The effect of crystal facets and induced porosity on the performance of monoclinic BiVO4 for the enhanced visible-light driven photocatalytic abatement of methylene blue

Abstract

In this study, a unique two-step approach has been developed to synthesize mesoporous BiVO4 (m-BiVO4) photocatalysts. The synthesized photocatalysts were characterized by means of XRD, SEM, EDS, UV-vis, Raman, PL, DRS, and N2-physiosorption analysis techniques. The hybrid BiVO4/KIT-6 composite and m-BiVO4 particles exhibited selective growth of the (040) crystal facet, a smaller size, high surface areas, a large pore volume as a result of the porosity induced by KIT-6 and, a greater number of active sites. The charge recombination rate of m-BiVO4 was remarkably lower than that of conventional BiVO4. In addition, the bandgap energy of m-BiVO4 was 2.2eV, which is suitable for visible light irradiation. It was observed that the photocatalytic activity of m-BiVO4 was superior to that of conventional BiVO4 under visible-light illumination, due to the synergistic effect of the highly active monoclinic phase and large surface area of m-BiVO4. Furthermore, the monoclinic m-BiVO4 was also tested for photocatalytic degradation ability by using an anonymous industrial effluent for 3 h under visible light irradiation.