Theoretical insights into the mechanism of oxygen evolution reaction (OER) on pristine BiVO4 (001) and BiVO4 (110) surfaces in acidic medium both in the gas and solution (water) phases

Abstract

Monoclinic scheelite bismuth vanadate is an efficient photocatalyst for water splitting. In this paper, we perform DFT + U calculations to investigate the structural, electronic, and optical properties, water adsorption and the oxygen evolution reaction processes on BiVO4 (001) and BiVO4 (110) surfaces in acidic medium both in the gas and solution (water) phases. The structural, electronic, optical, and water adsorption properties reveal that BiVO4 (001) surface is energetically more stable than BiVO4 (110) surface in vacuum. On other hand, the water oxidation mechanisms reveal that BiVO4 (110) surface in water and in strained form in vacuum is energetically more stable than BiVO4 (001) surface in water and in strained form in vacuum both U = 0 and 2.1 V. The free energy of adsorption for all systems at U = 2.1 V reduce about 2 times than that at U = 0 V. Such analyzes provide important insights into the role of different facets on BiVO4 surface for photocatalytic reactions.