Preparation,Characterization And Electrochemical Analysis Of Co And Fe-MOF Materials

As a series of hot-topic research nanomaterials,Metal-organic framework(MOF)materials own wide application fields and exhibit great application potentials.MOFs are widely used in energy storage,biomedicine,gas separation,electrochemical catalysis and other fields due to their advantages of large specific surface area,high porosity and good stability.Electrochemical sensor is an electrical analysis method with short detection time and simple detection method.It is mainly to prepare the synthetic material into modified electrode,and to measure the measured material.Selectivity,sensitivity and linear range are the important indexes of the sensor,and are the standards to evaluate the merits and demerits of the sensor.In this thesis,two kinds of MOF based nanomaterials were prepared by using solvothermal and chemosynthetic routes,and were utilizated to constructe the electrochemical sensor for the detection of dopamine,uric acid and nitrite,which are important substances for human health.The experimental contents are as follows:(1)Preparation of Fe-MOF and its electrochemical detection of dopamine and uric acid:In this chapter,Fe-MOF was synthesized via solvothermal method and dispersed into water to form stable suspension.The suspension was then dropped on the surface of the electrode to construct an electrochemical sensor.The SEM and TEM characterization confirm that the morphology of Fe-MOF is hexagonal bicone structure the cyclic voltammetry curves and differential pulse voltammetry technologies were employed for the electrochemical detection of dopamine and uric acid.The results showed that Fe-MOF modified electrode could detect both dopamine and uric acid in the linear range of 0.01 ?0.09 m M,and the limits of detection(S/N=3)were 3.34 ?M and 3.41 ?M,respectively.the sensor also exhibit excellent stability(2)Preparation of CoFe-MOF /CNTs composites and detection of nitrite:In this chapter,CoFe-MOF/CNTs composite materials were prepared via chemosynthesis method and characterized with SEM and TEM.The crystal structure of CoFe-MOF/CNTs and carbon nanotubes were characterized with XRD.By analyzing a series of cyclic voltammetry curves,the optimum conditions for nitrite detection of the composite material were obtained.The results show that the electrocatalytic performance of CoFe-MOF/CNTs modified electrode for nitrite detection is significantly better than that of other modified electrodes,and the detection linear range is up to 0.005 m M ? 2 m M with the detection limit of 1.68 ?M(S/N=3).What's more,the electrochemical sensor shows good stability and selectivity.When applicated for the real sample detection in the local river and tap water,it exhibits good recovery rate.