Tips and Tricks for the Surface Engineering of Well‐Ordered Morphologically Driven Silver‐Based Nanomaterials

Abstract

Particularly‐shaped silver nanostructures are successfully applied in many scientific fields, such as nanotechnology, catalysis, (nano)engineering, optoelectronics, and sensing. In recent years, the production of shape‐controlled silver‐based nanostructures and the knowledge around this topic has grown significantly. Hence, on the basis of the most recent results reported in the literature, a critical analysis around the driving forces behind the synthesis of such nanostructures are proposed herein, pointing out the important role of surface‐regulating agents in driving crystalline growth by favoring (or opposing) development along specific directions. Additionally, growth mechanisms of the different morphologies considered here are discussed in depth, and critical points highlighted.

Role of Phase Stabilization and Surface Orientation in 4,4′-Biphenyl-Dicarboxylic Acid Self-Assembly and Transformation on Silver Substrates

“…Molecular self-assembly on surfaces is a bottom-up approach for constructing atomically precise two-dimensional structures, providing unusual and even unique properties. − Diverse on-surface self-assembled architectures have already been created and tested, for example, as catalysts and host–guest systems. − However, applications of these architectures are still hindered, mainly due to large differences in structure and properties of molecular layers on substrates of different materials, with different crystallographic orientations, or even with different step densities because self-assembly is governed by a subtle interplay of involved intermolecular and molecule–substrate interactions. ,, In this regard, “model” molecular systems on single-crystal substrates serve as a vital source of information, that is, for the functionalization of nanoparticle surfaces exhibiting multiple facets , or polycrystalline metal sheets (e.g., electrodes), which requires the knowledge of molecular self-assembly on surfaces with various surface orientations.…”

Nanoscale Hydrophobicity and Electrochemical Mapping Provides Insights into Facet Dependent Silver Nanoparticle Dissolution

“…As PVP can selectively bind to Ag {100} to make its surface free energy lower than that of Ag {111}, the formation of cubic Ag composed of six square {100} facets is facilitated when adding PVP in a proper ratio. Similarly, as nanorod nanoparticles primarily have the {100} and {111} facets, by adjusting the surfactants (PVP) or Fe­(acac) 3 , Fe III was added to prevent the etching of twinned seeds by chloride and oxygen, the nanorod with two ends of the {111} facets could grow continuously via Ostwald ripening . Ag nanorod can elongate because its two end surfaces are largely uncovered and remain reactive toward new silver atoms until the depletion of available silver ions in the solution .…”

“…Similarly, as nanorod nanoparticles primarily have the {100} and {111} facets, by adjusting the surfactants (PVP) or Fe(acac) 3 , Fe III was added to prevent the etching of twinned seeds by chloride and oxygen, the nanorod with two ends of the {111} facets could grow continuously via Ostwald ripening. 33 Ag nanorod can elongate because its two end surfaces are largely uncovered and remain reactive toward new silver atoms until the depletion of available silver ions in the solution. 34 The five rod surfaces with {100} are passivated by PVP.…”