Atomic H-Induced Mo2C Hybrid as an Active and Stable Bifunctional Electrocatalyst
Yakobson, Boris I.
Goddard, William A. III
Hauge, Robert H.
Tour, James M.
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.
Mo2C; graphene nanoribbon; hydrogen evolution reaction (HER); oxygen reduction reaction (ORR); atomic H