Fig. 1: Response of interfacial structure to the applied potential.

a–c Distribution of water density along the direction perpendicular to the Cu(100)–water interface under different conditions, with the topmost Cu layer at the distance of 0. The gray dashed line indicates the first peak of chemisorbed water. d Schematic of the interfacial structure change under corresponding conditions to (a–c). CO₂ molecules are depicted as gray and red spheres, while H₂O molecules are represented as stick models for clarity. The applied potentials are obtained from the work function of the whole system. (Supplementary Note 1).