Fig. 5: Potentiostatic holding experiments.
From: Concurrent oxygen evolution reaction pathways revealed by high-speed compressive Raman imaging
a Ramp to potentials between 1.4 V and 1.7 V vs RHE followed by a 2 min potential hold at the given potential and then a spontaneous release of the potential for 8 mins. b Raman images integrating the intensity of the mode at 640 cm−1 for a single agglomerate particle at set points (labelled A to F in panel a) during the potential ramp, hold and release. The scale bar is 5 μm. c Velocity of the phase front associated with K+ ion diffusion back into the catalyst following release of the potential. Velocities are extracted from the spatial motion of the 640 cm−1 intensity front in the temporal region D to F in panel (a). Error bars are derived from repeat measurements over 35 particles and fitting errors.
