Thermally activated ZIF-8-based nanofibrous membranes for visible-light photocatalytic formaldehyde degradation and bacterial inactivation toward integrated indoor-air purification

Thermally activated ZIF-8 exhibits a narrowed bandgap of 2.19 eV. • PS@ZIF-8-T NFM achieves 98.1% PM 2.5 filtration with low pressure drop. • 90.4% formaldehyde degraded within 1 h under visible light. • 81.25% E. coli inactivation achieved after 30 min illumination. • Superhydrophobic surface (WCA 150.6°) ensures self-cleaning ability. Nanofiber membranes offer significant potential for air purification; however, conventional membranes are typically limited to particle filtration and lack functionality against bacteria or volatile organic compounds. To address this, this study fabricated a multifunctional photocatalytic nanofibrous membrane by electrospinning polystyrene (PS) with ZIF-8-T (the air-thermally treated ZIF-8) as a photocatalyst. ZIF-8-T has a specific functional group, isocyanate (-N=C=O), with a band gap of 2.19 eV and exhibits broad-spectrum photo-response properties (200–800 nm). The optimized membrane with a 150 wt% ZIF-8-T loading demonstrated excellent integrated performance: a high PM 2.5 filtration efficiency of 98.1%, rapid degradation of 90.4% formaldehyde within 1 h under illumination, and superhydrophobicity with a water contact angle of 150.6°. Moreover, it achieved an antibacterial rate of 81.25% against E. coli within 30 mins of light exposure. This work presents a viable strategy for designing MOF-based composite membranes that integrate efficient filtration, photocatalytic degradation, and antibacterial functions for advanced air purification. Download: Download high-res image (261KB) Download: Download full-size image