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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 paper, different chemical properties of bottom ash and fly ash from municipal solid waste incinerators were compared based on the results of the five measuring techniques: (1) total contents and leaching amounts by regulatory leaching test in Japan; (2) leaching properties by pH-dependent leaching tests using model compounds; (4) enriched chemical composition compared with bulk composition by an X-ray photoelectron spectrometer (XPS); (5) estimation of chemical states of elements by XPS analysis.
104 citations
TL;DR: In this paper, time-resolved in situ, energy-dispersive X-ray absorption spectroscopy and mass spectrometry were used to correlate changes in the chemical state of alumina and ceria-supported palladium nanopartic materials.
Abstract: Time-resolved in situ, energy-dispersive X-ray absorption spectroscopy and mass spectrometry are used to correlate changes in the chemical state of alumina- and ceria-supported palladium nanopartic...
103 citations
TL;DR: In this paper, a comparative study of ion induced effects in simple and complex oxides was carried out using XPS techniques, and the interpretation of altered layer composition has been qualitatively considered in terms of the preferential loss of oxygen and reverse chemical reactions.
Abstract: XPS techniques are used for a comparative study of ion induced effects in simple oxides (ZrO2, SiO2, TiO2) and complex oxides (ZrSiO4, CaTiSiO5, La2TiO5, PbTiO3). We have found that reduction effects in simple and complex oxides differ. The interpretation of altered layer composition has been qualitatively considered in terms of the preferential loss of oxygen and reverse chemical reactions.
102 citations
TL;DR: In this paper, high-energy-resolution fluorescence-detected X-ray absorption spectroscopy (HERFD-XAS) has been applied to study the chemical state of ∼1.2 nm size-selected Pt nanoparticles (NPs) in an electrochemical environment under potential control.
Abstract: High-energy-resolution fluorescence-detected X-ray absorption spectroscopy (HERFD-XAS) has been applied to study the chemical state of ∼1.2 nm size-selected Pt nanoparticles (NPs) in an electrochemical environment under potential control. Spectral features due to chemisorbed hydrogen, chemisorbed O/OH, and platinum oxides can be distinguished with increasing potential. Pt electro-oxidation follows two competitive pathways involving both oxide formation and Pt dissolution.
102 citations
TL;DR: In this paper, the authors combined electrochemical and XPS surface analytical methods to gain a deeper insight into the mechanisms underlying the corrosion resistance of electroless deposited Ni-P alloys with phosphorus content between 18 and 22.
Abstract: Electroless Ni–P alloys are produced as coatings on a broad variety of substrates. They exhibit a corrosion resistance that is superior to pure nickel but do not form a NiO oxide film (passive film) as pure nickel does. Despite the fact that many mechanisms have been proposed to explain this superior corrosion behaviour, no consensus has yet been reached. In this work electrochemical and XPS surface analytical methods have been combined in order to gain a deeper insight into the mechanisms underlying the corrosion resistance of electroless deposited Ni–P alloys with phosphorus content between 18 and 22 at.%. The anodic polarization curves in acidic and neutral solutions confirm a broad current plateau followed by a region with increasing current density. During potentiostatic polarization in the plateau region the current decays according to a power law with exponent ca. −0.5 indicating diffusion-limited dissolution of nickel. XPS/XAES measurements performed after potentiostatic polarization show that phosphorus is present in three different chemical environments. Based on the Auger parameter concept and on the chemical state plot, the three phosphorus states were assigned to phosphorus in the bulk alloy, phosphates and an intermediate phosphorus compound attributed to elemental phosphorus. Angle-resolved XPS analysis has shown that the elemental phosphorus is enriched at the interface between the alloy and the outermost surface in contact with the corrosive solution. These results suggest the following conclusions: the high corrosion resistance of electroless deposited Ni–P alloys can be explained by a strong enrichment of elemental phosphorus at the interface which limits the dissolution of nickel via a diffusion mechanism. A complementary explanation––not yet advanced––for the high corrosion resistance may lie in the electronic state of nickel in the Ni–P alloys.
102 citations