Corroded Fe78Si9B13 amorphous alloy as electrocatalyst for oxygen evolution reaction of water splitting

In this work, different amounts of FeOOH are in situ generated on an amorphous Fe ₇₈Si ₉B ₁₃ alloy ribbon by potentiostatic cathodic corrosion treatments for different time, including 0.5 h, 1 h, 2 h and 5 h, which are marked as the R-0.5h, R-1h, R-2h and R-5h, respectively. Afterwards, the corroded samples are investigated as electrocatalysts for the oxygen evolution reaction (OER) of water splitting in 1 M KOH. An appropriate amount of FeOOH not only provides more active sites, but also generates hydroxy1 radicals (OH ^˙) to greatly improve the efficiency of electronic transmission. However, when the surface of samples is covered by the thick and dense FeOOH layer, the catalytic reaction rate sharply decreases. The R-1h sample shows the best OER catalytic performances, which can achieve an overpotential of 356 mV at a current density of 10 mA cm ⁻² and the Tafel slope of 45 mV dec ⁻¹.