Ultrathin cadmium sulfide nanosheets for visible-light photocatalytic hydrogen production

Ultrathin nanosheets attract considerable attention with regard to both fundamental research and potential applications. Nevertheless, non-layer structured materials are hard to make into nanosheets due to their isotropous bonds in three dimensions. Herein, ultrathin Cd4S5 nanosheets were synthesized via chemical vapor deposition followed by chemical etching. These nanosheets show the thinnest thickness (1 nm) and largest lateral size (10 mu m) among those reported for CdS materials so far. As a catalyst for photocatalytic hydrogen production, ultrathin Cd4S5 nanosheets achieve a high apparent quantum efficiency of 4.15% under 420 nm light irradiation. The superior photocatalytic performance is ascribed to the unique structure (surface S- anions and a reconstructed surface structure), and the ultrathin structure endows 1 nm NSs with long-term durability. This work opens a new avenue for producing two-dimensional nanostructures of non-layered compounds and improving their photocatalytic properties.