Halloysite nanotubes reinforced TiO2-SiO2 hierarchical porous fiber membranes for multi-pollution purification

Inorganic hierarchical porous fibrous membranes demonstrate significant superiority in filtration, adsorption, and catalysis, while the inherent brittleness of inorganic materials and the mechanical fragility from porous structures pose a critical bottleneck to their durability. To overcome this limitation, halloysite nanotubes (HNTs) were integrated into the porous fibers, acting as “nano-rebars” to construct a robust skeleton. This structure facilitated efficient stress transfer and dissipation, significantly enhancing the mechanical robustness of the membrane and increasing the tensile strength to more than twofold. Leveraging the natural electret effect of HNTs, the fiber membrane achieved an exceptional filtration efficiency of 99.85% for the most penetrating PM 0.3 through additional electrostatic adsorption effects. Furthermore, the HNTs-optimized hierarchical pore structure resulted in a remarkably low filtration resistance of 55.2 Pa, while the filtration quality factor could reach up to 0.118 Pa −1 . Additionally, the fiber membrane exhibited remarkable photocatalytic efficacy for formaldehyde (HCHO) degradation, attaining a removal rate of 82.77% within an exceptionally short residence time of merely 0.18 s. This study elucidates the structure-property relationship in inorganic fiber membranes and provides a promising strategy for developing robust, multifunctional air purification materials capable of withstanding harsh conditions.