Fig. 5: Experimental validations of high intrinsic activity at tunnel mouth.
From: Tunnel-structured IrOx unlocks catalytic efficiency in proton exchange membrane water electrolyzers
a iR-corrected OER polarization curves of T-IrOx-400, T-IrOx-500, T-IrOx-600, and T-IrOx-700 measured in 0.1 M HClO4 electrolyte. The measurements were performed in O2-saturated 0.1 M HClO4 (pH 1) at 25 °C, with a scan rate of 1 mV s−1, the catalyst loading of 0.281 mg cm−2, and O2 flow rate of 10 mL min−1. E−iR presents iR-corrected potentials. jgeo presents current density which is normalized to geometric electrode area. The compensated resistances, measured via the iR compensation function of the electrochemical workstation, were 35.3 ± 1.2, 35.7 ± 1.1, 31.2 ± 0.1, and 35.2 ± 0.4 Ω for T-IrOx-400, T-IrOx-500, T-IrOx-600, and T-IrOx-700, respectively. b Intrinsic activities (jQ) at 1.54 V vs. RHE of T-IrOx synthesized at different temperatures versus their mouth area ratio. Intrinsic activity is calculated by normalizing current density by pseudocapacitive charge (Q). Mouth area ratio is the ratio of bipyramidal area and surface area of nanorod. The error bars of mouth area ratio and jQ represent the standard errors from two hundred and three measurements, respectively. Inset shows the fitting logarithmic curve of the relationship between jQ and mouth area ratio. Source data are provided as a Source data file.
