Development of iron-based MOF for enhanced adsorption of dyes: Statistical optimization and antibacterial activity

Abstract

The discharge of organic pollutants has become a significant environmental concern, posing serious threats to aquatic ecosystems. In this study, an iron-based metal–organic framework (Fe-MOF) was synthesized using ferric nitrate and 1,2,4-benzenetricarboxylic acid (BTC) through a solvothermal method and evaluated for its dual functionality in dye removal and antibacterial activity. Unlike the commonly used 1,3,5-BTC, the 1,2,4-BTC linker positions two carboxylic groups adjacent to each other, which enables intramolecular hydrogen bonding and alters the coordination geometry, thereby enhancing framework stability and providing interaction sites for pollutant binding. The morphology and surface characterizations of the Fe-MOF were confirmed by FTIR, XRD, SEM, TEM, EDX, XPS, vibrating sample magnetometer, Raman spectroscopy, and zeta-potential analysis, confirming its successful formation and surface charge. The Brunauer-Emmett-Teller analysis showed that the surface area of Fe-based MOFs was 157 m2/g, confirming the presence of mesopores and facilitating dye diffusion to the active sites. The batch adsorption experiments showed high efficiency in removing tropaeolin OO and sunset yellow dyes with maximum removal efficiencies of 89% and 96%, respectively. According to isothermal modeling, kinetic studies, and thermodynamic analysis, the adsorption process favored multilayer adsorption behavior and spontaneous dye removal. Statistical analysis, including regression modeling and one-way analysis of variance, revealed the significant influence of operational parameters, such as pH, temperature, and adsorbent dose. Fe-MOF presented antibacterial activity, achieving a 96.47% reduction in colony-forming units. Regeneration studies confirmed the reusability of the Fe-MOF, preserving over 92% of its efficiency after two cycles.