X‐ray photoelectron and Auger electron spectroscopic study of the CdTe surface resulting from various surface pretreatments: Correlation of photoelectrochemical and capacitance‐potential behavior with surface chemical composition

Three different modifications of manganese(IV) oxide, viz. cryptomelane, nsutite and todorokite-like, were synthesized by hydrothermal methods. The bulk chemical composition, phase composition, crystalline structure and particle morphology of the resulting materials were determined by thermogravimetry, atomic absorption spectroscopy, X-ray diffractometry, infrared spectroscopy and scanning electron microscopy. The surface chemical composition, texture and structure were assessed using X-ray photoelectron microscopy, nitrogen sorptiometry and high-resolution electron microscopy. The results highlighted the hydrothermal conditions under which such tunnel-structured modifications of manganese(IV) oxide can be successfully synthesized. Moreover, they revealed that (i) the bulk was microcrystalline, (ii) the crystallites were either fibrils (cryptomelane and nsutite) or rod-like (todorokite) with low-index exposed facets, (iii) the surface chemical composition mostly reflected that of the bulk and (iv) the surface texture was linked with high specific areas, slit-shaped mesopores associated with particle interstices and micropores which allowed surface accessibility to the bulk tunnels of the test oxides. The application of such test oxides as shape-selective oxidation catalysts appears worthy of investigation.

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X-ray photoelectron spectroscopic analysis of rice kernels and flours: Measurement of surface chemical composition

Food Chemistry ◽

10.1016/j.foodchem.2016.05.188 ◽

2016 ◽

Vol 212 ◽

pp. 349-357 ◽

Cited By ~ 11

Author(s):

Malik A. Nawaz ◽

Claire Gaiani ◽

Shu Fukai ◽

Bhesh Bhandari

Keyword(s):

Chemical Composition ◽

Spectroscopic Analysis ◽

Surface Chemical ◽

X Ray ◽

Surface Chemical Composition

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Applying Cryo-X-ray Photoelectron Spectroscopy to Study the Surface Chemical Composition of Fungi and Viruses

Frontiers in Chemistry ◽

10.3389/fchem.2021.666853 ◽

2021 ◽

Vol 9 ◽

Author(s):

Andrey Shchukarev ◽

Emelie Backman ◽

Samuel Watts ◽

Stefan Salentinig ◽

Constantin F. Urban ◽

...

Keyword(s):

Chemical Composition ◽

Photoelectron Spectroscopy ◽

Biological Systems ◽

Building Blocks ◽

Model Organisms ◽

Surface Chemical ◽

Surface Layers ◽

Xps Spectra ◽

X Ray ◽

Surface Chemical Composition

Interaction between microorganisms and their surroundings are generally mediated via the cell wall or cell envelope. An understanding of the overall chemical composition of these surface layers may give clues on how these interactions occur and suggest mechanisms to manipulate them. This knowledge is key, for instance, in research aiming to reduce colonization of medical devices and device-related infections from different types of microorganisms. In this context, X-ray photoelectron spectroscopy (XPS) is a powerful technique as its analysis depth below 10 nm enables studies of the outermost surface structures of microorganism. Of specific interest for the study of biological systems is cryogenic XPS (cryo-XPS). This technique allows studies of intact fast-frozen hydrated samples without the need for pre-treatment procedures that may cause the cell structure to collapse or change due to the loss of water. Previously, cryo-XPS has been applied to study bacterial and algal surfaces with respect to their composition of lipids, polysaccharides and peptide (protein and/or peptidoglycan). This contribution focuses onto two other groups of microorganisms with widely different architecture and modes of life, namely fungi and viruses. It evaluates to what extent existing models for data treatment of XPS spectra can be applied to understand the chemical composition of their very different surface layers. XPS data from model organisms as well as reference substances representing specific building blocks of their surface were collected and are presented. These results aims to guide future analysis of the surface chemical composition of biological systems.

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