Hefei National Laboratory for Physical Science at the Microscale, iChEM(Collaborative Innovation Center of Chemistry for Energy Materials), Hefei Science Center (CAS) and CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science & Technology of China, Hefei, Anhui 230026 (P.R. China).
Angew Chem Int Ed Engl. 2015 Dec 1;54(49):14710-4. doi: 10.1002/anie.201506480. Epub 2015 Oct 6.
Designing highly efficient electrocatalysts for oxygen evolution reaction (OER) plays a key role in the development of various renewable energy storage and conversion devices. In this work, we developed metallic Co4N porous nanowire arrays directly grown on flexible substrates as highly active OER electrocatalysts for the first time. Benefiting from the collaborative advantages of metallic character, 1D porous nanowire arrays, and unique 3D electrode configuration, surface oxidation activated Co4N porous nanowire arrays/carbon cloth achieved an extremely small overpotential of 257 mV at a current density of 10 mA cm(-2), and a low Tafel slope of 44 mV dec(-1) in an alkaline medium, which is the best OER performance among reported Co-based electrocatalysts to date. Moreover, in-depth mechanistic investigations demonstrate the active phases are the metallic Co4N core inside with a thin cobalt oxides/hydroxides shell during the OER process. Our finding introduces a new concept to explore the design of high-efficiency OER electrocatalysts.
设计高效的析氧反应 (OER) 电催化剂对于开发各种可再生能源存储和转换设备起着关键作用。在这项工作中，我们首次开发了直接生长在柔性基底上的金属 Co4N 多孔纳米线阵列作为高活性 OER 电催化剂。得益于金属特性、1D 多孔纳米线阵列和独特的 3D 电极结构的协同优势，表面氧化激活的 Co4N 多孔纳米线阵列/碳纤维布在碱性介质中实现了极小的过电位 257 mV，在 10 mA cm(-2) 的电流密度下具有低的 Tafel 斜率 44 mV dec(-1)，这是迄今为止报道的基于 Co 的电催化剂中最好的 OER 性能。此外，深入的机理研究表明，在 OER 过程中，活性相是内部的金属 Co4N 核，表面有一层薄的钴氧化物/氢氧化物壳。我们的发现为探索高效 OER 电催化剂的设计引入了一个新概念。
