Multi-Scale Nanoarchitectured Fibrous Networks for High-Performance, Self-Sterilization, and Recyclable Face Masks

Airborne particulate matter (PM) pollutants, especially with nanoscale size, have caused serious public health issues. The global demand for high-performance and recyclable face masks is increasing dramatically, especially during the COVID-19 pandemic. However, present masks suffer from low-efficiency interception of PM 0.3 /pathogen, limited air permeability, and incapacity to reuse and recycle. Here, multi-scale nanoarchitectured nanofiber/carbon nanotube (NF/CNT) networks are constructed by a needleless-electrospinning/spraying-netting strategy, enabling well-dispersed CNT networks (diameter ≈ 25 nm) welded on charged nanofibrous scaffolds (diameter > 100 nm) layer by layer. The optimized NF/CNT networks possess a fluffy structure with narrow-distribution small pores (size ≈ 400 nm), “free molecular flow” behavior, and electrostatic adsorption property, thereby exhibiting high filtration efficiency ( > 99.994% PM 0.3 removal) and low resistance ( < 0.05% atmosphere pressure). Furthermore, they demonstrate reliable and ultra-fast photothermal-driven self-sterilization ( > 99.986% in 5 min) under 1 sun and electrothermal-driven self-sterilization ( > 99.9999% in 2 min) in sunless scenes owing to their unique nanoarchitecture. Most importantly, the abandoned NF/CNT filters can be fully recycled as high-performance solar vapor generators to desalinate seawater (3.56 L m −2 d −1 ). This work offers a fascinating solution to reduce disease transmission, resource consumption, and environmental burdens.