Modification Of Activated Carbon And Its Applications In Gas Detection And Energy Storage

This thesis introduces the preparation,characterization,properties,and application of modified active carbon functional materials.The functional groups,surface morphologies,compositions,structures and specific surface area were determind by Fourier transform infrared spectroscopy（FT-IR）,scanning electron microscope（SEM）,element analysis（EA）,X-ray diffraction（XRD）,and nitrogen adsorption-desorption.The electrochemical performance and gas sensitive performance of the modified active carbon were evaluated by cyclic voltammetry,galvanostatic charge and discharge measurement,gas sensing measurement,and the specific research contents are as follows:（1）Two nitrogen doping methods were used to prepare nitrogen-doped active carbon.Nitrogen-rich reduced wood origin active carbon（NRWAC）was prepared by heat treatment of the mixture of active carbon and urea at 800 ^oC in N₂ atmosphere.Nitrogen-doped wood origin active carbon（NWAC）was prepared by autoignition of the mixture of active carbon and aminoguanidine.The results show that the nitrogen content of the NRWAC and NWAC is 6.5%and 7.8%（XPS）.In the organic electrolyte,NRWAC800 and NWAC exhibit specific capacitances of 197 and 245 F g^-1(current density 1 A g^-1),respectively.（2）Functionalized coconut origin active carbon（CAC）with phenylazo groups were synthesized by a diazo coupling reaction,and show higher capacitance.4-carboxyphenylazo groups grafting CAC（CPACAC）,4-nitrilephenylazo groups grafting CAC（NPACAC）,4-sulfophenylazo groups grafting CAC（SPACAC）,and 4-chloro-3-sulfophenylazo groups grafting CAC（CSPACAC）exhibit higher enhancement of capacitance,which is increase of22.8%,36.8%,67.2%,and 75.0%compared with CAC.Modified active carbon exhibit photosensitive properties and higher enhancement of the capacitance under sun illumination,which are increase of 40%,56%,45%,and 46%compared with that of under dark condition.（3）Functional coconut origin active carbon containing many amino groups was used as gas-sensing material to fabricate resistance carbon dioxide sensors.At room temperature,compared with commonly used carbon dioxide sensors on the market,this sensor displays higher sensitivity（18.8%for 200 ppm CO₂）and shorter response time（181.1 s）to carbon dioxide.