Construction And Application Of Hydrogen Peroxide Electrochemical Sensor Based On Carbon-based Composite Nanomaterial

Hydrogen peroxide（H₂O₂）,as a reactive oxygen species（ROS）,is widely used in chemical,environmental,medical,food and other fields.High concentrations of H₂O₂ are corrosive,which make contact with human skin,respiratory passage,and tunica mucosa,and may cause chronic diseases.In living organisms,abnormal concentrations in the body can cause cardiovascular disease,diabetes and other diseases.Therefore,the rapid and effective detection of H₂O₂ in the environment and living products is of great significance to humans.The existing H₂O₂ detection methods include titration analysis,chemiluminescence,chromatography,and electrochemistry.Among them,the electrochemical method of modifying different electrode materials shows the advantages of fast detection speed,high sensitivity,and low detection limit.Carbon-based nanomaterials have high electrical conductivity,and by exploring the combination with different materials,the electrocatalytic activity,stability and susceptibility of composite nanomaterials can be improved.In this paper,two kinds of H₂O₂ electrochemical sensors are constructed based on carbon-based nanomaterials.The specific research content is as follows:（1）The nitrogen doped carbon-loaded copper（N-C@Cu）composite nanomaterial was synthesized,and the copper nano-particles were loaded on the nitrogen doped carbon nanomaterial by post-solvothermal method,and the N-C@Cu/Nafion/GCE electrochemical sensor was prepared.The surface microstructure,element distribution and composition valence state of N-C@Cu were studied by characterization methods such as transmission electron microscopy,X-ray photoelectronic spectroscopy,and X-ray diffraction.The results showed that the copper,nitrogen,and carbon elements were evenly distributed on the synthetic nanosheets.Among them,the nitrogen content of pyridine was the highest in the form of nitrogen,which improved the catalytic activity.The electrochemical characterization of differential pulse voltammetry（DPV）,linear sweep voltammetry（LSV）and constant potential I-t curve（I-t）was used to study the electrochemical properties of N-C@Cu/Nafion/GCE to detect H₂O₂.The results showed that N-C@Cu/Nafion/GCE has good stability and repeatability,has good electrocatalytic activity for H₂O₂ in the range of 4～1400μM,and the detection limit is 2.98μM（S/N=3）.The prepared N-C@Cu/Nafion/GCE sensor has strong anti-interference properties and can be used in the determination of H₂O₂ content in environmental water bodies,whitening toothpastes and makeup remover,with a recovery rate of 95.39%～104.6%.N-C@Cu composite nanomaterials show the potential for electrochemical detection of actual samples.（2）The room temperature solvent method is used to synthesize covalent organic framework（COF）materials,and amino multi-walled carbon nanotubes（NH2-CNTs）are introduced to improve electrical conductivity to prepare COF@NH2-CNTs carbon-based composite nanomaterials.The binding of COF@NH2-CNTs was studied by scanning electron microscopy,Fourier transform infrared spectroscopy,Raman spectroscopy and other material characterization methods,and it was found that COF is evenly coated in NH2-CNTs.Electrochemical characterization through differential pulse voltammetry（DPV）,cyclic voltammetry（CV）and electrochemical impedance spectroscopy（EIS）,it is proved that the addition of NH2-CNTs improves the conductivity of the composite material.Under the best detection conditions,COF@NH2-CNTs/GCE has a fast and sensitive detection response to H2O2 in the range of 20 140 μM,with a detection limit of 0.14 μM.The COF@NH2-CNTs sensor has good repeatability and strong anti-interference.It is used in the determination of H2O2 in environmental water bodies and chicken claws,with a recovery rate of 97.09 % 107.98 %.The preparation method has the advantages of simplicity,low cost,green and environmental protection.