Co-Induced Electronic Optimization of Hierarchical NiFe LDH for Oxygen Evolution
Co-Induced Electronic Optimization of Hierarchical NiFe LDH for Oxygen Evolution
复制标题
多级 NiFe LDH 析氧的共诱导电子优化
DOI：
10.1002/smll.202002426
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发表时间：
2020-08-20
期刊：
影响因子：
13.3
通讯作者：
Gao, Lijun
中科院分区：
文献类型：
--
作者：
Lin, Yanping;Wang, Hao;Gao, Lijun
开发高效、稳定的非贵金属析氧电催化剂在实际应用中仍然具有挑战性。虽然NiFe-LDH（NiFe-LDH）是一种具有良好OER活性的新型催化剂，但其活性中心有限、导电性差、耐久性差等缺点限制了其催化性能。本文中，通过溶剂热处理ZIF-67/CF来合成分级镍-铁-钴LDH纳米片/碳纤维（NiFeCo-LDH/CF）。扩展的X射线吸收精细结构分析表明，Co的取代稳定了NiFeCo-LDH/CF中Fe的局域配位环境，促进了π对称成键轨道的形成，从而改变了电子结构.结合结构上的优势，包括大量暴露的活性表面位点和由CF确保的促进的电荷转移途径，所得NiFeCo-LDH/CF表现出优异的OER活性，在10 mA cm（-1）下的过电位为249 mV，并且稳定性超过20 h。
Developing efficient and stable non-noble electrocatalysts for the oxygen evolution reaction (OER) remains challenging for practical applications. While nickel-iron layered double hydroxides (NiFe-LDH) are emerging as prominent candidates with promising OER activity, their catalytic performance is still restricted by the limited active sites, poor conductivity and durability. Herein, hierarchical nickel-iron-cobalt LDH nanosheets/carbon fibers (NiFeCo-LDH/CF) are synthesized through solvent-thermal treatment of ZIF-67/CF. Extended X-ray adsorption fine structure analyses reveal that the Co substitution can stabilize the Fe local coordination environment and facilitate the pi-symmetry bonding orbital in NiFeCo-LDH/CF, thus modifying the electronic structures. Coupling with the structural advantages, including the largely exposed active surface sites and facilitated charge transfer pathway ensured by CF, the resultant NiFeCo-LDH/CF exhibits excellent OER activity with an overpotential of 249 mV at 10 mA cm(-1)as well as robust stability over 20 h.