Fig. 2: Exploring the role of PF₆⁻.
From: Hexafluorophosphate additive enables durable seawater oxidation at ampere-level current density
Operando Raman spectra collected from OCP to 1.75 V vs. RHE for NiFe LDH/NF in a PF₆⁻-free and b PF₆⁻-containing seawater. c Operando Raman spectra under the same potential range for PF₆⁻-intercalated NiFe LDH/NF in PF₆⁻-free seawater. d Normalized Ni K-edge XANES spectra for PF₆⁻-intercalated NiFe LDH/NF, NiFe LDH, NiO, and Ni foil. e Normalized Fe K-edge XANES spectra for PF₆⁻-intercalated NiFe LDH, NiFe LDH, Fe₂O₃, and Fe foil. f First-derivative Fe K-edge spectra of PF₆⁻-intercalated NiFe LDH, NiFe LDH, Fe₂O₃, and Fe foil. g TOF-SIMS mapping of PF₆⁻, Cl⁻, OH⁻, Ni, Fe, and K fragments on PF₆⁻-intercalated NiFe LDH/NF following a 120-h test. h Schematic of the proposed PF₆⁻ intercalation and surface adsorption mechanisms for Cl⁻ rejection. Source data are provided as a Source Data file.
