The Application Of Electrochemical Sensors Based On Bimetallic Cobalt-based Metal Oxide

The quantum size effect and surface effect of nanomaterials make them widely used in physics,chemistry and electrocatalysis.Electrochemical biosensors based on nanomaterials show excellent performance,such as small volume,high speed,high detection sensitivity and better stability,which can improve the performance of the sensor to a new level.Transition metal oxide is one of the most widely studied materials.Co₃O₄ is an kind of superduper electrochemical sensing material due to its good eagle capacitance,low price,long-term stability and good corrosion resistance.However,our country is lack of cobalt resources,reserves less than 4%of the world total reserves,so doping Co₃O₄ with Fe,Ni,Al and other metals help to reduce the amount of cobalt,and can improve the electrochemical properties of electrode materials.This paper is based on the good physical and chemical properties of Co₃O₄nano-materials by doping the transition metal elements into Co₃O₄ and preparing bimetallic cobalt-based metal oxide and constructed the electrochemical sensors,and obtained the ideal result.This thesis mainly has the following parts:1.We Prepared the three-dimensional porous chestnut-like NiCo₂O₄ structure nanomaterial by a simple hydrothermal method and constructed an electrochemical sensor for hydrazine detection.Due to the three-dimensional porous chestnut nickel-cobalt oxide with high electrochemical activity in alkaline electrolyte solutions,the modified electrode has a good catalytic effect on hydrazine.The morphology of nickel-cobalt oxide was characterized by scanning electrochemical microscope?SEM?,and the electrochemical behavior of hydrazine on modified electrode was studied with cyclic voltammetry and it-current technology.They all get the satisfactory results.2.We synthesized Ni doped Co₃O₄/rGO nano-composites by one pot of hydrothermal method,The high electron conductivity of graphene compensates poor conductivity of the transition metal oxide.By optimizing the doping amount of nickel in the composite materials,and then modified the composite material to the glassy carbon electrode for electrocatalytic testing of glucose.This nanocomposite has a good effect on glucose detection.3.We prepared ERGO/GCE using one-step electrodeposition technology and the MnCo₂O₄ nanoparticles synthesized by hydrothermal method were modified on it to prepare the nitrite electrochemical sensor,which showed excellent electrocatalytic performance,and it can be used for the actual testing of nitrite in the fermented bean curd samples.