In Situ Growth of ZIF-8 onto Aramid Nanofiber Composite Aerogel for Efficient Removal of Pollutants in Water

The public health and water ecosystems are affected by industrial wastewater, resulting in water pollution including heavy metal ions and organic matter, so that adsorbents with multiple adsorption effects are developed to achieve efficient adsorption. In this work, the porous zeolitic imidazolate framework-8 (ZIF-8) was assembled onto cellulose nanofiber (CNF)/poly(vinyl alcohol) (PVA)/aramid nanofiber (ANF) composites and the ZIF-8@CNF/PVA/ANF (ZIF-8@CPA) composite aerogel was designed and fabricated. The composite aerogel has good physical properties and optimal adsorption performance assembled with 20% ZIF-8 content. The ZIF8-20@CPA composite aerogel has high porosity of about 99.62%; the specific surface area is 120.53 m2/g, and pore size is as low as 11.82 μm with a lower volume shrinkage of 1.31%. The adsorption capacity of Cr6+ and rhodamine B about lightweight ZIF8-20@CPA composite aerogels reached 231 mg/g and 201 mg/g, respectively. Due to the 3D porous structure, electrostatic interaction, and ion synergism generated by its assembly with ZIF-8, the composite aerogels have good adsorption performance for heavy metal ions and conform to the relationship of a pseudo-second-order kinetic model. Thus, this study suggests a route to fulfill the multiple adsorbents.