ZIF-67 In Situ Growth Enabled on Poly(lactic acid) Nanofiber Membranes Doping Sulfonated Graphene Oxide for High-Efficiency Air Filtration

Composite air pollution, comprising particulate matter (PM), formaldehyde, and pathogenic microorganisms, poses a serious threat to human health, which has driven significant research interest in highly efficient multifunctional air purification materials. In this work, sulfonated graphene oxide (SGO) was prepared to facilitate the fabrication of ZIF-67-coated SGO-modified poly(lactic acid) (PLA) nanofiber membranes (denoted as Z-PG) via a combination of electrospinning and in situ growth techniques for high-efficiency air filtration. We employed SGO as a bridge to effectively promote the uniform and robust loading of ZIF-67 onto PLA nanofiber membranes. This approach simultaneously enhanced the membrane’s mechanical properties and multifunctionality, addressing the critical challenges of the uneven distribution and insufficient adhesion of ZIF-67 on flexible substrates. The results demonstrated that the incorporation of SGO significantly improved the mechanical properties of the nanofiber membrane, resulting in a tensile strength of 65.56 MPa and an elongation at break of 65.85%─representing enhancements of 243% and 41.3%, respectively, compared to those of pure PLA nanofiber membranes. Furthermore, the abundant sulfonic acid groups on SGO served as active sites that effectively facilitated the uniform deposition of ZIF-67. Z-PG achieved high-efficiency PM0.3 filtration (up to 99.995%) with a low airflow resistance of 80 Pa and exhibited excellent formaldehyde adsorption performance, with a removal rate of 98.3%. Notably, Z-PG also showed outstanding antimicrobial activity, achieving inhibition rates of 99.996% against Escherichia coli (E. coli) and 99.993% against Staphylococcus aureus (S. aureus). Moreover, Z-PG retained excellent cycling stability, maintaining a filtration efficiency of over 94% and an antimicrobial efficacy of over 98% after 10 consecutive cycles of filtration and antimicrobial tests. This work provides an innovative strategy for developing efficient, stable, and multifunctional air purification materials suitable for complex polluted environments.