Oxidation kinetics of plasmonic Ag particles in SiO2 nanofilms: Interlinking particle size to atmosphere–film–substrate system properties

• In situ optical monitoring of Ag:SiO2 nanofilms-on-glass assembly.
• Kinetics of Ag nanoparticles oxidation assessed in real time.
• Determination of activation energy from the temperature dependence of the process.
• A multistep reaction scheme is proposed in connection with experimental results.

A quantitative real-time assessment of the oxidation kinetics of Ag nanoparticles (NPs) embedded in nano-thin SiO2 films deposited on soda-lime glass has been carried out by a process-selective refinement of in situ optical microspectroscopy under ambient conditions. The temperature dependence of Ag NPs oxidation in the nanocomposite films was studied during thermal processing in air in the 673–773 K temperature range. An Arrhenius-type analysis of the exponential decay of the peak intensity of the surface plasmon resonance of the NPs allowed for estimating the activation energy of the process at 4.54 (±0.53)×104 J mol−1. Transmission electron microscopy and secondary ion mass spectrometry are further employed in an effort to discuss the real-time optical spectroscopy information in a broader context regarding the possible physico-chemical multistep interactions in the air–nanofilm–substrate system as a whole.