Fig. 4: Investigation of the OER performance and mechanism of Na-HE LDH.
From: Engineering oxygen nonbonding states in high entropy hydroxides for scalable water oxidation
a LSV curves with 95% iR correction, the solution resistance is 1.8 Ω and the loading of catalysts is ~1 mg cm−2. b Tafel plots. c Mass activity and ECSA-normalized current density of Na-HE LDH and HE LDH at η = 250 mV. d left is the LSV curves with 95% iR correction in KOH solution with pH = 12–14, the solution resistance is 1.8 Ω and the loading of catalysts is ~1 mg cm−2. right is the proton reaction orders (ρRHE = ∂logj/∂pH). e left is the LSV curves with 95% iR correction of Na-HE LDH and HE LDH in 1.0 M KOH and 1.0 M TMAOH, the solution resistance is 1.8 Ω and the loading of catalysts is ~1 mg cm−2. right is the shift of overpotential (Δη10) and shift of Tafel slopes values (ΔTafel) from 1.0 KOH to 1.0 TMAOH. f Raman spectra of Na-HE LDH and HE LDH after running in 1.0 M TMAOH and 1.0 M KOH (1.45 V vs RHE for 1 h). g Mass spectrometric results of 18O isotope labeling experiments. h Structure illustration of the electrolyzer cell. i LSV curves of Pt/C | | Na-HE LDH, Pt/C | | HE LDH and Pt/C | |NiFe LDH in 30 wt% KOH at 60 °C, no iR correction. j Comparison of voltage values for Pt/C | | Na-HE LDH, Pt/C | | HE LDH and Pt/C | |NiFe LDH at different current densities (error bars are from five repeated experiments). k i-t measurement for Pt/C | | Na-HE LDH, Pt/C | | HE LDH and Pt/C | |NiFe LDH at 1.56 V vs. RHE, 1.71 V vs. RHE and 1.69 V vs. RHE. l, Variation in the molar concentration of Fe in the electrolyte during the stability tests of Pt/C | | Na-HE LDH, Pt/C | | HE LDH and Pt/C | |NiFe LDH. Source data are provided as a Source Data file.
