Design of N, O-Rich Functionalized Core–Shell Adsorbent for Efficient Extraction of Co(II) and Reuse in Oxygen Evolution Reaction

As a core strategic element of new energy vehicle power batteries, the sustainable supply of cobalt (Co) resources has become a key bottleneck, restricting the development of clean energy technology. To overcome this challenge, the study innovatively adopted a multilevel structural engineering strategy. By precisely engineering the topological design of the metal organic framework substrate, we used in situ grafting technology to construct a heterogeneous interface (TpTTA-COF) with rich nitrogen and oxygen dual active sites on the surface. This process ultimately formed a core–shell adsorbent (UiO-66-NH2@TpTTA-COF) with spatial confinement effect, which exhibited exceptional Co(II) extraction performance (359.9 mg/g), selectivity, and recyclability. Furthermore, Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations showed that the excellent selective capture of UiO-66-NH2@TpTTA-COF for Co(II) is due to coordination interactions and hydrogen bonding between the abundant N/O atoms in the adsorbent and Co(II). Based on the principle of green sustainable development and the good catalytic performance of transition metal ions, UiO-66-NH2@TpTTA-COF adsorbed with Co(II) was used as an electrocatalyst for the oxygen evolution reaction (OER), which exhibited a low overpotential (270 mV) and Tafel slope (77.8 mV dec–1) for the OER, demonstrating its broad prospects in the field of metal resource recovery and recycling.