Photocatalytic and photoelectrochemical activities of strained BiVO4

We theoretically investigate the impact of strain on the photocatalytic and photoelectrochemical activities of BiVO4. Through first-principles hybrid functional calculations, the electronic and structural properties of three strained BiVO4 such monoclinic scheelite, tetragonal scheelite, and tetragonal zircon, are examined. For most of the BiVO4 polymorphs, the dependence of the out-of-plane lattice constant upon biaxial strain and of the bandgap upon in-plane biaxial and hydrostatic strains shows good linearity. Combined with calculated band alignment, we assess the impact of strain on the photocatalytic and photoelectrochemical activities of the material. Tensile strain shifts upward the positions of the conduction band edge in monoclinic scheelite and tetragonal zircon close to or even higher than the H+/H-2 level. These suggest that strain plays a crucial role in the experimentally observed performance of BiVO4-based systems for hydrogen production via water splitting.