A NiCo2O4 nanowire arrays decorated carbon felt cathode for synergistic treatment of complex uranium-organic wastewater in a self-driven solar coupling system

Abstract

The expansion of nuclear energy necessitates advancements in uranium recovery from radioactive wastewater containing persistent UO₂²⁺-organic complexes. We present a solar-driven coupling system (SSCS) integrating the TiO₂ nanorod (TNR) photoanode with the NiCo₂O₄ nanowire-decorated carbon felt cathode (NiCo₂O₄-CF), enabling simultaneous uranium removal and organic pollutant degradation. The SSCS enhances photo-generated charge excitation with providing a bias potential, which drives rapid electron transfer from organics to UO₂²⁺ adsorption and reduction sites. The NiCo₂O₄-CF cathode maintains excellent efficiency of 97.8 % and 98.0 % for uranium reduction and Rhodamine B (RhB) degradation, respectively, through 20 cycles in complex wastewater matrices. This study proposes a nanostructure-engineered electrode with excellent electrochemical performance, offering a straightforward, resourceful and sustainable solution for uranium-laden radioactive wastewater remediation that synergizes environmental decontamination with nuclear resource recovery within circular economy frameworks.