Propriedades fotocatalíticas de BFO sintetizado pelo método hidrotermal assistido por micro-ondas

Abstract

Bismuth ferrite, whose formula is BiFeO3 (BFO) is widely studied for its photovoltaic and photocatalytic properties. This study employed the microwave-assisted hydrothermal method to synthesize bismuth-iron oxide compounds chemically. The synthesis process utilized a 1:1 molar ratio of bismuth nitrate to iron nitrate, with the addition of potassium hydroxide, as mineralizer to the aqueous solution. Two syntheses were conducted at different temperatures, specifically at 140 °C and 160 °C. Subsequently, selected samples from each synthesis were subjected to thermal treatment at 750 °C. X-ray diffraction analysis revealed that the samples synthesized were in an amorphous state immediately after synthesis. Remarkably, the sample synthesized at 140 °C and treated at 750 °C exhibited a combination of BiFeO3 and Bi2Fe4O9 phases. In contrast, the sample synthesized at 160 °C and treated at 750 °C consisted predominantly of nearly monophasic Bi2Fe4O9, with residual BiFeO3. We conducted photocatalytic measurements to assess the ability of these materials to decompose Rhodamine B. The amorphous samples demonstrated the most promising photocatalytic performance, whereas the sample containing Bi2Fe4O9 exhibited the poorest performance. The sample synthesized at 140 °C successfully decolorized the solution within 60 min, suggesting its potential application in photocatalytic processes for removing of organic pollutants from effluents.