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 Fe78Si9B13 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.