Surface analysis: x-ray photoelectron spectroscopy, Auger electron spectroscopy and secondary ion mass spectrometry

Effect of Oxidation Level on the Interfacial Water at the Graphene Oxide–Water Interface: From Spectroscopic Signatures to Hydrogen-Bonding Environment

“…Graphene oxide (GO), whether a single layer or a few layers of exfoliated sheets from graphite oxide, has recently received a lot of attention in the literature due to a range of potential applications. − GO consists of graphene sheets with oxygenated groups, and a number of studies have revealed a wide range of oxygen functional groups, such as hydroxyls and epoxides, carboxylic acids, or sulfonates groups, , on these sheets as well as how these groups are arranged on the surface. − A key question that arises is how, depending on their number and partitioning, these oxygen functional groups can favor or prohibit reactions at the GO-liquid interface in aqueous media. To probe interfaces, several surface-specific techniques can be used such as environmental scanning electron microscopy (ESEM), secondary ion mass spectrometry (SIMS), Auger electron spectroscopy (AES), etc. − One method, vibrational sum-frequency generation (vSFG), , has received a lot of attention for characterizing interfaces experimentally − and in conjunction with simulations. ,,− The synergy between vSFG experiments and molecular simulations allows for an in-depth probing of the interface, permitting a finer molecular interpretation of the underlying interfacial region. In this paper, an analysis of the graphene-oxide-water interface by ab initio molecular dynamics (AIMD) at different levels of oxidation was performed to provide insight on the effect of the different structural domains of graphene-oxide (organic, aromatic rich regions vs oxygen-rich hydrophilic regions) on the...…”

Ionic clusters

“…Furthermore, although abundant data are not currently In addition to their application in elucidating the molecular details of condensed matter, studies on ionic clusters also serve to reveal the microscopic aspects of nucleation phenomena,9-11 including the formation of highly dispersed media having a large surface-to-volume ratio, e.g., aerosol particles.1112 Investigation of both the thermochemical properties as well as the kinetics of association reactions have been particularly important in this subject of phase transitions where progress has been impeded by lack of fundamental data for comparison with molecular theories.10 Related to both the study of the condensed phase as well as that of surfaces are investigations involving the scattering of high-energy neutrals and ionic particles from surfaces, where cluster ions are often the observed reaction products. 13 Studies of the factors influencing their size, stability, and mechanisms of formation serve to provide a basis for explaining the results of such experiments.…”

Application of particle desorption mass spectrometry to the characterization of minerals

“…Capillary column gas chromatography combined with mass spectrometry (CC/GC-MS) has become the most popular and effective analytical method for characterization of PAC in complex environmental samples (4)(5)(6). When employed in the conventional manner, the power of this technique is limited by the physical separation capabilities of the CC/GC, in that species that are well-resolved chromatographically are easily identified by the mass spectrometer.…”