Highly porous N-doped graphene nanosheets for rapid removal of heavy metals from water by capacitive deionization

This work reports on a highly porous N-doped graphene-based capacitive deionization device, which exhibits a high removal efficiency (90-100%), fast removal (<30 min), and good regeneration performance (10 cycles, 99% retention) for multiple heavy metals (Pb2+, Cd2+, Cu2+, Fe2+, etc.) in water with a wide range of concentrations (0.05-200 ppm).