General Strategy to Fabricate Metal-Incorporated Pyrolysis-Free Covalent Organic Framework for Efficient Oxygen...

Because of the permission of the manipulations of modular construction on the atomic level, covalent organic frameworks (COFs) have attracted extensive attention in the electrocatalytic field. Owing to the lack of metal sites in pristine COFs constructed only by metal-free organic building units, it generally exhibits extremely low electrocatalytic activity. Thereby, linking metal sites on the backbone of pyrolysis-free COFs but not loading them on the surface to enhance the electrocatalytic activity is highly desirable but still remains a huge challenge. To this end, herein, we report an efficient and general cation-exchange strategy to synthesize Ni/Fe metal-ion-incorporated COFs (NiFe_1-@COF-SO₃) for the oxygen evolution reaction (OER) based on the fundamental structure design of COFs. Impressively, the turnover frequency (TOF) value in Ni_0.5Fe_0.5@COF-SO₃ reaches 0.14 s^-1 at the overpotential of 300 mV, which outperforms most recently reported OER electrocatalysts, indicative of ultrahigh metal-atom utilization efficiency.