Laser structured nickel-iron electrodes for oxygen evolution in alkaline water electrolysis

In the present work, the ultra-short pulse laser ablation method is applied to create novel surface alloys on NiFe electrodes for the oxygen evolution reaction (OER) in alkaline water electrolysis. The nickel-to-iron ratio in the alloy can be controlled with the ultra-short pulse laser ablation method by varying the thickness of electrochemically deposited iron layers onto the nickel mesh substrate. Besides the application of the additional catalyst, the laser treatment enhances the surface area and a defined micro- and submicrometer structure is created in a single step. The laser structured nickel-iron electrodes show a significantly lower overpotential of 249 mV than an electrochemically deposited Ni-NiFe alloy with 292 mV at 10 mA cm−2, 298 K and 32.5 wt% KOH for the OER, although some loss of iron over time could not be prevented.