Hydrogen sulfide

Catalysis

Engineering

Metallurgy

Materials science

Mackinawite

Water splitting

Biochemistry

Iron sulfide

In situ

Chemical engineering

Organic chemistry

Sulfur

Chemistry

Sulfide

Photocatalysis

Bifunctional

Chem

Summary null Water splitting requires nonprecious materials that can catalyze efficiently both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Here, we report the synthesis of mackinawite FeS nanosheets grown on iron foam, which can serve as an efficient pre-electrocatalyst for both HER and OER in alkaline media. During electrochemical HER testing, core@shell iron@iron oxysulfide nanoparticles as the catalytically active phase are generated null in situ null on FeS nanosheets. During electrochemical OER testing, FeS nanosheets totally transform into porous amorphous FeO x null film that can mediate the OER efficiently. When assembled as the cathode and the anode in a single electrolyzer, the resulting Fe-based catalysts can give a good overall water-splitting output that outperforms the one obtained from a noble-metal-based Pt/C-IrO 2 -coupled electrolyzer. These results provide new insights on the active sites of Fe-based catalysts as well as an impetus for further research on low-cost, iron-containing water-splitting electrocatalysts.

In Situ Generation of Bifunctional, Efficient Fe-Based Catalysts from Mackinawite Iron Sulfide for Water Splitting