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The Kirkendall Effect for Engineering Oxygen Vacancy of Hollow Co 3 O 4 Nanoparticles toward High‐Performance Portable Zinc–Air Batteries
Author(s) -
Ji Dongxiao,
Fan Li,
Tao Lu,
Sun Yingjun,
Li Menggang,
Yang Guorui,
Tran Thang Q.,
Ramakrishna Seeram,
Guo Shaojun
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201908736
Subject(s) - kirkendall effect , overpotential , materials science , catalysis , nanoparticle , microstructure , vacancy defect , oxygen , zinc , chemical engineering , nanotechnology , cobalt , metallurgy , chemistry , crystallography , electrochemistry , electrode , organic chemistry , engineering
Structure and defect control are widely accepted effective strategies to manipulate the activity and stability of catalysts. On a freestanding hierarchically porous carbon microstructure, the tuning of oxygen vacancy in the embedded hollow cobaltosic oxide (Co 3 O 4 ) nanoparticles is demonstrated through the regulation of nanoscale Kirkendall effect. Starting with the embedded cobalt nanoparticles, the concentration of oxygen‐vacancy defect can vary with the degree of Kirkendall oxidation, thus regulating the number of active sites and the catalytic performances. The optimized freestanding catalyst shows among the smallest reversible oxygen overpotential of 0.74 V for catalyzing oxygen reduction/evolution reactions in 0.1 m KOH. Moreover, the catalyst shows promise for substitution of noble metals to boost cathodic oxygen reactions in portable zinc–air batteries. This work provides a strategy to explore catalysts with controllable vacancy defects and desired nano‐/microstructures.