Study On The Synthesis Of Covalent Organic Framework And Its Application In Adsorption Of Dyes

The rapid development of printing and dyeing and manufacturing has caused the dye wastewater to be directly discharged into the environment without proper treatment.The dye will cause the death of plants and animals after it seeped into the water.The toxicity of industrial dyes causes serious pollution to the environment,as well as harmful to the human and natural organisms.Sample pretreatment is an indispensable part of the analytical technology.Complex analytes,low content of targets,and the restriction of LOD,sensitivity performance of analytical instruments,it is urgent to carry out pre-treatment of analysis samples.There are many bottleneck problems in traditional sample pretreatment methods,such as low adsorption efficiency,adsorption material reuse efficiency is not high,poor selectivity and so on.Therefore,it is of great significance to select an efficient and simple method for sample pretreatment.With the gradual deepening of scientific research,the impact of materials science on biology,environment,food and medicine,energy and other aspects is increasingly prominent.The development of materials not only promotes the progress of scientific research,but also directly or indirectly affects people’s daily lives.Materials are the material basis of human existence and development in the history of development.Since the beginning of the 21 st century,as-synthesized and developed porous nanomaterials such as Covalent Organic Framework materials,its advantages such as large porosity,high specific surface area,flexible and controllable pore structure.In addition,it is possible to introduce functional,structural units and other advantages in a purposeful manner,which has made great achievements in the field of materials and set off a huge wave of research in the field of chemistryThis paper takes COFs materials as the core,comprehensively evaluates the prepared materials’ performance through multi-angle performance analysis,and studies the adsorption properties of different COFs materials to dyes.The follow-up work is mainly divided into the following two parts:Part I: Synthesis and Characterization of Spherical COFs at Room Temperature and Study on the Adsorption of Neutral RedIn general,the conditions required for the synthesis of COFs are demanding,so,in this paper,spherical COF-V was synthesized at room temperature and used as an adsorbent for organic dye neutral red.The adsorption behavior of spherical COF-V was studied.The material has high porosity and specific surface area,high crystallinity and good thermal stability.The material has high porosity and specific surface area,high crystallinity,The adsorption characteristics of COF-V on neutral red were studied by the UV absorption intensity of the dye under different adsorption times.The influence of external factors such as p H and ionic strength on the adsorption process was studied,and then the adsorption kinetics of COF-V on neutral red was explored,and it was found that the adsorption process was more in line with the second-order kinetic process.The method established in this experiment is green and efficient,and has a good application prospect in the adsorption of organic dyes from water samples.The influence of external factors such as p H and ionic strength on the adsorption process was studied,and then the adsorption kinetics of COF-V on neutral red was explored.It was found that the adsorption process was more in line with the second-order kinetic process.The method established in this experiment is green and efficient,and has a good application prospect in the adsorption of organic dyes from water samples.Part Ⅱ: Hydrothermal synthesis and characterization of covalent organic framework TRIPTA and its application in the adsorption of methylene blueIn this paper,COF-TRIPTA was synthesized by the hydrothermal method and used as an adsorbent to treat methylene blue,and the adsorption behavior was studied.The material has high porosity and specific surface area.We discussed the effect of p H and ionic strength on the adsorption process.The results show that as the p H increases gradually,the adsorption capacity gradually increases,but the adsorption efficiency of the whole maintained at more than 95%,which proves that the adsorption performance of our synthesized materials is affected by the p H and can be used for the treatment of dye wastewater in a wide p H range.With the increase of the concentration of coexisting ions,it was found that the amount of COF-TRIPTA adsorbed on MB decreased.Still,the decrease was not large,indicating that TRIPTA adsorbing MB’s performance is affected little by salinity and can be used for salt-containing Treatment of methylene blue wastewater.The experimental results show that COF-TRIPTA is a good adsorptive material for the adsorption of methylene blue with little external requirements.