Microwave-controlled facile synthesis of well-defined PbS hexapods

Controlled synthesis of well-defined PbS nanostructures in terms of size and shape has been strongly motivated by their potential applications ranging from solar photovoltaics to near-infrared optics. Hereby, we report a facile microwave-assistant method for ultrafast fabrication of PbS nanostructures, by which uniform PbS hexapods with six arms stretching along six (100) directions of the crystal seeds have been easily synthesized within minutes. Various morphologies including rectangle plates, uniform cubes as well as nanoparticles were obtained by tuning the parameters for the formation of PbS nanocrystals. The results reveal that both concentration and feed ratio of precursors determine the growth of PbS nanocrystals significantly. And higher initial precursor concentration favors the formation of the hexapod structures. The process of crystal growth is monitored through scanning electron microscopy of PbS from different durations of the reaction. This controlled ultrafast synthesis of PbS structures at nanometer and micrometer scale with various morphologies may be promising in large scale fabrication of nanostructures. Based on the systematically study of the growth process, a possible mechanism for the formation of the hexapod-like structure is discussed.