Estudo do zirconato de bário e do zirconato férrico de bário em sistemas fotoativos

Abstract

The textile industry often employs substances and processes with negative environmental impacts, such as the use of toxic and persistent dyes. In this context, photocatalytic compounds that degrade dyes in effluents emerge as promising alternatives. This study investigates the potential of iron-doped barium zirconate as a photocatalyst for the degradation of organic dyes. Despite the favorable properties of barium zirconate, certain characteristics, such as its high band-gap energy, limit its applicability in photocatalysis. However, the addition of iron presents itself as a promising strategy to enhance its properties and make it effective in treating industrial effluents contaminated with dyes. We synthesized BZO and BZFO (iron-doped) samples using the microwave-assisted hydrothermal method. Through X-ray diffraction and Raman spectroscopy, we obtained information about the crystalline structure, confirmed as the cubic phase of BZO. Scanning electron microscopy revealed spherical shapes in all samples, which decreased with the addition of iron. The band-gap values, analyzed by UV-Vis spectroscopy, decreased considerably. X-ray photoelectron spectroscopy indicated that iron caused structural alterations, an increase in the presence of hydroxyl radicals on the surface, and oxygen vacancy-type defects. However, in the luminescence analysis and Rhodamine B photocatalysis tests, the presence of iron had an adverse effect contrary to expectations. The interaction with oxygen sites and the structural defects caused by iron resulted in a reduction of photoluminescent properties and the efficiency of dye degradation compared to the pure sample. Nevertheless, despite this unfavorable effect, the efficient synthesis of doped samples establishes a solid foundation for future research and improvement of the material’s properties.