Experimental and modelling study of adsorption and diffusion of hexavalent chromium in zeolitic imidazolate framework-11

作者：Rachid Lamari, B. Benotmane, Hamza Megherbi, Aghilas Brahmi, Souad Djaoui, M. Trari · 发表于：International Journal of Environmental Analytical Chemistry · 年份：2025 · DOI：10.1080/03067319.2025.2511989 · 被引用次数：8

ABSTRACT In this study, Zeolitic Imidazolate Framework-11 (ZIF-11) was successfully synthesised at room temperature and characterised by XRD, SEM/EDAX, TGA/DSC, FTIR, and CO₂ adsorption techniques. The material exhibited high crystallinity, well-defined morphology, a thermal stability up to 350 °C, low synthesis cost, and the possibility of scaling up production. Motivated by these favourable properties, ZIF-11 was investigated as an adsorbent for the removal of $Cr\left({VI} \right)$CrVI from aqueous solutions. Optimal adsorption conditions were found to be a pH 2, a stirring speed of 400 rpm, a contact time of 70 min and a 20 mg dose of ZIF-11 for 50 mL of $Cr\left({VI} \right)$CrVI solution. Thermodynamic studies indicated that the adsorption process is spontaneous and endothermic. Kinetic analysis showed that the adsorption follows the pseudo-second-order model, suggesting chemisorption as the dominant mechanism. Isotherm modelling using Langmuir and Freundlich equations confirmed a uniform distribution of $Cr\left({VI} \right) $CrVIspecies on the ZIF-11 surface. The maximum adsorption capacity of ZIF-11 was found to be 10.61 mg/g, surpassing many reported adsorbents. These findings demonstrate that ZIF-11 is a highly promising material for the $Cr\left({VI} \right)$CrVI removal from water. Its excellent adsorption capacity, thermal stability, and ease of synthesis highlight its potential for practical applications in water treatment and environmental remediation.