Type-I CdSe/ZnS Heteronanoplatelets Exhibit Enhanced Photocatalytic Hydrogen Evolution by Interfacial Trap-Mediated Hole Transfer

Photoinduced carrier transfer pathways affect the optical and electronic properties of nanomaterials for photocatalytic H-2 evolution. The role of defects in semiconductor nanocrystals can improve our understanding of photocatalytic mechanisms. Here, we constructed various types of heterojunctions in CdSe/ZnX (X: S, Se) heteronanoplatelets (HNPLs). These were synthesized via heteronucleation and growth on CdSe nanoplatelets (NPLs). The HNPLs were used to identify novel photocatalytic mechanisms in H-2 evolution under visible-light irradiation. Time-resolved transient absorption and photoluminescence spectroscopic results suggest that CdSe/ZnS HNPLs with interfacial anomalous type-I hole transfer have advantages in terms of efficient charge separation and photocatalytic H-2 evolution over type-II CdSe/ZnSe HNPLs and pristine CdSe NPLs. These results clarify defect-mediated carrier transfer in visible-light-driven photocatalytic H-2 evolution.

Automated summary

Photoinduced carrier transfer pathways play a role in the optical and electronic properties of nanomaterials for photocatalytic H-2 evolution, while defects in semiconductor nanocrystals can enhance our understanding of photocatalytic mechanisms. CdSe/ZnS HNPLs with anomalous type-I hole transfer exhibit advantages in efficient charge separation and photocatalytic H-2 evolution, compared to type-II CdSe/ZnSe HNPLs and pristine CdSe NPLs. These results elucidate the role of defect-mediated carrier transfer in visible-light-driven photocatalytic H-2 evolution.