COUPLING ELECTROCHEMISTRY TO ELECTROSPRAY: A NOVEL PREPARATION OF GOLD NANOSTRUCTURES

Abstract

nanoparticles on ITO (Indium tin oxide) coated glass using the electrospray (ESI) method Method:The starting point of this study is that the ESI/MS spectrum (Figure 1) of an ethanolic solution of HAuCl 4 shows a reduction process of Au (III) strongly dependent on the Cone Voltage (CV) values (20, 80, 150 V), affording to the ion at m/z 197 (Au+). Further, the decrease of the abundance of this ion at the highest cone voltage suggests the subsequent its reduction with the formation of Au 0 . Figure 1: ESI/MS spectra of an ethanolic solution of HAuCl4 at various cone voltages: Conclusion: Such experimental evidence leads us to use electrospray technique as a preparative tool to obtain the formation and deposition of gold nanoparticles in a single step. In fact, using a home-made electrospray apparatus, we sprayed an ethanolic solution of HAuCl4, forming a very thin aerosol that has been uniformly deposited on ITO coated glass. Then, the deposit by SEM, UV-Vis, Optical-Microscopy and XPS has been characterized4,5. In particular, SEM micrographs show rod-like structures, while XPS spectra show that the deposited nanoparticles contain about 23% of Au0.