High interfacial charge carrier separation in Fe₃O₄ modified SrTiO₃/Bi₄O₅I₂ robust magnetic nano-heterojunction for rapid photodegradation of diclofenac under simulated solar-light

Solar-light powered environmental detoxification is surely a promising and sustainable approach for common goals of human development and ecosystem preservation. Focussing on this, we herein report fabrication of a novel solar active heterojunction Fe₃O₄@SrTiO₃/Bi₄O₅I₂ an in-situ hydrothermal route. The heterojunction was used for the degradation and mineralization of anti-inflammatory drug Diclofenac (DCF) as target pollutant under simulated solar-light irradiation. Current results reveal that the optimized junction displayed 98.4% diclofenac removal in 90 min with 87.2% mineralization. The ESR probe suggests that both ^●OH and ^●O₂⁻ radicals are active species involved in DCF degradation. Analysing the band structure, thermodynamic feasibility and the photocatalytic performance, a traditional mechanism was ruled out and a Z-scheme transfer was predicted. The charge separation was obviously drastically improved by the Z-scheme transfer and facilitation by Fe₃O₄ and Ti⁴⁺/Ti³⁺ in-built redox mediator. A degradation route was predicted on basis of intermediates detected by liquid-chromatography mass spectrometry analysis. This work promises to provide future possibilities for rational designing and fabrications of semiconductor heterojunctions for solar environmental applications.