Protecting the Nanoscale Properties of Ag Nanowires with a Solution-Grown SnO₂ Monolayer as Corrosion Inhibitor

Abstract

The chemical reactivity and/or the diffusion of Ag atoms or ions during thermal processing can cause irreversible structural damage, hindering the application of Ag nanowires (NWs) in transparent conducting films and other applications that make use of the material's nanoscale properties. Here, we describe a simple and effective method for growing monolayer SnO 2 on the surface of Ag nanowires under ambient conditions, which protects the Ag nanowires from chemical and structural damage. Our results show that Sn 2+ and Ag atoms undergo a redox reaction in the presence of water. First-principle simulations suggest a reasonable mechanism for SnO 2 formation, showing that the interfacial polarization of the silver by the SnO 2 can significantly reduce the affinity of Ag to O 2 , thereby greatly reducing the oxidation of the silver. The corresponding values (for example, before coating: 17.2 Ω/sq at 86.4%, after coating: 19.0 Ω/sq at 86.6%) show that the deposition of monolayer SnO 2 enables the preservation of high transparency and conductivity of Ag. In sharp contrast to the large-scale degradation of pure Ag-NW films including the significant reduction of its electrical conductivity when subjected to a series of harsh corrosion environments, monolayer SnO 2 coated Ag-NW films survive structurally and retain their electrical conductivity. Consequently, the thermal, electrical, and chemical stability properties we report here, and the simplicity of the technology used to achieve them, are among the very best reported for transparent conductor materials to date.

Facile synthesis of SnO2shell followed by microwave treatment for high environmental stability of Ag nanoparticles

“…18,19 Zhao et al presented overnight solution-grown SnO 2 monolayer as an anti-corrosion coating to protect Ag nanowires. 20 The proposed system was evaluated in different gases, such as the O 2 /O 3 mixture and H 2 S at room temperature; the biological applicability of SnO 2 coating in liquids with a high degree of complexation and at different pH has still not been tested.…”

Failing Forward: Stability of Transparent Electrodes Based on Metal Nanowire Networks

“…[ 37 ] More recently, Stucky et al. [ 41 ] implemented a simple wet‐chemistry process to coat AgNWs with a monolayer of SnO 2 . By introducing Sn 2+ precursors to an AgNW suspension in ethanol, a spontaneous redox reaction takes place on the AgNWs, forming a SnO 2 layer (Figure 14e–g).…”

“…With a slight addition of processing complexity in the system, the stability and electrical properties of MNW/encapsulant composites can be improved significantly. These encapsulants have been demonstrated using solution processing [ 36–48 ] or as a combination with vapor deposition, [ 35,49–53 ] each with their own advantages and tradeoffs. For example, transparent film heaters (TFHs) need very high temperature resiliency, while solar cell electrodes need good charge‐transfer characteristics between the active layer and the MNWs.…”

Rational Component and Structure Design of Noble‐Metal Composites for Optical and Catalytic Applications

“…[ 25,113–115 ] Recently, we synthesized highly uniform Ag NWs through a seed‐mediated synthesis in which the prepared Ag seeds selectively grow into NWs at relatively low temperature. [ 116 ] The Ag NWs were, then, subjected to Sn 2+ treatment as seeds resulting in the growth of Ag@SnO 2 . Ag and added Sn 2+ atoms undergo a redox reaction in the presence of H 2 O.…”

“…a–c) Reproduced with permission. [ 116 ] Copyright 2019, American Chemical Society. d) TEM image of Au@Ag nanocubes.…”