Dependence of a surface plasmon resonance absorption band on the concentration of gold nanoparticles in carbon-bearing matrixes

For fullerene matrixes doped by gold nanoparticles we have established experimentally a miss of a red concentration-induced shift of surface plasmon resonance absorption band maximum. Theoretical modeling has been made for spectral characteristics of carbon–bearing nanostructures. Numerical calculations of extinction factors for a spherical metallic particle in an absorbing surrounding medium were based on the Mie theory. Transmission spectra coefficients of densely packed plasmonic nanoparticles monolayers were calculated with the use of the single coherent scattering approximation modified for absorbing matrices. Thin-film Au-air and Au–C60 nanostructures have been fabricated on glass and quartz substrates by thermal evaporation and condensation in vacuum at an air pressure of 2 · 10–3 Pа. The surface mass density of Au into Au–C60 nanostructures was varied in the range (3.86–7.98) · 10–6 g/cm2. The comparison of theoretical and experimental data allowed making a conclusion that the absorbency in carbon-bearing matrix leads to the attenuation of lateral electrodynamics coupling and blocks collective plasmon resonance in densely packed gold nanostructures.

Plasmonic properties of Ag nanoparticles embedded in GeO2–SiO2 matrix by atom beam sputtering

Ag–Ge–SiO2 nanocomposites, synthesized by atom beam sputtering, exhibit tunable localized surface plasmon resonance absorption upon thermal annealing in air.

Aniline chlorination by in situ formed Ag–Cl complexes under simulated solar light irradiation

Ag speciation in a chloride medium was dependent upon the Cl/Ag ratio after releasing into surface water. In this study, the photoreaction of in situ formed Ag–Cl species and their effects on aniline photochlorination were systematically investigated. Our results suggested that formation of chloroaniline was strongly relevant to the Cl/Ag ratio and could be interpreted using the thermodynamically expected speciation of Ag in the presence of Cl−. AgCl was the main species responsible for the photochlorination of aniline. Both photoinduced hole and •OH drove the oxidation of Cl− to radical •Cl, which promoted the chlorination of aniline. Ag0 formation was observed from the surface plasmon resonance absorption during AgCl photoreaction. This study revealed that Ag+ released into Cl−-containing water may result in the formation of chlorinated intermediates of organic compounds under solar light irradiation.