Designed synthesis of a novel BiVO4–Cu2O–TiO2 as an efficient visible-light-responding photocatalyst.

A novel visible-light-responding BiVO 4 –Cu 2 O–TiO 2 ternary heterostructure composite was successfully fabricated via the preparation of BiVO 4 –TiO 2 followed by coupling with Cu 2 O through facile wet chemistry methods based on the strategy of energy gap engineering. The as-fabricated composite was characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV–vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. Benefited from the rational design and construction, BiVO 4 –Cu 2 O–TiO 2 exhibits a significantly enhanced photocatalytic activity for the degradation of rhodamine B (RhB) under the visible-light irradiation as compared with Cu 2 O and Cu 2 O–TiO 2 . Specifically, under the irradiation with an ordinary 9 W energy-saving fluorescent lamp for 8 h, the photocatalytic degradation ratio of RhB for 5 wt%BiVO 4 –40 wt%Cu 2 O–TiO 2 reaches 97.8%. The enhanced photocatalytic activity of BiVO 4 –Cu 2 O–TiO 2 can be ascribed to the matched band edge positions of BiVO 4 , Cu 2 O and TiO 2 , the heterojunction formations among them as well as the lower charge transfer resistance, favoring the separation of the photo-generated electron–hole pairs. A possible mechanism of the visible-light photocatalytic degradation of RhB is also proposed. [ABSTRACT FROM AUTHOR]