Preparation method and application of photocatalyst for removing manganese, copper, cadmium and lead from modified diatomite loaded organic photovoltaic material

Abstract

The invention discloses a preparation method and application of a photocatalyst for removing manganese, copper, cadmium and lead from a modified diatomite loaded organic photovoltaic material. The preparation method comprises the following operation steps: A, mixing diatomite with deionized water; b, adding a cross-linking agent epichlorohydrin (ECH) into the mixed solution in the step A; c, in an ice bath environment, adding an amino-rich material into the mixed solution obtained in the step B, and then stirring and reacting for 1 hour; d, filtering, washing and drying the solution after the reaction in the step C to obtain a modified diatomite material; e, mixing the organic photovoltaic material with chloroform; and F, uniformly coating the modified diatomite material with the mixed solution obtained in the step E, and drying to obtain the photocatalyst for removing manganese, copper, cadmium and lead from the modified diatomite loaded organic photovoltaic material. The photocatalyst obtained through the method can efficiently and rapidly remove Mn (II), Cu (II), Cd (II) and Pb (II) at the same time and can be repeatedly used, the problems of a photocatalyst loading process and cyclic utilization are solved, and a real green, environment-friendly and pollution-free treatment method is provided for removal of heavy metal.

Description

Technical Field

[0001] The invention relates to the technical field of functional material preparation, and in particular to a method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials and an application thereof. Background Art

[0002] Water is the source of life. Water resources play a vital role in human production and development. However, water, as an important resource, has been seriously polluted due to industrial development in recent decades. In particular, both surface water and groundwater have been polluted by heavy metals to varying degrees. Industries such as electroplating, ceramics, glass, mining and battery manufacturing are considered to be the main sources of heavy metals such as lead in water. With a high degree of industrialization, the content of lead and other heavy metals (such as cadmium, manganese and copper) in local water will be high, which is also a major hidden danger affecting public health.

[0003] The general methods for treating heavy metals include chemical precipitation, membrane filtration, ion exchange, alum coagulation and adsorption, which are the most commonly used methods for treating and disposing of metal-containing water. Among them, adsorption is considered to be a particularly economical and effective method for removing low-concentration heavy metals.

[0004] Diatomaceous earth (SiO2·nH2O) is a soft, lightweight rock composed mainly of silica microfossils of aquatic unicellular algae in various shapes and sizes. Diatomaceous earth is highly porous, with up to 80-90% of voids in its structure. It is used in many industrial applications, such as as a filtration medium for various beverages, inorganic and organic chemicals, and as an adsorbent for pet waste and oil spill drums. Despite the unique physical and chemical properties of diatomaceous earth, its use as an adsorbent in wastewater treatment has not yet been promoted. This is because raw diatomaceous earth often contains some metal oxides and organic components, which not only block the pores of diatomaceous earth, but also occupy the active sites of diatomaceous earth, resulting in a decrease in the specific surface area of ​​diatomaceous earth and a decrease in adsorption performance.

[0005] There are also studies on the use of diatomaceous earth to adsorb heavy metal ions, but most of them are aimed at exploring the impact of external factors on the adsorption effect. There is no research on how to reduce the toxicity of the heavy metal ions themselves, and they cannot be recycled.

[0006] Therefore, it is necessary to develop a photocatalyst preparation method that has high biological safety, can be recycled multiple times, and can perform secondary purification of water while removing Mn(II), Cu(II), Cd(II) and Pb(II). Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials and its application. The photocatalyst obtained by the method can realize the efficient removal of Mn(II), Cu(II), Cd(II) and Pb(II) at the same time and can be reused, thus solving the difficult problems of photocatalyst loading process and recycling, and providing a truly green, environmentally friendly and pollution-free treatment method for removing manganese, copper, cadmium and lead ions.

[0008] The present invention solves the above technical problems with the following technical solutions:

[0009] The present invention discloses a method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials, comprising the following steps:

[0010] Step A, mixing diatomaceous earth and deionized water to obtain a mixed solution A, wherein the dosage ratio of diatomaceous earth to deionized water is: 5 g diatomaceous earth, 50 ml deionized water;

[0011] Step B, adding crosslinking agent epichlorohydrin (ECH) to mixed solution A, and uniformly obtaining mixed solution B by mechanical stirring, wherein the amount of epichlorohydrin added is 2-8% by weight of mixed solution A;

[0012] Step C, slowly adding the amino-rich material dropwise to the mixed solution B in an ice bath environment, and then mechanically stirring and reacting for 1 hour to obtain a mixed solution C, wherein the amount of the amino-rich material added is 5-10% by weight of the mixed solution B;

[0013] Step D, filtering, washing and drying the mixed solution C to obtain a modified diatomaceous earth material;

[0014] Step E, mixing an organic photovoltaic material 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; the organic photovoltaic material is P3HT:PCBM;

[0015] Step F, uniformly coating the organic photocatalyst mixed solution obtained in step E on the modified diatomaceous earth material, and drying for 24 hours to obtain the modified diatomaceous earth-loaded organic photovoltaic material photocatalyst for removing manganese, copper, cadmium and lead.

[0016] In step B of the present invention, the mechanical stirring rate is 200-600 r / min, and the stirring time is 15 min.

[0017] In step C of the present invention, the rate of mechanical stirring is 300-500 r / min.

[0018] In step C of the present invention, the water temperature of the ice bath environment is 2-10°C.

[0019] In step C of the present invention, the amino-rich material is polyaniline or polyvinylamine.

[0020] In step D of the present invention, the filtering is to collect the diatomaceous earth using filter paper with a diameter of 0.1 to 1 μm; the washing is to rinse the collected diatomaceous earth with deionized water for 3 to 5 times; and the drying is to dry it in an oven at a temperature of 60° C. for 24 hours.

[0021] In step F of the present invention, the weight ratio of the organic photocatalyst mixed solution to the modified diatomaceous earth material is 1:5000-10000.

[0022] In step E of the present invention, the P3HT:PCBM is prepared by mixing P3HT and PCBM in a weight ratio of 1:1.

[0023] Application of the photocatalyst obtained by the preparation method of the present invention: the photocatalyst is used for removing heavy metal ions of manganese, copper, cadmium and lead in waste water.

[0024] The present invention has the following beneficial effects:

[0025] (1) The photocatalyst obtained by the method of the present invention can realize the efficient removal of Mn(II), Cu(II), Cd(II) and Pb(II) by the modified diatomite material at the same time, and the removal effect is very good, the removal rate can reach 100%, and it can be reused.

[0026] (2) Compared with inorganic catalysts, the photocatalyst obtained by the method of the present invention has unique advantages in wastewater purification: rapid and effective exciton dissociation, adjustable energy level, wide absorption spectrum and excellent chemical stability, etc., which can generate a large number of superoxide free radicals and electrons with strong reducing properties in water, and can reduce Mn(II), Cu(II), Cd(II) and Pb(II) into metal elements or insoluble salts, and can also be completely removed through electrostatic adsorption and complexation reaction of modified diatomaceous earth materials.

[0027] (3) The matrix material used in the present invention is a natural product, diatomaceous earth, which has many excellent properties such as hydrophilicity, greenness, high porosity, and large specific surface area. In addition, the organic photoelectric material can be loaded on the matrix material for repeated use and is degradable, thus achieving true green friendliness and no pollution to the environment, 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 development. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a stability test chart of the photocatalyst degradation of manganese, copper, cadmium and lead ions obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0030] Example 1

[0031] The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials of the present invention is carried out according to the following steps:

[0032] A. Put 5g of diatomaceous earth into a wall-breaking machine and grind for 45s;

[0033] B. 5 g of crushed diatomaceous earth was added into 50 ml of deionized water to obtain a mixed solution;

[0034] C. Add 4.4 g of crosslinking agent epichlorohydrin (ECH) to 55 g of the mixed solution of step B, and stir mechanically at a speed of 300 r / min for 15 min;

[0035] D. In an ice bath (water temperature is 2°C), add 5.94 g of polyvinyl amine to 59.4 g of the mixture obtained in step C.

[0036] The solution was stirred mechanically at 500 r / min for 1 h;

[0037] E. filtering the mixed solution obtained in step D (i.e., collecting the diatomite using filter paper with a diameter of 0.1 to 1 μm), washing it with deionized water for 5 times, and drying it in an oven at 60° C. for 24 hours to obtain a modified diatomite material;

[0038] F. Mix 0.01 g of P3HT:PCBM with 13 ml of chloroform to obtain an organic photocatalyst mixed solution, wherein

[0039] P3HT:PCBM is obtained by mixing P3HT and PCBM in a weight ratio of 1:1.

[0040] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the modified diatomaceous earth material, and after drying for 24 hours, a modified diatomaceous earth-loaded organic photovoltaic material photocatalyst for removing manganese, copper, cadmium and lead is obtained, wherein the weight ratio of the organic photocatalyst mixed solution to the modified diatomaceous earth material is 1:7500.

[0041] The photocatalyst prepared in this example is used for the adsorption and degradation photocatalysis of manganese, copper, cadmium and lead in wastewater. The removal rate is 100% in 15 minutes, and the efficient removal of Mn(II), Cu(II), Cd(II) and Pb(II) is achieved simultaneously, and the removal effect is very good.

[0042] Example 2

[0043] The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials of the present invention is carried out according to the following steps:

[0044] A. Put 5g of diatomaceous earth into a wall-breaking machine and grind for 45s;

[0045] B. 5 g of crushed diatomaceous earth was added into 50 ml of deionized water to obtain a mixed solution;

[0046] C. Add 1.1 g of crosslinking agent epichlorohydrin (ECH) to 55 g of the mixed solution of step B, and stir mechanically at a speed of 400 r / min for 15 min;

[0047] D. In an ice bath (water temperature of 6°C), 2.805 g of polyaniline was added to 56.1 g of the mixed solution obtained in step C.

[0048] The reaction was carried out in a liquid with mechanical stirring at a speed of 300 r / min for 1 h;

[0049] E. filtering the mixed solution obtained in step D (i.e., collecting the diatomaceous earth material using filter paper with a diameter of 0.1 to 1 μm), washing it with deionized water for 3 times, and drying it in an oven at 60° C. for 24 hours to obtain a modified diatomaceous earth material;

[0050] F. Mix 0.005 g of P3HT:PCBM with 10 ml of chloroform to obtain an organic photocatalyst mixed solution, wherein

[0051] P3HT:PCBM is obtained by mixing P3HT and PCBM in a weight ratio of 1:1.

[0052] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the modified diatomaceous earth material, and after drying for 24 hours, a modified diatomaceous earth-loaded organic photovoltaic material photocatalyst for removing manganese, copper, cadmium and lead is obtained, wherein the weight ratio of the organic photocatalyst mixed solution to the modified diatomaceous earth material is 1:5000.

[0053] The photocatalyst prepared in this example is used for the adsorption and degradation photocatalysis of manganese, copper, cadmium and lead, with a removal rate of 99.8% in 15 minutes, achieving efficient removal of Mn(II), Cu(II), Cd(II) and Pb(II) at the same time, and the removal effect is very good.

[0054] Example 3

[0055] The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials of the present invention is carried out according to the following steps:

[0056] A. Put 5g of diatomaceous earth into a wall-breaking machine and grind for 45s;

[0057] B. 5 g of crushed diatomaceous earth was added into 50 ml of deionized water to obtain a mixed solution;

[0058] C. Add 2.75 g of crosslinking agent epichlorohydrin (ECH) to 55 g of the mixed solution of step B, and stir mechanically at a speed of 500 r / min for 15 min;

[0059] D. In an ice bath (water temperature of 10°C), 4.33 g of polyvinyl amine was added to 57.75 g of the mixture obtained in step C.

[0060] The solution was stirred mechanically at 400 r / min for 1 h;

[0061] E. filtering the mixed solution of step D (i.e., collecting the diatomaceous earth material using filter paper with a diameter of 0.1 to 1 μm), washing it with deionized water for 4 times, and drying it in an oven at 60° C. for 24 hours to obtain a modified diatomaceous earth material;

[0062] F. Mix 0.005 g of P3HT:PCBM with 15 ml of chloroform to obtain an organic photocatalyst mixed solution, wherein

[0063] P3HT:PCBM is obtained by mixing P3HT and PCBM in a weight ratio of 1:1.

[0064] G. The organic photocatalyst mixed solution obtained in step F is evenly coated on the modified diatomaceous earth material, and after drying for 24 hours, a modified diatomaceous earth-loaded organic photovoltaic material photocatalyst for removing manganese, copper, cadmium and lead is obtained, wherein the weight ratio of the organic photocatalyst mixed solution to the modified diatomaceous earth material is 1:10000.

[0065] The photocatalyst prepared in this example is used for the adsorption and degradation photocatalysis of manganese, copper, cadmium and lead in wastewater. The removal rate is 100% in 15 minutes, and the efficient removal of Mn(II), Cu(II), Cd(II) and Pb(II) is achieved simultaneously, and the removal effect is very good.

Claims

1. A method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials, characterized in that: The steps include: Step A, mixing diatomaceous earth and deionized water to obtain a mixed solution A, wherein the dosage ratio of diatomaceous earth to deionized water is: 5 g diatomaceous earth, 50 ml deionized water; Step B, adding crosslinking agent epichlorohydrin (ECH) to mixed solution A, and uniformly obtaining mixed solution B by mechanical stirring, wherein the amount of epichlorohydrin added is 2-8% by weight of mixed solution A; Step C, slowly adding the amino-rich material dropwise to the mixed solution B in an ice bath environment, and then mechanically stirring and reacting for 1 hour to obtain a mixed solution C, wherein the amount of the amino-rich material added is 5-10% by weight of the mixed solution B; Step D, filtering, washing and drying the mixed solution C to obtain a modified diatomaceous earth material; Step E, mixing an organic photovoltaic material 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; the organic photovoltaic material is P3HT:PCBM; Step F, uniformly coating the organic photocatalyst mixed solution obtained in step E on the modified diatomaceous earth material, and drying for 24 hours to obtain the modified diatomaceous earth-loaded organic photovoltaic material photocatalyst for removing manganese, copper, cadmium and lead.

2. The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials according to claim 1, characterized in that: In step B, the mechanical stirring rate is 200-600 r / min, and the stirring time is 15 min.

3. The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials according to claim 1, characterized in that: In step C, the mechanical stirring rate is 300-500 r / min.

4. The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials according to claim 1, characterized in that: In step C, the water temperature of the ice bath environment is 2-10°C.

5. The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials according to claim 1, characterized in that: In step C, the amino-rich material is polyaniline or polyvinylamine.

6. The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials according to claim 1, characterized in that: In step D, the filtering is to collect the diatomaceous earth using filter paper with a diameter of 0.1 to 1 μm; the washing is to rinse the collected diatomaceous earth with deionized water for 3 to 5 times; and the drying is to dry it in an oven at a temperature of 60° C. for 24 hours.

7. The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-loaded organic photovoltaic materials according to claim 1, characterized in that: In step F, the weight ratio of the organic photocatalyst mixed solution to the modified diatomaceous earth material is 1:5000-10000.

8. The method for preparing a photocatalyst for removing manganese, copper, cadmium and lead by using modified diatomite-supported organic photovoltaic materials according to claim 1, characterized in that: In step E, the P3HT:PCBM is prepared by mixing P3HT and PCBM in a weight ratio of 1:

1.

9. Use of the photocatalyst obtained by the preparation method according to any one of claims 1 to 8, characterized in that: Photocatalysts are used to remove heavy metal ions such as manganese, copper, cadmium and lead from wastewater.

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