The characterization and application of prussian blue at graphene coated carbon fibers in a separated adsorption and electrically switched ion exchange desorption processes of cesium

Abstract Iron hexacyanoferrate/graphene/carbon fibers composite (PB/GN/CFs) was prepared by electrochemical method. Characterization of PB/GN/CFs in a separated adsorption and electrically switched ion exchange desorption processes (Ads-ESIX) of cesium ions (Cs + ) was confirmed by FE-SEM, XRD, IR, XPS and electrochemistry techniques. PB/GN/CFs displayed two quasi reversible transformations from Fe III 4 (Fe II (CN) 6 ) 3 to Fe III 4 (Fe III (CN) 6 Cl) 3 , or to (NH 4 ) 4 Fe II 4 [Fe II (CN) 6 ] 3 at a potential range of −0.1–1.2 V in pH 2, 0.1 M NH 4 Cl. The recovery of Cs + was investigated by PB/GN/CFs using Ads-ESIX method. Cs + could be selectively adsorbed by PB/GN/CFs from aqueous solution in pH 7.0, and desorbed in pH 2, 0.1 M NH 4 Cl. The desorption rate of Cs + depended on the introduction of potential at PB/GN/CFs in pH 2, 0.1 M NH 4 Cl. Both H 3 O + and NH 4 + could play dual role of electrolyte and competitor for the desorption of Cs + . PB/GN/CFs could be used to the recovery of Cs + from the residual salt lake brine in which potasium had been removed from Qarham playa of Qaidam Basin in China.