Harnessing nanomaterial-driven electron transfer for enhanced uranium recovery and toxicity mitigation in...

Microbial electrolysis cells (MECs) face challenges in hexavalent uranium (U(VI)) remediation due to inefficient extracellular electron transfer (EET), slow biofilm formation, and uranium toxicity. This study developed a cobalt nanoparticles and nitrogen-co-doped carbon (CoNPs/NC) modified biocathode to address these limitations. Material characterization, electrochemical analysis, and density functional theory (DFT) calculations demonstrate that CoNPs/NC enhances biocathode conductivity and promotes EET efficiency while alleviating the toxic inhibition of uranium on microorganisms. The confinement effect facilitates electron delocalization, accelerating electron transfer to adsorbed uranyl ions (UO₂²⁺) and driving U(VI) to tetravalent uranium (U(IV)) reduction. By optimizing electrode-microbe interactions, CoNPs/NC improves biofilm stability and uranium recovery efficiency. This work provides a novel strategy to synchronize uranium detoxification with sustainable resource recovery in contaminated water systems through nanomaterial-driven electron transfer enhancement.