Nanotechnology

Electrode

Electrocatalyst

Photocatalysis

Transition metal

Oxygen evolution

Engineering

Catalysis

Electrolysis

Physical chemistry

Hydrogen production

Chemistry

Materials science

Nitride

Layer (electronics)

Electrolyte

Water splitting

Chemical engineering

Electrolysis of water

Electrochemistry

Biochemistry

Advanced Materials

Electrochemical water splitting is a promising technology for sustainable conversion, storage, and transport of hydrogen energy. Searching for earth‐abundant hydrogen/oxygen evolution reaction (HER/OER) electrocatalysts with high activity and durability to replace noble‐metal‐based catalysts plays paramount importance in the scalable application of water electrolysis. A freestanding electrode architecture is highly attractive as compared to the conventional coated powdery form because of enhanced kinetics and stability. Herein, recent progress in developing transition‐metal‐based HER/OER electrocatalytic materials is reviewed with selected examples of chalcogenides, phosphides, carbides, nitrides, alloys, phosphates, oxides, hydroxides, and oxyhydroxides. Focusing on self‐supported electrodes, the latest advances in their structural design, controllable synthesis, mechanistic understanding, and strategies for performance enhancement are presented. Remaining challenges and future perspectives for the further development of self‐supported electrocatalysts are also discussed.

Self‐Supported Transition‐Metal‐Based Electrocatalysts for Hydrogen and Oxygen Evolution