2.4. Electrochemical cell test
The cathode current was measured by applying different voltage
in potentiometry tests (linear sweep voltammetry (LSV)) using
a three-chambered electrochemical cell containing a working electrode
(cathode electrode with 0.5 cm2 projected surface area), a
platinum plate counter electrode, and an Ag/AgCl reference electrode.
The catalyst-coated side of the cathode was placed facing
the solution, with the uncoated side exposed directly to air. LSV
studies were conducted using a potentiostat (VoltaLab 06) by
applying potential from 0.4 to 0.6 V with a scan rate of 10 mV/s
and recording the current. A curve of the cathode potentials against
current densities was used to evaluate the performance of cathodes.
For a fixed current density, the higher the potential the better
the performance of the cathode material. All the measurements
were conducted at room temperature (25 ± 2 C) in oxygen saturated
PBS.