Silver nanoshells with optimized infrared optical response: synthesis for thin-shell formation, and optical/thermal properties after embedding in polymeric films
Idioma
en
Article de revue
Este ítem está publicado en
Nanomaterials. 2023-02-03, vol. 13, n° 3, p. 614 (14 p.)
MDPI
Resumen en inglés
We describe a new approach to making ultrathin Ag nanoshells with a higher level of extinction in the infrared than in the visible. The combination of near-infrared active ultrathin nanoshells with their isotropic optical ...Leer más >
We describe a new approach to making ultrathin Ag nanoshells with a higher level of extinction in the infrared than in the visible. The combination of near-infrared active ultrathin nanoshells with their isotropic optical properties is of interest for energy-saving applications. For such applications, the morphology must be precisely controlled, since the optical response is sensitive to nanometer-scale variations. To achieve this precision, we use a multi-step, reproducible, colloidal chemical synthesis. It includes the reduction of Tollens' reactant onto Sn 2+-sensitized silica particles, followed by silver-nitrate reduction by formaldehyde and ammonia. The smooth shells are about 10 nm thick, on average, and have different morphologies: continuous, percolated, and patchy, depending on the quantity of the silver nitrate used. The shell-formation mechanism, studied by optical spectroscopy and high-resolution microscopy, seems to consist of two steps: the formation of very thin and flat patches, followed by their guided regrowth around the silica particle, which is favored by a high reaction rate. The optical and thermal properties of the core-shell particles, embedded in a transparent poly(vinylpyrrolidone) film on a glass substrate, were also investigated. We found that the Ag-nanoshell films can convert 30% of the power of incident near-infrared light into heat, making them very suitable in window glazing for radiative screening from solar light.< Leer menos
Palabras clave en inglés
nanoshells
silver
ultrathin
infrared
synthesis
thin film
solar energy control
Proyecto ANR
Initiative d'excellence de l'Université de Bordeaux - ANR-10-IDEX-0003
Orígen
Importado de HalCentros de investigación