1,721,077 research outputs found
chap. IV "Functional and Nanostructured Materials Investigated by XPS and NEXAFS Spectroscopies" in "Advances in Macromolecules: Perspectives and Applications" ed. Maria Vittoria Russo
No full textNew developments in X-Ray photoelectron spectroscopy applied to nanostructured materials
No full textThe study and characterization of nanostructured materials is growing very fast and potential applications of new materials at the nanoscale are envisaged, based on the general observation that the performance of matter at molecular scales will exhibit unexpected features, depending on size, shape and composition. The phenomena occurring at the nanoscale are of fundamental interest and involve synthesis and chemical-physical studies, optoelectronic and biotechnological characterization, for applications in several field of technology. One of the main goals to the study of nanostructured systems is to deeply understand the behavior of materials when the sizes are close to molecular dimensions. To address this purpose, different techniques have been developed and among surface sensitive techniques, X-ray Photoelectron Spectroscopy (XPS) is particularly suited and largely employed. In fact, XPS provides fundamental information on sample surface, elemental composition and chemical state of the elements of the material under analysis. By the analysis of the Binding Energy (BE) of core electrons, this technique allows qualitative elemental identification. Little BE variations, due to the chemical environment of the selected atom, determine the oxidation state and its perturbation due to the formation of new chemical bonds with interacting species. XPS surface sensitivity to the outmost layers of the investigated materials is an important peculiarity when the surface plays a fundamental role, as in nanostructured materials, in which the chemical nature of the surface, the surface reactions, the interface characteristics and molecular adhesion have a primary function. In this commentary the research developments and future perspectives of XPS characterization of nanostructured materials will be reviewed, with particular attention to surface and interface effects for nanoparticles of different sizes and shapes. Reports on these extremely important topics will be addressed. © 2011 Nova Science Publishers, Inc. All rights reserved
X-ray photoelectron spectroscopy study of THF interaction with iodine-doped polyethynylferrocene
No full text
H2S gas interaction with Pt(II)-containing polymetallaynes of selected chain length: An XPS and EXAFS study
No full textThe interaction between gaseous H2S and the surface of several metal-containing oligomers, investigated by emission and absorption spectroscopies, is presented and discussed. The polymetallayne trans-{Cl-[Pt(PBu3)(2)(C C-C6H4-C6H4-C C)](9)Pt(PBu3)(2)Cl} and related model molecules, i.e. the binuclear transition metal dialkynyl bridged Pt(II) square planar complex trans,trans-[ClPt(PBu3)(2)(C C-C6H4-C6H4 Pt(PBu3)(2)CI], the tetranuclear linear oligomer trans-[Cl-[Pt(PBu3)(2)(C C-C6H4-C6H4-C C)](3)Pt(PBu3)(2)Cl}, the tetranuclear cyclic oligomer cis- [Pt(PBu3)(2)(C C - C6H4-C6H4 -C C)](4), were exposed to hydrogen sulfide and then investigated by X-ray photoelectron (XPS) and X-ray absorption (XAS) spectroscopies, in order to shed light on the gas/polymer interaction associated to the sensing properties of these materials. XPS measurements evidenced the presence of S in the polymetallayne samples exposed to H2S, and the measured S2p binding energy values correlate with H2S adsorbed by means of sulfur atoms chemically bonded to metal atoms, owing to the formation of sulfur-containing adducts. XAS data analysis suggested a squarepyramidal geometry around the transition metal with H2S in the apical position for the pentacoordinated platinum units
5-methyl-2-mercaptobenzoxazole adsorbed on Cu2S surface studied by synchrotron radiation excited photoemission
No full text- …
