Novos híbridos baseados em oxihidróxido de ferro (III) e nanopartículas de ouro (AuNPs/FeOOH) como catalisadores para a redução de poluentes orgânicos ambientais

Abstract

Recebido em 24/10/2016; aceito em 22/02/2017; publicado na web em 24/04/2017 NEW HYBRIDS BASED ON IRON (III) OXYHYDROXIDE AND GOLD NANOPARTICLES (AuNPs / FeOOH) as CATALYSTS FOR THE REDUCTION OF ORGANIC ENVIRONMENTAL POLLUTANTS. A new δ-FeOOH supported nano-Au catalyst was prepared by a facile method using HAuCl 4 as the gold source and NaBH 4 as the reducing agent. The samples (denoted as AuNPs/FeOOH) were characterized by means of X-ray diffraction (XRD), UV-vis and infrared spectroscopies and scanning electron microscope (SEM). The obtained characterization data confirmed the formation of Au nanoparticles on the δ-FeOOH matrix surface. SEM observations showed that Au nanoparticles have a spherical morphology and good dispersion with a narrow size distribution on the surface of iron (III) oxyhydroxide. The catalyst exhibits significantly high catalytic activity for hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at room temperature. The high performance obtained can be attributed to the specific characteristics of the nanostructure of the catalyst of nano-Au deposited on the external surface of δ-FeOOH, including plenty of oxygen-containing groups of δ-FeOOH for anchoring AuNPs. Moreover, the catalytic activity increased when the AuNPs content in the δ-FeOOH support. The AuNPs-based δ-FeOOH hybrids are interesting catalysts for hydrogenation of nitrophenols to aminophenols.