Degradation efficiency of methyl orange dye by La0.5Sr0.5CoO3 perovskite oxide under dark and UV irradiated conditions

Abstract

Perovskite oxides have attracted much attention to oxidize and remove effectively several organic pollutants from wastewater. In this work, we report a perovskite oxide La0.5Sr0.5CoO3 (LSCO) for the degradation of methyl orange (MO), a frequently used textile dye, under dark and UV irradiation condition. The LSCO powder was synthesized via the Pechini method and characterized by several techniques. The obtained LSCO presented a rhombohedral phase with a R3‾C space group symmetry. LSCO exhibited a strong photoabsorption property with a bandgap energy of 1.6 eV. The catalytic activity of the LSCO powder was evaluated at different pH values under dark ambient conditions and the result exhibited a higher catalytic activity in the acidic conditions. The MO dye exhibited a degradation rate of 90% in 20 min under both dark ambient and UV irradiation conditions at pH 2.5. The fast degradation kinetics of MO using LSCO in dark was attributed to the double electron generation pathways. The kinetics and reusability of the catalyst were investigated. The MO degradation kinetics under UV irradiation was comparable to the dark condition and it may be due to the optical property of LSCO in the visible region. The results indicated that the LSCO present a good reusability, high catalytic and photocatalytic efficiency and could be used for applications such as wastewater treatment especially in the textile industry.