Magnetic Fe3O4 nanospheres supported N/S-SnO2 nanorod for highly effective visible light photocatalytic degradation of tetracycline

The global health landscape is increasingly threatened by antimicrobial resistance, prompting a search for pioneering interventions. The current study focused on the construction of non-metal doped SnO2 nanorod decorated with Fe3O4 nanospheres through hydrothermal techniques. The prepared N/S-SnO2@Fe3O4 nano-heterojunction was evaluated by performing photocatalytic degradation of tetracycline (TET) under visible light illumination. Out of various combinations tested, S-SnO2@Fe3O4 nano-heterojunction was found to degrade TET by 98.3% with a TOC removal of 97%. S-SnO2@Fe3O4 nano-heterojunction and its constituents were characterized by using TEM, SEM, XRD, DRS, PL, Raman, XPS, EIS, BET and FTIR. The influence of factors such as pH, ions, S-SnO2@Fe3O4 dosage and TET concentration on photodegradation were investigated. Furthermore, the stability and reusability of S-SnO2@Fe3O4 nano-heterojunction were assessed through six consecutive cycles of TET photodegradation. XPS and XRD analyses characterized the recovered nano-heterojunction, while scavenging assays and ESR analysis identified as •OH is the main reactive oxygen species involved in TET photodegradation. Additionally, GC-MS/MS analysis proposed a photodegradation pathway, and ECOSAR was used to predict the toxicity of intermediates.