ScholarWorks@동국대학교

초록

Molybdenum carbide (Mo2C) has emerged as a compelling nonprecious metal electrocatalyst for the hydrogen evolution reaction (HER), owing to its excellent catalytic activity and high stability. However, conventional synthesis strategies involving sacrificial templates or polymer self-assembly often face trade-offs, such as hazardous postprocessing, limited electrical conductivity, or uncontrolled particle growth, leading to diminished active sites. To address these challenges, we present a straightforward carburization strategy using N-doped mesoporous graphene (NMG), which simultaneously functions as the carbon precursor and a conductive matrix. The synthesized Mo2C nanoparticle-embedded NMG (MCNMG) nanohybrid is characterized by a homogeneous distribution of ultrafine beta-Mo2C nanoparticles (<3 nm) confined within the NMG framework. Significantly, the superior structural properties of MCNMG are attributed to a synergistic dual-confinement effect: (1) the physical restriction by the mesoporous architecture and (2) the anchoring effect by pyridinic- and graphitic-N species. These synergistic effects not only suppress particle agglomeration but also mitigate the excessive consumption of the carbon scaffold during carburization, thereby preserving an average pore diameter of similar to 7.0 nm and a large specific surface area of 696 m(2) g(-1), which maximize active site exposure and facilitate efficient charge/mass transport. In electrochemical evaluations, the MCNMG catalyst requires an overpotential of only 169 mV to deliver a current density of - 10 mA cm(-2), accompanied by a Tafel slope of 77 mV dec(-1). Furthermore, it exhibits robust durability over 120 h of continuous operation at high current densities (-50 mA cm(-2)), demonstrating its great potential for practical water electrolysis applications. This work highlights the critical role of anchoring effects in rational hybrid design, offering a pathway to durable, high-performance electrocatalysts for hydrogen production.

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