scholarly journals Electrochemical deposition and characterization of AgPd alloy layers

2018 ◽  
Vol 83 (5) ◽  
pp. 593-609 ◽  
Author(s):  
Nevenka Elezovic ◽  
Piotr Zabinski ◽  
Mila Krstajic-Pajic ◽  
Tomasz Tokarski ◽  
Borka Jovic ◽  
...  

The AgPd alloys were electrodeposited onto Au and glassy carbon disc electrodes from the solution containing 0.001 mol dm-3 PdCl2 + 0.04 mol dm-3 AgCl + 0.1 mol dm-3 HCl + 12 mol dm-3 LiCl under the non-stationary diffusion (quiescent electrolyte) and convective diffusion (? = 1000 rpm) to the different amounts of charge and at different current densities. Electrodeposited alloy layers were characterized by the anodic linear sweep voltammetry (ALSV), scanning electron microscopy, energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The compositions of the AgPd alloys determined by the EDS were almost identical to the theoretically predicted ones, while the compositions obtained by XPS and ALSV analysis were similar to each other, but different from those obtained by EDS. Deviation from the theoretically predicted values (determined by the ratio jL(Pd)/j(Ag)) was more pronounced at lower current densities and lower charges of AgPd alloys electrodeposition, due to the lower current efficiencies for alloys electrodeposition. The ALSV analysis indicated the presence of Ag and Pd, expressed by two ALSV peaks, and in some cases the presence of the additional peak, which was found to correspond to the dissolution of large AgPd crystals, formed at thicker electrodeposits (higher electrodeposition charge), indicating, for the first time, that besides the phase structure, the morphology of alloy electrodeposit could also influence the shape of the ALSV response. In addition to Ag and Pd, the XPS analysis confirmed the presence of AgCl at the surface of samples electrodeposited to low thicknesses (amounts of charge).

Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 316 ◽  
Author(s):  
Agata Markowska-Szczupak ◽  
Paulina Rokicka ◽  
Kunlei Wang ◽  
Maya Endo ◽  
Antoni Morawski ◽  
...  

Modified titania photocatalysts were synthesized by the pressure method using titanium(IV) oxide from Grupa Azoty Zakłady Chemiczne “Police” S.A., Police, Poland, and d-glucose solution. Characterization of obtained composites was performed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), elemental analysis, and measurements of zeta potential and specific surface area (SSA). The possibility of using glucose-titania composites as photocatalysts for simulated solar-assisted disinfection against gram-negative Escherichia coli and gram-positive Stapchyloccocus epidermidis bacteria were examined in two reaction systems, i.e., for suspended and immobilized photocatalysts (on the concrete). It was found that an increase in the d-glucose concentration, i.e., higher carbon content, led to a decrease in antibacterial properties. The sample obtained from 1% of d-glucose solution at 100 °C (TiO2-1%-G-100) showed superior photocatalytic activity under UV-Vis irradiation toward both bacteria species. Water disinfection was more efficient for suspended photocatalyst than that for supported one, where complete disinfection was reached during 55–70 min and 120 min of irradiation, respectively. For the first time, it has been shown that titania modified with monosaccharides can be efficiently used for water disinfection, and the immobilization of photocatalyst on the concrete might be a prospective method for public water supplies.


2015 ◽  
Vol 733 ◽  
pp. 292-295
Author(s):  
Bei Ping Yang ◽  
Li Qiang Chen ◽  
Xiu Mei Lin ◽  
Ming Xia Zhu

A new solid proton conductor Na7[CoCrW11O39 (H2O)]·15H2O has been synthesized for the first time. The percentage composition of the product were determined by inductively coupled plasma (ICP) and X-ray photoelectron spectroscopy (XPS). The product was characterized by infrared spectroscopy (IR) and X-ray diffraction (XRD), which indicate it possesses the Keggin structure. The TG-DTA curve shows the sequence of water loss in the compound, the amount of the loss, as well as the thermostability. Conductivity of the compound was investigated by four-electrode method at room temperature and different measuring temperatures, the results reveal that its proton conductivity is 9.42×10−7S·cm-1 at 25°C.


2011 ◽  
Vol 189-193 ◽  
pp. 653-657
Author(s):  
Su Yong Huang ◽  
Kai Fu Li

Small samples of Chinese fir/TiO2 composites were prepared by sol-gel method and MWLPD (microwave assistant liquid phase deposition) method for the first time. The surface of samples were analyzed by Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the microstructure and Ti distribution of samples was observed by scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS). Results show that Ti is not only distributed on the composites surface, but also go into the inside wood. The composites surfaces are covered with pure TiO2. Activities of composites are increased considerably for the oxygen content and number of oxygen containing groups on there surfaces are increased considerably.


2021 ◽  
Author(s):  
Berrin Özdil ◽  
Duygu Calik-Kocaturk ◽  
Cisem Altunayar-Unsalan ◽  
Eda Acikgoz ◽  
Fatih Oltulu ◽  
...  

Abstract The current cancer studies focus on the molecular-targeting diagnostics and their interaction with surrounding microenvironment, however, there are some missing points on the characterization of the cells with their topological differences and elemental composition. Glioblastoma multiforme (GBM) which is an astrocytic aggressive brain tumour with short survival time. GBM and astrocyte cells may differ at molecular level and the elemental and topological evaluation of these cells are vital for a definition of new potential targets for cancer research. Here, we report the topology and chemistry of cancer (GBM) and healthy (astrocyte) cells by atomic force microscopy (AFM), scanning electron microscopy (SEM) supported with energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), for the first time. Additionally, F-actin Immunofluorescence staining and Real-Time Polymerase chain reaction (RT-PCR) techniques were performed. Actin related genes were similar in level of gene expression; however, F-actin protein intensities were different. The gene expressions related to the invasion were elevated in GBM cells. Morphologically, GBM cells were found to be longer and narrower while astrocytes were shorter and more disseminated based on AFM. Furthermore, roughness values of these cells were relatively close to each other. SEM-EDS analysis demonstrated that elongated GBM cells exhibited several filopodial protrusions whereas the astrocyte surfaces were rougher in lamellipodial area. Our investigation provides considerable further insight into rapid cancer cell characterization field in terms of its combinatorial spectroscopic and microscopic approach.


Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract


1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.


Surfaces ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 106-114
Author(s):  
Yannick Hermans ◽  
Faraz Mehmood ◽  
Kerstin Lakus-Wollny ◽  
Jan P. Hofmann ◽  
Thomas Mayer ◽  
...  

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.


2014 ◽  
Vol 34 (3) ◽  
pp. 841-849 ◽  
Author(s):  
M. Kanuchova ◽  
L. Kozakova ◽  
M. Drabova ◽  
M. Sisol ◽  
A. Estokova ◽  
...  

2003 ◽  
Vol 18 (5) ◽  
pp. 1123-1130 ◽  
Author(s):  
V. Oliveira ◽  
R. Vilar

This paper aims to contribute to the understanding of column formation mechanisms in Al2O3–TiC ceramics micromachined using excimer lasers. Chemical and structural characterization of columns grown in Al2O3–TiC composite processed with 200 KrF laser pulses at 10 J/cm2 was carried out by scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction analysis. Fully developed columns consist of a core of unprocessed material surrounded by an outer layer of Al2TiO5, formed in oxidizing conditions, and an inner layer, formed in reducing conditions, composed of TiC and Al3Ti or an AlTi solid solution. Possible mechanisms of column formation are discussed.


Sign in / Sign up

Export Citation Format

Share Document