Carbon paper/graphite composite loaded with NiHCF thin film for alkaline ion separation

Nickel hexacyanoferrate (NiHCF) thin films were loaded within the porous channels of a carbon paper/graphite electrode by capillary chemical deposition. The composite film electrode was investigated for electrochemically controlled ion separation in an alkaline cation solution. The morphology and composition of the composite film electrode were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, infrared spectroscopy and X-ray photoelectron spectroscopy. Cyclic voltammetry was used to investigate the separation capacity, cycle life and regeneration ability of NiHCF film electrodes in 1 mol·L^-1 KNO₃ and CsNO₃ solution. Results show that the composite film electrodes had a high ion exchange capacity, low diffusion resistance, good cycling stability and regeneration ability. It is suggested that the composite film electrodes are suitable for the selective separation of alkaline cations.