Zeolitic Imidazolate Framework-8 Nanoparticles for Rhodamine B Adsorption

Abstract

Background: Dye removal from effluents is one of the major problems faced in the world. It is a very important environmental issue and it is crucial to solve this problem. In this sense, ZIFs are increasingly becoming important in the environmental area. Objective: This work presents the synthesis of metalorganic framework Zeolitic Imidazolate Framework- 8 (ZIF-8) nanoparticles, characterization, and then determines the potential to remove Rhodamine B (RhB) from an aqueous solution. Methods: ZIF-8 was synthesized under solvothermal treatment at 25°C and it was characterized by X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and infrared spectroscopy. To evaluate the capacity of the RhB, pH-influence and kinetic studies were carried out. The pseudo first- and second-order kinetic models were used to describe the kinetic data, and the rate constants were evaluated. Results: ZIF-8 had an average particle size of 47 ± 4.6 nm. The removal percentage increased significantly when the pH was in the range of 7.0-9.0. A pseudo-second-order kinetic of 13.00 mg/g was found for the RhB removal. The adsorption capacity at equilibrium was found to be 11.8 mg/g. Conclusion: According to the characterization results, the ZIF-8 synthesis was effective and produced a crystalline material. The ZIF-8 presented an affinity to the RhB dye. A pseudo-second- order kinetic model represented well the mechanism of interaction involved during RhB adsorption and ZIF-8.