Innovative modification of cyclodextrin metal-organic frameworks for enhanced adsorption in wastewater treatment

The synthesis of aminopyrimidine-modified cyclodextrin metal-organic frameworks (AP-β-CD-MOF) at room temperature with pentanal as a cross-linking agent is the main objective of this work. This process introduces additional adsorption sites and highly delocalized conjugated systems, consequently enhancing the adsorption performance of material. The maximum adsorption capacity for CR (pH = 6) and TC (pH = 6) are found to be 317.5 mg/g and 166.4 mg/g. Furthermore, the adsorption isotherms for CR and TC conform to Freundlich and Langmuir models, revealing an endothermic and spontaneous adsorption process through thermodynamic analysis. Additionally, after four reuse cycles, the adsorption rates remained at 86% for CR and 71% for TC. Analysis using zeta potential, FTIR, and XPS confirms that the adsorption mechanism of CR primarily involves electrostatic interactions between sulfonyl groups and amino pyridine, whereas Tetracycline's driving force predominantly relies on π-π EDA interactions. This study lays a solid foundation for further exploration of low energy modified CD MOFs and has important research significance.