Preparation method and application of iron porphyrin-artificial humic acid nanocarbon composite photocatalyst

Abstract

The application relates to a preparation method and application of an iron porphyrin artificial humic acid nanocarbon composite photocatalyst. The application aims to solve the problems of low catalytic activity, poor dispersibility and poor degradation effect on organic matters of the existing photocatalyst. The method comprises the following steps: one, preparing an iron-based porphyrin metal organic framework material with a three-dimensional space structure; two, preparing highly dispersed artificial humic acid nanocarbon; and three, compounding. The artificial humic acid nanocarbon has rich functional groups and a large specific surface area, has a good adsorption effect on pollutants in water, and further improves the dispersibility and photocatalytic efficiency of the single iron-based porphyrin metal organic framework material. The application compiles the artificial humic acid nanocarbon with the three-dimensional iron-based porphyrin metal organic framework, combines and improves the photocatalytic characteristics of the iron-based porphyrin metal organic framework, changes the dispersibility of the composite material by using the adsorption characteristics of the nanocarbon, and has a good performance in degrading organic pollutants.

Description

Technical Field

[0001] This invention relates to a method for preparing a photocatalyst and its application. Background Technology

[0002] Water pollutants originate from many sources. Many industrial processes generate wastewater containing organic pollutants. For example, wastewater from dyeing and printing plants contains large amounts of unreacted dyes, such as Congo Red and Rhodamine B. These organic dyes are complex in composition, difficult to degrade, and highly toxic. In the petrochemical industry, petroleum itself contains polycyclic aromatic hydrocarbons (such as naphthalene), and high-temperature heating processes can release these substances. If these wastes are not properly treated, they can enter water bodies. These organic pollutants pose a significant threat to human health, making water treatment a persistent and critical issue.

[0003] Currently, various physical, chemical, and biological remediation technologies have been developed for the remediation of organic pollutants in water bodies. Among them, photocatalytic degradation, with its advantages of being environmentally friendly, highly efficient, and able to directly utilize sunlight, has great potential in the removal of pollutants in water and has become a research hotspot. Common photocatalytic technologies include those modified by noble metal deposition. The principle is to deposit noble metals (such as Pt, Au, Ag, etc.) on the surface of the photocatalyst, thereby changing the surface electronic structure of the photocatalyst. Because noble metal nanoparticles have good conductivity, they can capture photogenerated electrons, thereby improving photocatalytic efficiency. In addition, there are also technologies that modify photocatalysts by combining multiple semiconductor materials together, utilizing their different band structures to achieve effective separation of photogenerated charge carriers. However, the disadvantage of using noble metals is that it increases the cost of the photocatalyst, limiting its application range. Some catalysts also suffer from poor stability and poor photocatalytic selectivity. For example, TiO2 may undergo crystal structure changes under prolonged light exposure, reducing its catalytic performance. Therefore, it is necessary to study a photocatalyst with strong stability, certain reaction selectivity, and low cost.

[0004] Iron-based porphyrin metal-organic frameworks (MOFs), as photocatalytic materials, have advantages such as low toxicity, minimal secondary pollution during photocatalysis, and environmental friendliness, and have been widely used in the removal of recalcitrant organic pollutants. However, the poor stability and dispersibility of iron-based porphyrin MOFs can affect the contact efficiency between the catalyst and the degradation products, and their catalytic activity still needs to be improved. Therefore, it is usually necessary to combine them with other materials to compensate for these shortcomings. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of low catalytic activity, poor dispersibility, and poor degradation effect of existing photocatalysts, and to provide a method for preparing and applying an iron porphyrin@artificial humic acid nanocarbon composite photocatalyst.

[0006] This invention first prepares a three-dimensional iron-based porphyrin metal-organic framework material, MON (3D-Fe-TCPP), via hydrothermal reaction. Then, artificial humic acid is calcined in a tube furnace to produce artificial humic acid nanocarbon (MSNC). The two materials are then transferred to a reaction vessel and subjected to hydrothermal treatment again. The resulting product is the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst (3D-Fe-TCPP-MSNC). This invention features a simple and easy-to-operate preparation method. Furthermore, calcining artificial humic acid into nanocarbon enhances the stability and activity of the catalyst to a certain extent. The obtained iron porphyrin@artificial humic acid nanocarbon composite photocatalyst exhibits excellent degradation effects on complex organic pollutants such as naphthalene, Congo red, or rhodamine B.

[0007] A method for preparing an iron porphyrin@artificial humic acid nanocarbon composite photocatalyst is specifically carried out according to the following steps:

[0008] I. Preparation of iron-based porphyrin metal-organic framework materials with three-dimensional spatial structures;

[0009] ① Mix ferric salt, polyvinylpyrrolidone, trifluoroacetic acid, N,N-dimethylformamide and anhydrous ethanol, and ultrasonically disperse them evenly to obtain precursor solution A;

[0010] ② Mix tetra(4-carboxyphenyl)porphyrin, N,N-dimethylformamide and anhydrous ethanol, and disperse evenly by ultrasonication to obtain precursor solution B;

[0011] ③ Mix precursor solution A and precursor solution B, disperse them evenly by ultrasonication, and then transfer them into a hydrothermal reactor. Perform a hydrothermal reaction at 90℃~100℃ for a period of time, then centrifuge, wash, dry, and grind to obtain a three-dimensional iron-based porphyrin metal-organic framework material (3D-Fe-TCPP).

[0012] II. Preparation of highly dispersed artificial humic acid nanocarbon:

[0013] Artificial humic acid, urea, zinc chloride and potassium chloride were mixed evenly and then placed in a tube furnace and calcined in nitrogen for a period of time. After cooling to room temperature, the mixture was washed with hydrochloric acid and deionized water in sequence, and finally dried and ground to obtain highly dispersed artificial humic acid nanocarbon (MSNC).

[0014] III. Preparation of iron porphyrin@artificial humic acid nanocarbon composite photocatalyst:

[0015] Three-dimensional iron-based porphyrin metal-organic framework material and highly dispersed artificial humic acid nanocarbon were dissolved in N,N-dimethylformamide, stirred evenly, and then transferred to a hydrothermal reactor. The hydrothermal reaction was carried out at 90℃~95℃ for a period of time, followed by centrifugation, washing, and drying to obtain iron porphyrin@artificial humic acid nanocarbon composite photocatalyst (3D-Fe-TCPP-MSNC).

[0016] A porphyrin@artificial humic acid nanocarbon composite photocatalyst for removing organic matter.

[0017] The principle of this invention:

[0018] Artificial humic acid (AHA) possesses abundant functional groups, which can enhance the activity and selectivity of catalytic reactions. The artificial humic acid (AHA) used in this invention is prepared by hydrothermal reaction of powder obtained from crushed waste straw with potassium hydroxide. The molten salt method ensures the carbonization of humic acid while retaining its functional groups, thus obtaining a carbon-based material with abundant surface functional groups. Artificial humic acid is obtained by simulating the formation process of humic acid in the natural environment or by modifying natural humic acid. Artificial humic acid contains abundant functional groups, such as carboxyl and hydroxyl groups, which can interact with the metal nodes or organic ligands of iron-based porphyrin MOFs, introducing more active sites on the surface of the iron-based porphyrin MOFs, thereby improving their adsorption and activation capabilities for reactant molecules and promoting photocatalytic reactions. This invention combines the porous structure and catalytic activity of iron-based porphyrin MOFs with the functional group characteristics of artificial humic acid, such as adsorption performance and complexation ability for metal ions. By combining the two, the catalyst's adsorption capacity for reactants can be improved, making it easier for reactants to accumulate on the catalyst surface, thereby enhancing the reaction. Furthermore, the high dispersibility of the artificial humic acid nanocarbon, combined with the iron-based porphyrin MOF, enhances the dispersibility of the composite material. This invention combines three-dimensional iron-based porphyrin MOF with artificial humic acid nanocarbon to enhance the stability and activity of the photocatalyst.

[0019] Advantages of this invention:

[0020] I. Iron-based porphyrin metal-organic framework materials have a unique porous structure and a large specific surface area, which can provide abundant active sites and are conducive to catalytic reactions. The introduction of artificial humic acid nanocarbon further enhances the material's light absorption capacity, reduces the energy required for photocatalysis, and enables the composite photocatalyst to exhibit excellent photocatalytic activity under visible light, which can efficiently degrade target substances such as organic pollutants.

[0021] II. The composite structure of the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst in this invention effectively improves the stability problem of single iron-based MOFs. Stable chemical bonds or interactions are formed between the artificial humic acid nano-carbon and the iron-based porphyrin metal-organic framework material, enhancing its stability. This allows the composite photocatalyst to maintain high catalytic activity and reduces usage costs.

[0022] Third, this invention provides a new way to increase the value of metal-organic frameworks and artificial humic acid, and the artificial humic acid used is low in cost, which is in line with the concept of sustainable development. Attached Figure Description

[0023] Figure 1 This is a scanning electron microscope image of the three-dimensional iron-based porphyrin metal-organic framework material prepared in step one of Example 1;

[0024] Figure 2 This is a scanning electron microscope image of the artificial humic acid nanocarbon prepared in step two of Example 1;

[0025] Figure 3 A scanning electron microscope image of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1;

[0026] Figure 4 The elemental energy spectrum image of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1;

[0027] Figure 5 X-ray diffraction patterns of the three-dimensional iron-based porphyrin metal-organic framework material, artificial humic acid nanocarbon, and iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in Example 1.

[0028] Figure 6 Fourier transform infrared spectra of the three-dimensional iron-based porphyrin metal-organic framework material, artificial humic acid nanocarbon, and iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in Example 1.

[0029] Figure 7 The catalytic reduction efficiency curve of naphthalene by the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1 is shown in Example 1.

[0030] Figure 8 The graphs show the degradation curves of organic dyes by the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst prepared in step 3 of Example 1 in Application Examples 2 and 3. In the graph, a is the catalytic reduction efficiency curve of Rhodamine B in Application Example 2, and b is the catalytic reduction efficiency curve of Congo Red in Application Example 3.

[0031] Figure 9The bar chart shows the removal rates of naphthalene, rhodamine B, and Congo red by the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1 in Application Examples 1-3. Detailed Implementation

[0032] Specific Implementation Method 1: This implementation method describes a preparation method for an iron porphyrin@artificial humic acid nano-carbon composite photocatalyst, which is specifically completed according to the following steps:

[0033] I. Preparation of iron-based porphyrin metal-organic framework materials with three-dimensional spatial structures;

[0034] ① Mix ferric salt, polyvinylpyrrolidone, trifluoroacetic acid, N,N-dimethylformamide and anhydrous ethanol, and ultrasonically disperse them evenly to obtain precursor solution A;

[0035] ② Mix tetra(4-carboxyphenyl)porphyrin, N,N-dimethylformamide and anhydrous ethanol, and disperse evenly by ultrasonication to obtain precursor solution B;

[0036] ③ Mix precursor solution A and precursor solution B, ultrasonically disperse them evenly, and then transfer them into a hydrothermal reactor. Perform a hydrothermal reaction at 90℃~100℃ for a period of time, then centrifuge, wash, dry, and grind to obtain a three-dimensional iron-based porphyrin metal-organic framework material.

[0037] II. Preparation of highly dispersed artificial humic acid nanocarbon:

[0038] Artificial humic acid, urea, zinc chloride and potassium chloride were mixed evenly and then placed in a tube furnace and calcined in nitrogen for a period of time. After cooling to room temperature, the mixture was washed with hydrochloric acid and deionized water in sequence, and finally dried and ground to obtain highly dispersed artificial humic acid nanocarbon.

[0039] III. Preparation of iron porphyrin@artificial humic acid nanocarbon composite photocatalyst:

[0040] Three-dimensional iron-based porphyrin metal-organic framework material and highly dispersed artificial humic acid nanocarbon were dissolved in N,N-dimethylformamide, stirred evenly, and then transferred to a hydrothermal reactor. The mixture was subjected to hydrothermal reaction at 90℃~95℃ for a period of time, followed by centrifugation, washing, and drying to obtain the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst.

[0041] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that: the ferric salt mentioned in step one ① is ferric nitrate nonahydrate; the mass ratio of the ferric salt to polyvinylpyrrolidone in step one ① is (2-2.1):(5-5.2); the mass-to-volume ratio of the ferric salt, trifluoroacetic acid, N,N-dimethylformamide, and anhydrous ethanol in step one ① is (0.0450g-0.0451g):(0.498mL-0.499mL):(112.14mL-112.15mL):(37.38mL-37.39mL). The other steps are the same as in Specific Implementation Method One.

[0042] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in the following ways: In step one ②, the mass-to-volume ratio of tetrakis(4-carboxyphenyl)porphyrin, N,N-dimethylformamide, and anhydrous ethanol is (0.055g~0.0551g):(37.38mL~37.39mL):(12.46mL~12.47mL); in step one ③, the hydrothermal reaction time is 23h~24h; in step one ③, the volume ratio of precursor solution A and precursor solution B is (150~150.02):(49.84~49.86); in step one ③, the washing solvent is N,N-dimethylformamide and deionized water; and the drying temperature is 60℃~80℃. Other steps are the same as in Specific Implementation Method One or Two.

[0043] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: the mass ratio of artificial humic acid, urea, zinc chloride, and potassium chloride in step two is (4.50g~4.51g):(4.50g~4.51g):(29.91g~29.92g):(15.09g~15.10g); the calcination temperature in step two is 400℃~500℃, and the calcination time is 4h~5h. Other steps are the same as in Specific Implementation Methods One to Three.

[0044] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the preparation method of artificial humic acid described in step two is specifically completed according to the following steps: First, the biomass waste is washed, dried, and pulverized to obtain biomass waste powder; the biomass waste powder and catalyst are dispersed in deionized water, then transferred to a hydrothermal reactor, and the hydrothermal reactor is placed in an oven for hydrothermal reaction, then cooled to room temperature to obtain a solid-liquid mixture; the solid-liquid mixture is filtered to collect the liquid; the pH of the liquid is adjusted to 1 using hydrochloric acid, and the solid is allowed to precipitate by standing; the precipitated solid is then washed with deionized water until neutral, dried, and ground into powder to obtain artificial humic acid. Other steps are the same as in Specific Implementation Methods One to Four.

[0045] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: the biomass waste is corn stalks; the catalyst is potassium hydroxide; the mass-to-volume ratio of the biomass waste powder, catalyst, and deionized water is 8g:2g:100mL; the hydrothermal reaction temperature is 200℃~250℃, and the hydrothermal reaction time is 24h~30h. Other steps are the same as in Specific Implementation Methods One to Five.

[0046] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in the following ways: the mass ratio of the three-dimensional iron-based porphyrin metal-organic framework material to the highly dispersed artificial humic acid nanocarbon in step three is (2-4):1; the mass ratio of the three-dimensional iron-based porphyrin metal-organic framework material to the volume ratio of N,N-dimethylformamide in step three is (0.2g-0.4g):(130mL-150mL); the hydrothermal reaction time in step three is 23-24 hours; the solvent used for washing in step three is N,N-dimethylformamide and deionized water; and the drying temperature is 60℃-80℃. Other steps are the same as in Specific Implementation Methods One to Six.

[0047] Specific Implementation Method Eight: This implementation method is an iron porphyrin@artificial humic acid nano-carbon composite photocatalyst for removing organic matter.

[0048] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One through Eight in that: an iron porphyrin@artificial humic acid nano-carbon composite photocatalyst is used to remove organic matter, specifically by following these steps:

[0049] An iron porphyrin@artificial humic acid nanocarbon composite photocatalyst is added to a solution containing organic matter, and a photocatalytic reduction reaction is carried out under light irradiation to obtain a solution with the organic matter removed. Other steps are the same as in specific embodiments one to eight.

[0050] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that: the organic matter is an organic dye or a polycyclic aromatic hydrocarbon; the organic dye is Rhodamine B or Congo Red; the polycyclic aromatic hydrocarbon is naphthalene; the dosage of the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst is 0.2 g / L to 0.21 g / L; the photocatalytic reduction reaction time is 10 min to 120 min; and the illumination is xenon lamp irradiation. Other steps are the same as in Specific Implementation Methods One to Nine.

[0051] The beneficial effects of the present invention are verified using the following embodiments:

[0052] Example 1: A method for preparing an iron porphyrin@artificial humic acid nanocarbon composite photocatalyst, specifically carried out according to the following steps:

[0053] I. Preparation of three-dimensional iron-based porphyrin metal-organic framework materials with three-dimensional spatial structure;

[0054] ① Ferric nitrate nonahydrate (Fe(NO3)) 3· Mix 9H2O), polyvinylpyrrolidone (PVP), trifluoroacetic acid, N,N-dimethylformamide and anhydrous ethanol, and ultrasonically disperse for 30 min to obtain precursor solution A;

[0055] The ferric nitrate nonahydrate (Fe(NO3)) mentioned in step 1① 3· The mass ratio of 9H2O to polyvinylpyrrolidone (PVP) is 2:5;

[0056] The ferric nitrate nonahydrate (Fe(NO3)) mentioned in step 1① 3· The mass-to-volume ratio of 9H2O, trifluoroacetic acid, N,N-dimethylformamide, and anhydrous ethanol was 0.045 g: 0.498 mL: 112.14 mL: 37.38 mL.

[0057] ② Mix tetra(4-carboxyphenyl)porphyrin (TCPP), N,N-dimethylformamide (DMF) and anhydrous ethanol, and sonicate for 30 min to obtain precursor solution B;

[0058] The mass-to-volume ratio of tetra(4-carboxyphenyl)porphyrin, N,N-dimethylformamide, and anhydrous ethanol mentioned in step 1② is 0.055 g: 37.38 mL: 12.46 mL;

[0059] ③ Mix precursor solution A and precursor solution B, ultrasonically disperse for 15 min, then transfer to a hydrothermal reactor and perform a hydrothermal reaction at 90℃ for 24 h. After centrifugation, wash the solid material three times with N,N-dimethylformamide and deionized water respectively, then vacuum dry at 60℃ for 12 h, and grind it with an agate mortar to obtain the three-dimensional iron-based porphyrin metal-organic framework material (3D-Fe-TCPP).

[0060] The volume ratio of precursor solution A and precursor solution B mentioned in step 1③ is 150mL:49.84mL;

[0061] II. Preparation of highly dispersed artificial humic acid nanocarbon:

[0062] 4.50g of artificial humic acid, 4.50g of urea, 29.91g of zinc chloride, and 15.09g of potassium chloride were mixed and ground, then placed in a tube furnace. The tube furnace was purged with nitrogen for 1 hour, and then heated from room temperature to 400℃ at a rate of 2℃ / min. The temperature was maintained at 400℃ under a nitrogen atmosphere for 4 hours. After cooling to room temperature, the reaction product was obtained. The reaction product was first immersed in 1.2mol / L hydrochloric acid and stirred and washed for 24 hours. After removal, it was immersed again in 1.2mol / L hydrochloric acid and stirred and washed for 24 hours. Then, it was washed multiple times with deionized water to remove residual hydrochloric acid. Then, it was vacuum dried at 60℃ for 24 hours. Finally, it was ground into powder using an agate mortar and pestle to obtain highly dispersed artificial humic acid nanocarbon (MSNC).

[0063] The preparation method of artificial humic acid described in step two is specifically completed according to the following steps:

[0064] First, the biomass waste is washed, dried, and pulverized to obtain biomass waste powder. The biomass waste powder and catalyst are dispersed in deionized water and then transferred to a hydrothermal reactor. The hydrothermal reactor is then placed in an oven for hydrothermal reaction and cooled to room temperature to obtain a solid-liquid mixture. The solid-liquid mixture is filtered to collect the liquid. The pH of the liquid is adjusted to 1 using hydrochloric acid, and the solid is allowed to precipitate. The precipitated solid is then washed with deionized water until neutral, dried, and ground into powder using an agate mortar to obtain artificial humic acid (A-HA).

[0065] The mass-to-volume ratio of the biomass waste powder, catalyst, and deionized water is 8g:2g:100mL;

[0066] The biomass waste is corn stalks; the catalyst is potassium hydroxide; the hydrothermal reaction temperature is 200℃, and the hydrothermal reaction time is 24h.

[0067] III. Preparation of iron porphyrin@artificial humic acid nanocarbon composite photocatalyst:

[0068] 0.20 g of three-dimensional iron-based porphyrin metal-organic framework material (3D-Fe-TCPP) and 0.05 g of highly dispersed artificial humic acid nanocarbon (MSNC) were dissolved in 130 mL of N,N-dimethylformamide and magnetically stirred for 30 min. The mixture was then transferred to a hydrothermal reactor and subjected to a hydrothermal reaction at 90 °C for 24 h. After centrifugation, the solid material was washed three times each with N,N-dimethylformamide and deionized water, and then vacuum dried at 60 °C for 12 h to obtain the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst (3D-Fe-TCPP-MSNC).

[0069] Figure 1This is a scanning electron microscope image of the three-dimensional iron-based porphyrin metal-organic framework material prepared in step one of Example 1;

[0070] Figure 2 This is a scanning electron microscope image of the artificial humic acid nanocarbon prepared in step two of Example 1;

[0071] Figure 3 A scanning electron microscope image of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1;

[0072] Scanning electron microscopy clearly shows that the three-dimensional iron-based porphyrin metal-organic framework material has a nanorod structure, the artificial humic acid nanocarbon has a highly dispersed block structure, and the composite structure is formed by the successful combination of the iron-based porphyrin metal-organic framework material and the artificial humic acid nanocarbon.

[0073] Figure 4 The elemental energy spectrum image of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1;

[0074] The elemental energy spectrum image clearly shows that carbon, nitrogen, oxygen, and iron elements are uniformly distributed on the surface of the composite iron porphyrin@artificial humic acid carbon nanotubes, indicating the successful preparation of the material.

[0075] Figure 5 X-ray diffraction patterns of the three-dimensional iron-based porphyrin metal-organic framework material, artificial humic acid nanocarbon, and iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in Example 1.

[0076] The X-ray diffraction pattern shows that 3D-Fe-TCPP and 3D-Fe-TCPP-MSNC have sharp peaks at 2θ=5°. The 3D-Fe-TCPP-MSNC composite material contains the characteristic peaks of 3D-Fe-TCPP and MSNC, proving the successful bonding of the composite material.

[0077] Figure 6 Fourier transform infrared spectra of the three-dimensional iron-based porphyrin metal-organic framework material, artificial humic acid nanocarbon, and iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in Example 1.

[0078] The Fourier transform infrared spectrum shows that 3D-Fe-TCPP and 3D-Fe-TCPP-MSNC are similar at 499 cm⁻¹. -1 The appearance of Fe-O stretching vibration peaks indicates the successful integration of 3D-Fe-TCPP and MSNC.

[0079] Application Example 1: The method for catalytic degradation of naphthalene using the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst prepared in step three of Example 1 is specifically carried out according to the following steps:

[0080] 12 mg of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step 3 of Example 1 was added to 60 mL of naphthalene solution with a concentration of 0.1 mmol / L. The system was then placed in a photochemical reactor with a light intensity of 250 W and reacted under natural light and 25 °C for 0–2 h. Samples were taken at specific times (0, 5, 10, 15, 30, 45, 60, 120 min), and 4 mL of the solution was passed through a 0.22 μm filter membrane. The filtered solution was then tested. The filtered naphthalene solution was placed into two liquid chromatography vials, and its peak area was observed by high performance liquid chromatography.

[0081] As a control, light was used alone, omitting the use of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1. The catalytic reduction efficiency curve of naphthalene is shown in [Figure 1]. Figure 7 As shown;

[0082] As a control, the use of light was omitted, and the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1 was used alone. The catalytic reduction efficiency curve of naphthalene is shown in [Figure 1]. Figure 7 As shown.

[0083] Application Example 2: The method for catalytic degradation of Rhodamine B using the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst prepared in step three of Example 1 is specifically carried out according to the following steps:

[0084] 12 mg of the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst prepared in step 3 of Example 1 was added to 60 mL of a 60 mg / L Rhodamine B solution. The system was then placed in a photochemical reactor with a light intensity of 250 W and reacted under natural light and 25 °C for 0–2 h. Samples were taken at specific times (0, 5, 10, 15, 30, 45, 60, 120 min), and 4 mL of the solution was passed through a 0.22 μm filter membrane. The filtered solution was then tested. The filtered Rhodamine B solution was placed in a cuvette and its absorbance was measured using a UV-Vis spectrophotometer (λ = 554 nm).

[0085] As a control, light was used alone, omitting the use of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1. The catalytic reduction efficiency curve of Rhodamine B is shown in [Figure number missing]. Figure 8 As shown;

[0086] As a control, the use of light was omitted, and the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1 was used alone. The catalytic reduction efficiency curve of Rhodamine B is shown in [Figure 1]. Figure 8 As shown.

[0087] Application Example 3: The method for catalytic degradation of Congo red using the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst prepared in step three of Example 1 is specifically carried out according to the following steps:

[0088] 12 mg of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step 3 of Example 1 was added to 60 mL of Congo red solution with a concentration of 60 mg / L. The system was then placed in a photochemical reactor with a light intensity of 250 W and reacted under natural light and 25 °C for 0–2 h. Samples were taken at specific times (0, 5, 10, 15, 30, 45, 60, 120 min), and 4 mL of the solution was passed through a 0.22 μm filter membrane. The filtered solution was then tested. The filtered Rhodamine B solution was placed in a cuvette and its absorbance was measured using a UV-Vis spectrophotometer (λ = 501 nm).

[0089] As a control, light was used alone, omitting the use of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1. The catalytic reduction efficiency curve of Congo red is shown in [Figure number missing]. Figure 8 As shown;

[0090] As a control, the use of light was omitted, and the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1 was used alone. The catalytic reduction efficiency curve of Congo red is shown in [Figure 1]. Figure 8 As shown.

[0091] Figure 7 The catalytic reduction efficiency curve of naphthalene by the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1 is shown in Example 1.

[0092] from Figure 7 It can be seen that applying a catalyst alone is more effective in degrading naphthalene than applying light alone; and applying light on top of a catalyst alone significantly improves the catalytic effect on naphthalene compared to using a catalyst alone. This indicates that 3D-Fe-TCPP-MSNC has a good photocatalytic effect on naphthalene.

[0093] Figure 8 The graphs show the degradation curves of organic dyes by the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst prepared in step 3 of Example 1 in Application Examples 2 and 3. In the graph, a is the catalytic reduction efficiency curve of Rhodamine B in Application Example 2, and b is the catalytic reduction efficiency curve of Congo Red in Application Example 3.

[0094] from Figure 8 It can be seen that the photocatalytic efficiency of 3D-Fe-TCPP-MSNC under illumination is significantly improved compared with light alone and catalyst alone, indicating that 3D-Fe-TCPP-MSNC has a very ideal catalytic effect on organic dyes Rhodamine B and Congo Red.

[0095] Figure 9 The bar chart shows the removal rates of naphthalene, rhodamine B, and Congo red by the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in step three of Example 1 in Application Examples 1-3.

[0096] from Figure 9 It can be seen that 3D-Fe-TCPP-MSNC has different degrees of photocatalytic activity for naphthalene, rhodamine B and Congo red, and has universality and relatively ideal catalytic effect.

[0097] In summary, the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared in this invention exhibits photocatalytic activity against organic pollutants such as polycyclic aromatic hydrocarbons. Compared with light alone, the photocatalyst has a higher degradation efficiency for materials, while the photocatalyst under illumination shows a significant increase in catalytic effect, making it more ideal.

Claims

1. A method for preparing an iron porphyrin@artificial humic acid nanocarbon composite photocatalyst, characterized in that... The preparation method is specifically carried out according to the following steps: I. Preparation of iron-based porphyrin metal-organic framework materials with three-dimensional spatial structures; ① Mix ferric salt, polyvinylpyrrolidone, trifluoroacetic acid, N,N-dimethylformamide and anhydrous ethanol, and ultrasonically disperse them evenly to obtain precursor solution A; The mass ratio of the ferric salt to polyvinylpyrrolidone mentioned in step 1① is (2~2.1):(5~5.2); The mass-to-volume ratio of the trivalent iron salt, trifluoroacetic acid, N,N-dimethylformamide, and anhydrous ethanol mentioned in step 1① is (0.0450g~0.0451g):(0.498mL~0.499mL):(112.14mL~112.15mL):(37.38mL~37.39mL); ② Mix tetra(4-carboxyphenyl)porphyrin, N,N-dimethylformamide and anhydrous ethanol, and disperse evenly by ultrasonication to obtain precursor solution B; The mass-to-volume ratio of tetra(4-carboxyphenyl)porphyrin, N,N-dimethylformamide, and anhydrous ethanol mentioned in step 1② is (0.055g~0.0551g):(37.38mL~37.39mL):(12.46mL~12.47mL); ③ Mix precursor solution A and precursor solution B, disperse them evenly by ultrasonication, and then transfer them into a hydrothermal reactor. Perform a hydrothermal reaction at 90℃~100℃ for 23h~24h, then centrifuge, wash, dry, and grind to obtain a three-dimensional iron-based porphyrin metal-organic framework material. The volume ratio of precursor solution A and precursor solution B mentioned in step 1③ is (150~150.02):(49.84~49.86); II. Preparation of highly dispersed artificial humic acid nanocarbon: Artificial humic acid, urea, zinc chloride and potassium chloride are mixed evenly, and then placed in a tube furnace and calcined in nitrogen at 400℃~500℃ for 4h~5h. After cooling to room temperature, they are washed with hydrochloric acid and deionized water in sequence, and finally dried and ground to obtain highly dispersed artificial humic acid nano carbon. The mass ratio of artificial humic acid, urea, zinc chloride and potassium chloride mentioned in step two is (4.50g~4.51g):(4.50g~4.51g):(29.91g~29.92g):(15.09g~15.10g); III. Preparation of iron porphyrin@artificial humic acid nano-carbon composite photocatalyst: Three-dimensional iron-based porphyrin metal-organic framework material and highly dispersed artificial humic acid nanocarbon were dissolved in N,N-dimethylformamide, stirred evenly, and then transferred to a hydrothermal reactor. The hydrothermal reaction was carried out at 90℃~95℃ for 23h~24h, followed by centrifugation, washing, and drying to obtain iron porphyrin@artificial humic acid nanocarbon composite photocatalyst. The mass ratio of the three-dimensional iron-based porphyrin metal-organic framework material and the highly dispersed artificial humic acid nanocarbon described in step three is (2~4):1; The mass ratio of the three-dimensional iron-based porphyrin metal-organic framework material to the volume ratio of N,N-dimethylformamide in step three is (0.2g~0.4g):(130mL~150mL).

2. The preparation method of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst according to claim 1, characterized in that... The ferric salt mentioned in step 1① is ferric nitrate nonahydrate.

3. The preparation method of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst according to claim 1, characterized in that... The solvent used for washing in step 1③ is N,N-dimethylformamide and deionized water; the drying temperature is 60℃~80℃.

4. The preparation method of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst according to claim 1, characterized in that... The preparation method of artificial humic acid described in step two is specifically completed according to the following steps: First, the biomass waste is washed, dried, and pulverized to obtain biomass waste powder; the biomass waste powder and catalyst are dispersed in deionized water, then transferred to a hydrothermal reactor, and then the hydrothermal reactor is placed in an oven for hydrothermal reaction, and then cooled to room temperature to obtain a solid-liquid mixture; the solid-liquid mixture is filtered to collect the liquid; The pH of the liquid was adjusted to 1 using hydrochloric acid, and the solid was allowed to precipitate out. The precipitated solid was then washed with deionized water until neutral, dried, and ground into powder to obtain artificial humic acid.

5. The preparation method of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst according to claim 4, characterized in that... The biomass waste is corn stalks; the catalyst is potassium hydroxide; the mass-to-volume ratio of the biomass waste powder, the catalyst, and deionized water is 8g:2g:100mL; the hydrothermal reaction temperature is 200℃~250℃, and the hydrothermal reaction time is 24h~30h.

6. The preparation method of the iron porphyrin@artificial humic acid nanocarbon composite photocatalyst according to claim 1, characterized in that... The solvent used for washing in step three is N,N-dimethylformamide and deionized water; the drying temperature is 60℃~80℃.

7. The application of an iron porphyrin@artificial humic acid nanocarbon composite photocatalyst prepared by the preparation method described in claim 1, characterized in that... An iron porphyrin@artificial humic acid nano-carbon composite photocatalyst for removing organic matter is specifically implemented through the following steps: An iron porphyrin@artificial humic acid nanocarbon composite photocatalyst was added to a solution containing organic matter, and a photocatalytic reduction reaction was carried out under light irradiation to obtain a solution with the organic matter removed. The organic compound is an organic dye or a polycyclic aromatic hydrocarbon; the organic dye is Rhodamine B or Congo Red; the polycyclic aromatic hydrocarbon is naphthalene. The dosage of the iron porphyrin@artificial humic acid nano-carbon composite photocatalyst is 0.2 g / L to 0.21 g / L; the photocatalytic reduction reaction time is 10 min to 120 min; and the illumination is xenon lamp irradiation.

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