Chemical state

About: Chemical state is a research topic. Over the lifetime, 2378 publications have been published within this topic receiving 78183 citations.

Study on distribution, chemical states and binding energy shifts of elements on the surface of gasification fine ash

Abstract: Using feed coal as a reference, a series of modern advanced analysis and measurement technologies such as X-ray photoelectron spectroscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy and X-ray diffraction have been used to analyze the gasification fine ash obtained from a pulverized coal gasification unit. The results show that the fine ash mainly consists of elemental carbon, oxygen, silicon, and aluminum. The elemental carbon distributes primarily on the foams structure, while the spherical particles mainly consisted of silicon and aluminum are embedded in the foams structure. The C1s spectrum is composed of five components in which the content of graphitized carbon is up to 38.36%, and the content of aromatic C–C or C–H, the main existing form on coal surface, is only 25.75%. The 67.31% of elemental silicon is combined with bridging oxygen (Si–O) and 32.69% of that connected to non-bridging oxygen (Si–O2). The existence of aluminum is in the form of aluminum oxides with two coordinated modes ([AlO6] and [AlO4]), and the content of [AlO6] group is nearly double that of [AlO4]. Simultaneously, the binding energies of silicon and aluminum increase by approximately 3 eV, while that of carbon almost no change because of the number of carbon atoms is significantly higher than that of other elements. The silicon atoms and aluminum atoms are surrounded by masses of carbon atoms for the special microstructure of FA. The different chemical states of carbon with higher electronegativity along with the role of high temperature and pressure make the binding energies of silicon and aluminum changed dramatically.

Cluster Beam Deposition of Cu2–XS Nanoparticles into Organic Thin Films

Abstract: Bulk-heterojunction films composed of semiconductor nanoparticles blended with organic oligomers are of interest for photovoltaic and other applications. Cu2–XS nanoparticles were cluster beam deposited into thermally evaporated pentacene or quaterthiophene to create bulk-heterojunction thin films. The nanoparticle stoichiometry, morphology, and chemistry within these all-gas phase deposited films were characterized by X-ray photoelectron spectroscopy (XPS) and electron microscopy. Cu2–XS nanoparticles were (at most) only slightly copper-deficient with respect to Cu2S; ∼2.5 nm diameter, unoxidized Cu2–XS nanoparticles formed in both pentacene and quaterthiophene, as the matrix was not observed to impact the nanoparticle morphology or chemical structure. Cluster beam deposition allowed direct control of the nanoparticle stoichiometry and nanoparticle:organic ratio. Chemical states or Wagner plots were combined with other XPS data analysis strategies to determine the metal oxidation state, indicating that C...

Microstructure and chemical state of Ti1-xYxN film deposited by reactive magnetron sputtering

Abstract: A feasibility of using Ti1−xYxN as a hard coating material was investigated. Coatings were made on a Si(100) surface as well as on a steel surface using a dual-target rf-dc reactive magnetron sputtering method with the range of Y varying from x=0 to x=0.16. By x-ray diffraction analysis, it was found that all the coated films were of a single phase with a NaCl structure, with their lattice parameters increasing with Y content. A transmission electron microscopy analysis of the coated film revealed fine columnar grains in the samples containing high NY. This was attributed to Y atoms of low surface mobility and a strong bonding tendency with oxygen. The Y atoms promote the rate of heterogeneous nucleation by easily forming fine oxide particles at the substrate surface. From x-ray photoelectron spectroscopy analysis, it was learned that the binding energies of Y 3d5/2 and N 1s in YN bonding were 157.8 and 397.5 eV, respectively. The optimum combination of microhardness and adhesion strength was obtained in ...