Morphological evolution and enhanced photoelectrochemical performance of V4+ self-doped, [010] oriented BiVO4 for water splitting

The V4+ self-doped m-BiVO4 samples with a specific growth and self-assemble direction of [010] were successfully prepared by tuning the amount of NaBH4 during the facial one-step hydrothermal route. In addition, NaBH4 not only can act as a reductant to introduce V4+ and oxygen vacancies directly, but also provided a higher pressure and stronger alkali environment during the hydrothermal process which promoted the morphology change from microspheres to ellipsoid/dumbbell shape. More importantly, the prepared samples had excellent photoelectrochemical performance which was mainly embodied in enhanced photocurrent density, smaller charge transfer resistance, longer electrons lifetime and improving separation of photogenerated electrons and holes, these were mainly attributed to the V4+ and oxygen vacancies can serve as charge carrier traps as well as adsorption sites where the charge transfer to adsorbed species inhibits the surface charge recombination. What's more, the morphology evolution mechanism and the function mechanism of the V4+-doped BiVO4 were discussed in detail simultaneously. (c) 2018 Elsevier B.V. All rights reserved.