High-Efficiency and Carbon-Lean Electrochemical Desalination Enabled by Nucleophilic Engineering of Organic Molecular...

The worsening global freshwater crisis positions seawater desalination as a critical solution. However, conventional desalination technologies remain constrained by a persistent sustainability trilemma involving high energy consumption, chemical reliance, and substantial carbon emissions. Here, we present an electrochemical strategy that overcomes these constraints by delivering high-performance desalination behaviors while generating substantial environmental and energy benefits. Our approach utilizes a molecularly nucleophilic-engineered dinitro-functionalized pyrenephenazine (PPZ-2NO₂) organic electrode integrated in a capacitive deionization (CDI) cell, enabling real seawater desalination. The electron-withdrawing nitro groups precisely modulate the electronic structure and electrochemical activity of the PPZ-2NO₂ electrode, unlocking the full utilization of redox-active sites. The resulting organic-based CDI configuration possesses high salt ion adsorption capacity and ultrafast rate under low-voltage operation without chemical additives. The validation at module scale demonstrates practical viability, producing industrial-grade freshwater at a 97.2% yield ratio in compliance with World Health Organization (WHO) criteria, while achieving an exceptional seawater desalination capacity of 349.91 mg g^-1. Furthermore, the process operates with low energy consumption and a carbon footprint of only 0.147 t CO₂ eq per ton of salt removed, which is ∼61.18% lower than state-of-the-art technologies. This work offers a molecular-level design for carbon-lean electrochemical desalination toward sustainable water-energy integration.