Spiky Nickel Electrodes for Electrochemical Oxygen Evolution Catalysis by Femtosecond Laser Structuring

Figure 1

(a) Schematic illustrations of the preparation process of the laser-structured Ni electrodes in air. The direction of the formed spikes depends on the incident angle of the laser beam; simultaneously oxidation of the Ni surface occurs. (b-g) SEM images of laser-structured Ni electrodes at different magnifications. The irradiation angle of the laser during the structuring was set to 0° (b-d) and 45° (e-g). The SEM images were taken at a sample tilt angle of 25°.