Construction Of Ti-MOFs And Photocatalytic Degradation Of MB

Metal–organic frameworks（MOFs）have showed a widely application prospects in the fields of gas storage and separation,molecular separation and catalysis,owing to their porous,large specific surface area,structural modification and polymetallic sites.In recent years,as a photocatalytic material,MOFs have attracted extensive attention in the degradation of organic pollutants,hydrogen production by photolysis,and reduction of CO₂.Specifically,titanium-based MOFs exhibit better catalytic activity in photocatalytic oxidation.In this article,a series of ferrocene-based ligands were designed and synthesized.The bivalent of Ti-MOFs materials were prepared by conditional controled and the products were analyzed by series of characterization and the mechanism of the reaction.Also studied the performance of Ti-MOFs used as photocatalysts to degrade organic pollution.The properties of the material were investigated for the effects of temperature,concentration,catalyst and its amount on the photocatalys effect.The more details are as follows:（1）Designed and synthesized a series of ferrocene-based carboxylic acids and diketone ligands:QUT-1,QUT-2,QUT-3,QUT-4,TCPP,and their structures were analyzed by ¹H NMR and other analytical methods.Characterization was carried out to confirm the accuracy of its structure.（2）The preparation of divalent Ti-MOF was carried out,which was synthetised by using solvothermal method and stirring synthesis method with TBOT or HC-TPT as titanium source,and the ligands that used were synthesized ferrocene-based.Studied the effect of temperature,solvent,reaction time,substrate and dosage on the product,and the reaction mechanism also was studied.The optimal conditions for the synthesis of divalent titanium MOF were explored:the solvothermal method,the optimum reactant molar ratio was 2:1,solvent was DMF,temperature on 120℃,time was 40 h.The Ti-MOF synthetised was knowed by powder X-ray diffraction（XRD）,scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS,PHI Quantera SXM）and other analytical methods.It was also verified that the titanium in the synthesized crystal MOF was positive divalent.At the same time,Zr-MOFs and Hf-MOFs were synthesized by solvothermal synthesis method,and compared with the photocatalytic performance of divalent Ti-MOF.The synthesized MOFs are named as QUT-5,QUT-6,QUT-18,and QUT-20.（3）In the application study of divalent Ti-MOFs,the experiments of photocatalytic degradation of MB and MO were carried out by using as photocatalysts QUT-5,QUT-6,QUT-18,QUT-20 and the traditional semiconductor material TiO₂.The effects of initial concentration of wastewater,catalyst dosage,illumination time and light source on the performance of the catalyst were investigated systematically.The effects of catalyst structure and composition on photocatalytic experiments were also explored.