Atomic H-Induced Mo2C Hybrid as an Active and Stable Bifunctional Electrocatalyst

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• 作者：Xiujun Fan ; Yuanyue LiuZhiwei Peng ; Zhenhua Zhang ; Haiqing Zhou ; Xianming Zhang ; Boris I. Yakobson ; William A. Goddard III ; Xia GuoRobert H. Hauge ; James M. Tour
• 刊名：ACS Nano
• 出版年：2017
• 出版时间：January 24, 2017
• 年：2017
• 卷：11
• 期：1
• 页码：384-394
• 全文大小：774K
• ISSN：1936-086X

文摘

Mo₂C nanocrystals (NCs) anchored on vertically aligned graphene nanoribbons (VA-GNR) as hybrid nanoelectrocatalysts (Mo₂C–GNR) are synthesized through the direct carbonization of metallic Mo with atomic H treatment. The growth mechanism of Mo₂C NCs with atomic H treatment is discussed. The Mo₂C–GNR hybrid exhibits highly active and durable electrocatalytic performance for the hydrogen-evolution reaction (HER) and oxygen-reduction reaction (ORR). For HER, in an acidic solution the Mo₂C–GNR has an onset potential of 39 mV and a Tafel slope of 65 mV dec^–1, and in a basic solution Mo₂C–GNR has an onset potential of 53 mV, and Tafel slope of 54 mV dec^–1. It is stable in both acidic and basic media. Mo₂C–GNR is a high-activity ORR catalyst with a high peak current density of 2.01 mA cm^–2, an onset potential of 0.93 V that is more positive vs reversible hydrogen electrode (RHE), a high electron transfer number n (∼3.90), and long-term stability.