Among rutile TiO 2 (110) and SnO 2 (110), BiVO 4 (010), SnO 2 (110) has the strongest water adsorption energy -1.5 eV with DFT studies (see Table ). Therefore, one would expect water molecules have a stronger tendency for dissociative adsorption and ∆A diss is smaller. This is indeed the case, as shown in Table 1. On the other hand, the water adsorption energy is smaller in the case of BiVO 4 (010) as compared to TiO 2 (110) , which would imply a higher water dissociation free energy. However, ∆A diss is instead smaller in BiVO 4 (010) than that of TiO 2 (110). This highlights the important difference between energy and free energy and the role of solvation dynamics.