Synergistic effect of amine/Ni-modification and electrochemical activation on prussian blue/carbon paper electrodes for robust cesium removal

Abstract

This study presents the rational design and systematic evaluation of Prussian Blue (PB)-based carbon paper electrodes for efficient and reversible cesium ion capture. By sequentially integrating surface amine functionalization, a conductive nickel interlayer, and electrodeposited Prussian Blue, the resulting PB/Ni/ACP electrode exhibits enhanced adhesion, improved electrical conductivity, and stabilized redox activity. Notably, CV activation in CsCl induces a robust lattice rearrangement driven by the insertion and partial fixation of Cs+ ions. This fixation stabilizes the Prussian Blue framework, maintaining expanded ion-transport pathways and preventing structural collapse during subsequent cycling. Consequently, the activated electrode (A-PB/Ni/ACP) achieves a high Cs+ uptake capacity of 284.9 mg g- 1 and an excellent desorption efficiency of 96.9 +/- 4.3%, markedly outperforming its Ni-free and non-activated electrodes. Moreover, it demonstrates highly reversible adsorptiondesorption behavior with negligible capacity loss over repeated cycles. Overall, the synergy of surface chemistry, interfacial engineering, and electrochemical activation provides a robust strategy for developing durable, reusable PB-based electrodes for electrochemical cesium remediation.