CN-117718073-B - Co-CN photocatalyst based on ZIF-L derivative and preparation method and application thereof

Abstract

The invention belongs to the technical field of preparation of photocatalytic materials, and particularly relates to a Co-CN photocatalyst based on ZIF-L derivatization, and a preparation method and application thereof. The invention takes melamine, dimethyl imidazole and cobalt nitrate as raw materials, and utilizes water bath heating, program temperature control and vacuum calcination methods to synthesize the Co single atom modified CN composite photocatalytic material derived from zeolite imidazole ester skeleton structure material (ZIF-L). The invention has the advantages of simple process, convenient operation, low cost, no toxicity, no harm, short reaction time and the like. The prepared photocatalytic material has excellent photocatalytic degradation performance on tetracycline in water environment. The method is applied to the removal of tetracycline pollutants in water, improves the removal efficiency while reducing the energy consumption and the reaction cost, is environment-friendly, and meets the environment-friendly requirement.

Inventors

• YU XIUNA
• LUO HONGYU

Assignees

• 河南城建学院

Dates

Publication Date

20260508

Application Date

20231215

Claims (6)

1. 1. A preparation method of a Co-CN photocatalyst based on ZIF-L derivatization, which is characterized by comprising the following steps: (1) Uniformly grinding melamine, then placing the ground melamine into a temperature-programmed muffle furnace for gradient heating, wherein the gradient heating is that the temperature is firstly increased to 500-600 ℃, reacting for 2-4 hours at the temperature, then reacting for 1-2 h at the temperature of 50-100 ℃ in the muffle furnace, and naturally cooling to room temperature to obtain a CN sample; (2) Mixing dimethyl imidazole, cobalt nitrate hexahydrate and methanol, and stirring at room temperature to obtain a mixed solution; (3) Transferring the CN sample prepared in the step (1) into the mixed solution obtained in the step (2), heating and stirring until methanol is evaporated to dryness, and placing the mixture into a vacuum oven for drying; (4) Transferring the powdery sample obtained in the step (3) into a thermal shock reaction furnace, quickly heating and then quickly cooling to room temperature to obtain a Co-single-atom-modified CN composite photocatalytic material Co-CN photocatalyst, wherein the dosage ratio of dimethylimidazole to cobalt nitrate hexahydrate to methanol in the step (2) is 0.13 g-0.39 g to 0.0582 g to 50 mL-100 mL, the dosage ratio of the CN sample to the mixed solution in the step (3) is 1.5 g to 200 mL-300 mL, and the temperature condition of the thermal shock reaction furnace in the step (4) is that the temperature is quickly increased from 25 ℃ to 100-300 ℃ and the temperature is quickly cooled to the room temperature.
2. 2. The method of claim 1, wherein the gradient of step (1) is to raise the temperature to 500 ℃ and react at 2h ℃ and then to raise the muffle temperature to 550 ℃ and react 2 h.
3. 3. The method according to claim 1, wherein in the step (3), the heating and stirring are performed in a water bath at 60-70 ℃, the temperature of the tube furnace is controlled by the program, the tube furnace is heated to 300-500 ℃ at a heating rate of 2.3 ℃ per minute under vacuum, and the reaction is performed at the temperature of 2-4 h ℃.
4. 4. A Co-CN photocatalyst prepared by the preparation method according to any one of claims 1 to 3.
5. 5. The use of the Co-CN photocatalyst according to claim 4 in the field of antibiotic degradation in water bodies.
6. 6. The use of the Co-CN photocatalyst according to claim 4 in the field of tetracycline degradation in water.

Description

Co-CN photocatalyst based on ZIF-L derivative and preparation method and application thereof Technical Field The invention belongs to the technical field of preparation of photocatalytic materials, and particularly relates to a Co-CN photocatalyst based on ZIF-L derivatization, and a preparation method and application thereof. Background The increasingly serious environmental pollution problem seriously hinders the green sustainable development of the modern society. In particular, the rapid economic growth over the last decades and the rapid urbanization and industrialization have resulted in the discharge of large amounts of organic waste (e.g., dyes, medicines, aromatic hydrocarbons and other persistent organic compounds) into the body of water, severely jeopardizing the ecological environment and human health. In addition, according to the report of global antibiotic resistance review, a large number of antibiotics enter surface water bodies through effluent water, so that pollution is caused to underground water and drinking water. The antibiotics in the water body can affect the dynamic balance of bacterial population and promote the propagation of antibiotic drug resistance after reaching a certain concentration, and the pathogenic bacteria can cause chronic poisoning and three-cause effect after obtaining multiple drug resistance, thereby causing potential threat to the safety of aquatic organisms and human health. Without effective measures, 1000 tens of thousands of people die each year worldwide by 2050, losing 100 trillion dollars of GDP. Therefore, developing efficient semiconductor photocatalysts and practically applicable water pollution treatments is a major problem currently faced. The tertiary amine-linked tri-s-triazine backbone structure and the stronger interlayer van der Waals forces in the graphite-like phase carbon nitride (g-C 3N4, CN) provide excellent heat resistance and chemical stability. In addition, the method has the advantages of proper oxidation-reduction potential, simple preparation process and the like, and becomes an ideal candidate for degrading organic pollutants in environmental wastewater. However, single CN still has the problems of high charge recombination speed, few catalytic active sites and the like, so that the photocatalytic degradation effect is not ideal. In recent years, the construction of a CN-based composite system can effectively improve the separation efficiency of photo-generated electron-hole pairs and improve the catalytic activity, and is considered as an effective way for improving the photocatalytic degradation efficiency of semiconductors, and the composite catalysts such as CoZnAl-LDH/RGO/CN, znIn 2S4/CN, co 3O4 @Au/CN and the like have stronger photocatalysis. In addition, the research of utilizing metal monoatoms to modify CN receives a great deal of attention, and the research shows that the metal monoatoms not only serve as reactive sites, but also can generate a local surface plasmon resonance effect, so that the visible light absorption capacity and the carrier separation efficiency can be remarkably improved, and the photocatalytic performance is improved. However, to date, research on a Co metal single-atom modified CN composite photocatalytic material based on zeolite imidazole ester skeleton structure material (ZIF-L) for wastewater treatment has not been reported. Disclosure of Invention In view of the above, the present invention provides a Co-CN photocatalyst based on ZIF-L derivatives, and a preparation method and application thereof. According to the invention, melamine, dimethyl imidazole and cobalt nitrate are used as raw materials, a single-atom Co-modified CN composite photocatalyst (Co-CN) with excellent performance is prepared and synthesized by utilizing a water bath heating method, a program temperature control vacuum calcination method and a thermal shock method, the synthesis process is simple and quick, and the prepared Co-CN photocatalyst can remove tetracycline in wastewater under the visible light of simulated sunlight and fixed wavelength. The above object of the present invention is achieved by the following technical solutions: the invention provides a preparation method of a Co-CN photocatalyst based on ZIF-L derivatization, which comprises the following steps: (1) Uniformly grinding melamine, then placing the ground melamine into a temperature-programmed muffle furnace for gradient heating, wherein the gradient heating is that the temperature is firstly increased to 500-600 ℃, reacting for 2-4 hours at the temperature, then reacting for 1-2 h at the temperature of 50-100 ℃ in the muffle furnace, and naturally cooling to room temperature to obtain a CN sample; (2) Mixing dimethyl imidazole, cobalt nitrate hexahydrate and methanol, and stirring at room temperature to obtain a mixed solution; (3) Transferring the CN sample prepared in the step (1) into the mixed solution obtained in the step (2), heating and sti