First principle calculations of photocatalytic properties of bismuth oxyhalides considering van der Waals correction

The photocatalytic properties of bismuth oxyhalides are explored via first principle calculations by incorporating van der Waals correction in this letter. Geometries calculations without the correction were not converged which resulted into bloated volumes. When van der Waals correction is introduced, the energy convergence analysis reveals that the optimized geometries align well with the experimental results. Based on the updated geometries with the correction, the photocatalytic properties of bismuth oxyhalides are provided. The band structures and optical properties are only slightly affected by van der Waals forces. We further conclude that van der Waals forces should account for the differences between the single layer and bulk bismuth oxyhalides.