Selective Synthesis of Different-Sized Gold Nanoclusters through HCl-Etching and -Growth Effect

Controllable syntheses of different-sized gold nanoclusters are of great significance for their fundamental science and practical applications.In this work, we achieve the controllable and selective syntheses of Au₇ and Au₁₃ clusters through adding HCl to the traditional Au₁₁ synthetic route at different reaction time.Time-dependent mass spectra and UVVis spectra were employed to monitor these two HCl-directed processes, and revealed the distinct roles of HCl as an etchant or a growth promotor, respectively.Furthermore, parallel experiments on independent synthetic routes involving only non-chlorine H⁺(acetic acid) or Cl^-(tetraethy lammonium chloride) instead of HCl were performed, which illustrated the main role of H⁺-etching and Cl^--assisted growth in HCl-directed cluster synthetic routes.We propose the HCl-etching is mainly achieved via the H⁺ action to break the Au (Ⅰ)-PPh₃ part of clusters, while the HCl-promoted growth is realized via the attachment of Au-Cl species to the pre-formed clusters.