Figure 4: HER activity characterizations.
From: Atomic cobalt on nitrogen-doped graphene for hydrogen generation
(a) LSV of NG, Co-G, Co-NG and Pt/C in 0.5 M H2SO4 at scan rate of 2 mV s−1. The inset shows the enlarged view of the LSV for the Co-NG near the onset region. (b) Plot showing the molar number of H2 produced as a function of time. The straight line represents the theoretically calculated amounts of H2 assuming 100% Faradaic efficiency, and the scattered dots represent the produced H2 measured by gas chromatography. The overlapping of these two sets of data indicates that nearly all the current is due to H2 evolution. The error bars arise from instrument uncertainty. (c) Tafel plots of the polarization curves in a. (d) TOF values of the Co-NG catalyst (black line) along with TOF values for other recently reported catalysts.
