Construction of an efficient Z-scheme CuS/BiOBr heterojunction photocatalysts for dye degradation and Cr(VI) reduction

In this work, an efficient Z-scheme CuS/BiOBr heterojunction photocatalysts were developed through anchoring the CuS nanoparticles on the surface of BiOBr nanoplates. Acid orange 7 (AO7), Rhodamine B (RhB), and Cr(VI) were selected as target reactant for the investigation of photocatalytic degradation and reduction ability for the sample irradiated by simulated sunlight. The experimental results imply that the CuS/BiOBr composite exhibits much higher photocatalytic removal activity than that of bare BiOBr. Further more, the photocatalytic activity of composite is highly related to the content of CuS, and the optimal photocatalytic efficiency is achieved by 12%CuS/BiOBr sample. On the other hand, the synergistic photocatalytic removal activity of CuS/BiOBr composite for the purification of mixture (AO7/Cr(VI)) was also evaluated under simulated sunlight irradiation. The separation rate of photogenerated charges in BiOBr can be effectively promoted after the decoration of CuS nanoparticles. The main active species play role in the photocatalytic degradation process of CuS/BiOBr composite was detected by trapping experiment. According to these results, the photocatalytic mechanism of Z-scheme CuS/BiOBr composite was proposed.