Layered Perovskite La₂Ti₂O₇ Nanostructures for Photocatalytic Degradation of Congo Red Dye Pollutant

Abstract

In photocatalytic innovation, there has been a lot of interest in creating broad spectral responsive photocatalysts to get superior catalytic performance. In this study, we synthesized highly visible‐light responsive La2Ti2O7 perovskite photocatalysts by the probe ultrasonication procedure followed by high‐temperature calcination. Such materials are characterized using UV‐vis diffuse reflectance spectra, powder X‐ray diffraction, X‐ray photoelectron spectroscopy, and scanning electron microscopy to illustrate the optical absorption activities, crystalline properties, chemical composition, and microscopic features. La2Ti2O7 extends optical absorption towards the visible light spectrum and narrows the band gap. The photocatalytic efficacy of the resulting La2Ti2O7 nanostructures was investigated by performing photocatalytic degradation of persistent Congo red (CR) dye while subjected to visible photon illumination using three Osram 150 W tungsten halogen lamp ((λ≥400 nm), 5000 lm nominal luminous flux, 80,600 lx radiation intensity. With effective efficiency, the optimum degradation of the 10 ppm CR dye with a percentage of 95.9 was achieved after 90 min during exposure to the La2Ti2O7 perovskite with a catalyst dosage of 30 mg/100 mL at pH 6. Consequently, La2Ti2O7 nanostructures alone depicted 19.8 % adsorption efficiency for CR dye. In addition, OH⋅ and holes were important in degrading CR dye, which included many different reaction pathways. The treated solution can also demonstrate the environment's safety for accepting water. In summary, under natural visible light irradiation, the synthesized La2Ti2O7 showed enormous promise for eliminating different organic contaminants using photocatalytic methodology.