Gold decoration of silica by decomposition of aqueous gold(III) hydroxide at low temperatures

MICAELA A. MACCHIONE; JOSÉ E. SAMANIEGO; RAQUEL MOIRAGHI; N. PASSARELLI; VICENTE A. MACAGNO; EDUARDO A. CORONADO; MIGUEL JOSÉ-YACAMÁN; MANUEL A. PÉREZ

RSC Advances

The Royal Society of Chemistry

Año: 2018 vol. 8 p. 19979 - 19979

he decomposition of gold hydroxide to give metallic gold is known to take place around 300°C in dry environments. However, few information about the gold hydroxide stability in wet environments has been recorded. Here we present experimental evidence which shows that aqueous/water-enriched gold(III) hydroxide colloids decompose spontaneously to form gold nanoparticles at temperature values above the water freezing point. Based on this reaction, we develop a method to decorate silica spheres with gold nanoparticles by precipitation and decomposition of gold(III) hydroxide onto the silica surface in wet media by a simple one-pot/one-step protocol. The silica|gold nanostructures are prepared in high yield and with low level of by-products.