Influence of molybdenum-based precursor on the morphological evolution of MoTe₂ nanostructures via one-pot synthesis method

Abstract

In this work, molybdenum ditelluride (MoTe₂) nanostructures have been synthesized using a hydrothermal route with different precursors and investigated for their morphological, structural and optical properties. Field-emission scanning electron microscopic images have revealed different morphological growth patterns, including nanorods, agglomerated nanoparticles and stacked sheet/flake-like structures, demonstrating significant influence of precursors and temperature on morphology. High-resolution transmission electron microscopy further confirmed the polycrystalline nature of the synthesized MoTe₂ nanostructures. X-ray diffraction patterns have confirmed the existence of 1T and 2H phases of MoTe2, depending on the selection of molybdenum precursors. The average crystallite size, calculated using the Williamson-Hall plot to be 144, 91, 57 and 41 nm for NAMo-1, NAMo-2, NHMo-1 and NHMo-2, samples respectively. The active Ag and B2g modes have been confirmed by Raman spectra and characteristic Mo-Te and Mo-O vibration modes by Fourier transform infrared spectra, further confirmed the formation of MoTe2 nanostructures. The precursor-dependent morphology has provided insights into the synthesis of phase-tunable nanostructures.