Photocatalytic properties of BiFeO3 (BFO) synthesized by microwave-assisted hydrothermal method

Abstract

Bismuth ferrite, whose formula is BiFeO₃ (BFO), is widely studied for its photovoltaic and photocatalytic properties. In this study, samples of this material were synthesized using the microwave-assisted hydrothermal method with the aim of measuring its ability to discolor contaminants present in water in previously formulated concentrations through photocatalysis. Photocatalysis is a process with great potential for applicability in the decontamination of effluents. The analysis process used a 1:1 molar ratio of bismuth nitrate to iron nitrate, with the addition of potassium hydroxide to the aqueous solution. Two samples were synthesized at different temperatures, specifically 140 °C and 160 °C. An X-ray diffraction analysis revealed that the synthesized samples were in an amorphous state. Photocatalytic tests were carried out to evaluate the ability of these materials to decolorize rhodamine B present in water in a previously known proportion. A sample synthesized at 140 °C successfully decolorized the solution within 60 min, providing its potential application in photocatalytic processes for decolorization of organic substances from wastewater. In turn, a sample synthesized at 160 °C discolored or contaminated in a slightly longer time. The samples were also subjected to a temperature of 750 ºC until crystallinity was reached. However, photocatalytic tests with crystalline samples performed less well than amorphous samples.