Dual‐Site Trigger Electronic Communication Effects to Accelerate H₂O₂ Activation for Colorimetric Sensing of Uranyl Ions in Seawater

Efficient activation of hydrogen peroxide (H 2 O 2 ) through biomimetic catalysis still faces a major challenge. In this work, inspired by the catalytic pocket of natural peroxidase, Cu single atom (Cu SA ) and AuCu nanoparticles (AuCu NPs ) anchored on nitrogen‐doped carbon skeleton (Cu SA ‐AuCu NPs /NC) serve as dual active sites that significantly accelerate the charge transfer process and thus achieve efficient H 2 O 2 activation. Meanwhile, the experimental and theoretical calculations show that the well‐established electronic communication effect between Cu SA and AuCu NPs results in moderate electronic modifications to Cu SA , which promotes the heterolysis of H 2 O 2 and the timely desorption of H 2 O. As a proof of concept, Cu SA ‐AuCu NPs /NC show remarkable performance in detecting uranyl ions in seawater. This work provides new insights into the H 2 O 2 activation for colorimetric sensing.