The facile synthesis of aerogel-like alumina highly-loaded with gold nanoparticles

A facile approach is proposed for the stabilization of gold nanoparticles within alumina matrix based on fast coprecipitation of colloidal gold and alumina sol in the supercritical carbon dioxide used as antisolvent. Acetylacetone was used as a stabilizer agent for the synthesis of alumina sol. Gold nanoparticles were synthesized from HAuCl 4 directly in liquid alumina sol in reaction with acetylacetone. Acetylacetone played the role of both a stabilizer agent for gold nanoparticles and a reducing agent. Obtained system is characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared (IR) spectroscopy, and UV–Vis adsorption spectroscopy. The method allows us to synthesize aerogel-like alumina highly loaded with gold nanoparticles firmly fixed on oxide surface and uniformly distributed within alumina matrix. The proposed approach combines sol-gel and supercritical fluid methods for the synthesis and opens the wide prospects for preparation composites consisting of gold nanoparticles in oxide matrix with a uniform distribution. These gold-bearing systems may be of interest to a wide range of applications.