Design and characterization of novel mesoporous Al-H4BTC metal-organic gels: Exploring the role of metal-to-ligand ratio in tuning porosity

Metal-organic gels (MOGs), an innovative class of porous, soft materials, extending the structure of metal-organic frameworks (MOFs), have recently garnered significant interest due to their mild synthesis conditions and tunable properties. Building on molecular docking studies that predicted the high potential of Al-H 4 BTC-MOF for adsorbing pollutants like tetramethrin and fluorene, this work combines that insight with the green synthesis of mesoporous MOG using the abundant metal aluminum and the cost-effective H 4 BTC ligand. By varying the metal-to-ligand ratio, we demonstrate a facile method to control the material’s porosity, yielding a range of structures from low-porosity materials to a novel mesoporous variant with a high surface area of 294 m 2 g −1 for the resulting xerogels after activation. Their structural and chemical properties were thoroughly characterized using chemical stability tests, PXRD, FTIR, FESEM, EDX, N 2 sorption measurements, and acid-base titration. The most porous material, a 2:1-Al-H 4 BTC-MOX synthesized in ethanol, exhibited a MIL-118-like structure with pore size of 3.9 nm. This unique mesoporosity is attributed to a templating effect of the solvent clusters during thermal activation. We demonstrate the material’s effectiveness as a green sorbent for removing fluorene and tetramethrin. The high surface area and mesoporosity of this material make it an effective sorbent for treating widespread aquatic contamination, demonstrating a removal capacity of ≥ 77% for fluorene and tetramethrin. • Novel mesoporous Al-based metal organic gel synthesized using H 4 BTC. • Materials achieved a wide range of BET surface area up to 294 m 2 g −1 . • Molecular docking showed Al-H 4 BTC-MOFs interaction with fluorene and tetramethrin. • 2:1-Al-H 4 BTC-MOX shows promise for fluorene and tetramethrin adsorption. • Spectroscopy characterization supported the interaction mechanism of the sorbent.