UV-Vis-NIR-light-driven Ag2O/Ag2S/CuBi2O4 double Z-scheme configuration for enhanced photocatalytic applications

The Ag2O/Ag2S/CuBi2O4 double Z-scheme heterostructures photocatalysts with different Ag2O proportion were successfully synthesized via the hydrothermal and coprecipitation methods. Compared with those of pure CuBi2O4 and Ag2S, the absorption of near-infrared light of Ag2O/Ag2S/CuBi2O4 samples is enhanced, their photocurrent intensity is significantly increased, and the charge transfer resistance is reduced. Obviously, all the Ag2O/Ag2S/CuBi2O4 samples exhibited significantly enhanced photoactivities under the UV, Vis or NIR light irradiation. Of them, under the simulated sunlight, Ag2O/Ag2S/CuBi2O4 with 36.7 wt% Ag2O showed the highest catalytic activity with RhB degradation rate of 99.2% and the reduction rate of Cr(VI) of 53%. The construction of double Z-scheme heterojunction reduced the recombination of electrons and holes and improved the separation efficiency of electron. Moreover, Ag2S and Ag2O broadened the photoresponse range to a wide spectrum, and then improved the photocatalytic efficiency. In addition, the stability of Ag2O/Ag2S/CuBi2O4 containing 36.7 wt% Ag2O was demonstrated through three successive cycling experiment.

Automated summary

The Ag2O/Ag2S/CuBi2O4 double Z-scheme heterostructures photocatalysts were successfully synthesized via hydrothermal and coprecipitation methods with different Ag2O proportions, exhibiting enhanced photocatalytic performance, especially under near-infrared light irradiation.