In Situ Growth of ZIF-71 on a Biodegradable Polylactide Aerogel with an Oriented Pore Structure for Effective Capture of Iodine

Metal–organic frameworks (MOFs) have emerged as promising iodine adsorbents for nuclear safety, yet the poor processability and recyclability of MOF powders severely limit their practical applications. Immobilizing MOFs onto green porous substrates offers an effective strategy to address these challenges while preserving their intrinsic porous structure and adsorption performance. This work employed biodegradable polylactide (PLA) aerogels with a vertically oriented pore structure (fabricated by directional freeze-drying technique) as the supports for the in situ growth and immobilization of ZIF-71 particles, successfully fabricating green ZIF-71@PLA composite aerogels. The ZIF-71 loadings on PLA aerogels could be effectively tailored by regulating the in situ growth time. The results revealed that the ZIF-71@PLA composite aerogels could well preserve the vertically oriented pore structures, therefore imparting excellent mechanical strength (up to 464.42 kPa) and outstanding iodine adsorption performance (maximum adsorption capacity of 320.02 mg/g at 50 °C) to ZIF-71@PLA aerogels. Additionally, the aerogels exhibited remarkable iodine adsorption stability and superior adsorption selectivity toward iodine, and the underlying adsorption mechanism was systematically investigated. This study provided a sustainable and green strategy for developing efficient, eco-friendly iodine adsorbent materials for nuclear safety applications.