Morphological Evolution of Noble Metal Nanoparticles in Chloroform: Mechanism of Switching on/off by Protic Species

O. A. DOUGLAS-GALLARDO, C. G. GOMEZ, M. A. MACCHIONE, F. P. COMETTO, E. A. CORONADO, V. A. MACAGNO, M. A. PÉREZ

RSC Advances

RSC

Lugar: SHEFFIELD; Año: 2015 vol. 5 p. 100488 - 100488

2046-2069

he morphological stability/morphological reshaping of noble metal nanoparticles are studied experimentally in order to unravel the chemical mechanisms lying beneath. Gold and silver nanoparticles (AuNPs and AgNPs, respectively) formed in chloroformic environment are used, as model synthetic systems, to study phenomena of morphological change. The morphological evolution of NPs that follows their formation, is characterized by spectroscopy (UV-Visible, Raman and FTIR) and TEM (Transmission Electron Microscopy). The change of NP morphology involves the increase of the average NP size and the broadening of size distribution, in a close resemblance with the effect characteristically obtained from the Ostwald ripening. The effect of the poor solvating properties of chloroform in stabilizing small charged species (H+, Ag+, Au+) as well as the principle of electroneutrality of matter are analyzed in order to formulate a feasible reaction scheme consisting of a three-step processes: the gener