The effect of surface roughness on the hydrogen evolution reaction kinetics with mild steel and nickel cathodes

Abstract

The effect of electrode surface roughness on the kinetics of the hydrogen evolution reaction has been studied for mild steel and nickel cathodes in 10 M NaOH at 348°K. With the nickel cathodes, the Tafel slope was independent of whether the electrode surface was smooth or roughened, but the exchange current density was about twice that for the roughened electrode. With the mild steel cathodes, the roughened electrode showed a considerably lower Tafel slope than the smooth electrode with b = 51 mV for the rough electrode and b = 110 mV for the smooth one. The exchange current density was also lower for the roughened mild steel cathode than for the smooth electrode: 1.0 × 10 t-5 A/cm 2 vs 2.3 × 10 −5 A/cm 2.