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

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.