Understanding of the intensified effect of super gravity on hydrogen evolution reaction

Hydrogen evolution reaction (HER) under super gravity field was studied in 0.5 M H2SO4 aqueous solution by cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS). Electrode surface during HER was observed by electronic endoscope. The original understanding of the intensified effect of super gravity on HER was discussed. The results indicated that HER was enhanced by super gravity field. Little visible hydrogen bubbles were observed on electrode surface under super gravity field. It was reasonable that the intensified effect of super gravity on HER was ascribed to the smaller critical radii of forming bubble nucleus and larger buoyancy force, which would promote the disengagement of gas bubbles and decrease the gas coverage on electrode surface. As a result, more active sites remained and HER rate increased.