Controllable Conversion of CdNCN Nanoparticles into Various Chalcogenide Nanostructures for Photo-driven Applications

Semiconductor nanocrystals of tunable shell/core configurations have great potential in photo-driven applications such as photoluminescence and photocatalysis, but few strategies realize a controllable synthesis with respect to both the size of the core and the shell with high crystallinity. Here, a new synthetic method based on cadmium cyanamide (CdNCN) nanoparticle anion exchange reactions was developed to access solid or hollow CdSe nanocrystals with tunable size and CdNCN@CdS heterostructures with modulated shell/core thickness. The gradual shift and narrow width of photoluminescence features demonstrate the high crystallinity and monodispersity of the resulting CdSe nanocrystals. In the CdNCN@CdS heterostructures, synergistic effects of the photocarrier separation is observed between the CdS shell and CdNCN core, which leads to great improvement in photocatalysis with optimized shell/core ratio.