2022年12月5日 · Herein, operando ultraviolet-visible (UV–vis) and Raman spectroscopies were used to probe the surface reconstruction behaviors of FeOOH@NiFe layered double hydroxides (LDH) hybrid catalysts, which revealed that FeOOH@NiFe LDH was converted into highly active FeOOH@ β-Ni (Fe)OOH phases during the OER process.

2019年5月29日 · Structural and electronic transformation taking place in α-FeOOH goethite have been studied by Fe K-edge x-ray absorption spectroscopy at pressures up to 50 GPa. These studies have shown the symmetrization of FeO 6 octahedra coinciding with the Fe 3+ high to low spin transition at pressure above ~45 GPa.

2022年6月15日 · Spectroscopy analyses (XPS and XAS) show simultaneous V-doping and the co-existence of both Fe and O vacancies, as well as the metallic Fe in the resulting β-FeOOH phase. ICP analysis shows that such self-reconstruction occurs due to the vanadium dissolution.

2021年9月15日 · In this study, S-modified FeOOH electrocatalysts were prepared via a facile hydrothermal method at 120 °C. The electrocatalyst exhibited an outstanding OER performance with an overpotential of 254 mV at 50 mA·cm−2. Morphological, structural, and electrochemical characterizations revealed that Fe ion is the most important active center.

2017年7月8日 · In the present study in situ Raman spectroscopy was employed to study the reduction and re-oxidation of α-FeOOH and γ-FeOOH deposited on titanium substrates. The pH was set to 11 in order to mimic the operational conditions at hydrogen evolution and with the aim to detect any changes in the composition of the surface layer upon polarization.

Fe 3 O 4 showed a better adsorption ability than α-FeOOH even though it had a lower surface area. XAS and XPS analysis strongly evidenced the production of stable Cr 3+ species of Fe (1−x) Cr x OOH and Fe (3−x) Cr x O 4 by Cr 6+ reduction and migration processes into the …

Here, comprehensive first-principles calculations of X-ray absorption near-edge structure (XANES) spectra of a series of Fe-based catalysts and battery electrodes, including FeO, Fe2O3, Fe(OH)2,...

Several methods such as synchrotron XRD measurements, X-ray absorption spectroscopy (XAS), and 57 Fe Mössbauer spectroscopy were employed to clarify their structural and electronic properties. Consequently, β-FeOOH was found to transform into ε-FeOOH along a different pressure–temperature phase diagram from that of α-FeOOH.

2020年4月2日 · Structural and electronic transformation taking place in α-FeOOH goethite have been studied by Fe K-edge x-ray absorption spectroscopy at pressures up to 50 GPa. These studies have shown the symmetrization of FeO. 6octahedra coinciding with the Fe3+high to low spin transition at pressure above ~45 GPa.

2019年8月14日 · Structural and electronic transformation taking place in α-FeOOH goethite have been studied by Fe K-edge x-ray absorption spectroscopy at pressures up to 50 GPa. These studies have shown the symmetrization of FeO 6 octahedra coinciding with the Fe 3+ high to low spin transition at pressure above ~45 GPa.