Ultrafast Uranium Capture via Phthalocyanine-Functionalized Collagen Fibers: Toward Efficient Nuclear Wastewater Remediation

The rapid recovery of uranium from large quantities of low-concentration industrial nuclear wastewater is critical for sustaining nuclear energy developments. Herein, a novel adsorbent (PC-CF) was successfully fabricated by grafting phthalocyanine functional groups onto collagen fibers. Compared with amidoxime functional materials, PC-CF exhibits excellent kinetics and good reusability. PC-CF achieves a high adsorption capacity of 0.524 mmol g–1 (pH 5.0, 333 K) with record-breaking kinetics. Its adsorption rate constant (k2 = 1.243 g mmol–1 min–1) far exceeds that of other materials, such as widely used amidoxime-based adsorbents (0.071 g mmol–1 min–1), highlighting the broader significance of this phthalocyanine-based strategy for achieving ultrafast uranium extraction. XPS analysis and theoretical calculations confirmed that phthalocyanine binds to the uranyl ion through four pyrrole nitrogen atoms, and the relatively low binding energy (−2449.6 kJ mol–1) explains its high selectivity for uranium. The fact that 92% of the adsorption capacity remained after eight cycles demonstrates excellent reusability. Notably, PC-CF maintains >99% uranium removal over 189 bed volumes in a dynamic adsorption test (flow rate: 0.5 mL min–1). This work establishes phthalocyanine-functionalized biomass adsorbents as a promising strategy for rapid and efficient uranium recovery from nuclear wastewater.