Realizing the Intrinsic Electrochemical Activity of Acidic N‐Doped Graphene through 1‐Pyrenesulfonic Acid Bridges

Abstract Electrochemical technology attracts much research interest for the treatment of metal complexes, but most electrocatalysts are incapable of effectively degrading metal complexes, which generally have highly stable cages with five or six rings coordinating with metal ions. To address this, a bridging agent linking the catalysts and metal complexes can lower the energy barrier, and thus holds much promise to facilitate the removal of such pollutants. In this study, 1‐pyrenesulfonic acid (PSA) functionalization of acidic nitrogen‐doped graphene (ANG) is successfully synthesized and found to effectively remove metal complexes through electrochemical membrane filtration. Results indicate that PSA, interacting with Cu‐EDTA via the strong ion exchange of super acidic sulfonic (−SO₃H) groups, acts as a conductive “bridge” connecting the electrocatalyst and metal complexes to overcome the challenge with penetrating the “cage” structure of metal complexes. The pyrrolic nitrogen of ANG is found to be the active sites in the electrochemical process, with the intrinsic electrochemical activity realized by the bridging agent, namely, PSA. This study highlights the importance of compounds with sulfonyl groups in circumventing the stable “cage” of the metal complexes, and thereby paves the way for effective degradation of such pollutants.