Fabrication of Structured Nickel Electrodes With Tailored Wettability and Enhanced Electrochemical Active Surface Area for Alkaline Water Electrolysis Using Direct Laser Interference Patterning

High-efficiency alkaline hydrogen evolution requires electrodes with tailored surface properties that improve electrolyte accessibility and gas release. In this work, Direct Laser Interference Patterning is applied to produce periodic, line-like microstructures on nickel electrodes. Using a picosecond pulsed laser with a wavelength λ = 1064 nm and a pulse duration of τ = 70 ps, patterns with a spatial period of 5.4 μm are fabricated on the nickel surface. The surface topography is characterized using white light interferometry and scanning electron microscopy, revealing texture depths up to 2.23 ± 0.41 µm. Wettability analysis on the laser-treated samples exhibits a progressive transition toward superhydrophilic behavior. Additionally, electrochemical characterization by cyclic voltammetry demonstrates a significant enhancement of the electrochemically active surface area due to the increased surface roughness. These analyses are performed both under ambient conditions at 22°C and at an elevated temperature of 60°C. Compared to unstructured electrodes, the electrochemically active surface is enhanced by a factor of 4.7 at 22°C and 8.2 at 60°C. These findings highlight the potential of laser-structured nickel electrodes for advancing scalable and efficient gas evolution reactions.