Ag2S nanocaps from AgBr nanoplates: Template symmetry breaking synthesis induced by the polar surfaces

Abstract

Hexagonal cap-like nanocrystals (nanocaps) of Ag₂S are synthesized through a simple ion-exchange reaction by using polar {111} faceted, hexagonally shaped AgBr nanoplates as sacrificial templates, in which the bottom/top surfaces presented distinct reactivity with S²⁻ ions due to their different atomic compositions and arrangements. Surprisingly, the Ag₂S nanocaps presented strong surface-enhanced Raman scattering activity.