Prussian blue and its analogs: A robust platform for efficient capacitive deionization

As water scarcity intensifies, the quest for developing sophisticated electrode materials with adjustable configurations, complex structures, and developed desalination performance garners important interest. Prussian Blue (PB) and its analogs (PBAs), owing to their cost-effectiveness, uncomplicated synthesis, innate open framework, and modifiable composition, have elicited considerable recognition. Herein, the paper provides a comprehensive overview and analysis of the advances made in capacitive deionization electrodes based on PB and PBAs. It commences by detailing the synthesis techniques, post-treatment processes, and derivatives of standard PBs and PBAs. Subsequent sections propose strategies to minimize auxiliary reactions in electrochemical processes, encompassing structural design, protective coatings, substitution, and the confinement effect. Subsequently, emphasis is placed on structures that have potential as electrode materials in applications such as desalination, heavy metal removal, resource recovery, and water softening. A summary of current achievements in the field is provided, alongside a critique of prevailing limitations and emergent challenges. As advancements in electrode materials continue to unfold, it aims to stimulate innovative ideas for utilizing PB and PBAs in environmental research, thereby catalyzing additional investigation into the desalination area.