From 1T to 2H: Engineering MoS2 phases through tunable hydrothermal routes

Abstract

Molybdenum disulfide (MoS<inf>2</inf>) has attracted a lot of attention in recent years due to its unique structural polymorphism, primarily the semiconducting 2H phase (2H-MoS<inf>2</inf>) and the metallic 1T phase. The 2H phase is widely employed in optoelectronics, catalysis, and energy storage devices due to its inherent bandgap, while the metallic 1T phase (1T-MoS<inf>2</inf>) exhibits excellent electrical conductivity and catalytic activity, indicating its potential for use in supercapacitors and hydrogen evolution processes (HER). The ability to tune the phase composition of MoS<inf>2</inf> is critical for optimizing its performance in such diverse applications. In this study, we report the controlled synthesis of MoS<inf>2</inf> phases using a single hydrothermal process by systematically varying synthesis parameters — such as precursor concentration, reaction time, temperature, and pH — we effectively tuned the energy kinetics governing phase formation. The optimized parameters used for selective synthesis of 2H-MoS<inf>2</inf>, 1T-MoS<inf>2</inf>, and mixed-phase compositions. Detailed characterization of the flower like MoS<inf>2</inf> Microspheres using X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM) confirmed the phase purity and morphological features of the synthesized materials. Our work provides a scalable and reproducible approach for phase-engineering of MoS<inf>2</inf>, enabling its tailored design for targeted applications in energy storage, catalysis, and nanoelectronics. © 2025 Elsevier B.V.