炭纸上原位生长CNF/CP复合体的氧气电催化反应性能

摘要

A carbon nanofiber/carbon paper (CNF/CP) composite was synthesized directly on CP by a catalytic chemical vapor-deposition method,and the physicochemical properties of and oxygen-reduction reaction (ORR) on this composite were investigated.Scanning electron microscopy shows that the CNFs are uniformly distributed on the CP,and high-resolution transmission electron microscopy results show that the CNFs have a narrow size distribution.The CNF/CP composite has a large surface area,and its mesoporous character is confirmed by N2physisorption.Raman spectrum studies show that the CNF/CP composite has a high ratio of edge atoms to basal atoms compared with that of CP.From cyclic voltammetry studies,the CNF/CP composite was found to be more active than CP in terms of ORR,which may be due to the contribution from the CNFs.The CNF/CP composite shows a higher exchange current density and more positive equilibrium potential than CP,as verified by Tafel analysis.Moreover,linear-sweep voltammetry confirms that ORR on the CNF/CP composite is conducted through a two-electron reaction pathway.%利用催化气相化学沉积(Catalytic chemical vapor deposition,CCVD)法在炭纸上原位生长得到CNF/CP复合体,并对这种复合体的物理化学性能和氧气电催化还原反应(Oxygen reduction reaction,ORR)性能进行了研究.结果表明:纳米炭纤维较为均匀地分散在炭纸上,其中纳米炭纤维具有窄的直径分布.所制CNF/CP复合体具有较大的比表面积和独特的中孔结构；相对于炭纸,CNF/CP复合体的端面碳原子和基面碳原子比例较高.另外,CNF/CP还具有较高的ORR反应活性,其ORR为2电子反应过程,原因可以归结于纳米炭纤维独特的微结构.同时,CNF/CP也具有较高的交换电流密度和较正的平衡电压.