Porous carbon nanofibers demonstrate exceptional capacitive deionization
Capacitive deionization (CDI) is energetically favorable to deionize water, but existing methods are limited by their desalination capacities and time-consuming cycles due to insufficient ion-accessible surfaces and slow electron/ion transport. In a new report on Science Advances, Tianyu Liu and a research team in the departments of chemistry, civil and environmental engineering, and nanoscience at Virginia Tech, U.S., demonstrated porous carbon fibers (PCF) as an effective CDI material. They derived the PCFs from microphase-separated poly(methyl methacrylate)-block-polyacrylonitrile (PMMA-b-PAN). The resulting PCFs maintained abundant and uniform mesopores interconnected with micropores to form a hierarchical porous structure with a large, ion-accessible surface area and high desalination capacity. The continuous carbon fibers and interconnected porous network allowed fast electron/ion transport to maintain a high desalination rate. The work highlights the promise of copolymer-based PCF for high capacity and high rate CDI.