Preparation, characterization and photocatalytic decolorization process for the removal of orange-green dye using perovskites Ba1-xBixFeO3-δ (x = 0, 0.05, 0.1)

Abstract

Recently, the preparation of novel nano-sized photocatalysts and studying of the ability of the prepared materials for the photocatalytic degradation of the harmful pollutants which often present in industrial effluents as model substances under solar/visible light paid particular attention. In this frame, nano-sized Ba1-xBixFeO3-δ system was prepared using Pechini method. All the samples are characterized using XRD, FTIR, optical absorbance spectra, TEM and BET. Cubic fluorite phase of BaFeO2.75 was detected for BaFeO3, Ba0.95Bi0.05FeO3-δ samples while cubic fluorite phase of BaFeO3 was detected for Ba0.9Bi0.1FeO3-δ sample. Minor phases of Orthorhombic BaFe2O4, Monoclinic Ba2Fe2O5 and Orthorhombic BaCO3 were detected for all the samples. Bi doping had obvious effect on the cubic lattice parameter, the cubic unit cell volume, the optical properties, lattice spacing, surface area and the photocatalytic activity. pH, simulated solar irradiation time and catalyst dose were optimized to be 3, 420 min, and 1 g L−1 respectively for degradation of 50 mg L−1 dye, the highest decolorization efficiency was 92.2% using Ba0.95Bi0.05FeO3-δ while, TOC removal was 90% for a photocatalytic and ammonia concentration attained 0.53 mg L−1 under the optimum operating conditions. The photocatalytic decolorization of the dyes was fitted with pseudo first-order rate. According to scavenger experiment, the main oxidative species for the decolorization of orange green dye The analysis of experimental design results demonstrated the significant effect of the irradiation time and pH for orange green on photocatalytic degradation process.