Cork activated carbon (CAC), derived from natural cork, was successfully prepared through two steps of carbonation and activation, and used for desalinating brackish water. The CAC presents a uniform honeycomb structure composed of porous carbon nanoflakes (200–300 nm) and large specific surface area (SSA) (2680 m2 g−1), offering transport channels and a large number of adsorption sites to NaCl solution. The CAC showed excellent capacitance (116 F g−1), small internal resistance and better charge-discharge performance. Moreover, the optimized CAC showed high desalting capacity (9.44 mg g−1), charge efficiency (46.72 %), and lower energy consumption (54.19 Wh m−3) in the desalination process, superior to that of the reported biomass-based activated carbons, which can be attributed to the stable honeycomb structure, high microporous volume (0.86 cm3·g−1) and large pore size (2.43 nm). This investigation demonstrates the potential application of cork granules-based CAC electrodes in the field of desalination.
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