The conversion of CoSe2 to Co oxide under the electrochemical water oxidation condition

•Hydrogen production by water electrolysis is a very promising way to store sustainable energies.•Cobalt selenide is highly attractive as catalysts for water oxidation.•CoSe2 is converted to cobalt oxide when used as a water-oxidizing.

Hydrogen production by water electrolysis is a very promising way to store sustainable energies. In practice, however, large-scale electrochemical production of hydrogen from water splitting is greatly limited by water-oxidation reaction. CoSe2 and its composites with other compounds are efficient catalysts for water oxidation. Herein for the first time, we report that CoSe2 is converted to cobalt oxide when is used as a water-oxidizing catalyst under the electrochemical water oxidation condition at pH = 13. The results are very important for water-splitting systems, which use CoSe2 as a water-oxidizing catalyst.

Graphical abstractCoSe2 is converted to cobalt oxide when it is used as water-oxidizing catalyst under the electrochemical water-oxidation condition at pH = 13 for long time.Figure optionsDownload full-size imageDownload as PowerPoint slide