Preparation of gold nanoparticles supported on glassy carbon by direct spray pyrolysis

Abstract

A method for the preparation of gold nanoparticles supported on glassy carbon by direct spray pyrolysis in air at low temperature is presented. The procedure is based on the property of some gold salts which, unlike many other metal salts, decompose by heating at low temperature to produce metallic gold and gaseous species which depend on the salt nature. In the case of the present work, HAuCl4.nH2O was used, which decomposed to solid Au and gaseous H2O and chlorine containing compounds such as HCl and Cl2. This behaviour was verified by thermogravimetric analysis and X-ray diffraction. The gold nanoparticles supported on a glassy carbon electrode were obtained by the impact of HAuCl4 solution droplets generated by an ultrasonic atomizer. These droplets are directed through a nozzle towards the glassy carbon substrate located on a stainless steel block heated by electrical resistance. The supported gold nanoparticles were electrochemically characterized by cyclic voltammetry in acid solution and the surface morphology was characterized by SEM and AFM operated in the tapping mode.