Spectral-Luminescence Properties of Water Dispersions of CdS and Ag Nanoparticles Stabilized with Na_2SiO_3

摘要

It was shown, that using of sodium metasilicate (Na_2SiO_3) as stabilizing agent for CdS quantum dots or Ag nanoparticles in water leads to the formation of stable colloids of CdS/SiO_3~(2-) and Ag/SiO_3~(2-) particles. These colloids are active in the visible range of the spectrum. According to transmission electron microscopy and ultraviolet-visible spectroscopy data, an average size of the particles in colloids was ~ 5 nm for CdS and 2-10 nm for Ag. Ag/SiO_3~(2-) water colloids showed an absorption band with a maximum at 380-410 nm. This band belonged to surface plasmon resonance. CdS/SiO_3~(2-) water dispersions were characterized by luminescence at the region of 500-800 nm. The luminescence intensity increased after addition of Ag~+ into the colloids of CdS/SiO_3~(2-).