Serrated Au Nanoplates via the Sharpening Etching Mode

In contrast to the conventional mode of etching where nanostructures always become rounder, we show a new etching mode that could generate lines of serrated sawteeth at the edge of Au nanoplates. Dynamic ligand control would lead to uniform etching, whereas static ligand control would completely inhibit etching, none of which could explain the sharpening teeth with partial etching. We propose to combine the concept of on–off ligand dynamics with curvature-dependent affinity and dynamic etching competition, so as to form a coherent mechanistic explanation. The ability to create regularly arranged teeth is a significant synthetic advance that would open new applications such as nanoscale cutting tools.