‘One-step’ controllable synthesis of Ag and Ag2S nanocrystals on a large scale

Abstract

Ag and Ag(2)S nanocrystals (NCs) were synthesized by a simple 'one-step' process. Dodecanethiol played three important roles in the synthesis: as the capping reagent, reducer (for the synthesis of Ag) and S(2-) source (for the synthesis of Ag(2)S). Due to the multifunctional characteristic of dodecanethiol, only two reactants (silver nitrate and dodecanethiol) are needed in the synthesis, avoiding the use of toxic organic solvents and a complex reaction procedure. X-ray powder diffraction and transmission electron microscopy studies indicated that both the phase (Ag or Ag(2)S) and the particle size were controlled by reaction parameters. The infrared spectra studies indicated that the nanoparticles were stabilized by dodecanethiol. As a result, the particles were stable (no irreversible conglomeration) in the solid state and in solution for several months. In addition, a large quantity of Ag and Ag(2)S NCs could be readily obtained. A possible formation and size evolution mechanism for Ag and Ag(2)S NCs was proposed.