Plasmonic Porous CeramicsWednesday (07.10.2020) 14:20 - 14:40
Plasmonic porous ceramics can be defined as a three-dimensional ceramic matrix with embedded plasmonic nanoparticles. Like regular ceramics, this material class shows advantages like high temperature and pressure stability along with dielectric properties. Plasmonic porous ceramics have a high potential for a broad range of applications in various fields, for example ultrasensitive chemical detection under high-temperature/high-pressure conditions, for biomarker detection in biological systems or for highly efficient energy generation through plasmonic photothermal heating. In general, plasmonic materials are developed because of their optical properties which enable highly sensitive and rapid detection of molecules, for example via surface-enhanced Raman spectroscopy (SERS). However, most of the present plasmonic materials are based on two-dimensional assemblies, which cannot be easily scaled for the production of complex three-dimensional structures.
In our present work, we utilize various strategies to embed plasmonic gold and silver nanoparticles inside bulk ceramics or ceramic foams. In order to maintain the stability of plasmonic nanoparticles inside the ceramic matrix, a core-shell structure using alumina as shell material (Au@Al2O3 and Ag@Al2O3) is synthesized. The alumina shell is designed to protect the plasmonic particles during the sintering process which takes place above the melting point of most metallic nanoparticles. Here, the thickness of the alumina shell is strictly controlled (2-4 nm) to maintain accessibility and activity of the plasmonic nanoparticles. We analyze these materials in terms of their sintering properties alongside regular alumina particles and monitor their SERS activity throughout the various processing steps. Additionally, we produce porous ceramics on which gold and silver nanoparticles are deposited from solution to create an active plasmonic surface coating on the complex internal surface of the porous body.