Electrode

Organic chemistry

Electrocatalyst

Hydrogen

Photocatalysis

Endocrinology

Oxygen evolution

Engineering

Catalysis

Electrolysis

Intercalation (chemistry)

Physical chemistry

Inorganic chemistry

Chemistry

Metallurgy

Materials science

Diselenide

Lithium (medication)

Bifunctional

Iridium

Electrolyte

Water splitting

Chemical engineering

Electrolysis of water

Electrochemistry

Selenium

Medicine

Angewandte Chemie International Edition

Developing bifunctional catalysts for both hydrogen and oxygen evolution reactions is a promising approach to the practical implementation of electrocatalytic water splitting. However, most of the reported bifunctional catalysts are only applicable to alkaline electrolyzer, although a few are effective in acidic or neutral media that appeals more to industrial applications. Here, a lithium-intercalated iridium diselenide (Li-IrSe2 ) is developed that outperformed other reported catalysts toward overall water splitting in both acidic and neutral environments. Li intercalation activated the inert pristine IrSe2 via bringing high porosities and abundant Se vacancies for efficient hydrogen and oxygen evolution reactions. When Li-IrSe2 was assembled into two-electrode electrolyzers for overall water splitting, the cell voltages at 10 mA cm-2 were 1.44 and 1.50 V under pH 0 and 7, respectively, being record-low values in both conditions.

Intercalated Iridium Diselenide Electrocatalysts for Efficient pH‐Universal Water Splitting