Facet-Selective Growth of Dots-on-Plate II-VI Heterostructures for Efficient Photocatalytic Hydrogen Evolution.

High-level control over the surface and interface of II-VI heterostructures is crucial for enhancing charge separation and optimizing active sites, thus improving photocatalytic performance. However, due to variations in surface energy and atomic arrangement among different crystal facets, achieving selective growth of specific facets remains a significant challenge. Herein, we have achieved the selective growth of CdSe or ZnSe dots on the lateral facets or basal facets of two-dimensional CdS or ZnS nanoplates by carefully selecting Se source precursors with different reaction activities. The lateral-ZnSe/CdS exhibit enhanced activity for photocatalytic hydrogen evolution compared to that of basal-ZnSe/CdS, attributed to the high exposure ratio of the basal facets and the effective modulation of photoinduced electron-hole pairs at the lateral-ZnSe/CdS interfaces. This work expands the structural diversity of II-VI heterostructures and also provides a viable strategy to enhance their photocatalytic performance by tailoring the surface and interface structures.