Seamlessly Conductive 3D Nanoarchitecture of Core-Shell Ni-Co Nanowire Network for Highly Efficient Oxygen Evolution

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• 作者：Seok-Hu Bae ; Ji-Eun Kim ; Hyacinthe Randriamahazaka ; Song-Yi Moon ; Jeong-Young Park and Il-Kwon Oh
• 刊名：Advanced Energy Materials
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：7
• 期：1
• 全文大小：3337K
• ISSN：1614-6840

文摘

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).