Turning the Surface Electronic Effect Over Core-Shell CoS─FeCoS Nanooctahedra Toward Electrochemical Water Splitting in the Alkaline Medium.

The long-term challenge in overall water splitting is the conflict in the pH condition of electrolytes for achieving efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at the same time, in addition to the typical cost issue in catalysts. It hence raises an intense research interest in seeking cost-efficient non-noble metal electrocatalysts as well as compromising electrolyte conditions for electrocatalytic HER and OER. To tackle the problems, various approaches are demonstrated to engineer the electronic effect on the active sites of catalysts for enhancing the activities.