To address the critical challenge of improving the performance and stability of metal–organic frameworks (MOFs) for nuclear wastewater treatment, we present an innovative strategy—a progressive proportional loading approach for incorporating graphene oxide (GO) and silica (SiO ₂ ) into the SU-102(Zr) MOF matrix. Although oxide/MOF composites have been extensively investigated, the crucial influence of oxide loading ratios—a fundamental design parameter—has been systematically neglected. Our findings indicate a nonlinear relationship between GO/SiO ₂ content and the structural stability and adsorption efficiency of the composite, consistent with the ‘optimality principle’ in interfacial engineering. By synthesizing a series of x SiO ₂ /GO@SU-102(Zr) composites ( x = 3.125, 6.25, and 12.5 wt%), we demonstrate that the 6.25 wt% loading ratio achieves unprecedented performance in highly acidic conditions (0.3 M HNO ₃ ). This optimized composite exhibits record-breaking thorium adsorption (76.28 mg g ⁻¹ (initial uptake) and 59.63 mg g ⁻¹ ), surpassing all reported MOF-based adsorbents in such harsh environments, and exceptional stability (superior thermal and acid resistance compared to its counterparts). Density functional theory calculations elucidate the synergistic adsorption mechanisms, emphasizing the enhanced interfacial interactions between Th(IV) ions and the composite components. This study establishes a generalized design framework for oxide/MOF composites and opens new avenues for applications in nuclear waste remediation, heavy metal recovery, and advanced separation technologies. Our findings highlight the transformative potential of precision loading strategies in realizing the full capabilities of MOFs for addressing real-world environmental challenges.

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.