Seamlessly Conductive 3D Nanoarchitecture of Core-Shell Ni-Co Nanowire Network for Highly Efficient Oxygen Evolution
Seamlessly Conductive 3D Nanoarchitecture of Core-Shell Ni-Co Nanowire Network for Highly Efficient Oxygen Evolution
复制标题
DOI：
10.1002/aenm.201601492
复制
发表时间：
2017-01-01
影响因子：
27.8
通讯作者：
Oh, Il-Kwon
中科院分区：
文献类型：
--
作者：
Bae, Seok-Hu;Kim, Ji-Eun;Oh, Il-Kwon
水的电化学裂解是一种有吸引力的生产氢燃料作为清洁和可再生能源的方法。然而，一个主要的挑战是加速阳极半电池反应的缓慢动力学，其中发生析氧反应（OER）。在这里，无缝导电的3D架构报告与碳壳镍钴纳米线网络作为一个高效的OER电催化剂。首先采用低成本的水热法在碳纤维编织物上生长出高度多孔和颗粒状的Ni-Co纳米线，然后通过葡萄糖碳化和退火工艺在Ni-Co纳米线上包覆导电碳壳。引入围绕纳米线的导电碳层以提供用于在整个集成的3D催化剂中进行简易电子传输的连续路径。这种3D分级结构提供了几种协同效应和有益功能，包括大量活性位点、水的易接近性、快速电子传输、氧气的快速释放、增强的电化学耐久性和更强的结构完整性，导致显著的OER活性，其在10 mA cm（-）的电流密度下提供302 mV的过电位和43.6 mV dec（-1）的Tafel斜率。2）在碱性介质电解质（1 M KOH）中。
Electrochemical splitting of water is an attractive way to produce hydrogen fuel as a clean and renewable energy source. However, a major challenge is to accelerate the sluggish kinetics of the anodic half-cell reaction where oxygen evolution reaction (OER) takes place. Here, a seamlessly conductive 3D architecture is reported with a carbon-shelled Ni-Co nanowire network as a highly efficient OER electrocatalyst. Highly porous and granular Ni-Co nanowires are first grown on a carbon fiber woven fabric utilizing a cost-effective hydrothermal method and then conductive carbon shell is coated on the Ni-Co nanowires via glucose carbonization and annealing processes. The conductive carbon layer surrounding the nanowires is introduced to provide a continuous pathway for facile electron transport throughout the whole of the integrated 3D catalyst. This 3D hierarchical structure provides several synergistic effects and beneficial functions including a large number of active sites, easy accessibility of water, fast electron transport, rapid release of oxygen gas, enhanced electrochemical durability, and stronger structural integrity, resulting in a remarkable OER activity that delivers an overpotential of 302 mV with a Tafel slope of 43.6 mV dec(-1) at a current density of 10 mA cm(-2) in an alkaline medium electrolyte (1 m KOH).