Anchoring LaFeO3 perovskites on the polyester filters for flowthrough photocatalytic degradation of organic pollutants

Over the last decades, the application of photocatalysis for the decomposition of persistent organic pollutants has emerged increasing attention. However, the scalable catalyst fabrication has not yet been examined in detail for the photocatalytic treatment. The present work focuses on the development of photo-active filter immobilized with LaFeO3 perovskites and utilization in photocatalytic reactor for decomposition of tetracycline antibiotic using batch and continuous reactors under visible light illumination. The catalytic filters (LFO@PE ) were synthesized by dip-coating method followed by hydrothermal treatment. The changes in surface functionality and morphology of polyester filter were investigated by Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM-EDS), X-ray diffraction (XRD) and UV-visible diffusion spectra (UV-vis DRS) analyses. SEM-EDS and XRD analyses confirmed the formation of well-crystalline LaFeO3 over the fiber structure of polyester filter, and UV-vis DRS spectra revealed enhancement of absorption in visible region. The as-synthesized catalytic filters exhibited greater photocatalytic performance with increasing LaFeO3 deposition ratio and the photocatalytic mechanism studies revealed that holes and super oxide radicals acted as reactive species in TC photodegradation. The photodegradation ability of the catalytic filter was also tested with different dyes (indigo carmine, orange II and tartrazine) and pharmaceuticals (sulfadiazine, cipmfloxacin and paracetamol). Furthermore, the efficiency of composite filter was evaluated in dynamic flow degradation tests in micro-reactor and the results demonstrated that the filter support was stable after eight hours of treatment, providing the basis for industrial catalyst design to be utilized in wastewater treatment plants.