Preparation method of photocatalyst for removing lead, cadmium and arsenic from carbon-based composite manganese dioxide loaded organic photovoltaic material

Abstract

The invention discloses a preparation method of a photocatalyst for removing lead, cadmium and arsenic from a carbon-based composite manganese dioxide loaded organic photovoltaic material. The method comprises the following operation steps: A, preparing a sodium hydroxide solution; preparing a solution A from manganese sulfate and an anionic surfactant; preparing a solution B from potassium permanganate and water; b, adding the solution A and the solution B into a sodium hydroxide solution; c, transferring the mixed solution into a polytetrafluoroethylene reaction kettle for reaction, and then filtering, washing and drying to obtain manganese dioxide; d, crushing a carbon material, and uniformly mixing the crushed carbon material with manganese dioxide to obtain a carbon-based composite manganese dioxide material; and F, mixing an organic photovoltaic material PM6: IDT6CN-M with chloroform to obtain an organic photocatalyst mixed solution, uniformly coating the carbon-based composite manganese dioxide material with the organic photocatalyst mixed solution, and drying to obtain the photocatalyst. The photocatalyst disclosed by the invention can simultaneously oxidize As (III) and efficiently and quickly remove As (V), Cd (II) and Pb (II), and can be repeatedly utilized.

Description

Technical Field

[0001] The invention relates to the technical field of functional material preparation, in particular to a method for preparing a photocatalyst for removing lead, cadmium and arsenic from a carbon-based composite manganese dioxide-loaded organic photovoltaic material. Background Art

[0002] With the development of industry and technology, heavy metal pollution in wastewater poses a serious threat to the environment and biological health. Complex water pollution composed of low-dose multiple cation and anion heavy metals such as lead, cadmium, and arsenic has become an urgent problem to be solved. At the same time, heavy metal ion wastewater with mixed anions and cations is difficult to remove quickly and simultaneously due to the competition for adsorption of cations and mutual interference, and the cost of complete removal is very high.

[0003] Currently, the main methods for degrading lead, cadmium and arsenic in wastewater are electrochemical method, membrane separation method, microbial method and adsorption method. These methods all have some technical difficulties: the electrochemical method consumes too much energy during the degradation process, the electrode material loss is high, and the processing cost is high; the membrane separation method has a very low adsorption capacity, low efficiency, high cost, and the membrane is easily contaminated; the microbial method has a long action time and is easily affected by factors such as temperature, nutrients, and ion concentration; the adsorption method is considered to be the most direct and effective technology for treating lead, cadmium, and arsenic, but the adsorbents used, such as iron-based composite materials, bentonite, modified TiO2, and carbon-based materials, still have some technical difficulties: iron-based composite materials and bentonite are easily corroded in acidic environments, and their lead, cadmium, and arsenic ion adsorption efficiency is proportional to the input amount. Large amounts of input will cause secondary pollution and are difficult to recover; modified TiO2 is an inorganic photocatalyst with a narrow absorption spectrum, a wide band gap, slow exciton generation and separation efficiency, and easy agglomeration in water, resulting in low adsorption efficiency of lead, cadmium, and arsenic ions, and excessive use will be accompanied by secondary pollution and is difficult to recover; carbon-based materials are non-polar solvents and have very weak adsorption of polar heavy metal lead, cadmium, and arsenic ions. Therefore, the effect of removing chromium, copper, cadmium and lead by traditional treatment methods is not ideal.

[0004] Therefore, it is urgent to develop a method for preparing a photocatalyst that is environmentally friendly, pollution-free, and can simultaneously and efficiently remove As(III), As(V), Cd(II), and Pb(II). Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing a carbon-based composite manganese dioxide-loaded organic photovoltaic material photocatalyst for removing lead, cadmium and arsenic. The photocatalyst obtained by the method can simultaneously realize the rapid oxidation of As(III) and the efficient removal of As(V), Cd(II) and Pb(II), and the removal effect is very good, providing a truly green, environmentally friendly and pollution-free treatment method for the removal of lead, cadmium and arsenic ions.

[0006] The present invention solves the above technical problems with the following technical solutions:

[0007] The present invention discloses a method for preparing a photocatalyst for removing lead, cadmium and arsenic by using a carbon-based composite manganese dioxide-loaded organic photovoltaic material, comprising the following steps:

[0008] A. Prepare three solutions according to the following weight ratios: dissolve 0.87 g of sodium hydroxide in 175 mL of water to prepare a sodium hydroxide solution; dissolve 3.8 g of manganese sulfate and 0.4 g of anionic surfactant in 45 mL of water to prepare a solution A; dissolve 1.26 g of potassium permanganate in 22 mL of water to prepare a solution B;

[0009] B. Add solution A and solution B dropwise into the prepared sodium hydroxide solution and stir for 15-45 minutes to obtain a mixed solution;

[0010] C. Transfer the mixed solution of step B to a polytetrafluoroethylene reactor, the reaction temperature is 100°C-180°C, and the reaction time is controlled to be 24h;

[0011] D. filtering, washing and drying the solution after the reaction in step C to obtain manganese dioxide;

[0012] E. The carbon material is crushed into 100-500 meshes and then evenly mixed with manganese dioxide to obtain a carbon-based composite manganese dioxide material, wherein the addition ratio of manganese dioxide is 10-30% of the weight of the carbon material;

[0013] F. Mixing the organic photovoltaic material PM6:IDT6CN-M and chloroform in the following weight ratio: 0.005-0.015 g of organic photovoltaic material: 10-15 ml of chloroform to obtain an organic photocatalyst mixed solution;

[0014] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the carbon-based composite manganese dioxide material, and dried at 60° C. for 24 hours to obtain a carbon-based composite manganese dioxide-loaded organic photovoltaic material photocatalyst for removing lead, cadmium and arsenic.

[0015] In step A of the present invention, the anionic surfactant is cetyltrimethylammonium chloride (CTAC) or cetyltrimethylammonium bromide (CTAB).

[0016] In step B of the present invention, the stirring is performed by mechanical stirring at a stirring rate of 300-500 r / min and a stirring time of 15-45 min.

[0017] In step E of the present invention, the filtering is to collect the carbon-based material using filter paper with a diameter of 0.1 to 1 μm; the washing is to rinse the collected carbon-based material with deionized water for 3 to 5 times; and the drying is to dry in an oven at a temperature of 60° C. for 24 hours.

[0018] In step G of the present invention, the weight ratio of the organic photocatalyst mixed solution to the carbon-based composite manganese dioxide material is 1:5000-10000.

[0019] In step F of the present invention, the PM6:IDT6CN-M are mixed in a weight ratio of 1:1.

[0020] The method of the present invention has the following beneficial effects:

[0021] (1) The photocatalyst obtained by the method of the present invention can realize the rapid oxidation of As(III) and the efficient removal of As(V), Cd(II) and Pb(II) by the modified carbon-based material, i.e., the carbon-based composite manganese dioxide material, and the removal effect is very good, with a removal rate of up to 100%, and can be reused.

[0022] (2) Compared with inorganic catalysts, the photocatalyst obtained by the method of the present invention has unique advantages in wastewater purification, and has the advantages of rapid and effective exciton dissociation, adjustable energy level, wide absorption spectrum and excellent chemical stability, so that it can produce a large number of highly oxidizing superoxide radicals and electrons in water, which can oxidize As(III) into less toxic As(V), and can also completely remove Cd(II), Pb(II) and As(V) through chemical bonding, electrostatic adsorption and complexation reaction of carbon-based composite manganese dioxide materials.

[0023] (3) The matrix material used in the present invention is a natural product carbon-based material with many excellent properties such as hydrophilicity, greenness, high porosity, and large specific surface area. The organic photovoltaic material loaded on the matrix material is reusable and degradable, achieving true green friendliness and environmental pollution-free, which is in line with the development concept of the national key research and development plan of "renewable energy technology" of the country's low-carbon, environmentally friendly and green. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a test chart of the stability of the photocatalyst obtained in Example 1 of the present invention in degrading lead, cadmium and arsenic ions. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0026] Example 1

[0027] The method for preparing a photocatalyst for removing lead, cadmium and arsenic from a modified carbon-based organic photovoltaic material according to the present invention is carried out according to the following steps:

[0028] A. Dissolve 0.87 g of sodium hydroxide in 175 mL of water to obtain a sodium hydroxide solution; dissolve 3.8 g of manganese sulfate and 0.4 g of CTAC in 45 mL of water to obtain a solution A; dissolve 1.26 g of potassium permanganate in 22 mL of water to obtain a solution B;

[0029] B. Add the prepared solution A and solution B dropwise into the prepared sodium hydroxide solution, stir at a mechanical stirring rate of 500 r / min for 30 min to obtain a mixed solution;

[0030] C. Transfer the mixed solution of step B to a polytetrafluoroethylene reactor with a stainless steel shell, the reaction temperature is 140° C., and the reaction time is controlled to be 24 hours;

[0031] D. filtering, washing and drying the solution after the reaction in step C to obtain manganese dioxide;

[0032] E. crushing the carbon material into 500 meshes and then uniformly mixing it with manganese dioxide to obtain a carbon-based composite manganese dioxide material, wherein the addition ratio of manganese dioxide is 20% of the weight of the carbon material;

[0033] F. Mixing the organic photovoltaic material PM6:IDT6CN-M and chloroform in the following weight ratio: PM6:IDT6CN-M 0.01 g: chloroform 13 ml, to obtain an organic photocatalyst mixed solution; wherein PM6:IDT6CN-M is a mixture of PM6 and IDT6CN-M in a weight ratio of 1:1;

[0034] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the carbon-based composite manganese dioxide material, and dried at 60° C. for 24 hours to obtain a modified carbon-based loaded organic photovoltaic material photocatalyst for removing lead, cadmium and arsenic; wherein the weight ratio of the organic photocatalyst mixed solution to the carbon-based composite manganese dioxide material is 1:7500.

[0035] The photocatalyst prepared in this example is used for the adsorption and degradation of lead, cadmium and arsenic. The removal rate is 100% in 15 minutes, and the rapid oxidation of As(III) and the efficient removal of As(V), Cd(II) and Pb(II) are achieved at the same time. The removal effect and stability are shown in Figure 1 shown.

[0036] Example 2

[0037] The method for preparing a photocatalyst for removing lead, cadmium and arsenic from a modified carbon-based organic photovoltaic material according to the present invention is carried out according to the following steps:

[0038] A. Dissolve 0.87 g of sodium hydroxide in 175 mL of water to obtain a sodium hydroxide solution; dissolve 3.8 g of manganese sulfate and 0.4 g of CTAB in 45 mL of water to obtain a solution A; dissolve 1.26 g of potassium permanganate in 22 mL of water to obtain a solution B;

[0039] B. Add the prepared solution A and solution B dropwise to the sodium hydroxide solution prepared in step A, and stir for 30 min at a mechanical stirring rate of 400 r / min to obtain a mixed solution;

[0040] C. Transfer the mixed solution of step B to a polytetrafluoroethylene reactor with a stainless steel shell, the reaction temperature is 140° C., and the reaction time is controlled to be 24 hours;

[0041] D. filtering, washing and drying the solution after the reaction in step C to obtain manganese dioxide;

[0042] E. The carbon material is crushed into 300 meshes and then evenly mixed with manganese dioxide to obtain a carbon-based composite manganese dioxide material, wherein the addition ratio of manganese dioxide is 20% of the weight of the carbon material;

[0043] F. Mixing the organic photovoltaic material PM6:IDT6CN-M and chloroform in the following weight ratio: PM6:IDT6CN-M 0.01 g: chloroform 13 ml, to obtain an organic photocatalyst mixed solution; wherein PM6:IDT6CN-M is a mixture of PM6 and IDT6CN-M in a weight ratio of 1:1;

[0044] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the carbon-based composite manganese dioxide material, and dried at 60° C. for 24 hours to obtain a modified carbon-based loaded organic photovoltaic material photocatalyst for removing lead, cadmium and arsenic. The weight ratio of the organic photocatalyst mixed solution to the carbon-based composite manganese dioxide material is 1:7500.

[0045] The photocatalyst prepared in this embodiment is used for the adsorption and degradation photocatalysis of lead, cadmium and arsenic, and the removal rate in 15 minutes is 99.7%, which realizes the rapid oxidation of As(III) and the efficient removal of As(V), Cd(II) and Pb(II) at the same time, and the removal effect is very good.

[0046] Example 3

[0047] The method for preparing a photocatalyst for removing lead, cadmium and arsenic from a modified carbon-based organic photovoltaic material according to the present invention is carried out according to the following steps:

[0048] A. Dissolve 0.87 g of sodium hydroxide in 175 mL of water to obtain a sodium hydroxide solution; dissolve 3.8 g of manganese sulfate and 0.4 g of CTAC in 45 mL of water to obtain a solution A; dissolve 1.26 g of potassium permanganate in 22 mL of water to obtain a solution B;

[0049] B. Add the prepared solution A and solution B dropwise to the sodium hydroxide solution prepared in step A, and stir for 30 min at a mechanical stirring rate of 300 r / min to obtain a mixed solution;

[0050] C. Transfer the mixed solution of step B to a polytetrafluoroethylene reactor with a stainless steel shell, the reaction temperature is 100° C., and the reaction time is controlled to be 24 hours;

[0051] D. filtering, washing and drying the solution after the reaction in step C to obtain manganese dioxide;

[0052] E. The carbon material is crushed into 100 meshes and then evenly mixed with manganese dioxide to obtain a carbon-based composite manganese dioxide material, wherein the addition ratio of manganese dioxide is 10% of the weight of the carbon material;

[0053] F. Mixing the organic photovoltaic material PM6:IDT6CN-M and chloroform in the following weight ratio: PM6:IDT6CN-M 0.005 g: chloroform 10 ml, to obtain an organic photocatalyst mixed solution; wherein PM6:IDT6CN-M is a mixture of PM6 and IDT6CN-M in a weight ratio of 1:1;

[0054] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the carbon-based composite manganese dioxide material and dried at 60° C. for 24 hours to obtain a modified carbon-based loaded organic photovoltaic material photocatalyst for removing lead, cadmium and arsenic. The weight ratio of the organic photocatalyst mixed solution to the carbon-based composite manganese dioxide material is 1:5000.

[0055] The photocatalyst prepared in this embodiment is used for the adsorption and degradation photocatalysis of lead, cadmium and arsenic, and the removal rate in 15 minutes is 99.7%, which realizes the rapid oxidation of As(III) and the efficient removal of As(V), Cd(II) and Pb(II) at the same time, and the removal effect is very good.

[0056] Example 4

[0057] The method for preparing a photocatalyst for removing lead, cadmium and arsenic from a modified carbon-based organic photovoltaic material according to the present invention is carried out according to the following steps:

[0058] A. Dissolve 0.87 g of sodium hydroxide in 175 mL of water to obtain a sodium hydroxide solution; dissolve 3.8 g of manganese sulfate and 0.4 g of anionic surfactant CTAC in 45 mL of water to obtain a solution A; dissolve 1.26 g of potassium permanganate in 22 mL of water to obtain a solution B;

[0059] B. Add the prepared solution A and solution B dropwise to the sodium hydroxide solution prepared in step A, and stir for 30 min at a mechanical stirring rate of 500 r / min to obtain a mixed solution;

[0060] C. Transfer the mixed solution of step B to a polytetrafluoroethylene reactor with a stainless steel shell, the reaction temperature is 180° C., and the reaction time is controlled to be 24 hours;

[0061] D. filtering, washing and drying the solution after the reaction in step C to obtain manganese dioxide;

[0062] E. crushing the carbon material into 200 meshes and then uniformly mixing it with manganese dioxide to obtain a carbon-based composite manganese dioxide material, wherein the addition ratio of manganese dioxide is 30% of the weight of the carbon material;

[0063] F. Mixing the organic photovoltaic material PM6:IDT6CN-M and chloroform in the following weight ratio: PM6:IDT6CN-M 0.015 g: chloroform 15 ml, to obtain an organic photocatalyst mixed solution; wherein PM6:IDT6CN-M is formed by mixing PM6 and IDT6CN-M in a weight ratio of 1:1;

[0064] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the carbon-based composite manganese dioxide material and dried at 60° C. for 24 hours to obtain a modified carbon-based organic photovoltaic material-supported photocatalyst for removing lead, cadmium and arsenic. The weight ratio of the organic photocatalyst mixed solution to the carbon-based composite manganese dioxide material is 1:10000.

[0065] The photocatalyst prepared in this embodiment is used for the adsorption and degradation photocatalysis of lead, cadmium and arsenic, with a removal rate of 99.8% in 15 minutes, achieving simultaneous rapid oxidation of As(III) and efficient removal of As(V), Cd(II) and Pb(II), and the removal effect is very good.

[0066] In step D of the preparation method of the above-mentioned embodiments 1-4, the filtering refers to collecting the carbon-based material with a 0.1-1 μm caliber filter paper; the washing refers to rinsing the collected carbon-based material with deionized water for 3-5 times; and the drying refers to drying in an oven at a temperature of 60°C for 24 hours.

Claims

1. A method for preparing a carbon-based composite manganese dioxide-loaded organic photovoltaic material photocatalyst for removing lead, cadmium and arsenic, characterized in that: The steps include: A. Prepare three solutions according to the following weight ratios: dissolve 0.87 g of sodium hydroxide in 175 mL of water to prepare a sodium hydroxide solution; dissolve 3.8 g of manganese sulfate and 0.4 g of anionic surfactant in 45 mL of water to prepare a solution A; dissolve 1.26 g of potassium permanganate in 22 mL of water to prepare a solution B; B. Add solution A and solution B dropwise into the prepared sodium hydroxide solution and stir for 15-45 minutes to obtain a mixed solution; C. Transfer the mixed solution of step B to a polytetrafluoroethylene reactor, the reaction temperature is 100°C-180°C, and the reaction time is controlled to be 24h; D. filtering, washing and drying the solution after the reaction in step C to obtain manganese dioxide; E. The carbon material is crushed into 100-500 meshes and then evenly mixed with manganese dioxide to obtain a carbon-based composite manganese dioxide material, wherein the addition ratio of manganese dioxide is 10-30% of the weight of the carbon material; F. Mixing the organic photovoltaic material PM6:IDT6CN-M and chloroform in the following weight ratio: 0.005-0.015 g of organic photovoltaic material: 10-15 ml of chloroform to obtain an organic photocatalyst mixed solution; G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the carbon-based composite manganese dioxide material, and dried at 60° C. for 24 hours to obtain a carbon-based composite manganese dioxide-loaded organic photovoltaic material photocatalyst for removing lead, cadmium and arsenic.

2. The method for preparing a photocatalyst for removing lead, cadmium and arsenic by using a carbon-based composite manganese dioxide loaded organic photovoltaic material according to claim 1, characterized in that: In step A, the anionic surfactant is cetyltrimethylammonium chloride (CTAC) or cetyltrimethylammonium bromide (CTAB).

3. The method for preparing a photocatalyst for removing lead, cadmium and arsenic by using a carbon-based composite manganese dioxide-loaded organic photovoltaic material according to claim 1 or 2, characterized in that: In step B, the stirring is performed by mechanical stirring at a rate of 300-500 r / min and a stirring time of 15-45 min.

4. The method for preparing a photocatalyst for removing lead, cadmium and arsenic by using a carbon-based composite manganese dioxide-loaded organic photovoltaic material according to claim 1 or 2, characterized in that: In step E, the filtering is to collect the carbon-based material using filter paper with a diameter of 0.1 to 1 μm; the washing is to rinse the collected carbon-based material with deionized water for 3 to 5 times; and the drying is to dry in an oven at a temperature of 60° C. for 24 hours.

5. The method for preparing a photocatalyst for removing lead, cadmium and arsenic by using a carbon-based composite manganese dioxide-loaded organic photovoltaic material according to claim 1 or 2, characterized in that: In step G, the weight ratio of the organic photocatalyst mixed solution to the carbon-based composite manganese dioxide material is 1:5000-10000.

6. The method for preparing a photocatalyst for removing lead, cadmium and arsenic by using a carbon-based composite manganese dioxide loaded organic photovoltaic material according to claim 1 or 2, characterized in that: In step F, the PM6:IDT6CN-M are mixed in a weight ratio of 1:1.

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