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Metallic Cobalt Nanoparticles Encapsulated in Nitrogen‐Enriched Graphene Shells: Its Bifunctional Electrocatalysis and Application in Zinc–Air Batteries
Author(s) -
Zeng Min,
Liu Yiling,
Zhao Feipeng,
Nie Kaiqi,
Han Na,
Wang Xinxia,
Huang Wenjing,
Song Xuening,
Zhong Jun,
Li Yanguang
Publication year - 2016
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201600636
Subject(s) - materials science , electrocatalyst , bifunctional , graphene , cobalt , prussian blue , catalysis , nanoparticle , chemical engineering , zinc , inorganic chemistry , metal , oxygen evolution , electrolyte , nanotechnology , electrode , electrochemistry , metallurgy , organic chemistry , chemistry , engineering
There has been a continuous call for active, durable, and low‐cost electrocatalysts for a range of energy applications. Among many different nonprecious metal based candidates, transition metal nanoparticles encapsulated in graphene layers have gained increasing attention over recent years. In this study, it is demonstrated that metallic cobalt nanoparticles sheathed by multilayered nitrogen‐enriched graphene shells can be facilely prepared using cobalt‐containing Prussian blue colloids as the single precursor. These metallic cobalt cores can be readily leached out by HCl treatment, resulting in hollow graphene spheres. Products with or without acid leaching exhibit great bifunctional activities for electrocatalytic oxygen reduction and hydrogen evolution in both alkaline and acidic electrolytes. Most importantly, it is found that the removal of the metallic cores does not deteriorate but rather enhances the electrocatalytic performance. Based on this and other experimental observations, Co‐N‐C moieties are proposed as the catalytically active sites. At last, it is shown that these catalysts can be employed as the air catalyst of primary zinc–air batteries with excellent current density, power density, and operation durability.