Estudo das propriedades fotocatalíticas do compósito AgCl/xGO

Abstract

In this work, silver chloride (AgCl), graphene oxide (GO) powders and AgCl/xGO composites were obtained with variations in GO concentration in 1, 2, 4 and 8% by mass. The powders were characterized by X-Ray Diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FEG-SEM), absorbance in the visible ultraviolet region and diffuse reflectance spectroscopy, UV-Visible spectroscopy (UV-Vis). The photocatalytic properties of the composites were evaluated by varying the concentration of the methylene blue dye, illuminated by UV lamps. The XRD standards express that the modification in the Hummer’s method and the use of the sonochemical tip are efficient in obtaining GO and AgCl powders. FESEM images indicate the formation of silver nanoparticles on the surface of the AgCl particles and the existence of an interface between the AgCl/GO particles. The addition of GO caused a potentiation in the optical properties of AgCl, increasing its absorption to length of larger waves and reducing its Egap. The interface obtained by AgCl/GO improves the photocatalytic efficiency of the composite, as a result of the impediment of recombination of the electron/hole pairs (e-/ h+). After 3 minutes of exposure to UV radiation, the composite with 8% GO caused complete degradation in the dye and the pure AgCl powder degraded 75.3%.