Multifunctional composite fibrous filters with integrated Joule heating for particulate matter removal and pathogen inactivation

The growing threat of airborne particulate matter and pathogenic microorganisms to public health necessitates advanced air purification technologies capable of simultaneously removing particles and inactivating pathogens. In this study, we present a composite air filter based on a copper nanowire-modified phenolic resin meltblown nonwoven mat (CuNWs-PRMBM), which integrates physical filtration with Joule heating-induced sterilization. The PRMBM substrate, fabricated via melt-blowing, exhibits excellent thermal stability (decomposition temperature >450 °C) and low thermal conductivity (0.0369 W/m·K), offering a robust platform for Joule heating applications. Surface-deposited copper nanowires establish an efficient conductive network, enabling rapid (≤10 s) and uniform heating up to 124.6 °C under a low voltage of 3.0 V, with exceptional cycling stability. The composite displays superior filtration efficiency, achieving 99.6 % PM 2 . 5 removal at a low pressure drop of 87 Pa under 32 L·min −1 airflow, and maintains 94.9 % efficiency even at 85 L·min −1 . Furthermore, at 2.5 V (102.6 °C), the filter achieves complete inactivation of both S. aureus and E. coli within 15 min. Long-term tests confirm consistent performance over 120 h with sustained removal efficiencies exceeding 99.7 %. This work demonstrates a practical strategy for developing energy-efficient and safe air purification systems suitable for air purifiers and heating, ventilation, and air conditioning applications.