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Chemical state
About: Chemical state is a research topic. Over the lifetime, 2378 publications have been published within this topic receiving 78183 citations.
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TL;DR: In this article, the shifts of the electron lines of an element can be correlated with its chemical state of oxidation, which is called ESC A (electron spectroscopy for chemical analysis).
Abstract: WE have already reported some applications of electron spectroscopy in the study of chemical binding1. We showed that the shifts of the electron lines of an element can be correlated with its chemical state of oxidation. Our method makes use of Auger and photo electrons produced by X-rays and is called ESC A (electron spectroscopy for chemical analysis). Most of the results reported were obtained from the element sulphur, and electron spectra from this element have, for example, been used to solve a specific problem concerning the molecular structure of cystine S-dioxide2.
23 citations
TL;DR: In this article, the chemical states of Cr ions in rutile were studied using mainly electron spectroscopy for chemical analysis (ESCA), electron spin resonance (ESR), and diffuse reflectance spectrography (DRS) for diffuse reflection spectrograms.
Abstract: The chemical states of Cr ions in rutile were studied using mainly electron spectroscopy for chemical analysis (ESCA), electron spin resonance (ESR), and diffuse reflectance spectroscopy. The study assumed that Cr3+ and Cr4+ which formed solid solutions with TiO2 possessed yellow and orange colors, respectively. A dark tinge accompanying the maple color of Cr-doped TiO2 probably was produced by undissolved CrO3−x (x∼ 0.5) occurring on the TiO2 grains. Incorporation of Sb into the Cr-doped TiO2 enhanced the solubility of Cr presumably because of the formation of Sb5+Cr3+ pairs and eventually decreased the dark tinge.
23 citations
TL;DR: In this paper, the surface and near-surface composition of ambient-exposed Al metal was studied using XPS, AES and EELS spectroscopies, and α2Al involving the ALVV transition was considered, which marks the difference between Al0 and Al2O3 with a chemical shift which is more than twice as great as that associated with the AlKLL-related Auger parameter used in the literature for characterizing the aluminum chemistry.
23 citations
TL;DR: This study uses highly ordered pyrolytic graphite (HOPG) as a model on which the fundamental properties of specific functional groups and their interactions with deposited nanoparticles can be characterised and it is shown that treatment of HOPG surfaces with low concentrations of hydrochloric acid results in significant topographic changes to the surface and a low concentration of oxygen containing species.
Abstract: The utility of carbon materials in applications as diverse as drug delivery and photocatalysis is often undermined by the complexity of their surface chemistry; different sources of carbon give rise to a varied mixture of functional groups and hence different properties. Considerable efforts have been made to identify specific groups at these surfaces and elucidate the complex interactions that take place but even on materials such as graphene and carbon nanotubes there remains uncertainty about the nature of the components present and their role in the nucleation of other functional materials at the surface. The present study uses highly ordered pyrolytic graphite (HOPG) as a model on which the fundamental properties of specific functional groups and their interactions with deposited nanoparticles can be characterised. We have shown that treatment of HOPG surfaces with low concentrations of hydrochloric acid results in significant topographic changes to the surface and a low concentration of oxygen containing species. From selective derivatization and a comparison of their XP spectra, the latter can be unambiguously identified as surface hydroxyls. DFT calculations have shown that these groups are stable in close proximity to each other. Heating to 573 K leads to conversion of the hydroxyls to mixture of two states, one of which is identified as a ketone whilst the other is proposed to be an ether. Gold deposition on the surface from aqueous solutions of chloroauric acid is shown to be strongly influenced by the nature of the oxygen species present.
23 citations
TL;DR: In this paper, bismuth ferrite nanoparticles (∼75nm and ∼155nm) were synthesized by a chemical method, using soft X-ray (1253.6
Abstract: We have investigated bismuth ferrite nanoparticles (∼75 nm and ∼155 nm) synthesized by a chemical method, using soft X-ray (1253.6 eV) and hard X-ray (3500, 5500, and 7500 eV) photoelectron spectroscopy. This provided an evidence for the variation of chemical state of bismuth in crystalline, phase pure nanoparticles. X-ray photoelectron spectroscopy analysis using Mg Kα (1253.6 eV) source showed that iron and bismuth were present in both Fe3+ and Bi3+ valence states as expected for bismuth ferrite. However, hard X-ray photoelectron spectroscopy analysis of the bismuth ferrite nanoparticles using variable photon energies unexpectedly showed the presence of Bi0 valence state below the surface region, indicating that bismuth ferrite nanoparticles are chemically inhomogeneous in the radial direction. Consistently, small-angle X-ray scattering reveals a core-shell structure for these radial inhomogeneous nanoparticles.
23 citations