Facile Synthesis of Magnetic Zn-Coordinated Carbonic Anhydrase Nanozyme Catalyzing CO2 Hydration for Enhanced Sustainable Uranium Extraction

CO₂ + O₂ neutral leaching represents a promising sustainable method for uranium extraction; however, its practical effectiveness is frequently limited by the slow kinetics of CO₂ hydration, which hinders the formation of bicarbonate ions essential for the complexation and dissolution of uranium. To overcome this kinetic limitation, a novel magnetic zinc-coordinated carbonic anhydrase-mimicking nanozyme (Fe₃O₄@ZnAC) was successfully developed via a facile one-pot sol–gel coating strategy. Comprehensive characterization confirmed that the nanozyme exhibits a distinctive core–shell heterostructure, consisting of a superparamagnetic Fe₃O₄ core enabling facile magnetic recovery and a zinc-rich organosilicate shell providing abundant, accessible Zn–N/O catalytic sites analogous to natural carbonic anhydrase. Enzymatic studies revealed that Fe₃O₄@ZnAC possesses outstanding carbonic anhydrase-mimicking catalytic performance, robust operational stability, and excellent recyclability, highlighting its potential for sustainable industrial applications. When integrated into a dual-reactor uranium leaching system, Fe₃O₄@ZnAC substantially increased bicarbonate ion production by approximately 47% compared to the uncatalyzed scenario. This catalytic improvement resulted in a uranium extraction efficiency of 45.79%, significantly higher than the 36.36% observed in control experiments. This study provides valuable insights into the rational design and practical application of biomimetic nanozymes, proposing an effective strategy for integrating efficient resource recovery with sustainability and global carbon neutrality goals.