We present the chemical vapor deposition (CVD) approach to grow MoSe2 thin films using colloidal molybdenum nanoparticles (Mo NPs). The synthetic protocol of Mo NPs was achieved using a wet-chemical method. The obtained Mo NPs were spin-coated on graphite substrates and heat-treated in the presence of selenium vapors at several temperatures (≥750 °C). The electrocatalytic activities of heat-treated MoSe2 thin
films were studied for hydrogen evolution reaction (HER) in 0.5 M sulfuric acid (H2SO4). The lowest recorded
overpotential of 218 mV at 10 mA cm−2 vs. a reversible hydrogen electrode was achieved with MoSe2−800°C catalyst. In addition, electrochemical impedance spectroscopy (EIS) was performed to access the chargetransfer resistance of the MoSe2 films. The colloidal approach combined with CVD is a promising route to produce carbon supported MoSe2 electrocatalyst for HER