Recyclable adsorbent aerogels by in-situ growth of ZIF-8 on aramid nanofibers/poly(vinyl alcohol) for multiple water pollutants

Water pollution from human activities such as sanitary wastewater, agricultural run-off and industrial discharges is becoming an increasingly serious issue, which has caused immeasurable damage to human health and the ecological environment. Therefore, it is urgent to develop an effective strategy for dealing with multiple water pollutants. Herein, we designed a ZIF-8@ANF/PVA composite aerogel by in-situ growth of zeolitic imidazolate frameworks-8 (ZIF-8) on aramid nanofibers (ANF) and poly(vinyl alcohol) (PVA) networks. The utilization of PVA provided more active hydroxyl groups on ANF for the in-situ growth of ZIF-8, so as to enrich the pore structure of the composite aerogel, thus improving the mechanical property and adsorption capacity significantly. Owing to its high surface area, extensive porosity and multiple size pores, the resultant ZIF-8@ANF/PVA composite aerogel exhibited excellent adsorption capacity for Cr(VI) (230.5 mg/g), tetracycline (319.5 mg/g), Congo red (547.0 mg/g), as well as organic oils and solvents. More importantly, the composite aerogel retained its remarkable adsorption capacity even after 10 cycles, demonstrating optimal cycling stability, superior reusability, and facilitated separation operations. This study provides an effective and sustainable strategy for fabricating MOF-derived composite aerogel as a promising adsorbent for the removal of diverse pollutants from water.