Impact of Modulating MoO3 Crystal Ctructure and Size on Electrolytic Hydrogen Evolution Catalysis

Carbonized MoO3 and graphene-MoO3 were successfully synthesized for hydrogen evolution, using glucose and graphene with (NH4)6Mo7O24·4H2O as precursors, respectively. The prepared products were comprehensively characterized using a suite of analytical techniques, including scanning electron microscopy, thermogravimetry and differential scanning calorimetry, and X-ray diffraction. The electrochemical performance of graphene-MoO3 was systematically evaluated through linear sweep voltammetry, while electrochemical impedance spectroscopy was used to investigate the hydrogen evolution reaction at the electrode interface. The hydrogen evolution overpotential of graphene-MoO3 modified GCE at 10 mA/cm2 was 462 mV vs RHE, exhibiting a Tafel slope of 184 mV dec–1, by regulating the structure, resistance, and crystal size of MoO3 crystals.