TY - JOUR A1 - Salih, Haujin A1 - Cieluch, Maximilian A1 - Maack, Philipp L. A1 - Kazamer, Norbert A1 - Wirkert, Florian Josef A1 - Rost, Ulrich A1 - Esen, Cemal A1 - Brodmann, Michael T1 - Femtosecond laser-induced surface structuring of porous nickel substituting anodic catalyst layers for alkaline oxygen evolution reaction JF - Applied Surface Science Advances N2 - Femtosecond laser-induced nano structuring offers a novel approach to enhance the performance of porous transport layers (PTLs) in anion-exchange membrane water electrolysis. By applying ultrashort laser pulses to nickel felts, distinct surface morphologies were generated, including high-spatial-frequency laser-induced periodic surface structures (HSFL-LIPSS), irregular ablated surfaces, and hybrid structures. Surface area analysis revealed increases of up to 4-fold for LIPSS, 6-fold for hybrid structures (LIPSS+Ablation), and 9-fold for ablated surfaces compared to untreated fibers. Electrochemical testing showed reduced overpotentials for laser-treated samples, comparable to state-of-the-art electrodes despite the absence of catalyst layers. Overpotentials could be reduced by up to 6.5 % at 10 mA cm−2 and by up to 9.6 % at 100 mA cm−2 compared to the unprocessed felt. Notably, ablated structures, with the highest surface areas, exhibited microcavities that may entrap oxygen bubbles, limiting active site and reaction rates. The LIPSS structures demonstrated the lowest activation losses and highest current density (1.32 A cm⁻² at 2.0 V) due to their periodic morphology and enhanced electrolyte flow, representing a 17 % improvement at 2.0 V compared to the untreated felts. Moreover, Tafel slopes down to 66 mV dec−1 denote a performant kinetic while oxidation charge measurements revealed pronounced peaks for laser-treated samples, with ablated surfaces achieving the highest charge of 16.76 ± 1.64 C cm⁻². Chronopotentiometry revealed the LIPSS structures showing the highest resistance to degradation among the structured samples. These findings suggest femtosecond laser nano structuring as a promising method to improve PTL performance. Further application of catalyst layers could amplify the electrochemical efficiency of these advanced materials. KW - Anion-exchange membrane water electrolysis (AEMWE) KW - Porous transport layer (PTL) KW - Oxygen evolution reaction (OER) KW - Laser ablation KW - Laser-induced periodic surface structures (LIPSS) KW - Laser surface structuring KW - Ultrashort laser pulses Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1010-opus4-47830 SN - 2666-5239 VL - 2025 IS - Volume 27 SP - 1 EP - 9 PB - Elsevier ER -