ZnO/POA functionalized metal-organic framework ZIF-8 nanomaterial for dye removal

Abstract

In this work, a novel metal-organic framework ZIF-8 is fabricated with poly-o-anisidine/zinc oxide (POA/ZnO) to obtain poly-o-anisidine/zinc-oxide nanohybrid material (PAZ@ZIF-8) via in-situ approach at room temperature. The characteristics of as-prepared nanocomposites were investigated by employing sophisticated techniques such as SEM, TEM, FTIR, XRD, and SEM-EDAX. The PAZ@ZIF-8 nanohybrid material exhibits a significant rational function for the adsorption of highly toxic organic pollutants. The as-synthesized nanohybrid materials are employed to remove Malachite Green (MG) dye from aqueous solutions. PAZ@ZIF-8 has displayed excellent removal efficiency towards the removal of MG dye, and almost 96% of the dye is removed within a very short period as compared to ZIF-8 (34%) and POA/ZnO (61%), respectively. The experiments were carried out at different pH values (3 - 9) and adsorbent amounts (1 - 1.5 mg/g). The Langmuir sorption model is a better fit for the removal of MG dye on PAZ@ZIF-8, and the maximum adsorption capacity of 613 mg/g is observed. The sorption kinetics of MG dye on PAZ@ZIF-8 is well followed by the pseudo-second-order model. PAZ@ZIF-8 has shown excellent recyclability for three consecutive cycles, and almost 90% of the dye is removed in the third cycle. This research will overlay the road to developing innovative nanohybrid 3D-MOF adsorbent systems for detoxification and wastewater treatment.