Universal Strategy to Fabricate a Two-Dimensional Layered Mesoporous Mo₂C Electrocatalyst Hybridized on Graphene Sheets with High Activity and Durability for Hydrogen Generation

Abstract

A universal strategy was developed for fabrication of a highly active and durable precious-metal-free mesoporous Mo2C/graphene (m-Mo2C/G) electrocatalyst with a two-dimensional layered structural feature via a nanocasting method using glucose as a carbon source and an in-stiu assembled mesoporous KIT-6/graphene (KIT-6/G) as a template. The m-Mo2C/G catalyst exhibits high catalytic activity and excellent durability for hydrogen evolution reaction (HER) over a wide pH range, which displays a small onset potential of 8 mV, owerpotential (η10) for driving a cathodic current density of 10 mA·cm(-2) of 135 mV, a Tafel slope of 58 mV·dec(-1), and an exchange current density of 6.31 × 10(-2) mA·cm(-2) in acidic media and an onset potential of of 41 mV, η10 of 128 mV, Tafel slope of 56 mV·dec(-1), and an exchange current density of 4.09 × 10(-2) mA·cm(-2) in alkaline media, respectively. Furthermore, such an m-Mo2C/G electrocatalyst also gives about 100% Faradaic yield and shows excellent durability during 3000 cycles of a long-term test, and the catalytic current remains stable over 20 h at fixed overpotentials, making it a great potential application prospect for energy issues.

Holey Reduced Graphene Oxide Coupled with an Mo2N–Mo2C Heterojunction for Efficient Hydrogen Evolution

“…The intimate contact of Mo 2 N with Mo 2 C can be seen, which should largely promote the development of a “synergistic effect” for highly effective electrocatalysis. Energy dispersive X‐ray spectroscopy (EDS) analysis (inset in Figure a) indicates the presence of C, N, O, and Mo elements in the hybrids, further supporting the formation of Mo 2 N and Mo 2 C. The O should be from the rGO and a slight oxidation of Mo 2 N and Mo 2 C . The elemental mapping suggests the well‐defined spatial distribution of C, Mo, and N in the hybrid (Figure f–i).…”

Non‐Noble Metal‐based Carbon Composites in Hydrogen Evolution Reaction: Fundamentals to Applications

“…Constructing hierarchical hollow structure can minimize the loss of reactive surfaces and promote the charge and mass transfer. For example, hierarchical β‐Mo 2 C nanotubes and mesoporous Mo 2 C/graphene (m‐Mo 2 C/G) composites were demonstrated as outstanding electrocatalyst for HER. The achieved highly porous structure enlarged the contact surface between electrode and reactant, and improved mass‐transport property.…”

Structural Design and Electronic Modulation of Transition‐Metal‐Carbide Electrocatalysts toward Efficient Hydrogen Evolution

“…To facilitate mass diffusion during HER, porous nanostructures of TMCs/GRs have been exploited. Huo et al synthesized mesoporous Mo 2 C/GRs and Mo 2 C–WC/GRs with a 2D structural feature using in situ assembled mesoporous KIT‐6/graphene as a template . The obtained composites possessed unique mesoporous structure of ultrasmall TMCs duplicated from KIT‐6, showing large surface area and high HER activity over a wide pH range.…”