Rapid room-temperature synthesis of cadmium zeolitic imidazolate framework nanoparticles based on 1,1'-carbonyldiimidazole as ultra-high-efficiency adsorbent for ultrasound-assisted removal of malachite green dye

摘要

In this paper, zeolitic imidazolate framework nanoparticles based on cadmium and 1,1'-carbonyldiimidazole (Cd-ZIF) were prepared. The Cd-ZIF was utilized for ultrasound-assisted removal of malachite green (MG) dye. The Cd-ZIF was characterized through scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectrometry, Brunauer-Emmett-Teller (BET), energy-dispersive X-ray spectroscopy (EDS) and X-ray powder diffraction (XRD). Experimental results revealed that Cd-ZIF could bind the cationic dye using ultra-high adsorption capacity more easily compared with other absorbents. The pseudo second-order and Sips models presented better fit for the uptake of MG as compared with other kinetic and isotherm models. The experimental maximum adsorption capacity of MG onto Cd-ZIF was 3324.17 mg/g at 25 degrees C. The extremely high performance of Cd-ZIF for adsorption of the MG dye with high adsorption capacity indicated that the Cd-ZIF could be developed to a large scale. The thermodynamic parameters and Ea values confirmed that the adsorption was a spontaneous, chemical and endothermic reaction. The investigation exhibited that the adsorption mechanism may be mainly controlled by both the pi-pi stacking and electrostatic interaction. Finally, regeneration results illustrated that the adsorbent can be recycled seven times such that its high stability and applicability will continue to be maintained.