Co-Doped Nanoporous Fe₃P Self-Supported Electrodes for Enhanced Alkaline Hydrogen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Transition-metal phosphides are key non-noble metal electrocatalysts for hydrogen evolution.
• Improving their efficiency in alkaline media remains a critical challenge.

Purpose of the Study:

• To fabricate a Co-doped nanoporous Fe3P electrode for enhanced alkaline hydrogen evolution reaction (HER).
• To investigate the effects of Co doping and nanoporous structure on HER performance.

Main Methods:

• Fabrication of Co-doped nanoporous Fe3P via melt spinning and electrochemical dealloying.
• Structural and chemical characterization using X-ray photoelectron spectroscopy (XPS).
• Electrochemical testing of HER performance in 1.0 M KOH.

Main Results:

• Successfully synthesized a 3D nanoporous Fe3P framework with incorporated Co.
• Co doping modified the local chemical environment of Fe and P, enhancing catalytic activity.
• The np-Co-Fe3P electrode achieved 10 mA cm-2 at only 70 mV overpotential, significantly lower than np-Fe3P (199 mV).
• np-Co-Fe3P exhibited a lower Tafel slope (94 mV dec-1), reduced charge-transfer resistance, and higher double-layer capacitance (109.4 mF cm-2).

Conclusions:

• Co incorporation and dealloying-induced nanoporous architecture effectively enhance alkaline HER performance.
• This strategy offers a promising pathway for developing advanced non-noble metal electrocatalysts.
• The developed np-Co-Fe3P shows great potential for efficient hydrogen production in alkaline electrolytes.