Facile Phase Transition Engineering of MoS2 for Electrochemical Hydrogen Evolution

Metallic phase molybdenum disulfide exhibits impressive charge transfer ability and this has made them interesting candidates for use in the field of nano-science and heterogeneous catalysis. However, the synthesis of 100% pure bare 1T-MoS2 is difficult due to the kinetic instability. The phase transition mechanism from semiconductor (2H) to the metallic (1T) phase can be explained only by theoretical calculations in the past. Herein, we used magnetron sputtering to deposit a series of MoS2 films containing various metal heteroatoms as the dopants. Density functional theory (DFT) calculations revealed that the single-doped Cu-MoS2, Au-MoS2, Ag-MoS2, and Al-MoS2 exhibited distinct phase transitions compared to Cr-MoS2, Hf-MoS2, Ta-MoS2, and Zr-MoS2, due to the introduction of additional charge. Furthermore, the hydrogen evaluation reaction (HER) activities of the series MoS2 films were explored, and the adsorption free energy of H atoms was evaluated by DFT calculations.