Modulating the crystallinity of 1D MoO3 and its conversion to 2D MoS2 nanosheets for efficient hydrogen evolution reaction catalysts

Molybdenum sulfide (MoS2) has been identified as a promising and ample electrocatalyst for hydrogen evolution reaction (HER). Herein, we have synthesized 2D MoS2 from 1D Molybdenum oxide (MoO3) prepared via hydrothermal method and subsequent annealing. The HER of the prepared MoO3 and MoO3 annealed at temperature varying from 100 to 700 degrees C is evaluated by utilizing linear sweep voltammetry (LSV) in acidic electrolyte medium with MoO3@300 degrees C displaying the best overpotential at 229 mV vs RHE, respectively. The enhanced HER activity of MoO3 annealed at 300 degrees C is attributed to its higher crystallinity. Further, the MoO3 annealed at 300 degrees C is converted to MoS2 exhibiting excellent HER performance with overpotential of 197 mV. The Tafel slope, electrochemical active surface area (ECSA) and turn over frequency (TOF) values of MoS2, MoO3, at different annealed temperatures have also been analysed in this work.