CN114514979A - Green method for reducing aflatoxin - Google Patents

Green method for reducing aflatoxin Download PDF

Info

Publication number
CN114514979A
CN114514979A CN202011303022.7A CN202011303022A CN114514979A CN 114514979 A CN114514979 A CN 114514979A CN 202011303022 A CN202011303022 A CN 202011303022A CN 114514979 A CN114514979 A CN 114514979A
Authority
CN
China
Prior art keywords
aflatoxin
composite
composite film
substrate
reducing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202011303022.7A
Other languages
Chinese (zh)
Other versions
CN114514979B (en
Inventor
李培武
毛劲
张奇
张文
张良晓
李慧
喻理
程玲
杨祥龙
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oil Crops Research Institute of Chinese Academy of Agriculture Sciences
Original Assignee
Oil Crops Research Institute of Chinese Academy of Agriculture Sciences
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oil Crops Research Institute of Chinese Academy of Agriculture Sciences filed Critical Oil Crops Research Institute of Chinese Academy of Agriculture Sciences
Priority to CN202011303022.7A priority Critical patent/CN114514979B/en
Priority to PCT/CN2021/131472 priority patent/WO2022105831A1/en
Publication of CN114514979A publication Critical patent/CN114514979A/en
Application granted granted Critical
Publication of CN114514979B publication Critical patent/CN114514979B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
    • A23L5/20—Removal of unwanted matter, e.g. deodorisation or detoxification
    • A23L5/27—Removal of unwanted matter, e.g. deodorisation or detoxification by chemical treatment, by adsorption or by absorption
    • A23L5/273—Removal of unwanted matter, e.g. deodorisation or detoxification by chemical treatment, by adsorption or by absorption using adsorption or absorption agents, resins, synthetic polymers, or ion exchangers
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23D—EDIBLE OILS OR FATS, e.g. MARGARINES, SHORTENINGS, COOKING OILS
    • A23D9/00—Other edible oils or fats, e.g. shortenings, cooking oils
    • A23D9/06—Preservation of finished products
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
    • A23L5/20—Removal of unwanted matter, e.g. deodorisation or detoxification
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/24—Chromium, molybdenum or tungsten
    • B01J23/30—Tungsten
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/24—Nitrogen compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/39—Photocatalytic properties
    • C—CHEMISTRY; METALLURGY
    • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
    • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
    • C11B3/00—Refining fats or fatty oils
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2235/00—Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2235/00—Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties
    • B01J2235/15—X-ray diffraction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2235/00—Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties
    • B01J2235/30—Scanning electron microscopy; Transmission electron microscopy

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Polymers & Plastics (AREA)
  • Food Science & Technology (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Biochemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Nutrition Science (AREA)
  • Microbiology (AREA)
  • Wood Science & Technology (AREA)
  • Catalysts (AREA)

Abstract

The invention discloses a green method for reducing aflatoxin. Fully contacting a sample containing aflatoxin with a composite film for reducing aflatoxin, selectively adsorbing and removing the aflatoxin in the sample by the composite film, then placing the composite film under sunlight or a xenon lamp light source for irradiation, and gradually degrading the aflatoxin, wherein the composite film for reducing aflatoxin comprises a substrate and g-C on the substrate3N4/WO3Composite material g-C3N4In a lamellar structure, WO3The nano particles are uniformly dispersed in the lamella g-C3N4The surface is tightly combined to form the composite semiconductor photocatalytic material.

Description

Green method for reducing aflatoxin
Technical Field
The invention belongs to the technical field of food harmful pollutant control, and particularly relates to a green method for reducing aflatoxin.
Background
Edible vegetable oil such as peanut oil, corn oil and the like is rich in unsaturated fatty acid, has good fatty acid composition and is easy to digest and absorb by human bodies. The peanut oil is also rich in various functional nutrient substances such as sterol, wheat germ phenol, vitamin E, choline, phospholipid and the like, and is popular with consumers. However, in recent years, the media reports that the aflatoxin in edible vegetable oil exceeds the standard, mainly because individuals or enterprises are in the process of purchasing peanuts, the aflatoxin in the edible oil exceeds the standard due to the fact that the peanuts and corn raw materials polluted by the aflatoxin are processed due to the fact that the peanuts and the corn raw materials are not strictly closed or the storage conditions after harvesting are limited. Aflatoxin is a potent carcinogenic and teratogenic substance designated as class i carcinogen by the international cancer organization. The malignant poisoning of people and livestock caused by excessive aflatoxin at home and abroad also occurs, and the malignant poisoning becomes an important factor for restricting consumption safety and industrial development. Therefore, how to safely and efficiently remove aflatoxin and ensure life health and consumption safety of consumers becomes a hot spot of current attention, and is also a difficult point of interest of researchers in various countries.
Currently, the detoxification and attenuation of aflatoxin mainly comprise methods such as chemistry, physics, biology and the like, wherein the chemical method usually uses a strong oxidant to destroy the structure of aflatoxin, but can also influence the flavor or nutrient substances in food or grease; physical methods include water washing or adsorption, but the molecular structure of the toxin is not changed, and secondary pollution can be caused when the toxin exists in the environment; the biological method has the characteristics of high efficiency, high selectivity and the like, but needs more objective theoretical data support in the aspects of large-scale application and safety evaluation. Therefore, from the perspective of high-quality development, a novel, energy-saving and green aflatoxin reduction technology is urgently needed in the current industry development.
Disclosure of Invention
The invention aims to provide a green reduction method of aflatoxin. The method is used for reducing aflatoxin, has the characteristics of greenness, high efficiency and safety, and does not influence nutritional functional components similar to benzene ring structures of aflatoxin in samples, such as phenolic substances containing benzene ring structures.
The method for reducing the aflatoxin comprises the steps of fully contacting a sample containing the aflatoxin with a composite film for reducing the aflatoxin, selectively adsorbing and removing the aflatoxin in the sample by the composite film, then placing the composite film under sunlight or a xenon lamp light source for irradiation, and gradually degrading the aflatoxin, wherein the composite film for reducing the aflatoxin comprises a substrate and g-C on the substrate3N4/WO3Composite material g-C3N4In a lamellar structure, WO3The nano particles are uniformly dispersed in the lamella g-C3N4The surface is tightly combined to form the composite semiconductor photocatalytic material.
According to the above scheme, g-C3N4/WO3In composite materials WO3The mass ratio of (A) is 5-20%; WO3The nano particles have uniform size of about 10nm and g-C3N4The size of the lamella is 100-200 nm.
According to the scheme, the substrate is ITO glass or fluorine-doped SnO2Conductive glass FTO.
According to the scheme, the wavelength of the xenon lamp light source is 420-700 nm.
According to the scheme, the method for contacting the sample containing the aflatoxin with the composite film comprises the following steps: fixing the composite film on a production line, wherein a sample slowly flows through the composite film in the production process and is in contact with the composite film; or the composite film is fixed on the blade of a propeller type stirrer and is placed into a container for storing samples, and the operation is convenient.
According to the scheme, the sample is edible vegetable oil, including peanut oil, corn oil and the like which are easily polluted by aflatoxin.
The composite film for reducing aflatoxin comprises a substrate and g-C on the substrate3N4/WO3Composite material, g-C3N4In a lamellar structure, WO3The nano particles are uniformly dispersed in the lamella g-C3N4The surface is tightly combined to form the composite semiconductor photocatalytic material.
According to the scheme, the composite material WO3/g-C3N4WO of Zhong3The mass ratio of (A) is 5 to 20 wt%, preferably 5 to 15 wt%, more preferably 10%, WO3The nano particles have uniform size of about 10nm and g-C3N4The size of the lamella is 100-200 nm.
According to the scheme, the substrate is ITO glass or fluorine-doped SnO2Conductive glass FTO.
The preparation method of the composite film material capable of selectively adsorbing and reducing aflatoxin by utilizing visible light catalysis is provided:
1) firstly, preparing carbon nitride through a high-temperature pyrolysis method, stripping at high temperature, and carrying out post-treatment to obtain carbon nitride nanosheets;
2) dispersing carbon nitride nanosheets in water, stirring, ultrasonically dispersing, adding a certain amount of sodium tungstate, stirring for dissolving, adding acid, converting the sodium tungstate into a precipitate, centrifuging to obtain a yellow precipitate, cleaning, adding acid, adjusting the pH value to 1.2-1.5, placing the yellow precipitate in a reaction kettle, carrying out hydrothermal reaction at 180-200 ℃ to prepare WO3/g-C3N4A composite material;
3) adding water into the composite material for dispersion, adding an organic solvent, fully grinding to obtain a uniform and viscous suspension, then dripping the suspension on a substrate for natural tape casting to form a film, and calcining, fixing and sintering under the protection of inert gas to enable the composite material to be more tightly combined with the substrate, thereby preparing the composite film for reducing aflatoxin.
According to the scheme, the high-temperature pyrolysis method for preparing carbon nitride in the step 1) comprises the following steps: urea and dicyanodiamine are mixed according to the mass ratio of 1: 2-3, dissolving in distilled water at 50-60 ℃, placing in an oven for recrystallization, after uniformly grinding crystals, placing in a crucible, covering, then placing in a tube furnace or a muffle furnace, heating to 550-560 ℃, and keeping for 3-4 hours;
the high-temperature stripping temperature is 580-600 ℃, and the stripping time is kept for 2-3 hours.
The post-treatment comprises the following steps: grinding, respectively washing with dilute nitric acid and ethanol solution for three times, and drying to obtain carbon nitride powder.
The hydrothermal time in the step 2) is 24-30 h. The post-treatment comprises the following steps: centrifuging to obtain yellow solid matter, washing with ethanol and distilled water for three times, and oven drying;
step 3) weighing 1.0-2.0 g of composite photocatalytic material, dissolving in 20-30 mL of distilled water, performing ultrasonic dispersion, adding 3-5 mL of dimethylformamide or methanol, fully grinding to obtain a uniform and viscous suspension, then dripping the suspension on an ITO glass sheet, and naturally casting to form a film, wherein N is an inert gas2And calcining, fixing and sintering at 300-350 ℃ under protection, so that the composite filter membrane is combined more tightly, and the aflatoxin-reduction composite membrane is prepared.
In the present invention, the catalyst is used in the reaction of3N4Nanosheet, WO3The composite film composed of the nanoparticles and the ITO glass is used for reducing aflatoxin including aflatoxin B1, aflatoxin B2, aflatoxin M1, aflatoxin M2 and the like, has excellent selective adsorption and visible light catalysis performances, and specifically comprises the following components in percentage by weight: on one hand, based on the pi-pi stacking effect of a ring aromatic conjugated structure in graphite type carbon nitride and a benzene ring in an aflatoxin structure, on the other hand, oxygen lone pair electrons on a lactone ring in the aflatoxin structure and a 5d empty orbit of a tungsten atom form a coordination bond, and the excellent capability of selectively adsorbing and removing aflatoxin can be realized by mainly utilizing the synergistic adsorption performance of the two materials, so that the aim of high-selectivity adsorption is fulfilled; the composite film can adsorb aflatoxin without affecting nutritional functional components with similar benzene ring structure of aflatoxin in a sample system, such as phenolic substances with benzene ring structure. In addition, the composite film also has excellent visible light catalytic activity, the Z-type semiconductor composite material is formed by two semiconductor catalysts of carbon nitride and tungsten oxide, has strong reduction capability and oxidation capability, generates a large number of active groups such as hydroxyl free radicals and superoxide free radicals under the excitation of visible light, gradually reduces aflatoxin, and is finally mineralized into CO2And H2O, c, dAvoid the toxin entering the environment or food chain and cause secondary pollution. Therefore, the composite film based on the principle has excellent selective adsorption and photocatalytic performance, and can safely and efficiently reduce aflatoxin in a sample.
In short, the method combines visible light catalysis and selective adsorption technology, firstly removes aflatoxin by selective adsorption to achieve reduction, then places the composite film in sunlight or xenon lamp light source for irradiation, and based on excellent visible light catalytic activity of the composite film, carbon nitride and tungsten oxide form Z-type semiconductor composite material with strong reduction capability and oxidation capability, gradually degrades toxin, and the final product is CO2And H2And O, the 'elimination' is achieved, so that the green, efficient and safe technology is realized for eliminating the aflatoxin in the sample.
The composite film prepared by the invention has good performance of reducing aflatoxin in AFB1Initial concentration 16.8ppb, 10% WO3/g-C3N4(WO3：g-C3N4The mass ratio is 10%), the aflatoxin reduction rate is 92.2%, the composite film can be recycled, and the composite film has the advantages of good economy, energy conservation, greenness, high efficiency, no secondary pollution and the like, and is expected to be used for AFB in samples such as peanut oil, corn oil and the like1The toxin is controlled and removed, and a new path is provided for ensuring the consumption safety and the industrial development of edible vegetable oil such as peanut oil.
Drawings
FIG. 1 is an electron diffraction XRD pattern of the composite material developed in example 1;
FIG. 2 is a transmission electron microscopy TEM micrograph of the composite developed in example 1;
FIG. 3 is an Atomic Force Microscope (AFM) spectrum of a composite filter developed in example 1;
FIG. 4 is the composite membrane abatement of AFB in peanut oil of example 21Performance;
FIG. 5 is the example 2 composite Membrane Recycling to reduce AFB in peanut oil1Effect graphs;
FIG. 6 is a graph of the effect of composite filters on total phenolic content in peanut oil.
FIG. 7 is a hydroxyl radical pattern and Z-system electron transport mechanism for composite filter ESR testing;
Detailed Description
Example 1: development of composite filter membrane
Dissolving 5.0g of urea and 10.0g of dicyanodiamine in distilled water at 50 ℃, placing the mixture in an oven for recrystallization, placing the mixture in a crucible after the crystallization is uniformly ground, covering the crucible, placing the crucible in a tubular furnace or a muffle furnace, heating the mixture to 550 ℃ at a heating speed of 5 DEG/min, keeping the temperature for 3 hours, heating the mixture to 580 ℃ for 2 hours, stripping the mixture at high temperature to obtain yellow powder, grinding the yellow powder, respectively washing the yellow powder with dilute nitric acid and ethanol solution for three times, and drying the yellow powder to obtain carbon nitride powder. Dispersing 1.0g of carbon nitride in 100mL of distilled water, stirring, performing ultrasonic dispersion, adding a certain amount of sodium tungstate, stirring for dissolution, adding a hydrochloric acid solution, adjusting the pH value to 1.2, centrifuging to obtain a precipitate, cleaning the precipitate with ethanol and distilled water, adding a nitric acid solution, placing the precipitate in a reaction kettle, performing hydrothermal treatment at 200 ℃ for 24 hours, separating and centrifuging to obtain a yellow solid substance, washing the yellow solid substance with ethanol and distilled water for three times respectively, and drying the yellow solid substance at 60 ℃ for later use to obtain a composite material (the composite material WO)3/g-C3N4WO of Zhong3In a mass ratio of 5%, 10%, 15%, 20%).
Weighing 2.0g of composite photocatalytic material, dissolving in 20mL of distilled water, performing ultrasonic uniform dispersion for 30min, adding 5mL of dimethylformamide, fully grinding to obtain a uniform and viscous suspension, pouring the suspension on an ITO glass sheet (20cm multiplied by 20cm) for natural flow casting to form a film, and performing N inert gas chromatography on the film to obtain the film2Under the protection, calcining at 300 ℃, fixing and sintering to ensure that the materials are combined more tightly, thus preparing the composite film for reducing aflatoxin.
FIG. 1 is a 10% WO developed in example 13/g-C3N4An electron diffraction (XRD) pattern of the composite material;
FIG. 2 is a TEM image of the composite material prepared in example 1 at different magnifications; wherein the sheet layer is g-C3N4A length of 100 to 200nm, WO3Is granular with the size of about 10 nm;
FIG. 3 is an atomic force microscope AFM spectrum of the composite filter developed in example 1. The film thickness was uniform, about 25 nm.
Example 2: AFB in peanut oil1Evaluation of abatement Performance
The formulations contained 5.6,11.2,16.8 and 22.4ppb AFB1The peanut oil of (1) was allowed to flow on the composite filter membrane developed in example 1 at a flow rate of 50mL/min, and then the composite filter membrane was exposed to natural sun for 10 hours, the surface was washed 3 times with distilled water and methanol, the composite filter membrane was recovered, and the above operation was repeated. Testing of AFB in peanut oil by liquid chromatography1Calculating the rate of decrease.
FIG. 4 shows 10% WO3/g-C3N4Composite film for reducing AFB with different initial concentrations1The peanut oil effect diagram shows that the composite film can reduce toxins by more than 80% through one-time reduction, which shows that the composite film can efficiently reduce aflatoxin in the peanut oil.
FIG. 5 shows 10% WO3/g-C3N4The reusability evaluation of the composite film shows that the composite filter film repeatedly reduces the peanut oil with the initial concentration of 16.8ppb, the reduction rate is about 92 percent, and the composite film is stable in performance and can be reused.
Different mass ratios WO3And g-C3N-developed composite filter membrane for once reducing AFB in peanut oil1The results are shown in Table 1 below, and it is clear from the results that 10% WO is obtained3/g-C3N4Best results (AFB)1Initial concentration 16.8 ppb). In conclusion, the composite filter membrane can not only efficiently remove aflatoxin, but also degrade toxin by utilizing solar catalysis, and the technology has the advantages of greenness, energy conservation, economy and the like, and is expected to become one of aflatoxin prevention and control technologies in edible vegetable oil such as peanut oil and the like.
TABLE 1 different mass ratios of composite materials photocatalytic reduction of initial concentration 16.8ppb AFB1Peanut oil performance
Figure BDA0002787495700000051
Example 3: effect of composite films on Total phenols in peanut oil
The effect of the filtration reduction process on the total phenol content of peanut oil was evaluated by testing the total phenol content of peanut oil using the folin phenol method, and the results are shown in fig. 6. After 4 rounds of repeated filtration, the content of total phenols in the peanut oil has no obvious change, which shows that the film can not only effectively remove AFB in the peanut oil1And the loss of phenols which are functional active ingredients containing benzene ring aromatic groups in the peanut oil can be avoided, and the method has the characteristics of greenness, low energy consumption, high efficiency, safety and the like. This is because although these phenolic substances contain a benzene ring structure, they may form pi-pi stacking with a ring aromatic conjugated structure in carbon nitride, but the composite film is comparable to AFB1The adsorption of the compound is synergistic, the combination is not tight, and the phenolic substances can be well preserved in the sample after the peanut oil continuously flows in the composite film or is stirred and shaken.
Example 4: composite film photocatalytic electron transfer mechanism
Oxygen free radicals, particularly hydroxyl free radicals, generated by the composite film are measured by an Electron Spin Resonance (ESR) method to confirm that the photocatalytic electron transfer mechanism of the composite film is a Z-type system. DMPO (5, 5-dimethyl-1-pyroline N-oxide) is used as a marker, and a German Bruker A200S-9.5/12 type electron paramagnetic resonance spectrometer is adopted for measurement under the conditions that the microwave frequency is 9.8GHz, the power is 2.2mW, the field strength is 3500G, a xenon lamp is used as a light source for illumination in the test process, and the wavelength is as follows: 420-700 nm.
ESR test results of hydroxyl radicals are shown in FIG. 7, a DMPO-OH spectrum consists of quadruple splitting peaks with peak heights of 1:2:2:1, the existence of the hydroxyl radicals is verified, and the WO is proved3/g-C3N4Can generate hydroxyl free radical after being excited by light. WO3And g-C3N4The valence bands of (A) are 3.2V and 1.4V, respectively, and if they form a heterojunction, photogenerated holes are generated from WO3To g-C3N4It cannot directly generate hydroxyl radicals because of g-C3N4Valence band ratio OH-H is difficult to oxidize with OH (+2.4V vs NHE) correction2O or OH-Hydroxyl groups are generated. Thus, WO3And g-C3N4Can be inferred to be Z-type system, and is first excited by lightThen, WO3Electron on conduction band and g-C3N4Hole recombination above the valence band, and WO3The hole(s) of (a) remains in its valence band, possesses a strong oxidizing power, is more negative than OH-/. OH (+2.4V vs NHE), and has sufficient capacity to oxidize OH in water-Hydroxyl radicals are generated. Therefore, the composite material has the advantages that the electron transfer is a Z-shaped system, the strong oxidation and reduction capability can be utilized, the photocatalytic activity is excellent, and the aflatoxin can be efficiently reduced.

Claims (10)

1. The method for reducing aflatoxin is characterized by comprising the following steps: fully contacting a sample containing aflatoxin with a composite film for reducing aflatoxin, selectively adsorbing and removing the aflatoxin in the sample by the composite film, then placing the composite film under sunlight or a xenon lamp light source for irradiation, and gradually degrading the aflatoxin, wherein the composite film for reducing aflatoxin comprises a substrate and g-C on the substrate3N4/WO3Composite material g-C3N4In a lamellar structure, WO3The nano particles are uniformly dispersed in the lamella g-C3N4The surface is tightly combined to form the composite semiconductor photocatalytic material.
2. The method of attenuating aflatoxins of claim 1, wherein: composite material WO3/g-C3N4WO of Zhong3In a mass ratio of 5 to 20 wt%, WO3The nano particles have uniform size of about 10nm and g-C3N4The size of the lamella is 100-200 nm.
3. The method of attenuating aflatoxins of claim 1, wherein: the substrate is Indium Tin Oxide (ITO) glass or fluorine-doped SnO2Conductive glass FTO.
4. The method of attenuating aflatoxins of claim 1, wherein: the method for contacting the sample containing the aflatoxin with the composite film comprises the following steps: fixing the composite film on a production line, wherein a sample slowly flows through the composite film in the production process and is in contact with the composite film; or fixing the composite film on a blade of a propeller stirrer, putting the composite film into a container for storing a sample, and stirring and contacting.
5. The method of attenuating aflatoxins of claim 1, wherein: the sample is edible vegetable oil, including peanut oil and corn oil which are easily polluted by aflatoxin.
6. A composite film for reducing aflatoxins, comprising: comprising a substrate and g-C on the substrate3N4/WO3Composite material g-C3N4In a lamellar structure, WO3The nano particles are uniformly dispersed in the lamella g-C3N4The surface is tightly combined to form the composite semiconductor photocatalytic material.
7. The method for preparing the composite film material for reducing aflatoxin of claim 6, which comprises the following steps:
1) firstly, preparing carbon nitride through high-temperature pyrolysis, and then obtaining carbon nitride nanosheets through high-temperature stripping treatment;
2) dispersing carbon nitride nanosheets in water, stirring, performing ultrasonic dispersion, adding a certain amount of sodium tungstate, stirring for dissolving, adding acid, converting the sodium tungstate into yellow tungstic acid precipitate, centrifuging to obtain precipitate, cleaning, adding acid, adjusting the pH value to 1.2-1.5, placing the precipitate in a reaction kettle, performing hydrothermal reaction at 180-200 ℃ to prepare WO3/g-C3N4A composite material;
3) adding water into the composite material for dispersion, adding an organic solvent, fully grinding to obtain a uniform and viscous suspension, then dripping the suspension on a substrate for natural tape casting to form a film, and calcining, fixing and sintering under the protection of inert gas to enable the composite material to be more tightly combined with the substrate, thereby preparing the aflatoxin-reduction composite film.
8. The method of claim 7, wherein: the high-temperature pyrolysis method for preparing carbon nitride in the step 1) comprises the following steps: urea and dicyanodiamine are mixed according to the mass ratio of 1: dissolving 2-3 of the raw materials in distilled water at 50-60 ℃, placing the raw materials in an oven for recrystallization, uniformly grinding crystals, placing the crystals into a crucible, covering the crucible, placing the crucible in a tubular furnace or a muffle furnace, heating to 550-560 ℃, and keeping the temperature for 3-4 hours.
9. The method of claim 7, wherein: the high-temperature stripping temperature is 580-600 ℃, and the stripping time is kept for 2-3 h;
the hydrothermal time in the step 2) is 24-30 h.
10. The method of claim 7, wherein: and step 3) weighing 1.0-2.0 g of the composite photocatalytic material, dissolving the composite photocatalytic material in 20-30 mL of distilled water, performing ultrasonic dispersion, adding 3-5 mL of dimethylformamide or methanol, fully grinding to obtain a uniform and viscous suspension, then dropping the suspension on a substrate to naturally cast a film, calcining at 300-350 ℃ under the protection of inert gas, fixing and sintering to enable the composite filter membrane to be more tightly combined, and thus obtaining the aflatoxin-reducing composite film.
CN202011303022.7A 2020-11-19 2020-11-19 Green method for reducing aflatoxin Active CN114514979B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202011303022.7A CN114514979B (en) 2020-11-19 2020-11-19 Green method for reducing aflatoxin
PCT/CN2021/131472 WO2022105831A1 (en) 2020-11-19 2021-11-18 Green method for eliminating aflatoxin

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011303022.7A CN114514979B (en) 2020-11-19 2020-11-19 Green method for reducing aflatoxin

Publications (2)

Publication Number Publication Date
CN114514979A true CN114514979A (en) 2022-05-20
CN114514979B CN114514979B (en) 2024-03-29

Family

ID=81594608

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011303022.7A Active CN114514979B (en) 2020-11-19 2020-11-19 Green method for reducing aflatoxin

Country Status (2)

Country Link
CN (1) CN114514979B (en)
WO (1) WO2022105831A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115445650A (en) * 2022-10-08 2022-12-09 青岛农业大学 Carbon nitride material, preparation method and application thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105536842A (en) * 2015-12-14 2016-05-04 西北师范大学 Carbon nitride/tungsten trioxide nano composite material and preparation method and application thereof
CN108745397A (en) * 2018-05-03 2018-11-06 东南大学 A kind of transient metal doped carbonitride/WO3Composite photo-catalyst and its preparation method and application
CN108993572A (en) * 2018-08-09 2018-12-14 中国地质大学（北京） A kind of preparation method of Fe2O3 doping tungstic acid-nitridation carbon compound film
CN109371446A (en) * 2018-11-01 2019-02-22 大连海事大学 A kind of C3N4The preparation method of film
CN211734294U (en) * 2019-11-05 2020-10-23 华南农业大学 Photocatalytic reaction device for degrading peanut oil aflatoxin

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10252253B2 (en) * 2012-12-21 2019-04-09 Riken G-C3N4 film
CN104772158B (en) * 2015-03-23 2017-01-25 上海应用技术学院 Preparation method of WO3/C3N4 mixed photocatalyst

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105536842A (en) * 2015-12-14 2016-05-04 西北师范大学 Carbon nitride/tungsten trioxide nano composite material and preparation method and application thereof
CN108745397A (en) * 2018-05-03 2018-11-06 东南大学 A kind of transient metal doped carbonitride/WO3Composite photo-catalyst and its preparation method and application
CN108993572A (en) * 2018-08-09 2018-12-14 中国地质大学（北京） A kind of preparation method of Fe2O3 doping tungstic acid-nitridation carbon compound film
CN109371446A (en) * 2018-11-01 2019-02-22 大连海事大学 A kind of C3N4The preparation method of film
CN211734294U (en) * 2019-11-05 2020-10-23 华南农业大学 Photocatalytic reaction device for degrading peanut oil aflatoxin

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
MAO J.等: "Geometric architecture design of ternary composites based on dispersive WO3 nanowires for enhanced visible-light-driven activity of refractory pollutant degradation" *
宋承钢等: "黄曲霉毒素脱毒研究进展" *
杜娟等: "有机酸介导合成WO_3/g-C_3N_4及其光催化性能" *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115445650A (en) * 2022-10-08 2022-12-09 青岛农业大学 Carbon nitride material, preparation method and application thereof
CN115445650B (en) * 2022-10-08 2023-08-11 青岛农业大学 Carbon nitride material, preparation method and application thereof

Also Published As

Publication number Publication date
WO2022105831A1 (en) 2022-05-27
CN114514979B (en) 2024-03-29

Similar Documents

Publication Publication Date Title
Zhang et al. Enhanced photocatalytic activity of TiO2 with acetylene black and persulfate for degradation of tetracycline hydrochloride under visible light
Shi et al. Construction of CuBi2O4/Bi2MoO6 pn heterojunction with nanosheets-on-microrods structure for improved photocatalytic activity towards broad-spectrum antibiotics degradation
Aadil et al. Mesoporous and macroporous Ag-doped Co3O4 nanosheets and their superior photo-catalytic properties under solar light irradiation
Zhang et al. Ultrathin Bi2WO6 nanosheets loaded g-C3N4 quantum dots: A direct Z-scheme photocatalyst with enhanced photocatalytic activity towards degradation of organic pollutants under wide spectrum light irradiation
Zhang et al. Microwave hydrothermally synthesized WO 3/UiO-66 nanocomposites toward enhanced photocatalytic degradation of rhodamine B
Ruan et al. A visible-light-driven Z-scheme CdS/Bi12GeO20 heterostructure with enhanced photocatalytic degradation of various organics and the reduction of aqueous Cr (VI)
Jabeen et al. Photo catalytic degradation of Alizarin red S using ZnS and cadmium doped ZnS nanoparticles under unfiltered sunlight
Shanmugam et al. Construction of high efficient g-C3N4 nanosheets combined with Bi2MoO6-Ag photocatalysts for visible-light-driven photocatalytic activity and inactivation of bacterias
Qi et al. Preparation and photocatalytic activity of Ag-modified GO-TiO2 mesocrystals under visible light irradiation
Wang et al. Novel Ag3PO4/boron-carbon-nitrogen photocatalyst for highly efficient degradation of organic pollutants under visible-light irradiation
Tian et al. Photocatalytic degradation of methyl orange with W-doped TiO2 synthesized by a hydrothermal method
CN108996655B (en) Microwave-assisted Fe/Fe3Method for rapidly catalyzing and degrading organic wastewater by using C @ C
Hosseinzadeh et al. TiO2/graphene nanocomposite supported on clinoptilolite nanoplate and its enhanced visible light photocatalytic activity
Bhavsar et al. Crystal structures, morphological, optical, adsorption, kinetic and photocatalytic degradation studies of activated carbon loaded BiOBr nanoplates prepared by solvothermal method
Hosseini et al. Elimination of dibenzothiophene from transportation fuel by combined photocatalytic and adsorptive method
Li et al. Interfacial heterojunction construction by introducing Pd into W18O49 nanowires to promote the visible light-driven photocatalytic degradation of environmental organic pollutants
Wang et al. Upconversion Tm3+: CeO2/palygorskite as direct Z-scheme heterostructure for photocatalytic degradation of bisphenol A
CN114514979A (en) Green method for reducing aflatoxin
Manikandan et al. Synthesis, structural and optical properties of phosphorus doped MnO2 nanorods as an under sunlight illumination with intensify photocatalytic for the degradation of organic dyes
Albouyeh et al. The green synthesis of magnesium oxide nanoparticles in MFI type zeolite and its application as a photocatalyst
Hasan et al. Enhanced ultraviolet-visible photocatalysis of RGO/equaixial geometry TiO 2 composites on degradation of organic dyes in water
CN113333003B (en) Nanometer flower-shaped composite catalyst and preparation method and application thereof
CN110038572A (en) A kind of α-Fe for degradable organic pollutant2O3/ Fe photochemical catalyst and preparation method thereof
Casillas et al. Coupled Al-Ga-xAg composites prepared by the sol–gel method and their efficient photocatalytic performance in the degradation of diclofenac
CN110180557B (en) Ag2S/TiO2Preparation method and application of composite photocatalyst

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant