Detecting H₂S oscillatory response using surface plasmon spectroscopy

Abstract

The oscillatory change in the optical absorbance of NiO-TiO2 film containing Au nanoparticles in the presence of H2S gas are investigated. The oscillatory phenomena could be monitored by looking at the variation of the surface plasmon resonance peak of the Au nanoparticles embedded in the TiO2-NiO matrix. Au nanoparticles act as optical probes in the detection of H2S, while the oxide matrix is responsible for the catalytic oxidation of H2S. To the best of our knowledge, it is the first time that oscillatory phenomena are monitored by optical spectroscopy

Sol-Gel Thin Films for Plasmonic Gas Sensors

“…To this extent, we discovered an interesting oscillatory behavior when our nanocomposites are exposed to hydrogen sulfide: a reversible, highly regular change in optical absorption is found to happen when specific samples were exposed to H 2 S ( Figure 2 d). Such evidence has been ascribed to a periodic change in local concentration of H 2 S and SO X at the surface of the sensing material, generating small but regular variations in the LSPR feature of Au NPs [ 49 ]. Notably, the oscillatory behavior stops as soon as H 2 S flow is stopped and the gas sensing cell is flushed with the carrier gas (air).…”