导电聚合物衍生掺杂碳微米管的可控制备及其电催化性能研究

Carbon Microtubes: the novel carbon materials with micro-level diameter and nano-level thickness of the tube wall, possess the unique properties in both nanotubes and graphene. However, there are few researches about carbon Microtubes have been reported since they are hard to be prepared. To obtain high electro-catalytic activity, the tubes' mechanical performances, electronic behaviors and physical/chemical properties should be varied via doping and/or diameter changes. For this project, we would like to prepared uniform doped carbon Microtubes derived from conducting polymers. The synthesis method, the effect of synthesis conditions on composition, diameter and microstructure, the growth mechanisms would be studied to reach controlled preparation of doped carbon Microtubes. The catalytic activity for oxygen reduction reaction will be tested, and then the structure-activity relationship of doped carbon Microtube will be investigated through combining the test results and several characterizations, moreover, optimizing the methods and conditions of preparing these carbon based catalysts will be performed. Fundamental and experimental achievement about the synthesis and application of these novel carbon materials can be shared with this project conducting successful.

碳微米管拥有微米级的管径和纳米级的管壁厚度，兼具碳纳米管和石墨烯的优良特性；但因缺少成熟的制备方法，国内外对碳微米管的研究寥寥无几。将杂原子掺入碳微米管，或对其内外径尺寸进行调控，能改变碳微米管的力学性能、导电性能和物理化学性能，以此获得电催化活性良好的掺杂碳微米管电催化剂。本项目拟从导电聚合物出发制备掺杂碳微米管，系统地研究控制碳化法制备高纯、均匀的掺杂碳微米管的可行方法；探讨各制备条件对碳管组成、内外管径及微结构的影响规律，探究碳管生长机理，实现可控制备；以氧还原催化活性为导向，评价所制备的掺杂碳微米管的电催化活性，结合各种表征，揭示这类掺杂碳基催化剂的结构-效能关系，优化催化剂制备方法与条件；为该类新型碳材料在制备、应用上提供理论和实验指导。

近十几年来，大量的掺杂碳管被制备出来，并在电催化领域做子大量应用。但是，对管径的调控始终缺乏有效的办法。也正因为管径的不可调控性，所以对于管径处于 100-1000nm 之间的亚微米级碳管，至今都没有形成成熟的制备方法，而对这类新型碳材料的性质、应用等方面的研究，自然也没有深入、系统地开展。本项目以导电聚合物、简单有机物、过渡金属盐为原料，制备了掺氮碳管，并且通过调节三种前驱物比例，达到了从纳米级到亚微米级对管径进行调控。采用循环伏安技术考察了所制备的掺氮碳管对于氧的电化学还原反应的催化活性。并采用锌-空气电池技术，考察在电池条件下掺氮碳管作为阴极膜电极的活性及稳定性。研究发现，管径在500-1000 nm的亚微米级掺氮碳管作为电催化剂的活性较差。此外，还制备了掺氮碳纳米管桥接三维网状碳构成的复材料，该材料在锌-空气电池中的开路电压和200 mA cm-2电流密度下的功率密度分别为1.46 V和22 mW cm-2，优于Pt/C催化剂，其作为金属-空气电池的阴极催化剂有可期待的应用前景。