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   °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 .