Synthesis of photocatalytic La(1–x)AxTiO3.5–δ (A=Ba, Sr, Ca) nano perovskites and their application for photocatalytic oxidation of congo red dye in aqueous solution

Abstract

A-site substituted La0.8A0.2TiO3.5–δ (A=Ba, Sr, Ca) nano perovskites were prepared by sol-gel method and characterized using thermogravimetry/differential thermal analysis (TGA/DTA), X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy and transmission electron microscopy (TEM). XRD analysis showed that the La0.8A0.2TiO3.5–δ (A=Ba, Sr, Ca) nano perovskites derived after calcination at 800 °C were in single phase with orthorhombic structure. The particle size of all nano perovskites was found to be ∼20 nm. The synthesized nano perovskites were tested for the photocatalytic decomposition of an azo dye, Congo red. The sequential behavior of La0.8A0.2TiO3.5–δ (A=Ba, Sr, Ca) nanoperovskites for photocatalytic decomposition of congo red in aqueous solution by visible light at room temperature was studied at various time intervals and the efficiency of degradation of the nanoperovskites was compared. Among all the A-site substituted La0.8A0.2TiO3.5–δ (A=Ba, Sr, Ca) nano perovskites, Ba substituted compound showed the highest dye degradation.