The patchy growth mode: Modulation of the Au-Au interface via phenynyl ligands

Surface ligands play critical roles in nano-synthesis and thus it is of great importance in expanding the scope of suitable ligands. In this work, we explore phenynyl ligands in modulating the Au-Au interface when growing Au domains on Au seeds. A patchy growth mode is observed where the emerging islands are flat-laying with holes and branches. This growth mode is distinctively different from the conventional facet-controlled growth using weak ligands, and the non-wetting island growth using strong ligands. Through manipulating the molecular structure and the packing of the phenynyl ligands on the Au seeds, the overgrown Au domains are continuously tuned, from patches to islands, extending the plasmon absorption peak into the near-infrared spectral range. We believe that the new ligand with intermediate affinity and the unusual growth mode would expand the control in both synthesis and application.