Prussian Blue Decoration on Polyacrylonitrile Nanofibers Using Polydopamine for Effective Cs Ion Removal

We prepared Prussian blue (PB) nanoparticles immobilized on the surface of nanofibers to adsorb the Cs ions effectively. The nanofibers were fabricated by electrospinning of polyacrylonitrile (PAN), and polydopamine (PD) was polymerized to immobilize PB on the surfaces of the nanofibers. PD is known to adhere easily on any substrate, and it could coat the surface of the PAN nanofibers. The catechol groups in PD could also bind to Fe­(III) and Fe­(II) ions, and subsequently, the Fe ions reacted further to form PB nanoparticles, in which PB was located on the surface of PAN nanofibers. The colloidal PB nanoparticles were immobilized on the substrate, and thus they could be easily separated from the metal mixture after Cs ion adsorption. The adsorption isotherm and kinetics of the nanofibrous adsorbent were investigated, indicating monolayer chemisorption of the Langmuir type. The PB-modified nanofibers were stable and the removal efficiency for Cs ions was not varied after five times of regeneration.