Free‐Standing Porous Conductive Carbon Foam Electrode for Capacitive Deionization‐Based Sustainable Water Purification

ABSTRACT The key challenge in advancing capacitive deionization (CDI) for water purification is developing cost‐effective, high‐performance electrode materials. Although flow‐through CDI offers significant promise, its potential application is hindered by the high cost of porous electrodes due to expensive current collectors and complex fabrication processes. Here, we report the synthesis of free‐standing porous carbon foam produced via direct pyrolysis and chemical activation of oxidized graphene framework (OGF) incorporated polymer nanocomposite foam, as a sustainable and economical electrode material. The highly interconnected porous network, along with sp ² hybridized carbon, enables in achieving enhanced electrical conductivity. 30% OGF incorporated activated pyrolyzed carbon foam (30GA) exhibited a high surface area of 1275.46 m ² g ⁻¹ and maximum specific capacitance of 203.52 Fg ⁻¹ at 0.5 Ag ⁻¹ in 1000 ppm NaCl as electrolyte, achieving 99.8% capacitance retention over 1000 cycles. In a flow‐through CDI configuration, a monolithic 30GA sample demonstrated a salt adsorption capacity (SAC) of 42.1 mgg ^{− 1} and an average salt adsorption rate (ASAR) of 2.1 mgg ⁻¹ min ⁻¹ , suggesting its potential application for scalable water treatment.