Ultrafast Room-Temperature Synthesis of Self-Supported NiFe-Layered Double Hydroxide as Large-Current-Density Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Water splitting offers a sustainable route to high-purity hydrogen, but is hindered by the slow oxygen evolution reaction (OER).
• Developing efficient electrocatalysts is crucial for overcoming kinetic limitations in water splitting technologies.

Purpose of the Study:

• To develop a time- and energy-saving method for synthesizing highly active OER electrocatalysts.
• To investigate the performance of vertically rooted NiFe-LDH nanosheets on nickel foam for overall water splitting.

Main Methods:

• Direct growth of NiFe-layered double hydroxide (NiFe-LDH) nanosheets on nickel foam at ambient conditions.
• Electrochemical characterization of the synthesized catalyst for oxygen evolution reaction (OER) and overall water splitting.

Main Results:

• The synthesized NiFe-LDH nanosheets formed a porous, vertically rooted array on nickel foam, enhancing active sites and charge/mass transport.
• The catalyst (NF@NiFe-LDH-1.5-4) demonstrated excellent OER activity with low overpotentials (190 mV at 100 mA cm⁻²; 220 mV at 657 mA cm⁻²) and a Tafel slope of 38.1 mV dec⁻¹.
• Stable overall water splitting performance was achieved, reaching 200 mA cm⁻² at 1.83 V for over 300 hours.

Conclusions:

• The facile and ultrafast synthesis produces a low-cost, highly active electrocatalyst for large-current-density OER.
• The developed NiFe-LDH catalyst meets industrial requirements for hydrogen production via water splitting, promoting commercialization.