Solvothermal synthesis of manganese sulfides and control of their phase and morphology

Manganese sulfides (MnS) with a diversity of well-defined morphologies and phases have been successfully synthesized by the solvothermal approach. The phase structure and morphology of MnS could readily be tuned by adjusting the sulfur sources and solvents. Hollow γ-MnS spheres were obtained by treating L-cysteine and manganese source in ethylene glycol (EG) at 200 °C for 2 h, whereas a replacement of the mixture solvent by EG and deionized water yields the hierarchical flower-like γ-MnS. γ-MnS tubes were also produced under the same condition by using diethylene glycol and deionized water as solvents. When thioacetamide used as the sulfur source and oleylamine used as the solvent, monodisperse α-MnS nanoparticles with the mean diameter of 17 nm could be synthesized successfully. The phase structures, sizes, and morphologies of samples were investigated in detail by powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The UV-vis absorption peak and the width of band gap with different morphologies of the as-prepared MnS were measured. The samples described in this paper are promising to be utilized in solar cells, biomedicine, short wavelength electronic devices, photocatalysis, and other fields.