Effect of femtosecond laser-texturing on the oxygen evolution reaction of the stainless-steel plate

We studied the effect of femtosecond (FS) laser-texturing of 316 L stainless steel (SS) plates on their oxygen evolution reaction (OER). Here, the FS laser texturing is adapted to create oxyhydroxide layers with dimple structures on the pristine SS (denoted as B-SS) electrode. The single-side textured SS electrode is represented as FSSS-SS, and the double-side textured SS electrode is described as FSDS-SS. Upon FS laser texturing, significant elements variations of diffraction and photoelectron peak intensities profoundly influence their OER activity. As a result, the above electrode's OER overpotentials in 6.0 M potassium hydroxide (KOH) follow the order of B-SS (257 mV) > FSSS-SS (254 mV) > FSDS-SS (251 mV). However, the above order is reversed in the case of Tafel slopes viz., FSDS-SS (56 mV dec(-1)) > FSSS-SS (50 mV dec(-1)) > B-SS (47 mV dec(-1)). The FS laser textured electrodes exhibit a favorable OER activity regarding overpotential and current density. Besides, based on the Tafel slope analysis, the B-SS electrode shows accelerated OER kinetics. These adverse results may be due to the dimple morphology, reconfiguration of elemental composition, O/Ni/Fe ratios, and the passive nature of catalyst layers, which define the OER performance of SS electrodes.