The development of reusable and efficient antiviral filtration materials has become increasingly critical in the context

of global health crises such as the COVID-19 pandemic. In this study, we present electrospun polymer nanofiber filters

embedded with CuxO-TiO2 photocatalysts, designed for visible-light responsiveness and long-term antiviral functionality.

The filters were fabricated via both pre-synthesized and in-situ formation methods, yielding nanofibers with uniform

morphology and homogeneously distributed photocatalyst domains, as confirmed by scanning electron microscopy (SEM)

and energy-dispersive X-ray spectroscopy (EDS) analyses. Antiviral performance, assessed using the model bacteriophage

ΦX174, was strongly dependent on the Cu/(Ti/C) atomic ratio, with optimal efficacy consistently observed in the 30–70

range. This trend was attributed to enhanced interfacial charge transfer and the light-driven generation and regeneration of

virucidal Cu(I) species. Durability tests confirmed that the filters maintained virucidal activity over multiple reuse cycles,

owing to a regenerative Cu(II)/Cu(I) redox mechanism. Collectively, these findings establish CuxO–TiO2–embedded nanofiber

filters as scalable and semi-permanent antiviral materials, offering a robust alternative to conventional disposable filters

and a transferable design strategy for next-generation personal protective equipment and air purification technologies.