Understanding the Impact of Wall Thickness on Thermal Stability of Silver–Gold Nanocages

Abstract

The thermal stability of nanocages is of great research value in both fundamental studies and practical applications. In this work, by focusing on silver−gold (Ag−Au) alloyed nanocages as a model system, we demonstrate that the wall thickness of the nanocage is a critical parameter in determining its thermal stability. We systematically evaluated the thermal stabilities of Ag−Au nanocages with different wall thicknesses in the range 3.8−13 nm in both solution and solid phases. The results showed that, in both phases, nanocages with thicker walls displayed better stabilities. At sufficiently high temperatures, the nanocages were deformed to thermodynamically more stable nanostructures. The deformation processes were found to be different for nanocages with various wall thicknesses, which were carefully monitored and analyzed by electron microscopy imaging. Changes in plasmonic properties of the nanocages during heat-induced deformation processes were also investigated.

Preventing the Galvanic Replacement Reaction toward Unconventional Bimetallic Core–Shell Nanostructures

“…Such metal cores are highly stable, and thus can well resist oxidative etching by the precursor of the shell metal. When less stable metals are employed as the cores, a galvanic replacement reaction readily occurs [26][27][28][29]. Upon mixing the less-stable-metal nanocrystals (cores) with noble metal salts (shell metal precursors), the less-stable-metal nanocrystals are oxidatively etched, while the noble metal salt is reduced and deposited onto the surface of the less-stable-metal nanocrystals.…”

Seeded Growth of AuAg Solid–Hollow Janus Nanocrystals with Tunable Sizes for Photothermal Eradication of Multidrug-Resistant Bacteria

“…10 Despite these well-known merits, the structural stability could be a difficult technique challenge to deal with due to intrinsic thermodynamically unfavorable atomic arrangement. 11 To solve this issue, the hybrid combination of solid and hollow nanostructures in one particle via a Janus form could be a feasible option. On the one hand, such hybridization could balance the atomic utilization efficiency and the structural instability.…”

“…Compared to solid ones, the hollow nanostructures have a larger specific surface area and a higher percentage of surface atoms, showing a better catalytic activity. , Meanwhile, the presence of hollow interior changes the electromagnetic distribution of surface free electrons, and thus the localized surface plasmon resonance (LSPR) properties can be dramatically varied . Despite these well-known merits, the structural stability could be a difficult technique challenge to deal with due to intrinsic thermodynamically unfavorable atomic arrangement . To solve this issue, the hybrid combination of solid and hollow nanostructures in one particle via a Janus form could be a feasible option.…”

On the role of wall thickness in determining the plasmonic properties of silver-gold nanocages

“…S5, ESI †) revealed that Ag and Au co-exist in the cages in the form of an alloy, which is consistent with the observations in our previous studies. 13,19 Taken together, these two sets of Ag-Au cages, which have the same void or outer size, shape, and elemental composition, but different wall thicknesses, could serve as an ideal platform to investigate the role of wall thickness in determining the plasmonic properties. We then evaluated the plasmonic properties of the as-prepared Ag-Au cages by analyzing their extinction spectra using a UV-vis spectrophotometer.…”