Corrosion Engineering on Iron Foam toward Efficiently Electrocatalytic Overall Water Splitting Powered by Sustainable Energy

Abstract Exploiting highly effective and low‐cost electrocatalysts for the hydrogen evolution reaction (HER) is a pressing challenge for the development of sustainable hydrogen energy. In this work, a facile and industrially compatible one‐pot corrosion strategy for the rapid synthesis of amorphous RuO 2 ‐decorated FeOOH nanosheets on iron foam (FFNaRu) within 1 h is reported. Corrosion is a common and inevitable phenomenon that occurs on metal surfaces without electricity input, high temperature, and tedious synthetic procedures. The FFNaRu electrode is superhydrophilic and aerophobic, which guarantees intimate contact with the electrolyte and accelerates the instantaneous escape of produced gas bubbles during the electrocatalytic process. Moreover, the strong electronic interactions between RuO 2 and FeOOH promote the electrocatalytic process via dramatically improving the electrochemical interfacial properties. Thus, the FFNaRu electrocatalyst presents excellent catalytic activity towards the HER (30 mV at 10 mA cm –2 ) and overall water‐splitting (230 mV at 10 mA cm –2 ) in 1 M KOH. The overall water‐splitting could be simply powered by sustainable and intermittent sunlight, wind, and thermal energies motivated Stirling engine. Density functional theory calculations confirm that coupling effects between RuO 2 and FeOOH are also responsible for promoting the electrocatalytic HER performance.