Optimization of synthesis parameters for molybdenum diselenide using hydrothermal method

Abstract

Transition metal dichalcogenides (MoSe2) have attracted significant attention because of their potential use for hydrogen evolution reactions and in other electronic and optoelectronic applications. However, the synthesis of layered MoSe2 through the hydrothermal route itself is an arduous task. Herein, we have observed that the selenium does not get easily dissolved during synthesis in water and ethanol. However, the same seems to partially dissolve in a solution containing sodium borohydride and hydrazine monohydrate. This complication leads to unreacted selenium in the reaction product, as confirmed by the X‐ray diffraction data. In the available literature, the authors have reported washing of as‐obtained Se‐rich MoSe2 with ethanol, acids and some have utilized annealing to remove unreacted selenium. However, we have adopted another method of removing the excess unreacted selenium powder from the synthesized product, thereby obtaining MoSe2. In addition, the reaction parameters such as temperature, duration of hydrothermal reaction and precursor are optimized.