Optimizing Platinum Location on Nickel Hydroxide Nanosheets to Accelerate the Hydrogen Evolution Reaction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Rational electrode design is critical for improving the activity, stability, and utilization of platinum (Pt) in alkaline electrolytes for the hydrogen evolution reaction (HER).
• Developing low-Pt content electrodes is essential for cost-effective and efficient HER catalysis.

Purpose of the Study:

• To fabricate a binder-free, low-Pt content HER electrode with enhanced performance.
• To investigate the location-selective anchoring of Pt nanoparticles on nickel hydroxide nanosheets for improved ohmic resistance and catalytic activity.
• To evaluate the electrocatalytic activity and long-term stability of the novel electrode in an alkaline medium.

Main Methods:

• Fabrication of a Pt-decorated nickel hydroxide electrode (Pt-Ni(OH)2-2h-NF20) on nickel foam at near room temperature.
• Location-selective anchoring of Pt nanoparticles on the bottom of Ni(OH)2 nanosheets utilizing mass transfer resistance.
• Electrochemical evaluation of HER performance, including current density, overpotential, and stability testing in 1 M KOH.

Main Results:

• The Pt-Ni(OH)2-2h-NF20 electrode achieved a current density of 35.9 mA cm⁻² at a 100 mV overpotential, exceeding commercial Pt/C by over 8 times.
• Exceptional stability was observed, with only a 20 mV increase in overpotential at 100 mA cm⁻² over 150,000 seconds.
• A large-area (840 cm²) electrode demonstrated a steady overpotential of 370 mV at 1000 mA cm⁻² with minimal potential increase over 50 hours.

Conclusions:

• The novel electrode design, featuring location-selectively anchored Pt nanoparticles on Ni(OH)2 nanosheets, significantly enhances HER electrocatalytic activity and stability in alkaline electrolytes.
• The synergistic effect between Pt and Ni(OH)2, coupled with excellent mass transfer and a stable structure, contributes to the superior performance.
• The simple fabrication process and demonstrated scalability suggest potential for practical applications in alkaline HER.