NiFeRu/C and Ru, Fe-Ni₅P₄/C as complementary electrocatalyst for highly efficient overall water splitting

Area of Science:

• Materials Science and Engineering
• Electrochemistry
• Renewable Energy

Background:

• Developing efficient and cost-effective electrocatalysts is crucial for electrocatalytic water splitting.
• Existing electrocatalysts often face challenges in terms of activity, stability, and cost.

Purpose of the Study:

• To design and fabricate novel, inexpensive electrocatalysts for overall water splitting.
• To investigate the synergistic effects of different metal components on catalytic activity.
• To evaluate the performance and durability of an asymmetrical electrolytic cell using these electrocatalysts.

Main Methods:

• Synthesis of NiFeRu/C nanofibers via electrospinning and carbonization.
• Synthesis of Ru, Fe dual-doped Ni5P4 (Ru, Fe-Ni5P4)/C nanofibers via electrospinning, carbonization, and phosphorization.
• Electrocatalytic activity testing for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER).
• Assembly and performance evaluation of an asymmetrical electrolytic cell for overall water splitting.

Main Results:

• NiFeRu/C nanofibers exhibited high HER activity, while Ru, Fe-Ni5P4/C nanofibers showed high OER activity.
• The synergistic interaction among metal components led to numerous active sites and optimized intermediate adsorption.
• The assembled asymmetrical electrolytic cell achieved high current densities at low voltages (e.g., 1.569 V at 100 mA cm-2) and surpassed Pt/C||IrO2.
• The electrolytic cell demonstrated excellent durability, operating for 100 hours at 500 mA cm-2 without degradation.

Conclusions:

• The developed electrocatalysts are highly competent and inexpensive for overall water splitting.
• The synergistic effects in the electrocatalysts are key to their enhanced performance.
• The novel method provides a promising pathway for designing efficient and durable electrocatalysts for clean hydrogen production.