Synergistic Sensing Property Of Nitrogen-Doped Porous Carbon/Magnetic Aerogel For Hydrogen Peroxide

With the rapid progress of science and technology,the development of highly efficient and sensitive hydrogen peroxide（H2O2）electrochemical sensors has become an important research topic.Among the many electrode modified materials,carbon nanocomposites are considered to be one of the most promising electrode materials for the preparation of electrochemical sensors due to their high specific surface area,good electrical conductivity,and low cost.After doping with nitrogen atoms,the pyridine-N configuration,which is bonded to two C atoms in the carbon materials,is proved to have better electrochemical activity.In addition,magnetic nanomaterials have also become a significant choice for electrode modified materials in electrochemical sensors on account of their unique properties.In this paper,A magnetic aerogel（MA）which encapsulates γ-Fe2O3 particles was prepared to construct a H2O2 electrochemical sensor and the properties of catalytic reduction were studied.A carbon nano-hybrid stabilizer was prepared,which and Span 80 were used as a dualstabilizer system to synthesize a porous carbon material（PCM）by concentrated emulsion templating method,and the PCM was pre-oxidized to obtain nitrogen-doped porous carbon（NPC）.The NPC was combined with MA to form a new type of H2O2 electrochemical sensor.The electrochemical sensing properties of this sensor were studied and the synergetic catalytic mechanism of the two materials was explored.The highest content of pyridine-N in NPC after pre-oxidation is 12.66%.MA has electrochemical catalytic reduced activity for H2O2 and the catalytic current has a good linear relationship with H2O2 between 80μM and 3649μM.The highest sensitivity is 1.71μA·mM-1 and the lowest detection limit is 91.93μM（S/N=3）.At the same time,the sensor also shows good selectivity and repeatability.NPC and MA,as electrode modified materials simultaneously,were drip-coated on the surface of glassy carbon electrode（GCE）to establish an electrochemical sensor based on NPC/MA composite material to sensitively detect H2O2.The results showed that NPC/MA has good electrical conductivity and electrochemical catalytic reduced activity.The constructed electrochemical sensor shows a good linear relationship with the catalytic current in the range of 60μM-1520μM and 1680μM-3335μM.The highest sensitivity is 5.56μA·mM-1 and the lowest detection limit is 4.478μM（S/N=3）.And It has great selectivity and repeatability as well.The recovery range of H2O2 was between 96.61%and 101.65%in the samples of orange juice.NPC/MA/GCE possessed better electrochemical performances than MA/GCE,which is mainly attributed to the synergistic sensing property of MA and NPC for H2O2.