Enhancement of the visible light photocatalytic activity of Cu2O/BiVO4 catalysts synthesized by ultrasonic dispersion method at room temperature

• Cu2O/BiVO4 catalysts were successfully prepared by a facile ultrasonic method.
• Cu2O/BiVO4 exhibits higher photoactivity than P25, pure Cu2O and BiVO4.
• O2−, h+ and H2O2, jointly dominate the photodegradation process of MB.
• A transfer process of photogenerated carriers was proposed.
• The photocatalytic mechanism of Cu2O/BiVO4 catalysts was discussed.

Cu2O loaded nano-BiVO4 (Cu2O/BiVO4) photocatalysts with various weight percents of Cu2O were successfully prepared by a facile and effective ultrasonic dispersion method at room temperature. Methylene blue (MB), methyl orange (MO) and phenol in an aqueous solution served as a probe reaction to evaluate the photocatalytic activities of the as-prepared Cu2O/BiVO4 catalysts under the irradiation of visible light. The photocatalytic activity of the Cu2O/BiVO4 catalysts was greatly enhanced, compared with that over commercial Degussa P-25 (TiO2), pure Cu2O and BiVO4. The remarkably enhanced photocatalytic activities could be mainly attributed to the effective transfer of the photogenerated electrons and holes at the interface of BiVO4 and Cu2O, which reduced the recombination of electron–hole pairs. A transfer process of photogenerated carriers was proposed based on the band structures of BiVO4 and Cu2O. The photocatalytic mechanism of Cu2O/BiVO4 catalysts was discussed.

When the Cu2O/BiVO4 sample is irradiated by visible light, BiVO4 and Cu2O are both excited; then, a large number of electrons and holes are produced in the system. Electrons will transfer from Cu2O to CB of BiVO4 and holes shift from BiVO4 to VB of Cu2O at the same time. In this way, the photoinduced electron–hole pairs were effectively separated.Figure optionsDownload as PowerPoint slide