Liu Teng, Yang Fulin, Cheng Gongzhen, Luo Wei
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei, 430072, P. R. China.
Small. 2018 Mar;14(10). doi: 10.1002/smll.201703748. Epub 2018 Jan 10.
Searching for highly efficient bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) using nonnoble metal-based catalysts is essential for the development of many energy conversion systems, including rechargeable fuel cells and metal-air batteries. Here, Co Fe S /Co,Fe-N-C hybrids wrapped by reduced graphene oxide (rGO) (abbreviated as S-Co Fe S @rGO) are synthesized through a semivulcanization and calcination method using graphene oxide (GO) wrapped bimetallic zeolite imidazolate framework (ZIF) Co,Fe-ZIF (CoFe-ZIF@GO) as precursors. Benefiting from the synergistic effect of OER active CoFeS and ORR active Co,Fe-N-C in a single component, as well as high dispersity and enhanced conductivity derived from rGO coating and Fe-doping, the obtained S-Co Fe S @rGO-10 catalyst shows an ultrasmall overpotential of ≈0.29 V at 10 mA cm in OER and a half-wave potential of 0.84 V in ORR, combining a superior oxygen electrode activity of ≈0.68 V in 0.1 m KOH.
使用非贵金属基催化剂寻找用于氧还原反应（ORR）和析氧反应（OER）的高效双功能电催化剂对于包括可充电燃料电池和金属空气电池在内的许多能量转换系统的发展至关重要。在此，通过使用氧化石墨烯（GO）包裹的双金属沸石咪唑框架（ZIF）Co,Fe-ZIF（CoFe-ZIF@GO）作为前驱体，采用半硫化和煅烧方法合成了由还原氧化石墨烯（rGO）包裹的Co Fe S /Co,Fe-N-C杂化物（简称为S-Co Fe S @rGO）。得益于OER活性CoFeS和ORR活性Co,Fe-N-C在单一成分中的协同效应，以及rGO涂层和Fe掺杂带来的高分散性和增强的导电性，所制备的S-Co Fe S @rGO-10催化剂在OER中10 mA cm时显示出约0.29 V的超小过电位，在ORR中半波电位为0.84 V，在0.1 m KOH中具有约0.68 V的优异氧电极活性。
