Preparation Of MOFs-derived Carbon-based Materials And Their Application In Electrochemical Detectio

Electrochemical methods have become a popular analytical method because of their high sensitivity,short reaction time,low detection limit,simple operation and wide linear range.With the development of society,people pay more and more attention to food safety,drug safety and environmental safety,etc.The use of electrochemical detection methods can quickly and efficiently detect water pollution,the content of heavy metals in food,the content of heavy metals in the atmosphere,etc.,and become a hot spot for analytical chemistry research work.Metal Organic Frameworks(MOFs)have unique physicochemical properties,such as large specific surface area,high porosity,ordered porous structure and exposed active sites,which make them widely used in the fields of catalysis,sensing,gas storage and separation.However,the poor electrical conductivity and stability of most MOFs materials themselves have limited their further applications in electrochemistry.The formation of carbon-based metal@C derivatives by calcination using MOFs as precursors can not only improve their poor conductivity and stability,but also inherit the advantageous features of MOFs such as porous structure and multiple active sites.Therefore,the design of carbon metal@C derivatives formed by calcination using MOFs as precursors can greatly promote the application of MOFs in electrochemistry.In this paper,three base composite modified electrodes were designed and prepared for the application of MOFs-derived carbon-based metal@C derivative composites in electrochemical detection as a starting point,and the specific research work is as follows:(1)The derivative Bi@C composites prepared by using Bi-MOF as precursor at different temperatures to enhance its electrical conductivity were characterized by using thermogravimetric analysis,X-ray powder diffraction,X-ray photoelectron spectroscopy and scanning electron microscopy to characterize the structure,elemental composition and morphology of the prepared materials.The Bi@C composite modified electrode was also constructed for the electrochemical detection of HQ,CC,nitrite and melamine.The linear ranges were 2-600 μM and 2-800 μM with the detection limits of 0.14 μM and 0.12 μM for HQ and CC,respectively,and the linear ranges were 2-600 μM and 0.49 μM and 0.13 μM for both 2-100 μM and 100-600 μM for nitrite,respectively,and the linear ranges were 2-600 μM,2-100 μM and 0.13 μM for melamine.The limits of detection were 0.32 μM and 0.084 μM for the 2-100 μM and 100-600 μM bands,respectively,and the Bi@C composites showed high selectivity,stability,reproducibility and ability to detect in real samples.(2)The derivative Cu@C composites prepared by using Cu-MOF as precursor at different temperatures were characterized by thermogravimetric analysis,X-ray powder diffraction,X-ray photoelectron spectroscopy and scanning electron microscopy to characterize the structure,elemental composition and morphology of the prepared materials.The Cu@C composite modified electrode was also constructed for the electrochemical detection of HQ,CC,nitrite and melamine.The linear ranges were 2-600 μM with the detection limits of 0.11μM and 0.18 μM for HQ and CC,2-600 μM for nitrite,and 0.43 μM and 0.16 μM for 2-100μM and 100-600 μM,respectively,and 2-600 μM for melamine with the detection limits of0.067 μM and the Cu@C composite had high selectivity,stability,reproducibility and the ability to detect in real samples.(3)The bimetallic organic framework materials composed of copper and bismuth are highly ordered with various types of pores,and the interaction of the two elements improves the catalytic activity and selectivity of the materials.The derivative Cu/Bi@C composites prepared using Cu/Bi-MOF as precursors at different temperatures to improve the catalytic performance,conductivity and chemical stability were characterized using thermogravimetric analysis,X-ray powder diffraction,X-ray photoelectron spectroscopy and scanning electron microscopy were used to characterize the structure,elemental composition and morphology of the prepared materials.The Cu/Bi@C composite modified electrode was also constructed for the electrochemical detection of HQ,CC,nitrite and melamine.The linear ranges were 2-600μM and 2-800 μM for HQ and CC with the detection limits of 0.08 μM and 0.38 μM(2-100μM)and 0.11 μM(100-800 μM),and the linear ranges were 2-600 μM and 0.04 μM for nitrite,respectively,and the linear ranges were 2-800 μM and 0.049 μM for melamine.The detection limit was 0.049 μM and the Cu/Bi@C composite had high selectivity,stability,reproducibility and the ability to detect in real samples.