Selenate promoted stability improvement of nickel selenide nanosheet array with an amorphous NiOOH layer for seawater oxidation

Seawater electrolysis offers significant potential for green hydrogen production, the presence of harmful chlorine species, nevertheless, can cause severe anode corrosion. Here, we present our recent finding that selenate anions adsorbed nickel selenide nanosheet array with an amorphous NiOOH layer on Ni foam (NiSe2@NiOOH/NF) serves as a high-efficiency and durable electrocatalyst for oxygen evolution reaction (OER) in alkaline seawater. It requires an overpotential of 460 mV to obtain 500 mA cm−2. Impressively, it shows at least 100 h of electrolysis tolerance at 500 mA cm−2. Insights from electrochemical in situ Raman spectroscopy and chlorine extraction tests unveil that selenite undergoes oxidation to selenate during the OER test, effectively suppressing hypochlorite generation.