Unique Hierarchical Mo₂C/C Nanosheet Hybrids as Active Electrocatalyst for Hydrogen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient electrocatalysts for hydrogen evolution reaction (HER) is crucial for clean energy.
• Non-noble metal catalysts offer a cost-effective alternative to precious metals for HER.
• Hierarchical nanostructures can enhance catalytic activity through increased surface area and synergistic effects.

Purpose of the Study:

• To synthesize hierarchical Molybdenum Carbide/Carbon (Mo2C/C) nanosheet hybrids.
• To investigate the potential of these hybrids as electrocatalysts for the hydrogen evolution reaction (HER).
• To explore a facile and scalable synthesis strategy for transition metal-based/carbon nanosheet materials.

Main Methods:

• Pyrolysis of precursors using sodium chloride (NaCl) crystals as a template.
• Characterization of the synthesized Mo2C/C nanosheet hybrids.
• Electrochemical evaluation of HER performance in alkaline and acidic media.

Main Results:

• Successfully synthesized well-dispersed, sheet-like Mo2C nanoparticles (approx. 20 nm thick) anchored on carbon nanosheets.
• Demonstrated excellent HER performance with low overpotentials (125 mV in 1 M KOH, 180 mV in 0.5 M H2SO4 for 10 mA cm-2).
• Exhibited remarkable stability, comparable to other non-noble metal HER electrocatalysts.

Conclusions:

• The hierarchical Mo2C/C nanosheet hybrids exhibit superior HER activity and stability due to synergistic effects and efficient charge transfer.
• The facile and low-cost pyrolysis method using NaCl templates is effective for creating advanced catalytic materials.
• This strategy is extendable for synthesizing other transition metal-based/carbon nanosheet hybrids for diverse applications.