Erdoan B.Y.,Bingol University
Journal of Alloys and Compounds | Year: 2010
The present paper reports on a systematic study of the influence of Zn alloying on the structural and optical characteristics of CuZnO thin films. Nanocrystalline CuZnO thin films were prepared on p-type Si (1 0 0) substrates by spin coating from a CuO solution mixed with Zn of 0-8.0 at.%. All the prepared samples were annealed in oxygen gas atmosphere at 673 K for 2 h. A detailed characterization of the films doped with zinc was performed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, atomic absorption spectroscopy (AAS), and energy dispersive X-ray spectroscopy (EDS). The structural analyses suggest that Zn successfully occupied the Cu sites and did not change the monoclinic structure of CuO. After 4.0 at.% Zn was doped, the crystalline quality and (0 0 2) preferential orientation of the thin film improved. However, when the Zn doping concentration was above 4.0 at.%, the crystalline quality and preferential orientation of the thin film weakened in turn. The XRD and FT-IR results showed single phase CuZnO for the lower (at.% ≤ 6.0) Zn concentration, while a secondary phase of ZnO evolved for 8.0 at.%. The optical band gap, determined from the absorbance spectra, showed a blue shift with increasing Zn content. The works showed that the structural and optical properties of CuO films doped with Zn can be improved and the 4.0 at.% Zn-doped CuO thin films have the best crystallization quality and the strongest emission ability. © 2010 Elsevier B.V.
Solmaz R.,Bingol University
Corrosion Science | Year: 2014
The adsorption and corrosion inhibition of mild steel in 0.5. M HCl solution by 5-(4-Dimethylaminobenzylidene)rhodanine (DABRh) were investigated by electrochemical and scanning electron microscopy (SEM) techniques. It was found that DABRh has high inhibitory efficiency against the corrosion of mild steel in HCl solution. This compound is classified as the mixed type corrosion inhibitor with predominant control of cathodic reaction. The high inhibitory efficiency of DABRh was related with the adsorption of DABRh molecules at the meal/solution interface and a protective film formation. The surface inhibitor film was found to be very stable at low anodic and cathodic overpotentials. © 2013 Elsevier Ltd.
Aydogan C.,Bingol University
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2015
This study describes the preparation and electrochromatographic application of a new open-tubular capillary column with triethanolamine functionalized stationary phase. The stationary phase was synthesized by in situ grafting polymerization with 3-chloro-2-hydroxypropylmethacrylate based reactive monomer, and followed triethanolamine functionalization. The different 3-chloro-2-hydroxypropylmethacrylate contents on the separation efficiency were studied. The results indicated that the 3-chloro-2-hydroxypropylmethacrylate content (e.g., 15.3. v/v%) on the inner surface of the capillary was very important for final preparation of the polymer stationary phase. The electrochromatographic characterization of the stationary phase was performed using alkylbenzene derivatives. The pH effect on the electroosmotic flow was also investigated. The open tubular column functionalized with triethanolamine allowed to operate in the anodic electroosmotic flow mode in the system. With anodic electroosmotic flow mode, favorable separations of the amino acids and the nucleosides were successfully achieved with high column efficiens ranging from 142. 000 to 257. 000 plates/m. Good repeatability was gained with relative standard deviation of the migration time and peak areas less than 2.2% for run to run (n= 5) and less than 3.2% day to day (n= 3). Furthermore, real sample applicability of this column to the separation of amino acids in white tea sample was demonstrated. © 2014 Elsevier B.V.
Solmaz R.,Bingol University
Corrosion Science | Year: 2010
The inhibition effect of 5-((E)-4-phenylbuta-1,3-dienylideneamino)-1,3,4-thiadiazole-2-thiol (PDTT) Schiff base on mild steel corrosion in 0.5. M HCl was studied for both short and long immersion time. For this purpose, potentiodynamic polarization, electrochemical impedance spectroscopy, linear polarization resistance, hydrogen gas evolution, the change of open circuit potential as a function of immersion time, SEM and AFM techniques were utilized. The PDTT Schiff base has shown remarkable inhibition on the corrosion of mild steel in 0.5. M HCl solution. The high inhibition efficiency was attributed to the blocking of active sites by adsorption of inhibitor molecules on the steel surface. © 2010 Elsevier Ltd.
Solmaz R.,Bingol University
International Journal of Hydrogen Energy | Year: 2013
The binary NiIr coatings as novel and effective catalysts were electrochemically prepared on a Ni-modified carbon felt electrode (C/Ni-NiIr) in view of their possible application as cathode materials for the alkaline water electrolysis. The surface morphology and chemical composition of the electrodes were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques. Their hydrogen evolution activity was assessed by electrochemical techniques. It was found that, the preparation of NiIr co-deposits on the Ni-modified C substrate enhances the hydrogen evolution activity. The electrodes have wide space, which is an advantage for diffusion of ions and hydrogen bubbles through inner zones and reduction of diffusion resistance. The high hydrogen evolution activity of the C/Ni-NiIr electrode was mainly attributed to the finer surface structure, high surface area and the higher numbers of the catalytically active centers. Copyright © 2012, Hydrogen Energy Publications, LLC.