Coral-like ZIF-8/PLA nanofiber membranes via controlled in situ secondary growth for sustainable and high-efficiency air filtration

Airborne particulate matter (PM) pollution poses a serious threat to public health and the environment, underscoring the urgent need for advanced air filtration membranes that combine high efficiency with environmental sustainability. Although polylactic acid (PLA) nanofiber membranes (NFMs) are a promising eco-friendly potential, their electret instability and rapid performance decay limit practical application in air filtration. Inspired by the efficient predation mechanism of corals, we developed coral-like ZIF-8/PLA NFMs featuring a unique “skeleton-tentacle” architecture via controlled in situ secondary growth. This method enables precise regulation of ZIF-8 crystal size and distribution, maximizing active site exposure while preserving inter-fiber pores. The resulting ZIF-8/PLA NFMs exhibit a synergistic “electrostatic-adsorption, physical-interception, and chemical-interaction” capture mechanism, achieving a stable PM filtration efficiency of >99.78% over 2 h with only a moderate increase in pressure drop (from 155 to 217 Pa). The quality factor ( Q F ) reached 0.028 Pa −1 , which is 12 times higher than pure PLA NFMs. Moreover, the membranes also demonstrated excellent gas permeability (1214 m 3 ·m −2 ·h −1 ·kPa −1 ) and mechanical strength (4.0 MPa). In addition, the sterilization rates of ZIF-8/PLA NFMs against both E. coli and S. aureus reached 99.99%, indicating outstanding antibacterial performance. This work not only provides a high-performance, low-resistance, and sustainable air filtration membrane but also establishes a versatile biomimetic paradigm for integrating MOFs onto biodegradable polymers, thereby offering a promising route toward next-generation green filtration media.