CN-121988391-A - Chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material and preparation method and application thereof

Abstract

The invention discloses a D-A porphyrin-based hydrogen bond organic framework material encapsulated by chitosan, and a preparation method and application thereof, and relates to the technical field of hydrogen peroxide preparation materials by photocatalysis. The preparation method of the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material comprises the steps of placing 5,10,15, 20-tetra (4-carboxyphenyl) porphyrin and 4,4' -bipyridine in an organic solvent, carrying out ultrasonic treatment, cooling after heating reaction, washing, filtering and drying to obtain a porphyrin-based hydrogen bond organic framework, preparing chitosan acetic acid aqueous solution, adding the organic framework, stirring to prepare a suspension, dripping into sodium hydroxide aqueous solution for curing, and washing and drying to obtain the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material. The chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material prepared by the invention can be used as a photocatalyst, so that the stability and photocatalytic activity of the hydrogen bond organic framework in the photocatalytic process are obviously improved, and CS/TB-HOF has biocompatibility and environmental friendliness, and high-efficiency and environment-friendly photocatalytic hydrogen peroxide preparation is realized.

Inventors

• QU WENWEN
• HE YAN
• ZHAO LI
• MAO QINGYAN
• YANG SHU
• XIAO HAN
• Yao Yimei
• YU YAO

Assignees

• 昆明理工大学

Dates

Publication Date

20260508

Application Date

20260120

Claims (10)

1. 1. The preparation method of the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material is characterized by comprising the following steps of: (1) Placing 5,10,15, 20-tetra (4-carboxyphenyl) porphyrin and 4,4' -bipyridine in an organic solvent, performing ultrasonic treatment to form a mixed solution, placing the mixed solution in a reaction container, heating for reaction, cooling after the reaction is finished, taking out a solid product, and sequentially washing, filtering and drying to obtain a porphyrin-based hydrogen bond organic framework; (2) Preparing an acetic acid aqueous solution of chitosan; (3) Placing the porphyrin-based hydrogen bond organic framework in acetic acid aqueous solution of chitosan, stirring to obtain suspension, dripping the suspension into alkali solution, then solidifying to obtain a solid crude product, washing and drying the solid crude product to obtain the chitosan-encapsulated D-A-type porphyrin-based hydrogen bond organic framework material.
2. 2. The preparation method of the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material according to claim 1, wherein in the step (1), 5,10,15, 20-tetra (4-carboxyphenyl) porphyrin and 4,4 '-bipyridine are added into an organic solvent according to a molar ratio of 1 (1-4), and the total addition amount of the 5,10,15, 20-tetra (4-carboxyphenyl) porphyrin and the 4,4' -bipyridine in a mixed solution is 0.00333-0.025 mol/L.
3. 3. The preparation method of the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material is characterized in that the ultrasonic time in the step (1) is 5-15 min, and the heating reaction conditions are that the reaction is carried out at 80-160 ℃ for 6-48 h.
4. 4. The preparation method of the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material is characterized in that the mass concentration of chitosan in the acetic acid aqueous solution of chitosan in the step (2) is 5-25 g/L, and the acetic acid aqueous solution of chitosan is prepared by adopting the acetic acid aqueous solution with the mass percentage concentration of 1-3%.
5. 5. The method for preparing the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material, which is characterized in that the adding amount of the porphyrin-based hydrogen bond organic framework in the suspension in the step (3) is 0.04-0.4 g/L.
6. 6. The method for preparing the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material according to claim 1, wherein the stirring condition in the step (3) is that stirring is carried out at 600rpm for 1-4 h.
7. 7. The preparation method of the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material is characterized in that the alkaline solution in the step (3) is a sodium hydroxide aqueous solution with the concentration of 1-4 mol/L, the dropping rate of the suspension liquid into the alkaline solution is 0.5-3 mL/min, and the curing time is 10-40 min.
8. 8. The preparation method of the chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material, which is characterized in that the drying condition of the solid crude product in the step (3) is that the solid crude product is dried at 40 ℃ for 8-12 h.
9. 9. The chitosan-encapsulated D-a porphyrin-based hydrogen bond organic framework material prepared by the method of any one of claims 1-8.
10. 10. The use of the chitosan encapsulated D-a porphyrin-based hydrogen bond organic framework material of claim 9 in photocatalytic synthesis of H 2 O 2 .

Description

Chitosan-encapsulated D-A porphyrin-based hydrogen bond organic framework material and preparation method and application thereof Technical Field The invention relates to a D-A porphyrin-based hydrogen bond organic framework material encapsulated by chitosan, and a preparation method and application thereof, and belongs to the technical field of hydrogen peroxide preparation materials by photocatalysis. Background Hydrogen peroxide (H 2O2) is an important green oxidant, and has wide application in the fields of environmental control, chemical synthesis, medical disinfection and wastewater treatment. The energy density of the aqueous solution is equivalent to that of the compressed hydrogen, and the storage and the transportation are more convenient, so the aqueous solution is considered to be a substitute carrier of hydrogen energy in the future, and therefore, the aqueous solution is paid attention to the fields of energy and environment. At present, the production of H 2O2 mainly depends on an anthraquinone method, and the method needs to use an expensive metal-based catalyst, has higher energy consumption, serious environmental pollution and causes serious economic cost pressure and environmental burden problems. In contrast, the use of solar-driven photocatalysis to convert water and oxygen into H 2O2 is a sustainable and low-cost alternative, which has the advantages of green, pollution-free and sustainable, and has great development potential. However, the existing photocatalytic semiconductor material generally has the problems of easiness in recombination of photon-generated carriers, low quantum utilization efficiency and serious photo-corrosion, so that the H 2O2 photo-synthesis efficiency is not ideal. Therefore, the development of the efficient and environment-friendly semiconductor photocatalyst is a key for promoting the H 2O2 photosynthesis to be practically applied. In order to solve the performance bottleneck of the existing catalyst in the field of producing hydrogen peroxide by photocatalysis, a novel high-efficiency photocatalysis material is continuously explored. The hydrogen bond organic framework (HOFs) is an emerging porous crystal material, and is formed by orderly assembling organic functional monomers by taking intermolecular hydrogen bonds as a dominant driving force and pi-pi stacking and van der Waals weak interaction as auxiliary materials. Compared with other organic frame materials, HOFs has the remarkable advantages of strong structural design, capability of realizing precise regulation and control of crystal structure and function by regulating and controlling monomer types, mild synthesis conditions, capability of being prepared by solution self-assembly, environment friendliness, no metal ions, capability of effectively avoiding secondary pollution caused by metal ion elution, easiness in functional modification and capability of providing flexible space for performance regulation and control. The porphyrin compound has an 18 pi electron conjugated structure and excellent optical performance, and the visible light absorption can be obviously enhanced and the photocatalytic performance can be improved by introducing porphyrin molecules into HOFs systems. However, the existing porphyrin-based HOFs still faces two key challenges. Firstly, a single porphyrin unit has strong light absorption characteristic, but the high exciton binding energy of the single porphyrin unit leads to easy recombination of photo-generated electron-hole pairs, thereby obviously restricting the photocatalysis quantum efficiency, secondly, in the aqueous phase reaction environment required by H 2O2 synthesis, the weak hydrogen bond action and the inherent hydrophilicity of the HOFs framework lead to insufficient structural stability of the material, and the material is easy to collapse due to the hydrogen bond damage in the aqueous phase or complex reaction environment, thereby being difficult to realize recycling. The chitosan is used as a natural polymer, the molecular chain of the chitosan is rich in hydroxyl and amino, the material can be effectively packaged through multiple hydrogen bonds and electrostatic action, the chitosan has good biocompatibility and sphericity, and the processing and recovery of the material are facilitated. At present, chitosan has been successfully used for packaging metal nano particles and quantum dot catalytic materials, and has shown excellent dispersion fixing and stability improving effects. However, the research on the use of the same for encapsulating porphyrin-based hydrogen-bonded organic framework materials to construct a composite photocatalyst having both high light absorption, rapid charge transfer and excellent aqueous phase stability has not been fully developed. Disclosure of Invention Aiming at the defects of the related technology, the invention provides a D-A porphyrin-based hydrogen bond organic framework material encapsulated by chitosan, and a p