Dynamic Reconstructed RuO₂ /NiFeOOH with Coherent Interface for Efficient Seawater Oxidation

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) in seawater electrolysis is crucial but challenging.
• Existing catalysts often suffer from poor activity and stability in harsh alkaline environments.

Purpose of the Study:

• To synthesize a novel precatalyst for efficient OER in seawater electrolysis.
• To investigate the dynamic reconstruction and catalytic performance of the synthesized material.

Main Methods:

• A facile one-pot synthesis of RuO2-incorporated NiFe-metal organic framework (RuO2/NiFe-MOF).
• In-situ electrochemical reconstruction of RuO2/NiFe-MOF into RuO2 nanoparticles-anchored NiFe oxy/hydroxide nanosheets (RuO2/NiFeOOH).
• Electrochemical characterization in 1 M KOH and simulated seawater, supported by density functional theory (DFT) calculations.

Main Results:

• The reconstructed RuO2/NiFeOOH exhibited an ultralow OER overpotential of 187.6 mV at 10 mA cm-2 and a Tafel slope of 31.9 mV dec-1 in 1 M KOH.
• The catalyst demonstrated excellent durability, sustaining high current densities of 840 and 1040 mA cm-2.
• For seawater oxidation, RuO2/NiFeOOH achieved 500 mA cm-2 at an overpotential of 326.2 mV and maintained stability for 100 hours.

Conclusions:

• The synergistic interaction and enhanced charge transfer at the RuO2/NiFeOOH interface significantly boost OER activity and stability.
• The dynamically reconstructed RuO2/NiFeOOH is a highly promising electrocatalyst for efficient and durable seawater electrolysis.