Influence of Oxygen Vacancies and Surface Facets on\nWater Oxidation Selectivity toward Oxygen or Hydrogen Peroxide with\nBiVO₄

Abstract

Bismuth vanadate\n(BiVO₄) is one of the most promising\nphotoanode materials for water oxidation. However, the water oxidation\nmechanism and selectivity on the different surfaces of BiVO₄ are still not well understood, partly because of the structural\ncomplexity introduced by the presence of oxygen vacancies in the material.\nUsing density functional theory, we show that the (001) surface of\nBiVO₄ with subsurface vacancies is the most suitable for\nthe oxygen evolution reaction, whereas the pristine (011) surface\nfavors the hydrogen peroxide evolution reaction. A mechanism by which\nthe vacancies can be removed from the surface, thereby influencing\nthe water oxidation selectivity, is also described. Our results thus\nemphasize the crucial impact of the local structure on the catalytic\nselectivity in ternary oxides.