Binder‐Free Wood Converted Carbon for Enhanced Water Desalination Performance

The design and synthesis of high-performance and economical carbon electrodes play a critical role in developing energy-efficient water desalination technologies. As a sustainable approach, low-cost and abundant biomass materials are promising candidates to prepare porous carbon for capacitive deionization. In this work, binder-free porous carbon sheets are successfully prepared using natural balsa, pine, and basswood by thermal carbonization and treated by chemical activation. The carbon electrode materials converted from balsa and pine exhibit a comparable salt adsorption performance by capacitive deionization due to the extensive surface area, substantial electrical property, and superior hydrophilic performance. The following activation treatment of the balsa-converted carbon further enhances the surface and electrical properties and benefits the desalination performance. The salt adsorption capacity of the activated balsa electrode exhibits 12.45 mg g(-1). Additionally, 19.52 mg g(-1) Pb2+ and 20.06 mg g(-1) Cr3+ heavy metal adsorption capacity is also observed with the activated balsa electrode in 100 mg L-1 PbCl2 and 50 mg L-1 CrCl3, respectively. To the best of authors' knowledge, this is the highest NaCl adsorption capacity performance reported thus far by using pure wood converted carbon as the electrode, and these promising results indicate that activated balsa is an extraordinary material for water desalination.