Single Source Precursor Path to 2D Materials: A Case Study of Solution-Processed Molybdenum-Rich MoSe2-x Ultrathin Nanosheets

Abstract

Two-dimensional Molybdenum diselenide is a versatile and promising material used for a wide range of applications and its synthesis in high quality and yield is currently the subject of intense research. Low temperature solution phase synthesis of nanomaterials using designed molecular precursors enjoys tremendous advantages over traditional high-temperature solid-state synthesis. However, molecular precursor chemistry of molybdenum selenide nanomaterials is almost non-existent. We report here synthesis and structural characterization of new molybdenum molecular precursors with selenoether and selenourea ligands, which due to their easy synthesis, desired Mo/Se composition and moderate processing properties, are highly promising as single source precursors for the scale-up production of 2D molybdenum diselenide materials. This is demonstrated by the solution-phase decomposition of the Mo-selenourea precursor which produced Mo-rich MoSe_2-x ultrathin nanosheets (NSs) in good yield. These NSs were characterized by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), Powder X-ray diffraction (XRD), Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) studies.