Sunlight mediated photo-Fenton degradation of tetracycline antibiotic and methylene blue dye in aqueous medium using FeWO4/Bi2MoO6 nanocomposite

An optimized batch of 0.25FeWO(4)/Bi2MoO6 nanocomposites has been developed as an efficient solar photo Fenton catalyst for degradation of tetracycline antibiotic and methylene blue in an aqueous medium. The catalyst is synthesized by hydrothermal route. Its structure, composition, and morphology are thoroughly characterized. The catalyst dose of 30 mg/50 mL spiked with 20 mu L of H2O2 (30% v/v) resulted in 97% degradation of tetracycline and 99% degradation of methylene blue within 90 min. The corresponding degradation rate constants are 0.026 min(-1) and 0.043 min(-1), respectively. The total organic carbon estimation indicated mineralization of similar to 80% tetracycline and similar to 90% methylene blue. The photo-Fenton degradation of tetracycline and methylene blue by FeWO4/Bi2MoO6 nanocomposites is significantly enhanced as compared to Bi2MoO6 photocatalyst, attributed to photo-Fenton heterojunction catalyst, charge carrier separation and mobility, and sustained reactive oxygen species (ROS) generation. The role of ROS, e.g., hydroxyl radicals and superoxide radicals, towards the degradation process is confirmed from ROS scavenging studies. The degradation mechanism has been discussed by identifying the degradation products by ultra-performance liquid chromatography (UPLC)-Q-Tof-MS technique. (c) 2022 Published by Elsevier Ltd on behalf of Institution of Chemical Engineers.

Automated summary

An optimized batch of 0.25FeWO(4)/Bi2MoO6 nanocomposites has been developed as an efficient solar photo Fenton catalyst for degradation of tetracycline antibiotic and methylene blue in an aqueous medium. The catalyst dose of 30 mg/50 mL spiked with 20 mu L of H2O2 (30% v/v) resulted in 97% degradation of tetracycline and 99% degradation of methylene blue within 90 min. The study confirms the significant enhancement of the photo-Fenton degradation of tetracycline and methylene blue by FeWO4/Bi2MoO6 nanocomposites compared to Bi2MoO6 photocatalyst. The role of reactive oxygen species (ROS) in the degradation process is confirmed through ROS scavenging studies.