Two-step solvothermal synthesis of α-MnS spheres:: Growth mechanism and characterization

Stable alpha-MnS spheres have been successfully synthesized by two-step solvothermal method and traditional solvothermal technique without any surfactant assistance. The XRD patterns and FE-SEM images show that the as-prepared samples are cubic alpha-MnS micro-spheres with different morphologies. The fort-nation of spheres was studied under different experimental conditions. The two-step solvothermal method helps us cognize the growth mechanism in the solvothermal synthesis better. The result shows that template-direct growth and Ostwald ripening for the formation of the alpha-MnS spheres are approved. In addition, both mechanisms can be effective at the same time. The UV-Vis absorption spectra reveal that the samples synthesized by different methods have the maximal absorption at the same wavelength (around 365 nm). (C) 2007 Elsevier B.V. All rights reserved.