Preparation method of nanometer graphene/chitosan composite membrane modified electrode for electrochemical sensor

Abstract

The invention discloses a preparation method of a nanometer graphene/chitosan composite membrane modified electrode for an electrochemical sensor. According to the method, potassium permanganate and concentrated sulfuric acid are used for oxidizing intercalation natural flake graphite; oxygen-containing groups such as hydroxy, epoxy groups and carboxyl are introduced between graphite layers; the gap of the graphite layers is increased; then, under the effect of a microwave field, the oxygen-containing groups inside the graphite are subjected to thermal decomposition to generate gas such as CO, CO2 and H2O; a graphite sheet layer fast expands due to the generation of impact force; the graphite sheet layer is supported open; the gap of the graphite layers is further increased; the Van der Waals force between the layers is weakened; the laminating and agglomeration problems of graphene oxide are effectively retarded; the developed hole system structure is realized; the specific surface area of the graphene is increased; the adsorption performance on substances such as heavy metal is improved, so that the current carrier migration speed is accelerated; the detection response time is shortened.

Description

technical field [0001] The invention relates to the field of electrochemical sensors, in particular to a method for preparing electrodes modified by nano-graphene / chitosan composite films for electrochemical sensors. Background technique [0002] At present, with the rapid development of industry and the continuous improvement of people's living standards, the degree of environmental pollution is also increasing, which seriously threatens the survival of human beings, animals and plants, and seriously restricts the sustainable development of economy and society. Therefore, sensitive detection of pollutants is very important. Electrochemical analysis methods have the advantages of simple operation, cheap price, sensitivity, rapidity, environmental protection and easy miniaturization, etc., and have been widely used in water quality monitoring, drug analysis and environmental monitoring. [0003] Graphene was first discovered in 2004. Because of its many excellent and unique...

AI Technical Summary

Problems solved by technology

However, the actual prepared graphene specific surface area is generally 600m 2 / g, the main reason is that the graphene sheets are easy to agglomerate with each other, resulting in a significant decrease in the specific surface area of ​​graphene

Therefore, the actual performance of graphene-modified electrodes prepared by conventional methods is much lower than the theoretical ones.