A novel composite (ZIF-8@PEI-CC) with enhanced adsorption capacity and kinetics of methyl orange

Metal-organic framework materials (MOFs) have shown efficient adsorption performance in organic dye removal . However, its relatively poor capacity and slow adsorption kinetics often limit its further application. Herein, polyethyleneimine (PEI) was cross-linked and encapsulated in ZIF-8 to prepare novel composite (ZIF-8@PEI-CC) by using cyanuric chloride (CC). It was found that the composite exhibited excellent adsorption performance for methyl orange (MO). Compared with ZIF-8 (183 ​mg ​g −1 ), the adsorption capacity (710 ​mg ​g −1 ) was significantly enhanced, and it was easier to separate than ZIF-8. Moreover, it shows a faster adsorption rate than ZIF-8. The adsorption kinetics of the ZIF-8@PEI-CC is more consistent with the pseudo-secondary kinetic model . Isotherm of the ZIF-8@PEI-CC is more in line with the Langmuir model. In addition, the ZIF-8@PEI-CC shows high adsorption capacity in a wide pH range (4-11). Therefore, the synthesized composite ZIF-8@PEI-CC has great potential as an effective adsorbent for removing MO.