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Conductive polymer composites (CPCs) with nanocarbon fillers are at the high end of modern materials science, advancing current electronic applications. Herein, we establish the interplay between the chemistry and electrophysical properties of reduced graphene oxide (rGO), separately and as a filler for CPCs with the segregated structure conferred by the chemical composition of the initial graphene oxide (GO). A set of experimental methods, namely X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy, van der Paw and temperature-dependent sheet resistance measurements, along with dielectric spectroscopy, are employed to thoroughly examine the derived materials. The alterations in the composition of oxygen groups along with their beneficial effect on nitrogen doping upon GO reduction by hydrazine are tracked with the help of XPS. The slight defectiveness of the graphene network is found to boost the conductivity of the material due to facilitating the impact of the nitrogen lone-pair electrons in charge transport. In turn, a sharp drop in material conductivity is indicated upon further disruption of the π-conjugated network, predominantly governing the charge transport. Particularly, the transition from the Mott variable hopping transport mechanism to the Efros–Shklovsky one is signified. Finally, the impact of rGO chemistry and physics on the electrophysical properties of CPCs with the segregated structure is evaluated. Taken together, our results give a hint at how GO chemistry manifests the properties of rGO and the CPC derived from it, offering compelling opportunities for their practical applications. [ABSTRACT FROM AUTHOR]

Composites of WS2 nanotubes (NT‐WS2) and gold nanoparticles (AuNPs) were prepared using aqueous HAuCl4 solutions and subjected to surface analysis. The obtained materials were jointly characterized by X‐ray photoelectron (XPS), Raman scattering (RSS), and ultraviolet photoelectron (UPS) spectroscopies. Optical extinction spectroscopy and electron energy loss spectroscopy in the scanning transmission electron microscopy regime (STEM‐EELS) were also employed to study plasmon features of the nanocomposite. It was found that AuNPs deposition is accompanied by a partial oxidative dissolution of WS2, whereas Au‐S interfacial species could be responsible for the tight contact of metal nanoparticles and the disulfide. A remarkable sensitivity of n‐type resistance of NT‐WS2 and Au‐NT‐WS2 to the adsorption of NO2 gas was also demonstrated at room temperature using periodical illumination by a 530 nm light‐emitting diode. Au‐NT‐WS2 nanocomposites are found to possess a higher photoresponse and enhanced sensitivity in the 0.25–2.0 ppm range of NO2 concentration, as compared to the pristine NT‐WS2. This behaviour is discussed within the physisorption‐charge transfer model to explore sensing properties of the nanocomposites. Go for gold: The study sheds light on the mechanism of WS2 nanotube (NT‐WS2) decoration with Au nanoparticles by a direct interaction of disulfide with HAuCl4 solutions (see graphics) and revealed the optoelectronic features of the obtained nanocomposites. Au‐NT‐WS2 nanocomposites possess higher photoresponse and enhanced n‐type photoresistive sensitivity, as compared to the pristine NT‐WS2. [ABSTRACT FROM AUTHOR]

A detailed study of the structure, morphology and electrochemical properties of Pt/C and Pt/x-SnO2/C catalysts synthesized using a polyol method has been provided. A series of catalysts supported on the SnO2-modified carbon was synthesized and studied by various methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical methods, and fuel cell testing. The SnO2 content varies from 5 to 40 wt %. The TEM images, XRD and XPS analysis suggested the Pt-SnO2 hetero-clusters formation. The SnO2 content of ca. 10% ensures an optimal catalytic layer structure and morphology providing uniform distribution of Pt-SnO2 clusters over the carbon support surface. Pt/10wt %-SnO2/C catalyst demonstrates increased activity and durability toward the oxygen reduction reaction (ORR) in course of accelerated stress testing due to the high stability of SnO2 and its interaction with Pt. The polymer electrolyte membrane fuel cell current–voltage performance of the Pt/10wt %-SnO2/C is comparable with those of Pt/C, however, higher durability is expected. [ABSTRACT FROM AUTHOR]

• Study of Nd0.9Sm0.1BaMn2O6 by X-ray emission and photoelectron spectroscopy. • The concentration of manganese with oxidation state 3 + is greater than manganese 4 +. • X-ray emission spectrum of Kβ transition shows the presence of satellite. In this paper, Mn 2p, Nd 3d and 4d core levels in Nd 0.9 Sm 0.1 BaMn 2 O 6 were studied by X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES). The obtained photoelectron spectra of Mn demonstrate the presence of Mn in oxidation states 3+ and 4+. From the shape of the XES spectrum of the Kβ line of manganese and the presence of the satellite Kβ' at energy E = 6476 eV, the spin state of the manganese ion in the compound can be determined. The experimental emission spectra of Mn are compared with the multiplet calculation. The analysis of XPS spectra of the double manganite Nd 0.9 Sm 0.1 BaMn 2 O 6 compound shows 3+ and 4+ oxidation states of Mn ions with 2:1 ratio, respectively. The analysis of Mn Kβ XES spectrum of the Nd 0.9 Sm 0.1 BaMn 2 O 6 based on multiplet calculations shows the Mn3+/Mn4+ ion ratio to be 1:1, which is often typical for the RBaMn 2 O 6 compounds. The calculation also reveals the high-spin state of Mn3+. [ABSTRACT FROM AUTHOR]