A kind of hydrothermal preparation method of carbon quantum dots used as visible light catalytic photosensitizer

Abstract

A hydrothermal preparation method for carbon quantum dots used as visible light catalytic photosensitizers, which is characterized by: using larch as raw material, after high temperature and high pressure hydrothermal treatment, the dark brown solid product is removed by centrifugal filtration to obtain a light yellow liquid product, Centrifuge the liquid product at high speed, control the centrifugal speed and time to remove insoluble small particle impurities, dialyze with a dialysis bag of a certain molecular weight to remove unreacted sugar, salt, etc., and then concentrate to obtain the target product - water-soluble fluorescent carbon quantum dots. Combine it with TiO 2 A photocatalytic composite system was prepared by combining antibiotics as a model substance to examine the photocatalytic degradation performance of the composite system on the model substance and the efficiency of carbon dots as photosensitizers. The main features of this operation process are that it uses larch, which is rich in resources in Heilongjiang Province, as raw material. It is environmentally friendly, cheap and easy to obtain. The hydrothermal reaction is at low temperature and low pressure. There is no need to add passivating agents such as acid, alkali and salts. The product is water-soluble and has a certain fluorescence effect. The reaction process is simple to operate and low in cost.

Description

[0001] Technical field: [0002] The invention relates to the field of preparation of nanomaterials, in particular to a hydrothermal preparation method for carbon quantum dots used as visible light catalyzed photosensitizers Background technique: [0003] Antibiotics are widely used in medical treatment, medical medicine and agricultural fields, but usually humans and animals have very low absorption capacity for antibiotics, and 50% to 80% of antibiotics are eventually excluded into the aquatic environment, causing soil toxicity, resistance Threats to human health, such as the production of antibiotics and pathogens, occur. Tetracycline is the second most used antibiotic in the world, so far there is still a lack of effective, comprehensive and systematic technical support for the removal of tetracycline. Compared with traditional adsorption and microbial degradation methods, photocatalytic degradation can effectively remove macromolecular organic components in aqueous solut...

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Problems solved by technology

[0003] Antibiotics are widely used in medical treatment, medical medicine and agricultural fields, but usually humans and animals have very low absorption capacity for antibiotics, and 50% to 80% of antibiotics are eventually excluded into the aquatic environment, causing soil toxicity, resistance Threats to human health, such as the production of antibiotics and pathogens, occur

Tetracycline is the second most used antibiotic in the world, so far there is still a lack of effective, comprehensive and systematic technical support for the removal of tetracycline

[0008] The Chinese patent whose publication number is CN102127431 introduces the preparation method of carbon quantum dots and the method of applying the quantum dots to prepare photocatalysts. In this method, ethanol and distilled water are mixed according to a certain volume ratio, and then an inorganic strong base is added to obtain an electrolyte and put into an electrolytic cell. Graphite carbon rods are used as electrodes, at 10-200mA / cm 2 The electrochemical reaction is carried out at a certain current density for 2 to 4 hours, and finally a desiccant is added to obtain carbon quantum dots through column chromatography separation. This method is performed in two steps, one electrolysis and one column chromatography separation, the reaction is complicated and the damage to the instrument is great.

[0009] In summary, the traditional methods of preparing carbon dots such as combustion, electrolysis, freeze-drying, and ultrasound are high-loss, complex reactions, and passivators such as strong acids and bases are required. Although some have excellent performance, they lack relevant practical application guidance.

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