The increasing levels of air pollution and the transmission of airborne pathogens have led to a substantial rise in the demand for personal protective equipment, particularly facemasks. However, conventional facemasks present significant limitations, including microbial colonization during prolonged use and improper disposal, which contributes to microplastic accumulation and long-term environmental damage. Consequently, there is a growing need for innovative protective materials that combine high filtration efficiency with antimicrobial functionality. Electrospinning has emerged as a promising technique for producing nanofibrous structures with ultrafine diameters, high porosity, and tunable surface properties, enabling the fabrication of filter media with enhanced particulate capture. Moreover, electrospun fibers can be functionalized with bioactive agents, such as metal oxide nanoparticles, to impart antibacterial activity. In this work, poly(vinyl alcohol) (PVA) and poly(ε-caprolactone) (PCL) electrospun nanofibrous membranes were fabricated and functionalized with synthesized zinc oxide (ZnO) and magnesium oxide (MgO) nanoparticles, respectively, using different incorporation approaches. The resulting membranes were characterized by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy coupled with Energy-Dispersive Spectroscopy (SEM-EDS), and Ground-State Diffuse Reflectance (GSDR). Additionally, antibacterial activity evaluation and filtration efficiency tests were performed to assess the performance of the membranes. ATR-FTIR confirmed the successful synthesis of the nanoparticles and their incorporation into the membranes, while SEM-EDS demonstrated their effective incorporation without compromising fiber morphology. GSDR analysis further verified the presence and availability of the nanoparticles within the electrospun matrices. Both the nanoparticles and the nanoparticle-functionalized membranes exhibited antibacterial activity against Gram-positive and Gram-negative bacteria, while maintaining high filtration efficiency following nanoparticle incorporation. Overall, these findings demonstrate the potential of metal oxide nanoparticle-functionalized electrospun membranes as sustainable and biodegradable filtration media for next-generation facemasks.