Engineering sustainable porous carbon electrodes for practical-level capacitive deionization desalination

Capacitive deionization (CDI) is an emerging desalination technique for eliminating diverse ionic species from water, utilizing porous carbon (PC) to capture ions via electrosorption. Compared with reverse osmosis and distillation, CDI is more energy-efficient and sustainable, posing significant advantages in disposal with low or moderate saline. However, PCs as the CDI core are subject to traditional fabrication processes, suffering from yield-performance imbalance, device corrosion and environmental pollution. Herein, based on the whole production chain, this review first deeply analyzes potential unsustainable problems in the PC preparation process and excavates possible desalting influence mechanisms. The span-new perspective of green inorganic salt- and organic salt-activators, and sustainable manufacturing processes are proposed to dock the PC preparation steps. Crucially, various optimization strategies involving structure, defect, process and prediction engineering are discussed to predict and boost the overall desalting performance. Ultimately, the review appraises scientific barriers and untapped opportunities around the development and application of high-yield-high-performance sustainable PCs, providing viable future outlooks for the expanding research field. Through wide investigation of the CDI field, the review aims to stimulate rapid innovation in sustainable PC-based CDI electrodes. • A comprehensive review to emphasize the fabrication of advanced sustainable PCs in CDI is presented. • Green activators and synthesis methods are adopted to dock unsustainable issues in the whole PC production chains. • Diverse engineering strategies are discussed to enhance the desalting performance. • The review appraises scientific barriers and opportunities around sustainable PCs.