Effects of Phosphonic Acid Groups and Benzene Ring Content on Crystallization Behavior and Thorium(IV) Adsorption Performance

作者：Yunyun Zhang, Haitham Saad Al-mashriqi, Shuang Zhang, Jing He, Mingxia Sun, Xinqiao Li, Zhao Wang, Jia Chen, Hongdeng Qiu · 发表于：ACS Applied Materials & Interfaces · 年份：2025 · DOI：10.1021/acsami.5c17593 · 被引用次数：4 · 研究领域：Radioactive element chemistry and processing、Chemical Synthesis and Characterization、Extraction and Separation Processes

In this study, we exploit the selective adsorption affinity of phosphonate groups toward thorium (Th) to synthesize three ionic organic crystals (IOCs) with systematically varied phosphonate group coverages. Using a green and energy-efficient synthetic strategy, we successfully prepared three IOCs with tunable properties, namely, TP-Py, BPBP-Py, and PMBP-Py, each crystallizing in the triclinic system with the formulas [C 75 H 88 N 3 O 23 P 6 S 4 ], [C 48 H 48 N 2 O 18 P 6 ], and [C 36 H 56 N 2 O 22 P 6 ]. The findings revealed how the number of phosphonate groups and benzene rings significantly affected the adsorption performance of the IOCs by regulating the hydrophilicity and occupancy of adsorption sites. The experimental data demonstrate the exceptional performance of the BPBP-Py ([4-(4-phosphonophenyl)phenyl]phosphonic acid-4,4′-dipyridyldimethiodide), exhibiting a remarkable separation ( S Th–U = 6.77) and enrichment capabilities ( Q e = 467 mg/g), in addition to its notable thermal stability (300 °C) and durability (≥3 cycles). Moreover, it was confirmed by utilizing various characterization methods, including EDX mapping (energy-dispersive X-ray spectroscopy), FTIR (Fourier transform infrared spectroscopy), XPS (X-ray photoelectron spectroscopy), and DFT (density functional theory) calculations, which indicate that the oxygen and phosphorus atoms in the phosphonate groups may be the primary coordination adsorption sites. What’s more, as the DFT calculation results sho...