Interlayer Covalent Reinforcement‐Enabled Lattice Reprogramming for Durable Capacitive Deionization

ABSTRACT Capacitive deionization (CDI) offers a low‐energy route for desalination but is hindered by electrodes lacking both high ion storage and durability. Here we present a covalently supported interlayer engineering strategy that transforms layered molybdenum sulfide (MoS 2 ) into a high‐performance electrode with exceptional capacity and stability. By precisely intercalating butane‐1,4‐diol, we replace weak van der Waals interactions with rigid covalent linkages, simultaneously expanding interlayer spacing and inducing local 2H‐to‐1T lattice reconstruction. This dual structural reprogramming fundamentally reconfigures Mo‐S orbital hybridization, generating high‐energy antibonding states that promote strong Na + chemisorption while preventing framework collapse. Consequently, the engineered electrode delivers an ultrahigh salt removal capacity of 77.4 mg g −1 , over threefold higher than pristine MoS 2 , without measurable decay over 50 cycles, and demonstrates scalable brine treatment outperforming state‐of‐the‐art 2D electrodes. This work establishes a generalized paradigm for covalently reinforced 2D frameworks, resolving the long‐standing performance‐stability paradox in CDI and advancing practical, high‐capacity desalination.