Ultrahigh Performance Self‐Supported Cl‐Cu₂O@Cu Foam Electrode Fabricated by Sonochemical Surface Reconstruction Approach

Abstract Unlike powdery transition metal oxide (TMO) coated electrodes, self‐supported TMO electrodes have attracted considerable interests for optimizing the electrocatalytic performances of electrodes due to sufficient exposure of active sites and improved TMO‐substrate interfaces. However, conventional manufacture methods for self‐supported electrodes are faced with inefficiency and high complexity. Herein, a facile sonochemical surface reconstruction approach is proposed to fabricate Cl‐doped Cu₂O@Cu foam (Cl‐Cu₂O@Cu) electrode with ultrahigh sensitivity for glucose sensing. The intensive collapse of cavitation bubbles near Cu foam under sonication within NH₄Cl solution, for this reason, massive Cu complex ions and highly active Cu surfaces are simultaneously generated. Then the nanosized Cu₂O particles with large active surfaces are in situ formed and tightly anchored on the Cu surface, which undergoes Cl doping in Cu₂O, resulting in ascending electrical conductivity. The Cl‐Cu₂O@Cu electrode shows excellent catalytic performance to glucose, presenting ultrahigh sensitivity of 28 mA cm⁻² × 10⁻³ m and ultralow limit of detection of 0.35 × 10⁻⁶ m (S/N = 3). This work promotes a novel approach for the rational design of self‐supported electrochemical electrodes by sonochemistry.