Nanotubular Iridium-Cobalt Mixed Oxide Crystalline Architectures Inherited from Cobalt Oxide for Highly Efficient Oxygen Evolution Reaction Catalysis
- 주제(키워드) cobalt , electrocatalyst , electrospinning , iridium , mixed metal oxide nanotubes , oxygen evolution reaction
- 등재 SCIE, SCOPUS
- 발행기관 American Chemical Society
- 발행년도 2017
- URI http://www.dcollection.net/handler/ewha/000000146883
- 본문언어 영어
- Published As http://dx.doi.org/10.1021/acsami.7b12247
- 저작권 이화여자대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Here, we report the unique transformation of one-dimensional tubular mixed oxide nanocomposites of iridium (Ir) and cobalt (Co) denoted as IrxCo1-xOy, where x is the relative Ir atomic content to the overall metal content. The formation of a variety of IrxCo1-xOy (0 ≤ x ≤ 1) crystalline tubular nanocomposites was readily achieved by electrospinning and subsequent calcination process. Structural characterization clearly confirmed that IrxCo1-xOy polycrystalline nanocomposites had a tubular morphology consisting of Ir/IrO2 and Co3O4, where Ir, Co, and O were homogeneously distributed throughout the entire nanostructures. The facile formation of IrxCo1-xOy nanotubes was mainly ascribed to the inclination of Co3O4 to form the nanotubes during the calcination process, which could play a critical role in providing a template of tubular structure and facilitating the formation of IrO2 by being incorporated with Ir precursors. Furthermore, the electroactivity of obtained IrxCo1-xOy nanotubes was characterized for oxygen evolution reaction (OER) with rotating disk electrode voltammetry in 1 M NaOH aqueous solution. Among diverse IrxCo1-xOy, Ir0.46Co0.54Oy nanotubes showed the best OER activity (the least-positive onset potential, greatest current density, and low Tafel slope), which was even better than that of commercial Ir/C. The Ir0.46Co0.54Oy nanotubes also exhibited a high stability in alkaline electrolyte. Expensive Ir mixed with cheap Co at an optimum ratio showed a greater OER catalytic activity than pure Ir oxide, one of the most efficient OER catalysts. © 2017 American Chemical Society.
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