Engineering yolk-double-shell Au@CN@ZnIn₂S₄ architecture with enhanced photocatalytic properties

The efficient utilization of light and the prolonged lifetime of photo-induced charge carriers are essential elements that contribute to superior photocatalytic activity. Yolk-shell nanostructures with porous shells and mobile cores offer significant structural advantages in achieving these goals. However, designing yolk-shell multicomponent nanocomposites with diverse architectures remains a persistent challenge. The present study involves the utilization of zinc indium sulfide (ZnIn₂S₄) flakes, which are uniformly incorporated into the yolk-shell Au@CN structure. The inclusion of ZnIn₂S₄ flakes in carbon nitride (CN) significantly enhances the performance of the overall system, allowing for efficient and rapid charge transfer. The uniform distribution of ZnIn₂S₄ flakes throughout the yolk-shell matrix ensures the catalytic activity is maximized, resulting in superior performance compared to conventional systems. The designed photocatalyst has a hollow interior which strengthens light absorption, a thin shell that shortens the electron migration distance, tight adhesion between shells, which makes it easier to separate and transfer carriers, and a movable Au core with localized surface plasmon resonance (LSPR) which can facilitate additional charge carrier generation for CN and ZnIn₂S₄. The yolk-shell microsphere composite of Au@CN@ZnIn₂S₄ shows a TC photodegradation rate of 72% within 2 h, which is more than double the photodegradation rate of hollow CN and ZnIn₂S₄. The present study's experimental demonstrations valuable insights into the rational design of sophisticated metal-semiconductors double yolk-shell nanocrystals, particularly those composed of metal sulfides cocatalyst, for superior photocatalytic applications.