Direct Laser Interference Patterning of Nickel Foils for Enhanced Bubble Nucleation in Oxygen‐Oversaturated Environment

This study investigates the functionalization of high‐purity nickel (Ni) surfaces for the oxygen bubble nucleation via direct laser interference patterning (DLIP). Line‐like surface structures with spatial periods of 6.0, 15.0, and 30.0 µm and depths of 1 and 5 µm are fabricated using a picosecond pulsed laser source. The structuring process involves material ablation, redeposition, and the formation of laser‐induced periodic surface structures (LIPSS), resulting in hierarchical surface textures. The influence of topographical parameters resulting from the DLIP treatment on the oxygen bubble nucleation dynamics is examined in a specifically prepared oxygen‐oversaturated aqueous solution. The periodic patterns having a spatial period of 6.0 µm and a structure depth of 5 µm show the strongest surface area enlargement ( S dr = 117%), with a 278‐fold increase in bubble nucleation density, and significantly smaller average bubble sizes (∼140 µm) compared to the nonstructured reference (∼340 µm). Furthermore, enhanced coalescence and faster bubble detachment suggest improved gas release characteristics. These findings underscore the potential of DLIP‐based surface structuring to optimize performance for gas evolution applications.