Síntese e aplicação de catalisadores baseados em nanopartículas de ouro suportadas em óxidos de grafeno

Abstract

Gold nanoparticles have been widely used as catalysts in oxidation reaction. Their gold nanoparticle activity strongly depends on their size and interaction with support. Graphene oxide and reduced graphene oxide are materials that can be used as support for nanoparticles. In this context, the main goal of the present work was related to the synthesis of gold nanoparticles followed by their accommodation on the surfaces of graphene oxide and reduced graphene oxide. The materials obtained with distinct gold proportions were tested as a catalysts. The supports were synthesized from exfoliation and oxidation of graphite according to modified Hummers method. Gold nanoparticles were obtained through sol-gel method. Exfoliation, oxidation, and nanoparticle deposition was supported by Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), Infrared Spectroscopy (IR), X-ray Diffraction (XDR), Raman Spectroscopy, Energy-dispersive X-ray spectroscopy (EDS), Ultraviolet-visible spectroscopy and Field Emission Gun Scanning Electron Microscopy (FEG-SEM). The catalyst potential of the materials was investigated for hydrogen peroxide decomposition reactions and for the oxidation of benzyl and butyl alcohol. The experimental information indicates that reduced graphene oxide with lower gold nanoparticle content is more active in the alcohols oxidation.