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CN-118268031-B - Preparation method and application of organic/inorganic photocatalytic composite material of poly-triazine imide/cadmium sulfide quantum dot

CN118268031BCN 118268031 BCN118268031 BCN 118268031BCN-118268031-B

Abstract

The invention discloses a preparation method and application of a poly-triazine imide/cadmium sulfide quantum dot organic/inorganic photocatalysis composite material, and belongs to the technical fields of functional nano material preparation, solar energy utilization and environmental protection. The preparation method of the composite material comprises the steps of taking urea as a precursor, adopting a low-temperature molten salt method to prepare high-crystallinity triazine imide, then adding the poly triazine imide into an absolute ethyl alcohol solution containing a cadmium sulfide raw material, preserving heat in a hydrothermal reaction kettle, and washing the product to obtain the composite material. According to the invention, the high-crystallinity triazine imide is used as a matrix, the cadmium sulfide quantum dots are grown on the surface, and the problems of low visible light utilization rate of the poly-triazine imide and difficult carrier separation of the single-component material are effectively solved by constructing the organic/inorganic heterojunction. The photocatalytic reduction material can be directly applied to the removal of pathogenic microorganisms in sunlight water, and solves the problem of low efficiency of the traditional photocatalytic material.

Inventors

  • XIAO JUN
  • ZHANG KECHEN

Assignees

  • 中国科学院金属研究所

Dates

Publication Date
20260512
Application Date
20221231

Claims (9)

  1. 1. The preparation method of the organic/inorganic photocatalytic composite material of the polytriazineimide/cadmium sulfide quantum dot is characterized by comprising the following steps: (1) Weighing 100-200 mg of poly-triazine imide, 1-2 mmol of cadmium salt and sulfide, adding 60-80 ml of absolute ethyl alcohol, and stirring for 1-2 hours at room temperature to obtain a mixture; (2) Transferring the mixture obtained in the step (1) into a hydrothermal reaction kettle, heating to 150-180 ℃ in an oven, and preserving heat for 1-3 hours; (3) And (3) washing, drying and grinding the mixture treated in the treatment (2) in sequence to obtain the organic/inorganic photocatalytic composite material of the poly-triazine imide/cadmium sulfide quantum dot.
  2. 2. The preparation method of the organic/inorganic photocatalytic composite material of the polytriazine imide/cadmium sulfide quantum dot, which is disclosed in the claim 1, is characterized in that in the step (1), the polytriazine imide is in a powder form, and the preparation process comprises the following steps (a) - (c): (a) Weighing 5-10 g of nitrogen-rich substances, placing the substances into a crucible, heating the substances to 500-600 ℃ in a muffle furnace, preserving heat for 2-4 hours, cooling and grinding to obtain graphite carbon nitride powder; (b) Weighing 200-500 mg of graphite carbon nitride prepared in the step (1), 1-4 g of potassium chloride and 1-4 g of lithium chloride, and grinding for 3-10 minutes to obtain a uniform mixture; (c) Transferring the mixture in the step (b) into a crucible or a quartz tube, heating to 500-600 ℃ in a tube furnace, preserving heat for 12-24 hours, cooling, washing, drying and grinding to obtain the poly-triazine imide powder.
  3. 3. The preparation method of the organic/inorganic photocatalytic composite material of the polytriazinyl imide/cadmium sulfide quantum dots is characterized in that in the step (a), the crucible is an alumina crucible with a cover, and in the step (c), the quartz tube is required to be sealed in vacuum.
  4. 4. The preparation method of the organic/inorganic photocatalytic composite material of the polytriazinyl imide/cadmium sulfide quantum dots, which is disclosed in claim 2, is characterized in that in the step (a), the temperature rising rate of a muffle furnace is 3-5 ℃ per minute, in the step (C), the temperature rising rate of a tube furnace is 5-30 ℃ per minute, and nitrogen with the flow rate of 50-200 ml/min is introduced into the tube furnace.
  5. 5. The method for preparing the organic/inorganic photocatalytic composite material of the polytriazineimide/cadmium sulfide quantum dot according to claim 2, wherein in the step (a), the nitrogen-rich substance is any one of urea, thiourea, melamine, dicyandiamide or cyanamide.
  6. 6. The preparation method of the organic/inorganic photocatalytic composite material of the polytriazinimide/cadmium sulfide quantum dots, which is disclosed in claim 1, is characterized in that in the step (1), the cadmium salt is cadmium chloride or cadmium acetate, and the sulfide is sodium sulfide or potassium sulfide.
  7. 7. The preparation method of the organic/inorganic photocatalytic composite material of the polytriazinimide/cadmium sulfide quantum dots is characterized in that in the step (1), the stirring mode is magnetic stirring, the rotating speed is 500-800 rpm, the drying is carried out in a vacuum drying oven, the temperature is 50-80 ℃, and the time is 12-15 hours.
  8. 8. The preparation method of the organic/inorganic photocatalytic composite material of the polytriazine imide/cadmium sulfide quantum dots, which is disclosed in claim 1 or 2, is characterized in that an agate mortar is used for grinding, the grinding speed is 60 revolutions per minute, the detergent is deionized water, the separation mode of the material and water is centrifugation, the centrifugation speed is 7000-9000 revolutions per minute, and the washing times are 3-5 times.
  9. 9. An application of the organic/inorganic photocatalytic composite material of the polytriazineimide/cadmium sulfide quantum dot prepared by the method of claim 1 is characterized in that the composite material is applied to photocatalytic sterilization.

Description

Preparation method and application of organic/inorganic photocatalytic composite material of poly-triazine imide/cadmium sulfide quantum dot Technical Field The invention relates to the technical field of organic polymer functional materials, in particular to a preparation method and application of an efficient sterilization poly-triazine imide/cadmium sulfide quantum dot organic/inorganic photocatalytic composite material. Background With rapid development of urban and industrial production and population growth, the problem of water pollution is increasingly serious. The traditional disinfection modes such as chlorination, fenton, biodegradation and the like are easy to cause secondary pollution, or have strict requirements on reaction conditions, high energy consumption or slow reaction rate. The photocatalysis technology which is raised in the 70 th century takes sunlight as direct energy, has the advantages of no toxicity, no drug resistance and the like, and is an efficient and safe disinfection mode. The basic principle of photocatalysis is that a semiconductor material absorbs light energy to enable electrons to be energy-converted to form free electrons and holes, and the semiconductor material can react with oxygen-containing substances such as oxygen, water and the like to form oxygen active species with strong oxidability, and can effectively inactivate pathogenic microorganisms. Conventional semiconductor materials have their drawbacks, which limit their photocatalytic activity. The preparation method of CdS nano particles [ J ]. Material guide, 2003,17 (3): 4. ] is characterized in that the photocatalytic activity of the CdS nano particles is limited by higher bulk photo-generated carrier recombination rate, while the synthesis method of the conventional organic polymer semiconductor material graphite carbon nitride is mainly to directly calcine nitrogen-rich substances to form amorphous material (Wang X,Maeda K,Thomas A,et al.A metal-free polymeric photocatalyst for hydrogen production from water under visible light[J].Nature Materials.),, so that the photocatalytic activity of the amorphous material (Wang X,Maeda K,Thomas A,et al.A metal-free polymeric photocatalyst for hydrogen production from water under visible light[J].Nature Materials.), is lower due to lower carrier migration rate and high recombination rate caused by low crystallinity. In the prior art, a high-crystallinity graphite carbon nitride (poly-triazine imide crystal form) is prepared by a molten salt assisted method, and a photoelectrochemical experiment and a fluorescence spectrum result show that compared with amorphous graphite carbon nitride, the high-crystallinity graphite carbon nitride has larger improvement in carrier separation and migration, but the novel problem is generated, namely the reported poly-triazine imide has weaker light absorption capacity, has no visible light response at the absorption cut-off side of 400 nanometers or below, has lower utilization rate of sunlight, and is a very large defect restricting the application of the large-scale industry. Disclosure of Invention The invention aims to provide a preparation method and application of a high-efficiency sterilization poly-triazine imide/cadmium sulfide quantum dot photocatalysis composite material aiming at the defects in the prior art. Graphite carbon nitride is obtained through a thermal polymerization method, secondary calcination is carried out in a molten salt environment to obtain the polytriazine imide, so that the crystallinity and the photo-generated charge separation and transfer efficiency of the polytriazine imide are improved, and finally, cadmium sulfide quantum dots are loaded on the polytriazine imide through a solvothermal method, so that the light absorption performance is improved, and the photocatalytic sterilization capability of the polytriazine imide is greatly improved. The invention adopts the following technical scheme for achieving the purpose: a preparation method of a high-efficiency bactericidal poly-triazine imide/cadmium sulfide quantum dot photocatalysis composite material comprises the following specific steps: 1) Weighing 5-10 g of nitrogen-rich substances, placing the substances into a crucible, heating the substances to 500-600 ℃ in a muffle furnace at a heating rate of 2-5 ℃ per minute, preserving heat for 2-4 hours, and grinding the substances after cooling to obtain graphite carbon nitride powder; 2) Weighing 200-500 mg of graphite carbon nitride, 1-4 g of potassium chloride and 1-4 g of lithium chloride, and grinding for 3-10 minutes to obtain a uniform mixture; 3) Transferring the mixture in the step 2) into a crucible or a quartz tube, heating to 500-600 ℃ in a tube furnace at a heating rate of 2-5 ℃ per minute, preserving heat for 12-24 hours, and performing washing, drying and grinding after the mixture is cooled with nitrogen gas with the tube furnace air flow of 50-200 ml/minute to obtain polytriazin