Aplicação de fotocatálise heterogênea com perovskitas de nióbio e óxido de zinco na degradação de poluentes.

Abstract

The Search for materials and Technologies to minimize air and water contamination consequences has been a research topic in the last years. Heterogeneous photocatalysis is a relevant technology for this application due to its capacity to promote microorganisms degradation and pollutants removal with minimum contaminants generation. This work aims to synthesize, characterize, and apply three photocatalyst materials: silver niobate (AgNbO3), sodium niobate (NaNbO3), both obtained by sol-gel route, and zinc oxide (ZnO), obtained by green synthesis with Eucalyptus Globulus leaves. The materials were characterized by X-Ray Diffraction (XRD), Raman Spectroscopy, BET specific surface area, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS), which indicated a satisfactory synthesis result with the ideal crystal formation for niobates. The zinc oxide demonstrated good results, although, still needs synthesis improvements. The materials were analyzed for their photocatalytic activity in powder, ceramic supported, and biochar supported forms and then tested for methylene blue degradation (liquid phase) and fungus growth inhibition (bioaerosol). It was observed that the three materials were effective in methylene blue degradation, demonstrating reductions of 90 %, 99 %, and 98 % respectively in AgNbO3, NaNbO3, and ZnO powder form. The supported catalysts were slightly less effective for the process. Fungus growth inhibition was analyzed by impaction method, and a reduction of 46 % and 37 % CFU/m³ were observed, respectively, for the AgNbO3 and ZnO catalysts.