PPy-encapsulated multiphase CuCo synergistic electrode for high-efficiency uranium extraction from strongly acidic wastewater

A binder-free, self-supporting electrode was prepared via two-step electrodeposition. • Electrosorption capacity of PPy/Cu-Co-MHM@GF electrode reached 711.2 mg/g at pH 2. • PPy coating provides amino/imino groups and protects active sites from corrosion. • The synergistic effect among multiple active sites ensures excellent uranium removal. Electrochemical technology has attracted much attention for the removal of uranium(VI). However, it still faces the contradiction of balancing electrode stability and removal capacity under acidic conditions. In this work, a conductive polymer protection strategy was proposed to construct a novel in-situ polypyrrole (PPy) encapsulated Cu 0 /CuO-Co x O y multiphase hybrid material (MHM) on graphite felt (GF). The binder-free, self-supporting composite electrode denoted as PPy/Cu-Co-MHM@GF was fabricated via a facile electrodeposition method. This electrode achieved highly efficient uranium removal under acidic conditions. At pH = 2.0, as high as 98.2% of uranium could be effectively removed by PPy/Cu-Co-MHM@GF, and the electrosorption capacity could reach 711.2 mg/g. Moreover, the PPy/Cu-Co-MHM@GF electrode had excellent selective removal ability for uranium, and the K d value reached 43,173.01 mL/g. The experimental and characterization results indicated that the outstanding electrosorption capacity of PPy/Cu-Co-MHM@GF was not only due to the formation of electrical double layer, but also originated from the synergistic effect of various types of active sites (Co(OH) 2 , CoO, CuO and PPy). PPy acted as a physical barrier to reduce H + corrosion and provided abundant amino/imino groups to enhance UO 2 2+ coordination, ultimately realizing the synergistic removal of uranium. This study has opened up new horizons for the treatment of acidic radioactive wastewater. Download: Download high-res image (216KB) Download: Download full-size image