Electroactive PVDF/Ti3C2Tx MXene functionalized nanofiber mats with high surface potential for high-efficiency indoor & outdoor submicron PM(0.3-2)μm filtration.

Fine PM0.3-2.0 rapidly penetrates the respiratory system and causes health problems. Commercial filters remove 0.3 μm particles at ∼95 % efficiency but impose high pressure drops that make breathing difficult. We fabricate a novel electrospun PVDF-Ti3C2Tx nanofiber mat for PM0.3-2.0 filtration. Where a high electric field stretched PVDF and PVDF-Ti3C2Tx solutions into ultrafine fibers that were collected as porous nanofibrous mats. PVDF was chosen for its electroactive behavior and high dielectric constant, enabling efficient electrostatic filtration. The incorporation of Ti3C2Tx MXene enhances surface charge density and interfacial polarization, strengthening particle-fiber interactions for improved submicron particulate capture. The mat delivers 99.99 % filtration efficiency at 0.3 μm with a nominal pressure drop of 14.38 Pa/cm2 and a quality factor of 0.05 Pa-1. Filtration is governed by van der Waals and enhanced dipole-dipole/induced-dipole interactions between fibers and particles. We attribute the improved performance to surface-terminating polar groups (O, OH, F) on Ti3C2Tx flakes that raise conductivity and surface potential, strengthening intermolecular forces (Si-OH, C-OH, C=O). PM0.3 adsorption rates for pure Ti3C2Tx film, PVDF nanofiber, and PVDF-Ti3C2Tx are 52 μg/cm2/h, 12.1 μg/cm2/h, and 88.8 μg/cm2/h, respectively, consistent with interaction forces of 7 nN (PVDF/PM) and 22 nN (PVDF-Ti3C2Tx/PM). SKPM mapping shows nearly uniform electrostatic profiles with surface potentials of -7.32 to -8.44 V (PVDF) and -8.93 to 9.0 V (PVDF-Ti3C2Tx). Both mats remain hydrophobic by contact-angle analysis. Overall, this first-time PVDF-Ti3C2Tx nanofiber filter matches or exceeds commercial products, offering low ΔP and high efficiency for PM0.3 removal. These results clarify capture mechanisms and support scalable use in breathable face masks.