Effect of temperature on structural properties and antibacterial performance of Fe–Co–Al@BTC MOF: A molecular docking and computational perspective

Abstract

In this study, the impact of temperature on metal-organic framework (Fe-Co-Al @BTC) structural properties and antibacterial activity was investigated. It was synthesized by both hydrothermal method and at room temperature. It exhibited remarkable differences in crystallinity, porosity, morphology, and antibacterial activity. Fe-Co-Al@BTC prepared at room temperature exhibited higher crystallinity, larger average particle size, distinct morphology, and enhanced antibacterial activity compared to the hydrothermally synthesized sample. The estimated optical band gap was found to be ~ 2.48 eV and 2.25 eV for MOF synthesized at room temperature and hydrothermal conditions, respectively which was confirmed by PL results. Antibacterial performance, evaluated using optical density measurements and the cut plug method, demonstrated 100% bacterial growth inhibition at 600 mg/L for the room temperature sample, whereas the hydrothermal sample showed 50% inhibition at the same concentration. Density functional theory (DFT) calculations with the LANL2DZ basis set revealed the MOF's electronic and photocatalytic properties, indicating stability, moderate reactivity, and potential for photocatalytic applications through analysis of the HOMO-LUMO gap and metal-to-ligand charge transfer. Thermodynamic analysis indicated that room temperature synthesis is more favorable despite slower crystallization, while hydrothermal synthesis is faster but energetically more demanding. Both syntheses were exothermic; however, higher temperature reduces spontaneity due to entropic penalties, with Gibbs free energy confirming room-temperature synthesis as the preferred approach.