Three-Dimensional Nano Polyaniline Modification Graphite Fiber as High-Capacity Electrode Material for Uranium (VI) Electrosorption

Abstract

To improve the adsorption performance of graphite felt, aniline was directly polymerized on the surface of graphite felt by electrochemical method. The material test results showed that the electropolymerized polyaniline presented a three-dimensional nanofiber structure and the specific surface area of the electrode increased from 24.23 to 42.17 m2 g−1 after modification. The electrochemistry test results showed that the electrode had a large specific capacitance 144.6 F g−1 in 1 M NaCl at a sweep speed of 5 mV s−1. When pH = 4 and E = −0.9 V (vs SCE), the adsorption capacity of the electrode can reach 187.8 mg g−1. 94.6% adsorbed uranium can be eluted by 0.1 M hydrochloric acid. After 7 cycles, the performance loss was only 25%, which indicated that the electrode had a good regeneration performance. The uranyl ions combined with the amino and imino groups of polyaniline on the electrode surface, and were partially reduced to U (V), which greatly improved the adsorption capacity of electrode. All the results show that the electrode had exceptional potential applications in the extraction of U(VI) from aqueous solution, and it provides a feasible method for U(VI) environmental pollution cleanup in uranium mining and fuel processing.