In situ growth of ZIF-8 onto porous carbons as an efficient adsorbent for malachite green removal

Zeolite imidazolate frameworks (ZIFs) exhibit great potential for organic pollutant removal from water by adsorption. However, it is difficult to remove nanosized ZIFs after adsorption. Here, well-dispersed ZIF-8 is successfully grown onto porous carbons by an in situ growth method. The resultant ZIF-8/Carbon shows excellent adsorption removal efficiency for malachite green (MG) with a maximum adsorption capacity of 3056 mg/g at 30 degrees C. The adsorption kinetics and isotherm data fit well with the pseudo-second-order kinetic model and Langmuir isotherm model, respectively. The influences of temperature, solution pH and salts are also investigated. In addition, the adsorbent can be separated easily by filtration because of its large particle size. Moreover, regeneration experiments reveal that the used adsorbent still exhibits excellent applicability after at least four recycling runs. These features enable ZIF-8/Carbon to be a promising adsorbent for the removal of MG from water.