Mesoporous carbon derived from ZIF-8 for high efficient electrosorption

In this work, the capacitive deionization (CDI) behavior of mesoporous carbons (MCs) through direct carbonization of ZIF-8 at 1000 degrees C under Ar + 4%H-2 atmosphere has been explored. The obtained MCs exhibit a well-defined mesoporous structure, with a high specific surface area of 723.41 m(2.)g(-1) and average pore diameter of 3.2 nm. The specific electrochemical capacitance of MCs was evaluated in a three-electrode configuration with 1 M NaCl electrolyte, showing that the capacitance reached as high as 215.72 F.g(-1) at the scan rate of 5 mV.s(-1) and 186 F.g(-1) with current density of 100 mA.g(-1), respectively. Moreover, it is found that the electrosorption capacity of MCs was 4.8 mg.g(-1) in NaCl solutions with an initial concentration of 250 mg.L-1 and cell voltage of 1.2 V. Remarkably, the theoretical maximum electrosorption capacity was estimated at 17 mg.g(-1) from Langmuir isotherm when the cell voltage was fixed at 1.2 V. Finally, the well regeneration of MCs electrode was demonstrated, indicating the great potential application of MCs in desalination.