STRUCTURAL PROPERTIES OF A SOL-GEL GENERATED BiFeO3 AND ITS PHOTOCATALYTIC ACTIVITY

Abstract

BiFeO₃ (BFO) was synthesized using a combustion sol-gel method from reactants of Bi(NO₃)₃.5H₂O and Fe(NO₃)₃.9H₂O with various complexation reagents. The XRD results indicated that the synthesized BFO materials, which were obtained by using a complexation reagent of tartaric acid and annealed at 600 ºC or 700 ºC in two hours, have a single phase of orthorhombic perovskite structure, belongs to R3c symmetry group. The absorbance and photocatalytic activity of BFO on Methylene Blue (MB) decomposition were studied using infrared (IR) and UV-Vis spectroscopy. With a hollow porous morphology and a narrow bandgap of ~2.20 eV, our obtained bulk BFO material almost does not absorb but become a solar photocatalyst for degradation of MB. Using BFO at 1.0 g/L, the degradation of MB can reach 90% after 90 minutes of illumination with MB concentrations of 10 - 30 ppm. This was confirmed that photoexcited e-h pairs are responsible for the degradation of MB under sunlight.