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

The thermal stability of nanocages is of great research value in bothfundamental studies and practical applications. In this work, by focusing onsilver-gold (Ag-Au) alloyed nanocages as a model system, we demonstrate thatthe wall thickness of the nanocage is a critical parameter in determining itsthermal stability. We systematically evaluated the thermal stabilities of Ag-Aunanocages with different wall thicknesses in the range 3.8-13 nm in both solutionand solid phases. The results showed that, in both phases, nanocages with thickerwalls displayed better stabilities. At sufficiently high temperatures, the nanocageswere deformed to thermodynamically more stable nanostructures. Thedeformation processes were found to be different for nanocages with variouswall thicknesses, which were carefully monitored and analyzed by electronmicroscopy imaging. Changes in plasmonic properties of the nanocages duringheat-induced deformation processes were also investigated.