, demonstrating how the ferroelectric semiconductor CuGaO2 separates charge carriers and excites SO42 under visible light when the CGO dosage is adjusted. ·- The ability to degrade RhB, such as Figure 9 As shown. To express its degradation rate, a kinetic graph was plotted based on a pseudo-first-order kinetic model and linear fitting, with the slope representing the apparent rate constant k, as shown. Figure 10 As shown.

[0074] Comparative Example 3:

[0075] Prepare 10, 20 mg L -1 Prepare three 50 mL aliquots of Rhodamine B solution in a 1000 mL volumetric flask. -1 RhB solution was placed in quartz bottles a, b, and c, and 25 mL of 20 mg / L solution was measured. -1 RhB solution was placed in quartz bottle d. For quartz bottles c and d, 50 mg of CuGaO2 powder was weighed and added to each bottle, and the bottles were magnetically stirred in the dark for 1 hour to ensure that the powder was in full contact with the contaminant.

[0076] For quartz bottles b and c, weigh and add 500 mg of ammonium oxalate (AO) powder respectively; for quartz bottle d, measure and add 25 mL of MeOH. At this point, the volume of quartz bottle a is: 10 mg L -1 RhB;b contains: 10mg L -1 RhB+10g L -1 AO; c contains: 10mg / L -1 RhB+10g L -1 AO+1g L -1 CGO; d contains: 10mg L -1 RhB + 50% MeOH.

[0077] Prepare 1.25 mol L -1 Potassium hydrogen peroxide solution (1.25M PMS): 40 μL of 1.25M PMS was pipetted into each reaction system, adding 1 mM PMS. Simultaneously, the xenon lamp light source was turned on, and the timer was started. Because SO42- under visible light... ·- Almost no excitation was achieved, and the degradation of pollutants was barely observable under pure visible light. Therefore, the UVCUT420 filter was omitted in this comparative example, and the ultraviolet light band of the xenon lamp was retained.

[0078] Samples were taken every 10 minutes for the first hour of the reaction, and then every 30 minutes thereafter. Each time, 1 mL of sample was quickly transferred into a centrifuge tube pre-filled with 4 mL of MeOH to terminate the reaction. For quartz flasks (d), careful sealing is necessary before and after sampling. The reaction was carried out at 11000 rpm. -1 After centrifugation for 5 minutes, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 556 nm, and the concentration was calculated. If necessary, the centrifugation step was repeated 2-3 times with the supernatant, and the absorbance was measured again. The curve of Rhodamine B concentration versus time was obtained, and a pseudo-first-order kinetic diagram was plotted.

[0079] Ammonium oxalate (AO) can quench holes (h + Methanol (MeOH) can quench hydroxyl radicals and sulfate radicals (HO). · SO4 ·- In Comparative Example 3, the photogenerated h of the ferroelectric semiconductor CGO was further determined by adding AO and MeOH. + and the SO4 it generates ·- The role played in the reaction. Figure 11 To add h + Scavengers and SO4 ·- The trapping agent separates charge carriers from CuGaO2 and excites SO4. ·- The degradation graph of RhB is plotted to represent its degradation rate. A kinetic graph was calculated and linearly fitted based on a pseudo-first-order kinetic model, and its slope represents the apparent rate constant k. Figure 12 As shown. Figures 11-12 It showed the addition of h + Scavengers and SO4 ·- The trapping agent separates charge carriers from CuGaO2 and excites SO4. ·- The effect of RhB degradation capability confirms the invention's proposed method of separating charge carriers using the built-in electric field of ferroelectric semiconductors and driving photogenerated holes to overcome bandgap limitations and reach higher potentials to excite SO42-. ·- The mechanism of participation in photocatalytic oxidation reaction.

[0080] Firstly, when 50% MeOH is added, CGO drives the SO42-induced SO42- in PMS. ·- It is rapidly eliminated and cannot participate in photocatalytic oxidation reactions, showing only a slight degradation effect in the initial stage before stagnating. This further confirms the existence of SO4. ·- It is the main active species participating in the reaction. Secondly, 10g L was added. -1 During AO, light generates h + The removal of SO42- can no longer generate SO42-. ·- SO4 can only be inefficiently excited by ultraviolet light.·- Therefore, it has some degradation ability, but the effect is generally not as good as the degradation effect of PMS alone under the same conditions. This further confirms that the ferroelectric semiconductor CGO relies on its built-in electric field to separate photogenerated h + It is SO4 ·- The main excitation steps also confirmed the photogenerated h + It has indeed broken through the narrow bandgap limitation of CGO and has higher performance than SO4. ·- The redox potential. Thirdly, the degradation rates of AO+PMS and AO+CGO+PMS are almost identical, which eliminates the interference of AO and further confirms the presence of h in CGO. + The role it plays in the reaction.

[0081] Example 6

[0082] Prepare 10mg L -1 Rhodamine B solution was prepared in a 1000 mL volumetric flask. Three 50 mL aliquots of the solution were measured into quartz bottles, each weighed, and 50 mg of CuGaO2 powder was added to each. These bottles were then placed in the reaction chamber of the PCX-50C Discover multichannel photocatalytic reaction system. Due to the low stirring speed of this instrument's stirring system, the stirring time in the dark was extended to 2.5 h to ensure sufficient contact between the powder and the contaminant in order to achieve adsorption equilibrium of the solid-phase catalyst.

[0083] Prepare 1.25 mol L -1 Potassium hydrogen peroxide solution (1.25M PMS): 20, 40, and 80 μL of 1.25M PMS were pipetted into three 50 mL aliquots, respectively, thus adding 0.5, 1, and 2 mM PMS to each reaction system. Simultaneously, the LED light source was turned on and the timer started. The LED light source simulates the visible light spectrum of sunlight in the range of 420–760 nm, reducing light intensity and effectively controlling the photothermal effect compared to a xenon lamp.

[0084] Samples were taken every 2 minutes throughout the reaction. Each time, 1 mL of sample was quickly transferred into a centrifuge tube containing 4 mL of MeOH to terminate the reaction. The centrifuge was set at 11000 rpm. -1 After centrifugation for 5 min, 3 mL of the supernatant was collected in a 10 mm quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance was measured at 556 nm, and the concentration was calculated. If necessary, the centrifugation step was repeated 2-3 times with the supernatant, and the absorbance was measured again. This yielded the Rhodamine B concentration versus time curve, i.e., the separation of charge carriers and excitation of SO42 by CuGaO2 under an LED light source when the PMS dosage was adjusted. ·- The ability to degrade RhB, such as Figure 13As shown, the inset in the upper right corner is a kinetic graph calculated and linearly fitted based on a pseudo-first-order kinetic reaction model, with its slope being the apparent rate constant k.

[0085] Example 7

[0086] This embodiment uses the oxidation and degradation of pollutants in water by ferroelectric semiconductor CuGaO2 and persulfate (PMS) as an example to demonstrate the rationality of our hypothesis. Under existing experimental conditions, it achieved a nearly 100-fold increase in the degradation rate of water pollutants. This strategy also includes the effects achievable by all similar strategies, differing only in the type of ferroelectric semiconductor matched with the corresponding strong oxidizing / reducing catalyst and the method of application. This embodiment uses first-principles static calculations of Gibbs free energy thermodynamic data and mechanical stability to confirm its stable existence. The wurtzite phase β-type AMO2 ferroelectric has rich properties due to differences in its band gap, valence band top, and conduction band bottom positions, as shown in Table 1. Table 1 lists the stably existing lead-zinc oxide phase β-type AMO2 ferroelectric semiconductors, with * representing a stable phase. Combinations based on these intrinsic parameters are expected to significantly improve photocatalytic performance. Commonly used strong oxidants, besides persulfate, include hydrogen peroxide, iodates, and borates. In addition to the strong oxidizing degradation of pollutants in water as shown in this patent, it also includes applications in fuel synthesis, nitrogen fixation reactions, and medical antibacterial applications.

[0087] Table 1

[0088]

[0089]

[0090] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for degrading an organic contaminant, characterized by, The method comprises: mixing the catalyst and the organic pollutants to provide energy to start the degradation reaction; the energy comprises light, force or heat; the catalyst is an AMX2 type ferroelectric semiconductor composite catalytic composition, the AMX2 type ferroelectric semiconductor composite catalytic composition comprises an AMX2 type ferroelectric semiconductor and a strong oxidant, and the concentration ratio of the AMX2 type ferroelectric semiconductor and the strong oxidant is 0.2-2.0 g / L:0.5-5.0 mmol / L the strong oxidant is selected from peroxysulfate, hydrogen peroxide, persulfate or sulfite; the AMX2 type ferroelectric semiconductor is at least one of a CuGaO2 ferroelectric semiconductor or an AgFeO2 ferroelectric semiconductor.

2. The method of claim 1, wherein, the strong oxidant is selected from potassium peroxomonosulfate, potassium persulfate, ammonium persulfate, sodium persulfate or hydrogen peroxide.

3. The method of claim 1, wherein, the organic pollutants comprise at least one of tetracycline pollutants, penicillin pollutants, beta-lactam pollutants, organophosphorus pollutants, carbamate pollutants, carbamate pollutants, azo pollutants, thiazine pollutants, triphenylmethane pollutants or phenolic pollutants.

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