Studies Of Electrochemical Sensing Methods Based On UiO-66 Nanocomposites

Metal-organic frameworks（MOFs）have become one of the hot spots in electrochemical and biosensing research due to their extended network structure,large specific surface area,tunable coordination space,and modifiable pore size.In this thesis,Ui O-66 was used as the base material to prepare three nanocomposites,and a new method for electrochemical sensing of nitrite（NO₂^?）and Hydrazine hydrate（N₂H₄）based on the above materials was constructed.This thesis can provide a new method for electrochemical sensing research,and can also broaden the application scope of metal-organic framework materials.The thesis is divided into three chapters,and the main innovations are as follows:1.The PPy/Ui O-66 was prepared,and a PPy/Ui O-66-based electrochemical sensing method for NO₂^?was constructed.The results showed that the prepared polypyrrole were uniformly loaded on the surface of MOFs,and the particle size of PPy/Ui O-66 is about 200nm.Electrochemical studies showed that the sensitivity was 297.7μA m M^–1cm^–2and the detection limit was 0.04μM when NO₂^?was added linearly from 0.050μM to 1055.50μM.Compared with the related sensing methods in literatures,the linear range of this method is extended by one order of magnitude,and the sensitivity is increased by 2.5 times.2.The Cu Pd@Ui O-66-NH₂、Zr O₂-C-700 composites were prepared,and the N₂H₄electrochemical sensing methods based on above two composites were constructed.The research shows that the synthesized former material is a regular octahedral core-shell structure,and the small-sized Cu Pd are successfully combined with MOF.The N₂H₄sensing method constructed based on this composite material has a wide linear range of0.25μM–1390.00μM,a sensitivity of 386.7μA·m M^–1·cm^–2and a detection limit of 0.08μM;The morphology of the Zr O₂-C-700 composite is preserved,the particle size of the composite was about 80 nm,and the zirconia nanoparticles were uniformly dispersed on the porous carbon.The sensing method based on on the latter material has a linear range of0.050μM to 3055.50μM,a sensitivity of 338.3μA·m M^–1·cm^–2,and a detection limit of0.02μM.The research found that the linear range of the latter sensing method was 11times wider than the former,and the detection limit was reduced 4 times;the sensitivity of the former sensing method is 1.1 times higher than that of the latter sensing method.