Engineering of sp2-Carbon-Conjugated porous polymer electrodes for Solar-Driven electrochemical uranium extraction

The sp 2 -carbon-conjugated porous polymers (sp 2 c-CPPs) that possess high porosity, chemical stability, and carrier mobility are potential for uranium extraction from seawater, which is tremendous meaningful for the rapidly growing demands of the nuclear industry due to the abundant uranium resources (4.5 billion tons) in ocean. Here, we report the synthesis of three sp 2 c-CPP films (DMPN-TFPT, BN-TFPT and TMTN-TFPT) directly on Cu substrate that can work as electrodes for electrochemical uranium extraction. Furthermore, we designed a photovoltaic-electrocatalysis (PV-EC) system to enhance the uranium extraction capacity, meanwhile, modified oxime groups on sp 2 c-CPPs film to enhance uranium ion selectivity. The DMPN-TFPT electrode shows ultra-high uranium extraction performance (1022.02 mg m −2 ) in 8 ppm uranyl-spiked simulated seawater, which is higher than that of BN-TFPT film (426.27 mg m −2 ) and TMTN-TFPT film (607.30 mg m −2 ) because of the higher in-plane electron delocalization. Additionally, in ultra-low concentration of simulated seawater (3.3 ppb), the DMPN-TFPT film also exhibited a high capacity up to 81.74 mg m −2 within 30 days. This work shows the great potential of sp 2 c-CPP films on solar-driven electrochemical uranium extraction.