Tailoring synthesis parameters of Zr-based xerogels to enhance fluorene sorption performance

Document Type

Article

Publication Date

3-2026

Abstract

Background: Metal-organic gels (MOGs) are promising sorbents, offering tunable porosity and scalable, ecofriendly synthesis. Their adsorption capacity is strongly influenced by structure and morphology, which depend on synthesis parameters. This study applied a novel Zr-based MOG, aiming to enhance fluorene adsorption through systematic manipulation of these parameters. Methods: Zr-MOG was synthesised using 1,2,4,5-benzene tetracarboxylic acid via a green method. Key synthesis parameters, including reactant molar ratio, ligand concentration, solvent, and activation method, were optimised. Comprehensive characterisation employed chemical stability tests, PXRD, FT-IR, FESEM, EDX, TGA, wettability analysis, N2 sorption, and acid-base titration. Adsorption properties were evaluated through kinetic, thermodynamic, and isotherm studies. The material's reusability, along with the influence of coexisting compounds and ionic strength was also investigated. Significant Findings: The optimised Zr-MOG (0.0025 M-2:1-Zr-MOX(F)-M), synthesized with MeOH/H2O, a 2:1 metal-ligand ratio, and freeze-drying, exhibited defect-rich UiO-66-(COOH)2 structure. Its hierarchical porosity and mild-hydrophilicity improved mass transport and host-guest interactions, achieving maximum adsorption capacity of 427 mg g-1. Adsorption data fit the Avrami model and Sips isotherms. The material demonstrated green synthesis process, good reusability through an eco-friendly regeneration method, and long-term stability. These findings offer valuable insights into the structure-performance relationship of MOGs, advancing their use in environmental remediation applications.

Keywords

Metal-organic gel (MOG), 1, 2, 4, 5-benzene tetracarboxylic acid (H4BTC), Polycyclic aromatic hydrocarbons (PAHs), Green adsorbent, Adsorption

Publication Title

Journal of the Taiwan Institute of Chemical Engineers

ISSN

1876-1070

DOI

10.1016/j.jtice.2025.106452

Volume

180

First Page

106452

Publisher

Elsevier

Link to Full Text

Share

COinS