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

MACCHIONE, M. A.; SAMANIEGO, J. E.; MOIRAGHI, R.; PASSARELLI, N.; MACAGNO, V. A.; CORONADO, E. A.; YACAMAN, M. J.; PÉREZ, M. A.

RSC Advances

RSC

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, little 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 valuesabove the freezing point of water. Based on this reaction, we developed 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 a low level of by-products.