Growth of MoSe2 electrocatalyst from metallic molybdenum nanoparticles for efficient hydrogen evolution

Molybdenum diselenide (MoSe2) is an emerging alternative to platinum-group-metal electmcatalysts for the hydrogen evolution reaction (HER). Herein, the chemical vapor deposition (CVD) approach was demonstrated to be a successful route to grow MoSe2 thin films using colloidal molybdenum nanoparticles (Mo NPs). The synthesis of Mo NPs was achieved using a wet-chemical method. After spin-coating of Mo NPs onto graphite substrates, heat treatments in the presence of selenium vapors at several temperatures (>= 750 degrees C) were carried out. Electrocatalytic activities of the obtained MoSe2 films were evaluated for HER using linear sweep voltammetry (LSV). The best performing MoSe2 film (800 degrees C) showed an overpotential of 218 mV at 10 mA cm(-2) in 0.5 M sulfuric acid (H2SO4). In addition, electrochemical impedance spectroscopy (EIS) was used to access the charge-transfer resistance (R-ct) of the MoSe2 films. The colloidal approach combined with CVD is a promising route to produce carbon supported MoSe2 electrocatalyst for HER.