title: Atomic H-Induced Mo2C Hybrid as an Active and Stable Bifunctional Electrocatalyst.
abstract: 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.
authors.affiliation: Institute of Crystalline Materials, Shanxi University , Taiyuan, Shanxi 030006, China.
authors.forename: Xiujun
authors.initials: X
authors.lastname: Fan
authors.forename: Yuanyue
authors.identifier: 0000-0002-5880-8649
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Peng
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Zhang
authors.forename: Haiqing
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Institute of Crystalline Materials, Shanxi University , Taiyuan, Shanxi 030006, China.
authors.forename: Xianming
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Institute of Crystalline Materials, Shanxi University , Taiyuan, Shanxi 030006, China.
authors.forename: Boris I
authors.initials: BI
authors.lastname: Yakobson
authors.forename: William A
authors.identifier: 0000-0003-0097-5716
authors.initials: WA
authors.lastname: Goddard
authors.forename: Xia
authors.initials: X
authors.lastname: Guo
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hauge
authors.forename: James M
authors.identifier: 0000-0002-8479-9328
authors.initials: JM
authors.lastname: Tour
keywords: Mo2C; atomic H; graphene nanoribbon; hydrogen-evolution reaction; oxygen-reduction reaction