Novel core-shell structured BiVO4 hollow spheres with an ultra-high surface area as visible-light-driven catalyst

In recent years, BiVO4 has been extensively studied as a promising visible-light-driven catalyst candidate due to its great visible-light absorbing ability. In this paper, novel core-shell structured (CSS) BiVO4 hollow spheres with an ultra-high specific surface area were synthesized via a one-pot, surfactant-and template-free hydrothermal route. The as-obtained products were characterized by scanning electron microscopy, X-ray diffraction, nitrogen adsorption-desorption experimentation, Raman and UV-vis absorption spectroscopy, respectively. The formation mechanism of the BiVO4 products was proposed in terms of the morphological evolution with prolonging the reaction time. The as-prepared CSS BiVO4 hollow spheres similar to Russian dolls were comprised of an inner core and an open outer shell, leading to an ultra-high specific surface area about fifty times that of solid spherical counterparts fabricated by the traditional solid-state reaction method. As a result, the CSS BiVO4 hollow spheres exhibited a superior photocatalytic activity over not only solid BiVO4 spheres but also other morphological products such as biscuits and plates in the photodegradation of rhodamine B under visible-light irradiation.