Hollow Octahedral Cu_2–<i>x</i>S/CdS/Bi₂S₃ p–n–p Type Tandem Heterojunctions for Efficient Photothermal Effect and Robust Visible-Light-Driven Photocatalytic Performance

Abstract

Reasonable design of the nanostructure of heterogeneous photocatalysts is of great significance for improving their performance and stability. We report the design and fabrication of hollow sandwich-layered octahedral Cu_2-<i>x</i>S/CdS/Bi₂S₃ p-n-p type tandem heterojunctions constructed via the continuous growth deposition method on the surface of hollow octahedral Cu_2-<i>x</i>S with well-defined structures and interfaces. The unique hollow sandwich nanostructure has a large specific surface area and abundant reaction sites and enhances the separation and transfer of photogenerated carriers. In addition, the formation of a p-n-p heterojunction coupled with the surface plasmon resonance effect of Cu_2-<i>x</i>S could also aid in photocatalytic H₂ evolution performance and photocatalytic degradation efficiency. Under vis-NIR light irradiation, the optimized Cu_2-<i>x</i>S/CdS/Bi₂S₃ photocatalyst displays a notable H₂ production rate of 8012 μmol h^-1 g^-1, and 2,4-dichlorophenol is almost completely photocatalytically degraded in 150 min. This strategy and rational design offer a new path toward the design of specific nanocatalysts with enhanced activity and stability and challenging reactions.