Island Growth in the Seed-Mediated Overgrowth of Monometallic Colloidal Nanostructures

Abstract

Gold islands, gold colonies: by controlling reaction kinetics and surface chemistry, Yin and colleagues have discovered an unconventional growth mode of Au nanocrystals whereby Au islands are formed. The resulting Au islands showed excellent properties in surface-enhanced Raman scattering. This finding opens great opportunities for building sophisticated structural features of noble metals with intriguing properties and applications. SUMMARYManipulating the growth mode of colloidal nanocrystals is of both fundamental interest and technological importance because it is often connected to the control of their shape, morphology, and physicochemical properties. In conventional wisdom, island growth during thin-film deposition is restricted to lattice-mismatched materials. Here, we show that deposition of Au on Au nanostructures (e.g., nanoplates, nanorods, and nanospheres) can produce separate Au islands on the seed surface with tunable size and density while preserving the original crystal structure. The island growth in the system is ascribed to the synergistic effect of fast redox kinetics and surface capping of large polymeric ligands. Decreasing the reaction rate or changing the capping ligands could readily transform the deposition of Au on Au nanostructures from island growth to layer-by-layer mode. We further take advantage of the dense hotspots of the islands-on-plate nanostructures and demonstrate their excellence in surfaceenhanced Raman scattering detection.

Gold Nanotriangles with Crumble Topping and their Influence on Catalysis and Surface‐Enhanced Raman Spectroscopy

“…Similar results were observed by Wang et al. by decorating PVP‐capped AuNTs with “gold islands” due to a local development of Au deposits into “colonies” …”

“…Similar results were observed by Wang et al by decorating PVP-capped AuNTs with "gold islands" due to a local development of Au deposits into "colonies". [13] Sample B shows extra reflections, indicating the presence of separate spherical particles on the platelet surface. Similar results we have obtained after decorating AuNTs with silver nanospheres.…”

“…Recently, Wang et al. have shown, after a ligand exchange of CTAB‐capped AuNTs with polyvinylpyrrolidine (PVP), the formation of gold islands on the gold platelets surface, and there effect for surface‐enhanced Raman scattering (SERS) …”

“…Recently, Wang et al have shown, after a ligand exchange of CTAB-capped AuNTs with polyvinylpyrrolidine (PVP), the formation of gold islands on the gold platelets surface, and there effect for surface-enhanced Raman scattering (SERS). [13] Herein, we report a successful synthesis of biocompatible crumble AuNTs with improved SERS performance while maintaining the absorption in the NIR region, which is of relevance for in vivo imaging. [11] We have coated the AOT-based AuNTs in the present work with high molecular weight HA, a skin-tolerated biopolymer with carboxylic groups.…”

Rational construction of Au–Ag bimetallic island-shaped nanoplates for electrocatalysis

“…However, the lattice constants of gold and silver are almost the same (suitability: 0.1%) [21]. Etching, dealloying corrosion kirkendall effect and pitting processes have been widely studied in high lattice match Au-Ag nanoalloys materials [22][23][24]. All Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.…”