From polymer choice to pathway control of Nb2O5 nanofibers for acetaminophen degradation

The removal of emerging contaminants such as acetaminophen (ACT) from water is an increasing environmental concern due to their persistence and potential health impacts. Photocatalysis provides a sustainable route for pollutants degradation, and Nb 2 O 5 is a promising material owing to its high stability and low toxicity. In this study, Nb 2 O 5 nanofibers were synthesized via electrospinning using two polymeric matrices, polyvinylpyrrolidone (PVP) and polyacrylonitrile (PAN), followed by annealing at 500 °C and 700 °C to tailor their structural and surface properties of the resulting Nb 2 O 5 nanofibers. Four distinct samples were obtained: NA500 and NA700 (PAN-derived) and NV500 and NV700 (PVP-derived). The nanofibers were characterized by X-ray diffraction (XRD), N 2 sorption (BET analysis), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) performed in air confirmed the progressive decomposition of the polymer matrices and the effective removal of organic components during calcination. Photocatalytic tests under UV irradiation revealed that both polymeric matrices and annealing temperature strongly influenced ACT degradation. NA500 exhibited the highest activity, achieving 62.5% acetaminophen degradation within 60 min. Radical scavenging experiments indicated that photogenerated holes, hydroxyl, and superoxide radicals were the main reactive species. The superior performance of NA500 compared to NV500 arises from the higher thermal stability of the PAN matrix, which preserves fibrous morphology, enhances mesoporosity, and improves light absorption for efficient charge separation and radical generation. • Nb 2 O 5 nanofibers were successfully synthesized via electrospinning using PVP and PAN matrices. • Annealing temperature and polymer matrix strongly influenced structural and surface properties. • NA500 showed the highest photocatalytic activity, degrading 62.5% ACT in 1 h under UV. • Photogenerated holes, hydroxyl and superoxide radicals were identified as key reactive species.