Effects of Mo/W codoping on the visible-light photocatalytic activity of monoclinic BiVO4 within the GGA + U framework

Abstract

The formation energy, electronic properties, and photocatalytic activity of Mo, W mono-doped and Mo/W codoped BiVO₄ were investigated using density functional theory plus U calculations (DFT + U). The calculated formation energies show that both Mo and W atoms prefer to substitute V atoms under the oxygen-rich condition, in agreement with previous experimental results. Mo or W atom doping on the V site can form continuum states above the conduction band edge of BiVO₄, which is advantageous for the photochemical catalysis response. Moreover, we found that the W doped BiVO₄ has a smaller band gap than the Mo doped one, and the effect of Mo and W doping on the electronic structure of BiVO₄ is different. Mo/W/Mo and W/Mo/W co-doped BiVO₄ have smaller formation energies and smaller band gaps than the other doping case, which may enhance the optical absorption. Thus, Mo/W/Mo and W/Mo/W co-doped BiVO₄ is particularly suitable for visible-light photocatalysis.