Insights into the Structural Evolution of MoS<sub>2</sub> from the Semiconductive 2H to Metallic 1T Phase
Qizhang Huang, Jingli Shen, Yuan Lü, Rongda Ye, Sheng Gong
Abstract
Molybdenum disulfide (MoS 2 ) possesses distinct electrochemical and electronic properties, as a unique material, and raises a growing amount of interest in both its synthesis and application. Compared with the most stable and widely existing triangle prismatic (2H) phase of MoS 2, 1T-MoS 2, a metallic octahedral but metastable crystal phase, occupies a more important position within the application in electrochemical reactions, photoelectron catalysis, photodetectors, photothermal agents, energy storage devices, and biosensors. In this article, an exploration of the key reasons for the different stabilities of 1T- and 2H-MoS 2 is conducted via density functional theory (DFT) calculations. Meanwhile, simple but facile bonding patterns of valence orbits in 1T- and 2H-MoS 2 are proposed with an emphasis on their properties and stability. Consequently, the electron count and density of state (DOS) unification of MoS 2 are considered as the secrets for the 2H-to-1T phase transition, where the most reported manners for obtaining 1T-MoS 2 can be well explained. The finding here has a profound hint for the phase engineering of MoS 2 and promotes the development of crystal material nowadays.