Gold Nucleation Inhibition by Halide Ions: a Basis for a Seed-Mediated Approach

RAQUEL MOIRAGHI; O. A. DOUGLAS GALLARDO; E. A. CORONADO; VICENTE A. MACAGNO; MANUEL A. PÉREZ

RSC Advances

Royal Society of Chemistry

Año: 2015 vol. 5 p. 19329 - 19329

2046-2069

n the present work we examine the effect on gold nucleation of halide ions, a typical synthetic variable in the wet-chemical production of gold nanostructures. It was found that the gold homogeneous nucleation by chemical reduction of aqueous gold ions is kinetically quenched by the rise in the halide ions concentration and this effect is stronger as the Au-halide complex stability increases. The nucleation quenching is not exclusively related to a specific reducing agent but appears to be a more general behavior and is affected by the pH of the media. While no nucleation is observed, Au(I) metastable species coexist together with the reducer constituting metastable solutions. It is demonstrated that the nucleation inhibition by halide ions can be employed as a basis for a seed-mediated approach to produce gold nanostructures. The metastable solutions are proved to function as growth baths where Au(I) reduction is triggered on the surface of previously synthesized gold nanoparticles d