Tunable synthesis of multi-shaped PbS via l-cysteine assisted solvothermal method

• PbS of multi-morphologies have been prepared under systemic reaction conditions.
• The formation mechanism of these morphologies was discussed in detail.
• Infrared absorption spectra of these samples have been measured and discussed.

Lead sulfide (PbS) with multi-morphologies were synthesized via solvothermal route under the assistance of l-cysteine. Reaction conditions such as concentration of l-cysteine, reacting temperature, reacting time and solvents have been systemically investigated in order to obtain shape-controlled PbS micro-crystals. A series of morphologies, such as cubic, Dendritic Hierarchical, Octagonal Hierarchical flowerlike and Vertebration shapes were obtained successfully. Self-assembly and a hypothesis based on Boltzmann distribution were introduced for illustration of morphology evolution obtained under different reacting temperatures, and the effect of the solvents and the role of l-cysteine were also discussed in detail. To testify the effects of different morphologies on the optical properties of PbS, the absorption spectra of some samples were measured. These results demonstrated that our work offers an effective way to develop the tunable synthesis of multi-shaped PbS for various applications.