L-cysteine-assisted synthesis of PbS nanocube-based pagoda-like hierarchical architectures

Nanocube-based pagoda-like PbS hierarchical architectures have been fabricated by hydrothermal treatment of Pb(Ac)(2) and L-cysteine solution. It was suggested that a biomimetic mineralization process happened during the growth of the hierarchical architectures. The biomolecule, L-cysteine, exerts coordination, oriented nucleation of crystals, and the morphology modulating effect. By studying the intermediates of the reaction, we observed that 4-fold symmetric star-shaped microcrystals were formed at first, and a second nucleation process resulted in the generation of nanocube-based pagoda-like hierarchical architectures. By varying the concentration of the reaction system, we got PbS nanocubes and octahedron microcystals. The morphology evolutions of PbS materials are explained by the growth rule of fee nanocrystals. This facile L-cysteine-assisted technique is expected to be employed for the shape-controlled synthesis of other fee structural nanomaterials.