Synthesis Of Multi-carboxylic Ligands Metal-organic Framework Materials And Performance Research

Metal-Organic Frameworks are coordination compound,formed by inorganic metal ion or metal ion cluster and carboxyl group or amino group in organic compound,having a large specific surface area and a porous network structure.Because of its unique properties such as adsorption,hydrogen storage,and catalysis,as well as huge potential application value,it has attracted the attention of researchers.Common ligands for MOFs include carboxyl,amino,alcohol,and mercaptans functional groups,but currently,the ligands with two,three or four carboxyl are used more.And it is mainly applied in the fields of gas storage,separation and purification of chemicals,catalysts,sensors,magnetic materials,optical devices,fluorescence,and drug delivery.With the development of industrial technology,environmental pollution has become more and more serious.In particular,dyes and heavy metals have great influence on people's health and the environment due to their difficult degradation and high toxicity.Physical,chemical and microbiological methods are usually used to remove pollutants from wastewater.Since the 1990s,MOFs have been used in the environment,but its preparation methods are relatively complicated.At present,MOFs are mainly prepared by solvothermal,electrochemical,mechanical,chemical,ultrasonic,etc.,which are required long reaction time and are not conducive to environmental protection.Therefore,a new method,which time saving,does not require the use of organic solvents,simple equipment,and environmentally friendly,is needed.It has important theoretical and practical significance.1.In this paper,the microwave assisted ball milling was used to prepare MOFs for the first time.The method mainly uses microwaves and ball mills to provide energy together,and the energy is transferred to the organic chain and metal ions through water as a medium to make them react.In this paper,a series of MOFs materials were successfully prepared by using the existing reaction equipment in the laboratory,using trimesic acid and terephthalic acid as organic chains,and copper acetate and cobalt acetate as metal ions.The prepared materials were used to remove Congo Red?CR?,and the experimental results were compared with theoretical analysis.The results showed that the experiment was consistent with the theory.2.Fe?II?-MOFs and Fe?III?-MOFs were prepared by using trimesic acid as organic chain,FeSO₄·7H₂O and Fe₂?SO₄?₃ as metal ions.The characterized materials were used for the removal of organic dyes and heavy metal Cr?VI?ions from wastewater.The removal rate is different that Fe?II?-MOFs were used to remove Cr?VI?at different concentrations,solution volumes and illumination?Xe light and natural light?.The experimental data were compared with the theoretical research.The results showed that the theory and the experiment were consistent.The Fe?II?-MOFs were used to removed the Congo red,orange II and Rhodamine B in the aqueous solution under the action of natural light,and their removal rates were discussed at 15°C and 35°C,respectively,and were researched under linear and nonlinear conditions.The research proved that the experimental results are consistent with the theory.Fe?III?-MOFs were used to remove orange yellow II,Congo red and methylene blue,and the pseudo-first-order kinetic and pseudo-second-order kinetic were studied under linear and nonlinear conditions,respectively.And the results were consistent with the experiments.3.GO/In-MOFs-1,GO/In-MOFs-2 and GO/Co-MOFs were prepared by using InCl₃·4H₂O and Co?CH₃COO?₂·4H₂O as metal ions,trimesic acid and 2-aminoterephthalic acid as organic chains.The prepared materials were used to remove Congo red solution and compared with the corresponding MOFs materials.The results showed that the removal rate of MOFs combined with graphene oxide was obviously improved,which proved that graphene oxide can promote the removal of Congo red in the composite.H₂O₂ was added during the removal of the dye,and the speed and removal rate of the organic dye removed by the composite were studied.The experimental data of all materials to remove organic dyes were subjected to kinetic studies,and analyzed under linear and nonlinear conditions.The results showed that the experimental results were consistent with the theoretical analysis.4.Zn-MOFs were prepared by using zinc acetate as metal ion and trimesic acid as organic chain.The prepared material was used to remove tetracycline hydrochloride.The effects of the quality of Zn-MOFs and the amount of H₂O₂ on the removal rate were studied,and the mechanism of Zn-MOFs removal of tetracycline hydrochloride was investigated.The experimental results were analyzed by the pseudo-first-order kinetic model,and the results showed that the experimental results were in good agreement with the pseudo-first-order kinetic model.In summary,the use of MOFs materials to treat wastewater is inexpensive,feasible,and effective.The microwave assisted ball milling method provides a new method for the preparation of MOFs.MOFs materials have wide application prospects in future research and application of wastewater treatment.