磁性Fe,N共掺杂分级多孔石墨化碳气凝胶的制备及其电化学、吸附性能  

Praperation of magnetic Fe,N co-doped nano-sized graphitized carbon aerogel with hierarchical porous structure and its electrochemical and adsorption performance

作　　者：曹启花[1,2] 谷雨星 刘雅茜 肖玲[1] 汪的华[1] Qihua Cao;Yuxing Gu;Yaxi Liu;Ling Xiao;Dihua Wang(School of Resource and Environmental Sciences,Wuhan University,Wuhan 430072,China;Wuhan University Scientific Journals Press,Wuhan 430072,China)

机构地区：[1]武汉大学资源与环境科学学院,武汉430072 [2]武汉大学科技期刊中心,武汉430072

出　　处：《科学通报》2021年第32期4129-4143,共15页Chinese Science Bulletin

基　　金：国家自然科学基金(21673162)资助。

摘　　要：以天然含氮聚多糖壳聚糖作为碳源和氮源,Fe Cl_(3)作为铁源,经溶胶-凝胶、高温碳化和KOH高温活化3个步骤,得到一种Fe,N共掺杂的分级多孔石墨化纳米碳材料(Fe NC气凝胶).该系列样品均具有大的比表面积(最高达3103 m^(2)/g)、较低的密度(约27 mg/cm^(3))和良好的磁响应能力,氮掺杂量接近4%,Fe以纳米Fe@Fe_(3)O_(4)和Fe-N形式掺杂.电催化氧还原(ORR)性能测试表明,Fe NC气凝胶样品均表现出良好的ORR活性,且随着铁掺入量的增加而增强;电容性能测试表明,Fe NC气凝胶均表现出良好的双电层电容性能和循环使用稳定性,且随着铁掺入量的增加而减弱.吸附性能测试表明,Fe NC(1-20)-K800样品对阴离子染料甲基橙、中性染料罗丹明B、阳离子染料结晶紫和孔雀石绿的饱和吸附量均在400 mg/g以上;其中,对孔雀石绿表现出特异性吸附,饱和吸附量达816 mg/g,且能通过外加磁场很好地分离回收.Nano-sized carbon materials have received intensive preoccupation owing to their extraordinary properties such as high specific surface area,abundant porous structure,and excellent electronic properties.Doping non-metallic element N can effectively modulate the electronic properties of graphene,and doping metallic element Fe can further improve their catalytic activity.To date,applications of Fe-N/C materials are mostly concentrated in supercapacitors,electrochemical double layer electrode materials or adsorption.In this communication,we present a novel route for fabricating Fe,N co-doped nano-sized graphitized carbon materials (Fe NC aerogels) by a chelate-carbonization-activation process using chitosan-Fe^(3+)chelate and KOH as precursor and activator respectively.Chitosan-Fe^(3+)chelate aerogel was first formed via sol-gel process,and Fe^(3+)was chelated by chitosan and evenly distributed in 3D networks of aerogel.Then in a nitrogen atmosphere,Chitosan-Fe^(3+)chelate aerogel was pyrolyzed at elevated temperature,and Fe^(3+)was reduced to Fe nanoparticles under the control of chitosan molecular in this carbonization process.At the last stage of KOH activation process,most of the amorphous carbon was etched,and abundant nanoscale pores appeared.Upon mild heating at 70°C in air,core@shell Fe@Fe_(3)O_(4)nanoparticles were formed due to the reaction of Fe nanoparticles inside the Fe-N/C aerogels with oxygen in air.The morphology,structure,and properties of the obtained Fe NC aerogels were characterized using field emission scanning electron microscope (FESEM),high-resolution transmission electron microscope (HRTEM),element mapping,Raman spectra,X-ray diffraction analysis (XRD),X-ray photoelectron spectroscopy (XPS),and vibrating-samplemagnetometer (VSM).Fe NC aerogels were confirmed to be Fe,N-contained carbon aerogels with 3D hierarchical porous scaffold including macropores,micropores and mesopores,displayed low density and good magnetic response.The asprepared Fe NC(1-100)-K800 showed extremely large specific s

关 键 词：纳米碳气凝胶 铁氮共掺杂 分级多孔结构 氧还原反应 超级电容器 吸附 

分 类 号：TQ427.26[化学工程]