Effects of\nSolvation and Temperature on the Energetics\nof BiVO<sub>4</sub> Surfaces with Varying Composition for Solar Water\nSplitting

Photoelectrodes used in solar water splitting must operate\nin aqueous\nmedia. However, computational studies that explicitly compare the\ndry and solvated photoelectrode energetics at finite temperature and\nthe impact of the photoelectrode surface composition and surface defects\nare lacking. Here, we used first-principles molecular dynamics simulations\nto investigate the solvation and thermal effects on the energetics\nof the BiVO<sub>4</sub>(010) surface with different surface compositions\nand oxygen vacancies, a common defect responsible for the intrinsic\nn-type behavior of BiVO<sub>4</sub>. We find that the alignment of\nthe photoelectrode electronic bands with the water redox potentials\nis modified in the presence of water and that solvation effects and\nthermal fluctuations are more prominent for Bi-rich surfaces, especially\nso in the presence of oxygen vacancies. Our results provide a detailed\nunderstanding of the behavior of BiVO<sub>4</sub> photoanodes operating\nin aqueous media, as a function of surface composition, and are directly\ncomparable with experiments.