Bacterial cellulose-based composite carbon aerogels functionalized with nitrogen-enriched carbon nanospheres as electrode materials for capacitive deionization

Capacitive deionization (CDI) is widely regarded as a promising water treatment technology, in which electrode materials are crucial for determining the CDI performance. Recently, bacterial cellulose (BC) stands out as an ideal precursor for fabricating CDI electrodes owing to its unique nanofiber network and sustainability. In this work, utilizing BC as both the carbon source and structural matrix, with sodium phytate (SP) being added as a phosphorus source to induce cross-linking, the BC/SP-derived carbon aerogels served as a P-doped skeleton. Following the incorporation of nitrogen-enriched carbon nanospheres (N-CNS) to optimize pore distribution and enhance surface reactivity, a BC-based composite carbon aerogel (BSNCA Y ) was successfully fabricated. By adjusting the N-CNS/SP mass ratio, the optimal BSNCA 1.5 possesses a high specific surface area (3014.22 ± 5.23 m 2 ·g −1 ) and remarkable wettability, thus delivering an impressive desalination capacity of 29.70 mg·g −1 , a rapid salt adsorption rate of 3.31 mg·g −1 ·min −1 , and excellent cycling stability. Besides, density functional theory calculations further reveal that the synergistic effect of N and P doping enhances the electrosorption capacity toward Na + and Cl − ions. Hence, this work offers new insights into the design and synthesis of innovative BC-based composites, thereby demonstrating the viability as electrode materials for energy storage devices.