Boron and nitrogen co-doped porous carbon derived from sodium alginate enhanced capacitive deionization for water purification

Capacitive deionization can alleviate water shortage and water environmental pollution, but performances are greatly determined by the electrochemical and desalination properties of its electrode materials. In this work, B and N co-doped porous carbon with micromesoporous structures is derived from sodium alginate by a carbonization, activation, and hydrothermal doping process, which exhibits large specific surface area (2587 m2·g−1) and high specific capacitance (190.7 F·g−1) for adsorption of salt ions and heavy metal ions. Furthermore, the materials provide a desalination capacity of 26.9 mg·g−1 at 1.2 V in 500 mg·L−1 NaCl solution as well as a high removal capacity (239.6 mg·g−1) and adsorption rate (7.99 mg·g−1·min−1) for Pb2+ with an excellent cycle stability. This work can pave the way to design low-cost porous carbon with high-performances for removal of salt ions and heavy metal ions.