Synthesis Of Non-precious Metal-based Electrochemical Sensing Materials And Their Applications In Phenolic Compounds Detection

Phenolic compounds and their derivatives are widely used in industrial production,and their abnormal levels will cause serious problems to the human body.Therefore,the efficient and accurate detection of phenolic compounds is particularly important.The synergistic interaction between the metal components and the nitrogen-doped carbon(NC)support in the non-precious metal nitrogen-carbon materials(M-N-C)endows unique electronic structure and properties,along with a large specific surface area and abundant active sites,resulting in great application potential in the sensing field.In this thesis,two kinds of electrode materials for the simple and efficient detection of phenolic compounds by electrochemical sensing were prepared based on NC materials.The main research contents are as follows:A molten salt-assisted method was described to construct cobalt clusters deposited on nitrogen-doped carbon electrochemical sensing material(Co NC).This catalyst was prepared by grinding zinc acetate,cobalt acetate,2-methylimidazole,and potassium chloride,followed by high-temperature pyrolysis.The N atom in 2-methylimidazole was coordinated with Zn and Co,and the volatilization of Zn component and the removal of KCl molten salt during pyrolysis resulted in abundant defects in the catalyst,giving rise to outstanding electrocatalytic activity.The electrode material showed excellent performance in the detection of dopamine under simulated body fluid conditions.The minimum detection limit was 2.1 n M(S/N=3)and the linear detection range was 0.005-102.4 μM.In addition,it exhibited good specificity and stability.This study shed light on the construction of efficient electrochemical sensing material for the detection of dopamine.The Ni-MOF-74 precursor was synthesized by a solvothermal method.After dopamine coating,high-temperature pyrolysis,and acid treatment,Ni SA/NC was obtained.The physical and chemical properties of the catalyst were characterized by XPS,FT-IR,Raman and XAFS.Compared with the previously reported catalysts,Ni SA/NC showed excellent electrochemical activity and achieved accurate simultaneous detection of dopamine and hydroquinone.The detection limits were determined to be 1.8 n M and 1.7 n M(S/N=3),and the linear ranges were0.007-1800 μM and 0.005-74 μM,respectively.Moreover,it shows better accuracy and recovery rate in actual sample detection.This work provides insights into the design of nonprecious metal single atom sensing materials.