Journal of Supercritical Fluids, Vol.140, 159-164, 2018
Effect of wavelength in laser-assisted synthesis of silver nanoparticles by supercritical deposition technique
The use of laser irradiation for conversion in supercritical deposition (SCD) provides flexible opportunities for fast synthesis with high spatial resolution and for tuning the characteristics of resulting metal phase. Here, silver nanoparticles (AgNPs) are synthesized in the pores of Vycor glass; the influence of the irradiation wavelength on the properties of the ensemble is analyzed. The synthesis is performed under supercritical conditions using laser irradiation at three different wavelengths: two resonant ones, matching the plasmon band of i) spherical AgNPs, ii) prolonged AgNPs, and iii) an off-resonant one that is red-shifted from the former two. AgNPs are characterized by extinction spectroscopy and by transmission electron microscopy (TEM). We show that the wavelength of irradiation noticeably influences both the rate of synthesis and homogeneity of the synthesized ensemble of AgNPs. In particular, the mass fraction of non-spherical particles can be increased using irradiation that is in resonance with their plasmon band.