In-situ growth of ZIF-8 on layered double hydroxide: Effect of Zn/Al molar ratios on their structural, morphological and adsorption properties

• Published in: Journal of colloid and interface science 2017-11, Vol.505, p.206-212
• Main Authors: Yang, Yingli, Yan, Xinlong, Hu, Xiaoyan, Feng, Rui, Zhou, Min
• Format: Article
• Language: English
• Subjects: Arsenic adsorption; In-situ growth; Layered double hydroxides; Zeolite imidazolate frameworks; Zn/Al molar ratios
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2017.05.100

[Display omitted] In-situ growth of Zeolite imidazolate frameworks (ZIFs) on layered double hydroxides (LDHs) to form porous composites is a promising and challenging strategy to develop materials for separation application. Herein, the Zn-Al LDH with different Zn/Al molar ratios was prepared and used as matrix for the growth of ZIF-8 on its surface. The resulting composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 physisorption, thermogravimetric (TG), scanning electron microscope (SEM) and elemental analysis followed by testing for AsV removal from aqueous solution. Results showed that ZIF-8 could form on the surface of LDH with different Zn/Al molar ratios. At low Zn/Al molar ratios, the morphology and surface area of the ZIF/LDH composites and the content of ZIF-8 in the composites were little affected by the Zn/Al molar ratio. With increasing Zn/Al molar ratio, ZIF-8/LDH exhibited a lower surface area, which resulted from reduced content of ZIF-8 caused by impurities generated in the LDH matrix. All ZIF-8/LDH samples showed high AsV adsorption capacity, which was significantly higher than that of pure LDH or ZIF-8.