The synthesis of a BiOCl Br nanostructure photocatalyst with high surface area for the enhanced visible-light photocatalytic reduction of Cr(vi).

The photocatalytic reduction of poisonous Cr(vi) to environmentally friendly Cr(iii) driven by visible-light is highly foreseen. The construction of heterojunctions is a promising and solid strategy to tune the photocatalytic performance of BiOCl in the visible region. Herein, for the first time, we report Cr(vi) reduction by a BiOClBr composite produced a facile synthetic process at room temperature while making use of PVP (MW = 10 000). In this study, a series of BiOCl Br nanocomposites with different concentrations of chlorine and bromine have been prepared. The results show that BiOClBr has crystalline lattice, a large surface area (147 m g), a microporous structure (0.377 cm g), and very high chemical stability. It is revealed that the BiOClBr composite is much more active than those synthesized using different molar concentrations of chlorine and bromine. The DRS analysis and high photocurrent suggested that BiOClBr possessed absorption properties under visible light, which is beneficial for the efficient generation and separation of electron-hole pairs. In addition, we evaluated the photocatalytic activity of BiOClBr on the reduction of Cr(vi) under visible light irradiation and found that the obtained composite material exhibited a higher photocatalytic activity than single BiOCl or BiOBr without any decline in the activity after five cycles and is the best performing photocatalyst among those tested.