Octahedral noble-metal nanoparticles and their electrocatalytic properties

Octahedrally shaped noble-metal nanocrystals are fascinating for their unique properties, such as electrocatalytic, catalytic, plasmonic, and optical behavior, owing to their exclusively exposed {111} facets; O_h symmetric structure; and close-packed surface atoms in low-index surface categories, which are normally stable in a reaction. A series of protocols in the preparation of noble-metal nano-octahedra through a wet-chemical synthetic strategy have been developed in recent years. Herein, advances in synthetic approaches and mechanistic studies of noble-metal nano-octahedra are systematically discussed and key factors, including reduction kinetics, selective capping, and epitaxial growth, are outlined. Their unique performance as advanced electrocatalysts towards fuel-cell reactions is highlighted as well. Get in shape! Octahedrally shaped noble-metal nanocrystals are fascinating for their unique properties, owing to their exclusively exposed {111} facets, O _h symmetric structure, and close-packed surface atoms in low-index surface categories. Advances in synthetic approaches, mechanistic studies, and electrocatalytic performances of noble-metal nano-octahedra are systematically discussed (see picture).