Fabrication of nickel hexacyanoferrate film on carbon fibers by unipolar pulse electrodeposition method for electrochemically switched ion exchange application

•NiHCF film was uniformly deposited on the surface of single carbon fiber by UPED method.•High pulse potential resulted in excellent ESIX performances of NiHCF film.•The optimum fabrication condition was found.•Insoluble NiHCF film showed good regeneration ability and long-term cycle stability.•Fabric ESIX film could be prepared for separation of Cs ions from radioactive liquid wastes.

Nickel hexacyanoferrate (NiHCF) film was successfully deposited on carbon fibers by unipolar pulse electrodeposition (UPED) method. The effects of pulse potential and cycle number during the film deposition on the composition, regeneration ability and cycle stability of the film were investigated.The morphology, composition and electrochemical behavior of the as-fabricated NiHCF film were varied with the deposition conditions, and two structural analogues, i.e., soluble and insoluble NiHCFs, could be appeared together or alone in the finally obtained films. Especially, it is found that higher pulse potential was necessary to obtain high-quality NiHCF film on the carbon fiber than on metal electrode. In this study, when the pulse potential during the unipolar deposition of NiHCF film was set at a condition of 0.8 V with 0.5 s on-time, 0.5 s off-time and 3000 cycles, a film with insoluble structural analogue was obtained and it showed large ion exchange capacity, good regeneration ability and long-term cycle stability.

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