Preparation and formation process of α-MnS@MoS2 microcubes with hierarchical core/shell structure

alpha MnS@MoS2 microcubes with hierarchical core/shell structure are prepared by one-step hydrothermal method in a reaction system of delta-MnO2 nanowires, thioacetamide and Na2MoO4 at 200 degrees C for 24 h, and the formation process and phase transition behavior has been investigated in detail. Research results indicate that uniform nanosheets of MoS2 with thickness of about 20 nm and size up to hundreds of nanometers are vertically grow on the surface of alpha-MnS core, and the amount of sodium molybdate plays a crucial role in adjusting the crystal phase and structure of the obtained materials. The formation process of alpha-MnS@MoS2 microcubes with hierarchical core/shell structure consist of four stages, delta-MnO2 nanowires with layered structure are firstly transforms into tetragonal Mn3O4 nanoparticles, then into gamma-Mns hexagonal prisms and alpha-MnS microcubes, and finally into alpha-MnS@MoS2 microcubes. In compare with beta-MnS and gamma-MnS phases, alpha-MnS can be formed in alpha-MnS@MoS2 microcubes because it has not only higher lattice energy, but also the lowest Gibbs free energy and the sufficient activation energy at high hydrothermal treatment temperature. By using this one-step hydrothermal technology without template assisted route, other transition metal sulfide materials with novel core/shell structure and morphology can be designed and prepared by selecting transition metal and adjusting the amount of sulfur source. (C) 2017 Elsevier Inc. All rights reserved.