Large scale synthesis of PbS tipped ZnS nanorods heterostructures by long-pulse-width laser ablation in liquid

A large scale of PbS tipped ZnS nanorods heterostructures (PbS/ZnS heterostructures) was successfully synthesized by laser ablation of Zn/Pb binary metal target immersed in dodecyl mercaptan (DDM) using long-pulse-width millisecond laser at room temperature and atmospheric pressure. The PbS/ZnS heterostructures were observed both on the surface of Zn/Pb target and in the ablated products after laser ablation. SEM and TEM results showed that the length and diameter of ZnS nanorods was in the range of 200–300 nm and 50–60 nm, the diameter of PbS tips in the one end of the ZnS nanorods was in the range of 70–80 nm, respectively. The pulse-width of laser, liquid media and weight ratio of Pb/Zn was critical for the synthesis of PbS/ZnS heterostructures. In addition, we proposed the growth mechanism of PbS/ZnS under laser ablation. This method is a simple but effective method for simultaneously fabricating of heterostructures directly onto a substrate and formation of heterostructures in the liquid from the ablated products, which implied a prospective application for the selective surface area chemical modification.