As what we've seen in metal oxide systems, the adsorbed water molecules point toward the electrolyte solution (Fig. ), and the angle θ between the water dipole and surface normal is counted as 61 • at the PZC. In response to electric field E in the protonic and deprotonic EDLs, the values of angle θ down-shifted and up-shifted, respectively, consistent with previous DFTMD studies. However, with the low water adsorption energy, the values of θ shifted have big difference especially at negatively charged surface (from 61 • shifted to 69 • ), comparing to TiO 2 (Fig. ) and SnO 2 (Fig. ) systems. In addition, it is found that both adsorption and desorption processes occur between interfacial water and near-surface water (Fig. ), leading to a wide orientation peak at PZC (Fig. ).