For the new generation of thorium-based molten salt reactors to operate in the future, irreversible adsorption of radioactive thorium ions is required. Therefore, designing highly irradiation-resistant, high-adsorption capacity porous adsorbents for the adsorptive removal of radioactive thorium ions is a great challenge. Herein, based on the radiation stability rules of MOFs (Al³⁺ metal nodes and unmodified organic ligands), we used a simple solvothermal method to synthesize an aluminum-based MOF, Al-MOF. The strong β-ray resistance with Al-MOF was confirmed by XRD and FT-IR characterization as well as adsorption isotherm experiments under β-ray irradiation with a total dose of 1000 kGy. Additionally, Al-MOF exhibits ultra-high Th(IV) adsorption capacity (1324.64 mg g⁻¹) and Th(IV) adsorption selectivity (K^Th _d/K^M _d ≥ 6 × 10³). This study provides guidance for the design of efficient MOF-based adsorbents for applications in spent fuel reprocessing and further expands the practical application of MOFs.

The removal of thorium from contaminated water sources is crucial for environmental protection and nuclear waste management. Herein, we present a dual-strategy design of a thiophene-integrated porphyrin covalent organic framework (TAPP-BTD-COF) that combines rigid macrocyclic scaffolds with flexible thiophene linkages, incorporating complementary N and S donor sites. This tailored COF achieves efficient and selective capture of Th(IV) from acidic aqueous solutions. By leveraging the topological arrangement of the porphyrin core to modulate the conformation of thiophene-based connectors, a coordination environment with N–S synergistic sites is created, which significantly enhances Th(IV) selectivity over competing ions. At pH 4.5, the synthesized TAPP-BTD-COF exhibits a high adsorption capacity of 437.18 mg g-1 and reaches equilibrium within 20 minutes. It demonstrates exceptional selectivity for Th(IV), with a separation factor exceeding 2.6×10³ relative to common interfering ions, and retains over 90% adsorption capacity after three consecutive cycles. Mechanistic studies confirm that the high performance originates from N–Th / S–Th dual-dentate coordination. This work provides a strategic design of functional COFs for thorium recovery and represents a highly efficient adsorbent system for Th(IV) removal from aqueous streams.