Three‐Dimensional N‐doped Porous Carbon Derived from Monosodium Glutamate for Capacitive Deionization and the Oxygen Reduction Reaction.

Capacitive deionization (CDI) is a promising desalination technology and its development is highly dependent on the electrode materials. Here, a three‐dimensional N‐doped porous carbon (3D‐NPC) was fabricated for use as a CDI electrode material through the one‐step carbonization process with C5H8NO4Na as the carbon and nitrogen source and NaCl as a template. Benefiting from high‐level N doping (4.93 at %) and a high surface area of 1481 m2 g−1 with an interconnected hierarchical porous structure propitious to the ion and electron transportation, the 3D‐NPC exhibited an excellent desalination capacity in CDI. It was also very impressive that 3D‐NPC was used as an electrode material for a Zn‐air battery, displaying outstanding catalytic performance with an open‐circuit voltage of 1.34 V. Furthermore, the Zn−air battery can drive the operation of a CDI device, showing a high salt adsorption capacity of 19.4 mg g−1 and good applicable stability. The findings in this work will pave a way to develop energy‐integrated capacitive deionization technology. Double or nothing: Three‐dimensional N‐doped porous carbon (3D‐NPC) is successfully constructed by using a one‐step carbonization process. Owing to the high specific surface area, multistage pores, and high N‐doping level, it shows excellent performance in capacitive deionization (CDI) and in Zn−air batteries. The 3D‐NPC assembled Zn‐air batteries can be further used to drive a 3D‐NPCassembled CDI device, exhibiting a high salt adsorption capacity of 19.4 mg g−1 and good applicable stability. [ABSTRACT FROM AUTHOR]