Revealing oxidation kinetics of dielectric-embedded Ag nanoparticles via in situ optical microspectroscopy

The oxidation kinetics of Ag nanoparticles (NPs) embedded in an aluminum oxide film deposited on quartz have been assessed via an in situ real-time monitoring of plasmonic evolution during thermal processing in air. A temperature-dependent exponential decay in the peak intensity of Ag NPs’ absorption was revealed, which was analyzed through first-order kinetics. An activation energy of 3.28 (±0.27) × 104 J mol−1 was estimated in good agreement with the oxidative dissolution of similar-sized Ag NPs in liquid phase reported by Ho et al. [11]. Results are discussed in the context of mechanistic parallelisms and physico-chemical interactions in the air-atmosphere/nanocomposite-film/substrate system.