Substrate dependent surface plasmon resonance evolution of Ag nanoparticles treated in atmospheres

The evolution of surface plasmon resonance (SPR) with alternate air and H 2 treatment was investigated for silver nanoparticles on different SiO 2 -based substrates (soda-lime glass, quartz glass and mesoporous SiO 2 ). It has been shown that evolution behaviours on the three substrates are very different. For silver nanoparticles on the mesoporous SiO 2 substrate, alternate air and H 2 heat treatment led to the alternate disappearance and appearance of the SPR, showing the reversibility of optical changes. For a soda-lime glass substrate, the SPR absorption also disappeared after the first run heat treatment in air and re-appeared after subsequent H 2 heat treatment, but the second run heat treatment in air could not induce the re-disappearance of the SPR. After alternate heating of the sample in air and H 2 for four or more cycles, the SPR stayed almost unchanged. For a quartz glass substrate, however, the SPR absorption became negligible after alternate air and H 2 heat treatment. Such effects of the substrate on the SPR are explained in terms of the subtle difference of the three SiO 2 -based substrates in micro-structure or chemical composition, and the redox of silver in the treatment atmospheres. This study could be important for the design and architectonics of new optical devices based on SiO 2 materials and could also promote the understanding of the interaction of silver nanoparticles with the environment.