节点文献
氮掺杂微纳米碳材料的制备表征及性能研究
Synthesis, Characterization and Applications of Nitrogen-doped Micro/Nano-sized Carbon Materials
【作者】 范彦如;
【导师】 赵宗彬;
【作者基本信息】 大连理工大学 , 化学工程与技术, 2012, 硕士
【摘要】 微纳米碳材料如碳纳米管、碳微米管等由于其自身独特的结构而具有不同于块体材料优异的电学和化学等性能,从而在能量存储、场发射等方面具有潜在的应用前景。理论和实验研究均表明氮掺杂可改变碳材料的晶体结构和电子结构从而提高其电化学性能和催化性能。目前,如何低成本、大规模制备氮掺杂的微纳米碳材料并对其结构和性能实现精确调控仍然面临着巨大的挑战。本论文以三聚氰胺为氮源和碳源,无水三氯化铁为催化剂前驱体,浮游催化气相沉积法制备了形貌新颖的氮掺杂碳微米管及氮掺杂铁填充双功能化的碳纳米管,并采用高温热解法成功制备得到了石墨相氮化碳(C3N4)材料以及氮化碳/石墨烯(C3N4/Graphene)复合材料。同时,本论文对上述制备的氮掺杂微纳米碳材料进行了详细的分析表征,并进行了磁性能、场发射性能、电磁波吸收和电化学性能方面的应用研究,主要研究内容及结果如下:1.氮掺杂碳微米管的合成。采用浮游催化法,以三聚氰胺为碳源和氮源,无水三氯化铁为催化剂前驱体,在氢气条件下制备了形貌新颖、管壁为网状结构的氮掺杂碳微米管,氮掺杂碳微米管的外径为0.5-1μm。考察了实验操作参数对产物形貌和氮掺杂量的影响。电化学性能研究发现,氮掺杂碳微米管是超级电容器理想的电极材料。2.氮掺杂铁填充碳纳米管的原位合成。采用浮游催化法,以三聚氰胺为碳源和氮源,无水三氯化铁为催化剂前驱体,在惰性气氛下制备了氮掺杂、铁填充双功能化的碳纳米管。考察了反应温度对产物形貌和氮掺杂量、铁填充率的影响。TEM表征显示所得碳纳米管的外径在250nm左右,氮的引入使纳米管的管壁具有较多褶皱。性能测试研究表明产物具有优异的磁性能、场发射和电磁波吸收性能。此外,产物经过惰性气氛下的高温退火处理可使Fe3C转化为a-Fe,空气氧化处理可实现Fe填充物向管壁的迁移扩散。3.石墨相氮化碳/石墨烯复合材料的制备。采用高温热解法,在高压釜中以三聚氰胺为原料制备了石墨相氮化碳材料。将三聚氰胺和氧化石墨不同比例混合后采用高温热解法制备了氮化碳/石墨烯的复合材料。电化学测试研究表明所得复合材料在超级电容器方面有潜在应用。
【Abstract】 Carbon based micro/nano-sized materials, including carbon nanotubes (CNTs), carbon microtubes (CMTs), have potential applications in various fields, such as energy storage and field emission display due to their unique chemical and electrical properties. Theoretical and experimental results demonstrate that doping carbon with nitrogen can tailor the crystal and electronic structure of carbon materials. However, the synthesis of nitrogen doped micro/nano carbon materials in large-scale is still a challenge.In the present work, we prepared nitrogen doped carbon nanotubes (N-CNTs) filled with iron, nitrogen doped carbon microtubes (N-CMTs) and carbon nitrides via floating catalyst chemical vapor deposition (CVD) and pyrolysis method. Finally, the applications of these as-prepared nitrogen doped micro/nano carbon materials have been investigated. The major results are briefly summarized as follows.N-CMTs with net-like structures have been synthesized using anhydrous ferric chloride as a catalyst precursor and melamine as both carbon and nitrogen sources by means of a floating catalyst CVD method. The N-CMTs from our floating catalyst method have a diameter of0.5-1urn, and the products exhibit stable performance as supercapacitor materials.N-CNTs filled with iron have been synthesized using anhydrous ferric chloride as a catalyst precursor and melamine as both carbon and nitrogen sources by means of a floating catalyst CVD method. It is noteworthy that the N-CNTs with an outer diameter of250nm exhibit an irregular and corrugated morphology due to the nitrogen incorporation. The products exhibit potential applications in magnetic data storage devices, field emission display and electromagnetic wave adsorption. Finally, annealing treatment and air oxidation were applied on the products respectively in order to investigate the conversion of iron in the N-CNTs.Graphitic carbon nitrides/graphene composites have been successfully synthesized via a high pressure and high temperature pyrolysis route using melamine and graphite oxide as starting materials. The composites exhibit potential application in supercapacitors.
【Key words】 Nitrogen-doped; Carbon Nanotubes; Carbon Microtubes; Floating CatalystChemical Vapor Depositon; Carbon Nitrides;