Carbon nanotubes encapsulating Pt/MoN heterostructures for superior hydrogen evolution.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient hydrogen evolution reaction (HER) catalysts are crucial for electrochemical water splitting.
• Scaling up water splitting requires catalysts with enhanced activity and stability.
• Current catalysts face challenges in achieving high performance in alkaline media.

Purpose of the Study:

• To synthesize and characterize a novel PtNi/MoN@C electrocatalyst for improved HER.
• To investigate the synergistic effects of Pt doping, MoN, and nitrogen-doped carbon nanotubes (NCNTs) on catalytic activity.
• To evaluate the electrocatalyst's performance in alkaline solutions and compare it with commercial standards.

Main Methods:

• Synthesis of PtNi/MoN@C electrocatalyst using a simple strategy.
• Characterization of material morphology and electronic structure.
• Electrochemical testing of HER activity in alkaline solution.
• Theoretical calculations to understand reaction mechanisms.

Main Results:

• The PtNi/MoN@C electrocatalyst exhibited strong interphase effects and significantly improved HER activity.
• Pt doping altered surface morphology and the electronic structure of MoN, enhancing conductivity and optimizing binding energies.
• The catalyst achieved an overpotential of 18 mV to reach 10 mA cm⁻², outperforming commercial Pt/C.
• Theoretical studies confirmed enhanced electron transport and reduced H* binding energy (△G_H*).

Conclusions:

• The developed PtNi/MoN@C electrocatalyst demonstrates superior HER performance in alkaline media.
• The synergistic effects between Pt, MoN, and NCNTs are key to the enhanced catalytic activity.
• This work offers a promising pathway for developing efficient and cost-effective electrocatalysts for water splitting.