Size-controlled synthesis of monodisperse Ag2S nanoparticles by a solventless thermolytic method

Monodispersed and size-controlled Ag2S nanoparticles were synthesized successfully via a green and simple surfactant-free solventless thermolysis of silver xanthates as single-source precursors. As-prepared Ag2S nanoparticles were characterized by transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectrometry. Moreover, a possible growth mechanism of Ag2S nanoparticles was proposed. It has been found that the size of Ag2S nanoparticles can be effectively controlled by changing the alkyl chain length of the precursors. Ag2S nanoparticles prepared from silver carnaubyl xanthate have the smallest mean diameter of 8.9±1.2 nm, while the same products obtained from silver hexadecyl xanthate and silver octyl xanthate have a larger mean diameter of 19.5±0.9 nm and 48.3±3.6 nm, respectively.

► Size-controlled Ag2S nanoparticles were synthesized through solventless thermolytic surfactant-free method.
► “Size-control” was achieved by simply changing the alkyl chain length in the precursor.
► The longer the alkyl chain length, the smaller the particle size.