In previous reports, it has been known that the local surface potentials and photoelectrochemical performance depend strongly on the pH of the ambient electrolyte and the interaction of H 2 O with the BiVO 4 surface. To further understand how the chemisorbed water response to surface potential as well as affect the molecular structure and capacitance of EDLs, we next simulate the electrified BiVO 4 /NaCl interface with finite-field DFTMD (Fig. ).