Figure 2. High-resolution spectra of Co (A), O 1s (B), and B 1s
(C) of CoB/Ni flow-through
electrode before and after HER/OER
activation.
The AWE performance of each prepared electrode has been investigated in
1 M KOH solution. In this study, three different pore sizes of Ni foam
have been chosen, with 35, 75, and 110 PPI. The thickness of each Ni
foam is 1 mm, and the diameter of each Ni foam is 10 mm. The linear scan
voltammetry (LSV) polarization curves (Figure 3A, Figure S6) were used
to assess the performance of AWE at a scan rate of 5 mV
s-1. As can be seen, the catalytic performance can be
enhanced after loading catalysts, with a reduction in the potential of
almost 150 mV at 400 mA cm-2. The best catalytic
performance can be achieved by Co(OH)2/Ni electrode with
a pore size of 75 PPI (Figure S7-S10), due to the largest
electrochemical surface area (ECSA, 38.38 mF cm-2) and
the smallest reaction resistance (6.481 ohm).