Compósito AG2MOO4/AG3PO4/Grafeno aplicado à degradação fotocatalítica de hidrocarbonetos aromáticos

Abstract

Advanced oxidative processes stand out due to their direct contribution to the degradation of pollutants, such as those derived from gasoline, including volatile organic compounds (VOCs) like BTEX, which are highly harmful to human health. Therefore, the development of new materials aimed at degrading organic pollutants— those that may eventually reach aquatic environments inhabited by marine fauna or even groundwater sources used for human consumption—is of great importance. In this context, photocatalysts, which are semiconductor materials used in advanced oxidative processes, can be employed to mineralize these pollutants. When supported on or combined with other materials, they allow for more effective removal of the photocatalyst after the degradation process. Thus, the overall objective of this work was to synthesize a silver molybdate and silver phosphate composite on graphene (Ag2MoO4/Ag3PO4/Graphene) for the photocatalytic degradation of BTEX. The photocatalyst was synthesized via a simple precipitation method, adapted from methodologies available in the literature. The graphene was obtained from the epicarp of the babassu coconut (Attalea speciosa), collected at the Federal University of Maranhão. The materials obtained were characterized using the following techniques: Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), and Diffuse Reflectance Spectroscopy (DRS). Photocatalysis tests, under visible light in a custom-built reactor, showed that after 60 minutes of irradiation, the amount of BTEX present in the samples complied with the parameters established by the Ministry of Health for drinking water. These results indicate that the Ag2MoO4/Ag3PO4/Graphene composite has potential for use as a photocatalyst.