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

• Published in: Process safety and environmental protection 2022-03, Vol.159, p.862-873
• Main Authors: Kumar, Gandharve, Dutta, Raj Kumar
• Format: Article
• Language: English
• Subjects: Antibiotics; Aqueous solutions; Catalysts; Chemical synthesis; Current carriers; Degradation; Degradation kinetics; Degradation product analysis; Degradation products; Dyes; FeWO4/Bi2MoO6 nanocomposite; Free radicals; Heterojunctions; Hydrogen peroxide; Hydroxyl radicals; Liquid chromatography; Methylene blue; Mineralization; Nanocomposites; Organic carbon; Rate constants; Reactive oxygen species; Scavenging; Solar photo-Fenton degradation; Total organic carbon
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2022.01.063

[Display omitted] An optimized batch of 0.25FeWO4/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 µL 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 ~80% tetracycline and ~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.