Fe-Based Metal Organic Framework-Derived FeNiP/N-Doped Carbon Heterogeneous Core-Shell Structures for Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Precious metal-free electrocatalysts are crucial for reducing energy consumption in water electrolysis for hydrogen production.
• Metal-organic frameworks (MOFs) serve as effective precursors for synthesizing transition metal electrocatalysts due to their ordered structures.

Purpose of the Study:

• To develop a highly active, durable, and cost-effective electrocatalyst for the oxygen evolution reaction (OER).
• To explore the use of MOFs as precursors for creating novel electrocatalytic materials.

Main Methods:

• Synthesis of nanoscale Fe-soc-MOFs.
• In situ conversion to nickel-iron double-layer hydroxide/MOF (FeNi LDH/MOF) via Ni2+ etching.
• Calcination and phosphating to obtain nickel-iron phosphide/nitrogen-doped carbon cubic nanocage (FeNiP/NC).
• Density functional theory (DFT) calculations to understand catalytic mechanisms.

Main Results:

• The synthesized FeNiP/NC catalyst exhibited a low overpotential of 240 mV at 10 mA/cm2 for OER.
• The catalyst demonstrated outstanding durability, with continuous electrolysis for 45 hours.
• DFT calculations confirmed the synergistic effect between FeNiP and N-doped carbon, enhancing catalytic activity.

Conclusions:

• The FeNiP/NC catalyst presents a promising, precious metal-free alternative for efficient hydrogen production.
• The MOF-derived core-shell structure and synergistic effects contribute to the catalyst's high performance.
• In situ conversion to MOOH active sites during electrolysis enhances long-term stability.