Hexagonal Arrays of Cylindrical Nickel Microstructures for Improved Oxygen Evolution Reaction.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Conversion

Background:

• Fuel-cell systems offer non-fossil fuel power generation but face inefficiencies in electrochemical fuel production.
• Gas passivation on electrode surfaces is a key challenge limiting the efficiency of electrochemical fuel generation.

Purpose of the Study:

• To systematically investigate the correlation between surface morphologies and performance in the oxygen evolution reaction (OER).
• To develop microstructured nickel surfaces for improved efficiency in electrochemical fuel generation.

Main Methods:

• Fabrication of uniform microstructured nickel surfaces using photolithographic techniques.
• Preparation of hexagonal arrays of microstructured Ni cylinders with dimensions optimized for oxygen bubble release.
• Comparative analysis of OER performance between microstructured (recessed and pillared) and planar nickel electrodes in alkaline media.

Main Results:

• Microstructured nickel electrodes, particularly arrays of cylindrical recesses, demonstrated enhanced OER efficiency compared to planar electrodes.
• The microstructured electrodes achieved twice the current density of planar electrodes at an overpotential of 100 mV.
• Investigated the influence of microstructured features on OER performance and bubble release dynamics.

Conclusions:

• Tailored microstructuring of nickel electrode surfaces significantly improves efficiency in the oxygen evolution reaction.
• These findings provide a pathway for designing more efficient electrodes for water electrolysis and fuel generation.
• Optimized surface morphology is crucial for overcoming gas passivation and enhancing electrochemical processes for clean energy.