No abstract

Zeolite imidazole framework-8 (ZIF-8) and the iron doped ZIF-8 (Fe-ZIF-8) were synthesized by the hydrothermal process. The obtained materials were characteristic of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), nitrogen adsorption/desorption isotherms, and atomic absorption spectroscopy (AAS). The results showed that the obtained Fe-ZIF-8 possessed the ZIF-8 structure with a large specific area. ZIF-8 and Fe-ZIF-8 were used for the removal of Remazol Deep Black (RDB) RGB dye from aqueous solutions. The various factors affecting adsorption such as pH, initial concentration, contact time, and temperature were investigated. The results showed that the introduction of iron into ZIF-8 provided a much larger adsorption capacity and faster adsorption kinetics than ZIF-8 without iron. The electrostatic interaction and π-π interaction between the aromatic rings of the RDB dye and the aromatic imidazolate rings of the adsorbent were responsible for the RDB adsorption. Moreover, the coordination of the nitrogen atoms and oxygen in carboxyl group in RDB molecules with the Fe2+ ions in the ZIF-8 framework played a vital role for the effective removal of RDB from aqueous solution.

Zeolite imidazole framework-8 (ZIF-8) was prepared by the hydrothermal process. e obtained ZIF-8 was a characteristic of X-ray-diffraction (XRD), transmission electron microscope (TEM), thermal gravity-differential thermal analysis (TG-DTA), and dynamic light scattering (DLS). e obtained ZIF-8 possessed large specific area and was highly dispersed. Its morphology consisted of nanospherical particles with 30-50 nm in diameter. Chemical stability of ZIF-8 in different conditions was studied.e ZIF-8 was used as an electrode modifier for the determination of trace levels of lead. e parameters including solvents and solution pH were investigated. e repeatability, reproducibility, accuracy, linear range, limit of detection, and limit of quantitation were also addressed. e results showed that ZIF-8 is a potential electrode modifier for differential pulse anodic stripping method to determine Pb(II) in aqueous solution.