Rational Design Strategy for High-Valence Metal-Driven Electronically Modulated High-Entropy Co-Ni-Fe-Cu-Mo...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Developing durable and efficient multifunctional electrocatalysts is essential for industrial hydrogen production.
• High current densities at low applied potentials are critical for economically viable hydrogen generation.

Purpose of the Study:

• To synthesize a novel Co-Ni-Fe-Cu-Mo (oxy)hydroxide electrocatalyst for enhanced hydrogen production.
• To investigate the structure-activity relationship and the role of grain boundaries and elemental synergy in electrocatalysis.

Main Methods:

• Scalable coating method followed by chemical precipitation to synthesize the Co-Ni-Fe-Cu-Mo (oxy)hydroxide on nickel foam.
• Characterization using advanced analytical techniques and synchrotron radiation studies.
• Electrocatalytic performance evaluation in 1 m KOH solution.

Main Results:

• The synthesized catalyst features hierarchical nanoparticles with abundant grain boundaries in ultrafine crystalline regions (<4 nm).
• Achieved a low overpotential of 199 mV at 10 mA cm² with a Tafel slope of 48.8 mV dec¹.
• Demonstrated excellent stability over 72 hours and confirmed synergistic elemental interactions and enhanced lattice oxygen activation via the lattice oxygen mechanism (LOM).

Conclusions:

• The high-entropy Co-Ni-Fe-Cu-Mo (oxy)hydroxide electrocatalyst exhibits superior activity and durability for hydrogen production.
• Abundant grain boundaries and synergistic elemental effects significantly enhance catalytic performance.
• High-entropy strategies are effective for advancing electrocatalytic materials in alkaline media for energy applications.