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

Abstract

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.