RESEARCH / A0355
Engineering Spatial Interface in Supported Molecular Complexes for Ampere-Level Electrocatalytic Oxygen Evolution
Read the original paper · 10.1021/jacs.5c02247 ↗
Source figures may contain other techniques and soft X-ray spectra. C, N and O measurements are outside our current hard-XAFS testing range.
Figure 2. X-ray absorption spectroscopic characterizations. (a,b) XANES spectra at (a) Fe and (b) Ni K-edge of FeNi-BPDA/C(O) and FeNi- BPDA/C. (c,d) Valence state analysis of (c) Fe and (d) Ni in FeNi-BPDA/C(O) and FeNi-BPDA/C. (e,f) Detailed k2-weighted FT-EXAFS fitting at (e) Fe and (f) Ni K-edge of FeNi-BPDA/C(O), FeNi-BPDA/C, FeNi-BPDA, Fe2O3, and NiO in R-space. Details in Tables S6 and S7. Inset: schematic model of FeNi-BPDA/C(O) and FeNi-BPDA/C. (g) The Fe−O2/C2 and Ni−O2/C2 bonds length in FeNi-BPDA/C(O) and FeNi- BPDA/C. Inset: schematic model of FeNi-BPDA/C(O). Colors: Fe, brown; Ni, blue; C, gray; O, red; H, white.
Figure 4. Dynamic structural evolution during OER. (a,b) ATR-SEIRAS spectra of (a) FeNi-BPDA/C(O) and (b) FeNi-BPDA/C at various potentials. The Si−O−Si absorption peak is present at 1250 cm−1.48 (c) Comparison of normalized absorbance intensity of the ν (metal-O*) signal under different OER potentials. (d,e) In situ Raman spectroscopy of (d) FeNi-BPDA/C(O) and (e) FeNi-BPDA/C at various potentials. (f,g) k2- Weighted FT-EXAFS fitting spectra at (f) Fe K-edge and (g) Ni K-edge. Scatters: experimental data; solid line: fitting data. (h) Comparison of Fe− O and Ni−O bond lengths in FeNi-BPDA/C(O) and FeNi-BPDA/C before and after the OER process.