Ultralight, robust, and high Prussian blue-loading polyacrylonitrile aerogel: Preparation, characterization and efficient adsorption/removal of Cs+

Highly efficient and selective adsorption/removal of Cs+ is greatly essential for both resource utilization and radioactive pollution control. To overcome the poor water stability of Prussian blue (PB), a highly selective Cs+ adsorbent, PB-based polyacrylonitrile (PAN) aerogel was prepared using PB-loaded PAN nanofibers. Pre-doping of Fe3+ in PAN nanofibers through electrospinning provides abundant and evenly distributed active sites for the in-situ growth of PB, thus endowing resultant PAN/PB aerogel with much higher PB-loading capacity than reported PB-based composite adsorbents. Systematic structure characterization and property investigation show that as-prepared PAN/PB aerogel has interconnected porous structure, ultralight density, greatly improved water stability, increased thermal stability, robust mechanical elasticity, high hydrophilicity, excellent Cs+ adsorption selectivity. Its practical application potential was well demonstrated by the excellent performances in highly efficient, rapid and selective adsorption/removal of Cs+ from simulated seawater and salt lake brine. The maximum Cs+ adsorption amount of PAN/PB aerogel reached up to 152.67 mg∙g−1 within 1 min. In this work, co-spinning active groups (e.g., Fe3+) in PAN nanofibers is demonstrated to be an effective strategy for increasing the PB-loading of aerogel, which not only provides an excellent Cs+ adsorbent, but also paves a promising way for preparing high-performance aerogels.