▎ 摘　　要

Capacitive deionization (CDI) is a novel desalination technology for brackish water purification. Here, we report the rational design of an efficient asymmetric CDI system considering several steps. First, three-dimensional graphene nanostructures (3DG) were synthesized using the hydrothermal method, followed by the freeze-drying process, and then drop casting onto the carbon fiber paper (CFP) substrate. Second, a facile and controllable electrodeposition technique was used for the in-situ synthesis of MnO2 nanospheres and NiO nanoparticles onto the CFP/3DG surface to prepare CFP/3DG/MnO2 cathode and CFP/3DG/NiO anode. Third, the prepared nanocomposite electrodes were used to fabricate an asymmetric CDI cell. Here, MnO2 (pI= 4.5) and NiO (pI = 10) nanostructures provide opposite surface charges due to their dissimilar isoelectric points, enhancing cations and anions electrosorption. The surface morphology, chemical and electrochemical charac-teristics, as well as the capacitive performance of the fabricated CFP/3DG/MnO2 and CFP/3DG/NiO electrodes, were investigated using SEM, EDX, XRD, FTIR, TGA, BET/BJH, and electrochemical techniques. Besides, impedance-derived capacitive analysis was used to evaluate the ions retention time on the fabricated electrodes. Finally, the fabricated CFP/3DG/NiO||CFP/3DG/MnO2 asymmetric CDI cell was used in water desalination with high reversibility, good regeneration rate, and high electrosorption capacity (21.01 mg g(-1)) for the initial salt concentration of 1000 mg L-1 in 1.2 V. These results suggest that the proposed asymmetric CDI system is a promising candidate for the efficient capacitive desalination process.