Thermoplasmonic Heat Generation Efficiency by NonmonodisperseCore–Shell Ag 0 @SiO 2 Nanoparticle Ensemble

The plasmon-induced heat generation by core–shell Ag0@SiO2 nanoparticle ensemble, i.e., Ag0 nanoparticles coated with a nanometric, amorphous SiO2 layer, has been studied for nanoparticles dispersed in liquid suspensions or deposited in film. Nonmonodispersed, fractal-like Ag0@SiO2 ensembles were synthesized by flame spray pyrolysis, varying Ag0 particle size distribution, and SiO2 shell thickness, ranging from 1 nm up to 5 nm. The particles were characterized by TEM, XRD, XPS, and UV–vis, while the thermoplasmonic heat-generation efficiency was monitored in situ by measuring the temperature rise over the nanoparticle ensembles by an infrared thermal imager under UV–vis irradiation or ambient solar light. We have carried out a systematic investigation of parameters regarding (i) the particle characteristics, (ii) the surrounding medium, and (iii) the irradiation characteristics. The data reveal the determinant role played by the SiO2 shell in the plasmonic heating by Ag0@SiO2. Thus, for the thinner SiO2 c...