Capacitive　Deionization　(CDI)　has　emerged　as　an　ideal　alternative　strategy　for　energy-efficient　brine　water　treatment.　However,　as　an　essential　component　of　the　CDI　electrode　system,　anode　materials　with　efficient　ability　for　anion　capture　have　not　been　adequately　addressed.　Herein,　we　have　successfully　developed　a　kind　of　iron　nitride　(Fe4N)　material　with　a　unique　pseudocapacitive　nature　into　CDI　anodes.　Specifically,　the　Fe4N　nanoparticles　are　controllably　encapsulated　within　interconnected　graphene　cavities　to　form　binder-free　monolithic　electrodes　(GF@FeN)　through　stepwise　assembly　strategies.　The　intrinsic　electrochemical　desalination　potential　of　the　Fe4N　species　can　be　effectively　unlocked　with　the　assistance　of　the　graphene　porous　frameworks.　For　the　typical　Cl−　anions,　the　optimized　GF@FeN　anode　exhibits　competitive　dechlorination　capabilities　of　~140.32　mg·g−1　(~　231.23　mg·g−1　for　NaCl)　and　long-term　cycling　stability　(over　88　%　retention　rate　after　50　cycles).　Mechanistic　discussions　indicate　that　the　excellent　Cl−　capture　ability　of　the　Fe4N　species　mainly　stems　from　the　reversible　redox　reactions　involving　the　divalent　and　trivalent　iron　(Fe2+/Fe3+)　components　on　its　surface.　Furthermore,　the　GF@FeN　electrodes　can　also　effectively　capture　other　representative　toxic　anions,　such　as　F−　and　CrO42−,　and　achieve　very　high　removal　rates　(~　99　%)　under　certain　conditions,　demonstrating　their　broad　applicability　as　CDI　anodes.　This　work　establishes　the　feasibility　of　iron　nitride　as　a　promising　CDI　anode,　which　not　only　provides　alternative　electrode　materials　for　effective　anion　removal　but　also　opens　up　vast　opportunities　for　the　design　of　high-performance　hybrid　CDI　electrode　systems.　©　2025