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Cobalt Nanocrystals Encapsulated in Heteroatom‐Rich Porous Carbons Derived from Conjugated Microporous Polymers for Efficient Electrocatalytic Hydrogen Evolution
Author(s) -
Wang Haige,
Hou Bo,
Yang Yang,
Chen Qianwang,
Zhu Meifang,
Thomas Arne,
Liao Yaozu
Publication year - 2018
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201803232
Subject(s) - cobalt , materials science , heteroatom , overpotential , nanocrystal , tafel equation , conjugated microporous polymer , chemical engineering , electrocatalyst , graphene , microporous material , carbon fibers , polymer , inorganic chemistry , electrochemistry , nanotechnology , electrode , composite number , organic chemistry , chemistry , composite material , metallurgy , engineering , ring (chemistry)
Cobalt nanocrystals encapsulated in N,O‐dual‐doped porous carbons as efficient and stable electrocatalysts for hydrogen evolution reaction (HER) are reported. A heteroatom‐rich‐conjugated microporous polymer is first chemically deposited on a carbon fiber cloth, and after addition of a cobalt salt, pyrolyzed to produce a heteroatom‐doped C/Co nanocrystal composite. With this process, the use of additional binders for preparation of electrodes can be avoided. With a trace cobalt loading (0.46 wt%), the electrodes achieve a low Tafel slope of 46 mV dec −1 and overpotential of only 69 mV at a current density of 10 mA cm −2 in 0.5 m H 2 SO 4 . Experimental and computational studies reveal that the superior HER behavior is due to a decreased free energy of hydrogen adsorption, induced by i) electrons transferred from the cobalt nanocrystals to graphite layers and ii) N,O‐dual doping reduced the Fermi level of neighboring C atoms.