离子液体具有绿色环保、不易挥发、加工性强、稳定性高以及结构设计性强等特点,最近几年在合成碳纳米材料中的应用引起了人们的广泛关注。虽然对离子液体的成碳机理,尤其是成碳时介孔的形成机理尚没有完整的认识,但由其制备的碳纳米材料已初步应用于燃料电池、锂离子电池及电化学电容器等领域。本文介绍了离子液体作为新型前驱体制备含氮碳纳米材料的优势、结构要求及影响含氮量的主要因素,论述了离子液体在制备含氮碳纳米材料(包括介孔碳、碳纳米纤维和辅助碳纳米材料)中的最新研究进展,尤其是利用离子液体可实现含氮介孔碳材料的无模板法合成,并从前驱体的交联、碳化、阴/阳离子组成和孔的缺陷等方面讨论了影响介孔结构形成的因素。
As novel precursors in fabrication of carbon nanomaterials, ionic liquids have attracted much attention due to their remarkable properties, such as low toxicity, nonvolatility, processing flexibility, high stability and flexible designability. Even though the mechanism of carbonization, especially the formation of mesopores is not clear, ionic liquid-based carbon nanomaterials have been successfully applied in different fields, such as fuel cells, lithium ion batteries and supercapacitors. In this paper the advantages and structure requirements of ionic liquids as nitrogen-containing carbon precursors and the main factors about nitrogen content have been elaborated. The recent progress of ionic liquids in synthesizing nitrogen-containing carbon nanomaterials (including mesoporous carbon, carbon nanofibers and auxiliary carbon nanomaterials) has been presented. Furthermore template-free synthesis of nitrogen-containing mesoporous carbon by employing ionic liquids as precursors has been particularly introduced. The influence factors of the formation of mesopores, such as the cross linking, carbonization conditions, composition of precursors and pore defects, have been systematically discussed.