Cobalt nanoparticles/nitrogen-doped graphene with high nitrogen doping efficiency as noble metal-free electrocatalysts for oxygen reduction reaction

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• 作者：Jingwen Liang ; Mehboob Hassan ; Dongsheng Zhu ; ^{zhuds206@nenu.edu.cn} ; Liping Guo ; Xiangjie Bo ; ^{baoxj133@nenu.edu.cn}
• 关键词：High doping efficiency ; Oxygen reduction reaction ; Cobalt nanoparticles ; Nitrogen-doped graphene ; Noble metal-free electrocatalyst
• 刊名：Journal of Colloid and Interface Science
• 出版年：2017
• 出版时间：15 March 2017
• 年：2017
• 卷：490
• 期：Complete
• 页码：576-586
• 全文大小：4003 K
• 卷排序：490

文摘

Nitrogen-doped graphene (N/GR) has been considered as active metal-free electrocatalysts for oxygen reduction reaction (ORR). However, the nitrogen (N) doping efficiency is very low and only few N atoms are doped into the framework of GR. To boost the N doping efficiency, in this work, a confined pyrolysis method with high N doping efficiency is used for the preparation of cobalt nanoparticles/nitrogen-doped GR (Co/N/GR). Under the protection of SiO2, the inorganic ligand NH3 in cobalt amine complex ([Co(NH3)6]3+) is trapped in the confined space and then can be effectively doped into the framework of GR without the introduction of any carbon residues. Meanwhile, due to the redox reaction between the cobalt ions and carbon atoms of GR, Co nanoparticles are supported into the framework of N/GR. Due to prevention of GR layer aggregation with SiO2, the Co/N/GR with high dispersion provides sufficient surface area and maximum opportunity for the exposure of Co nanoparticles and active sites of N dopant. By combination of enhanced N doping efficiency, Co nanoparticles and high dispersion of GR sheets, the Co/N/GR is remarkably active, cheap and selective noble-metal free catalysts for ORR.