Browsing by Publisher "Turkish Chemical Society"
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Item Macro and trace element contents of some wild plants consumed as vegetable in Manisa District, Turkey(Turkish Chemical Society, 2018) Targan Ş.; Yelboğa E.G.; Cittan M.In this study, macro elements (Na, Mg, and Ca) and trace elements (Li, Fe, Zn, Mn, Se, Al, V, Cr, Ni, Cu, Pb, As, Co, Cd, and Hg) in wild edible plant samples (Campanula sp, Anethum graveolens, Malva sylvestris, Onopordum tauricum, Cichorium endivia, Rumex patientia, Urtica diocia, Papaver rhaeas, Opopanax hispidus, Rumex acetosella, Eradium sp, Petroselinum crispum, Metha viridis, Eruca sativa, Sinapis arvensis, Lepidium sativum, and Cardaria draba) purchased from three different markets in Manisa district were analyzed using inductively coupled plasma-mass spectrometry after microwave digestion procedure. Selected plants for analysis are mostly consumed by people throughout the season. The mean concentrations of Na, Mg, Ca, Li, Fe, Zn, Mn, Se, Al, V, Cr, Ni, Cu, Pb, As, Co and Cd were determined as 201 to 15896, 1597 to 4783, 3676 to 13290, 0.27 to 4.37, 144 to 666, 18.0 to 52.0, 21.2 to 86.5, 0.08 to 0.25, 111 to 693, 2.18 to 5.67, 2.62 to 13.4, 1.32 to 6.30, 6.40 to 38.7, 0.12 to 0.78, 1.07 to 3.25, 0.05 to 0.47, 0.08 to 0.50 (µg g-1,dry weight), respectively. Hg values for plant samples were well below the detection limit of the method. © 2018, Turkish Chemical Society. All rights reserved.Item Effect of annealing temperatures on the crystallization and photocatalytic activity of micro-nanoporous TiO2 films produced by electrochemical anodization(Turkish Chemical Society, 2018) Yurddaskal M.; Yurddaskal M.; Dikici T.; Durmus H.In this study, micro-nanoporous TiO2 films were prepared by electrochemical anodization of titanium (Gr-2) in an aqueous solution containing 0.5 wt. % HF solution at a constant potential of 30 V and then annealed in ambient air at 500, 600, 700 and 800 °C for 2 h to obtain crystalline structures. The crystalline phase and surface morphology of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The photocatalytic performances of the samples were evaluated by the photocatalytic degradation of aqueous methylene blue (MB) solutions under UV light illumination for different periods. XRD results indicated that at annealing temperatures higher than 600°C, anatase started to transform into rutile. Increasing annealing temperatures resulted in reduced micro-nanopores diameter and increased wall thickness. At 800°C, the structure completely disappeared. The results demonstrated that changes in both the crystalline structure and surface morphology have a strong influence on the photoactivity of the nanostructured TiO2 films. © 2018, Turkish Chemical Society. All rights reserved.Item Removal of cesium from aqueous solution by adsorption onto sivas-yildizeli (Türkiye) vermiculite: Equilibrium, kinetic and thermodynamic studies(Turkish Chemical Society, 2018) Akalin H.A.; Hiçsönmez Ü.; Yilmaz H.In this study, cesium adsorption performance of raw vermiculite obtained from Sivas-Yıldızeli region of Turkey was investigated using batch adsorption method. In order to obtain the optimum adsorption conditions; different adsorbent dosages, contact times, solution pH’s, initial cesium concentrations and temperature ranges were investigated. The concentration of cesium in solution was determined by ICP-OES. Kinetic studies demonstrated that adsorption process was in accordance with pseudo-second order kinetic model and equilibrium isotherm modeling studies showed that the process was compatible with Langmuir, Freundlich and Temkin adsorption isotherm models, indicating that Cs adsorption process had both physical and chemical character. Negative Gibbs energy values obtained from thermodynamic studies revealed that the adsorption process was spontaneous and had a high feasibility. Additionally, the negative enthalpy value indicated that process was exothermic, suggesting that the adsorbed Cs+ ions decreased with increasing reaction temperatures. Positive entropy value showed that disorderliness between solid-liquid phase increased during adsorption. Results clearly indicate that vermiculite mineral has a promising potential in removing Cs+ ions from aqueous media which leads mineral may also be used in decomposing and efficiently removing radioactive cesium from contaminated waters. © 2018, Turkish Chemical Society. All rights reserved.Item Enhanced photocatalytic properties of Sn-doped ZnO nanoparticles by flame spray pyrolysis under UV light irradiation(Turkish Chemical Society, 2018) Yurddaskal M.; Yildirim S.; Dikici T.; Yurddaskal M.; Erol M.; Aritman I.; Celik E.Zinc oxide (ZnO) is widely used in different areas thanks to its unique photocatalytic, optic and electrical properties. Sn doped ZnO nanoparticles were synthesized through flame spray pyrolysis (FSP) technique. The Sn dopant concentrations were 1, 3, 5, 7 and 9 at. % in produced ZnO nanoparticles. The structural analysis of the produced powders was performed by X-Ray Diffraction (XRD) methods. The surface morphology and particle size distribution of the nanoparticles were identified using scanning electron microscopy (SEM), and dynamic light scattering (DLS) techniques. In addition to this, produced photocatalysts were evaluated for degradation of aqueous methylene blue (MB) solutions under UV light irradiation. Sn-doped nanoparticles have superior photocatalytic activity compared to un-doped ZnO. © 2018, Turkish Chemical Society. All rights reserved.Item Effects of Zn-doping on the photocatalytic activity and microstructures of nanocrystalline SnO2 powders(Turkish Chemical Society, 2018) Yurddaskal M.; Yildirim S.; Dikici T.; Yurddaskal M.; Erol M.; Aritman I.; Uygun H.D.E.; Celik E.In this study, undoped and Zn-doped SnO2 nanoparticles in different concentrations were synthesized by flame spray pyrolysis (FSP) technique. The produced particles were post-annealed after FSP process at 600 °C in order to obtain a crystalline structure. The structural analysis of the produced powders was performed by X-Ray Diffraction (XRD) methods. The surface morphology of the nanoparticles was identified using scanning electron microscopy (SEM). In addition, photocatalytic degradation of aqueous methylene blue (MB) solutions were evaluated using undoped and Zn-doped SnO2 nanoparticles under UV light illumination. Photocatalytic degradation of the MB solutions followed the pseudo-first-order-kinetics and the effect of the Zn doping amount on the photocatalytic reaction was investigated. © 2018, Turkish Chemical Society. All rights reserved.Item Adsorption Studies of Radionuclides by Turkish Minerals: A Review(Turkish Chemical Society, 2022) İnan S.; Hiçsönmez Ü.Hazardous radionuclides are produced during normal operation of nuclear power plants and research facilities. They can also be spread to the environment due to fallout from nuclear accidents and nuclear weapon tests. The removal of hazardous radionuclides and the safe management of radioactive waste are of vital necessity. Natural minerals have been widely used for the removal of heavy metals and radionuclides because of their low cost, high capacity, and radiation resistance properties. Turkey has abundant natural mineral deposits. These deposits include clinoptilolite, bentonite, montmorillonite, kaolinite, vermiculite, illite, red clay, sepiolite, diatomite, perlite, and volcanic tuff. Within the scope of this review, Turkish minerals were classified as three main groups: zeolites, clay minerals, and other minerals. The review consists of sections on the general properties of natural minerals such as zeolites and clays, the characteristics of Turkish minerals, and the adsorption performance of these minerals against some radionuclide ions (Sr, Cs, U, Th and Po). © 2022, Turkish Chemical Society. All rights reserved.Item Evaluation of the Structural, Near-Infrared Luminescence, and Radioluminescence Properties of Nd3+ Activated TTB-Lead Metatantalate Phosphors(Turkish Chemical Society, 2023) İlhan M.; Keskin İ.Ç.The study reports the structural and spectroscopic properties of Nd3+ doped lead metatantalate phosphor series fabricated by conventional solid state method. XRD results of the PbTa2O6 phase confirm the tungsten bronze symmetry and single-phase structure between 0.5 and 10 mol% Nd3+ concentrations. The lead decrease in the structure can be associated with maintaining the charge balance and single phase due to evaporation during sintering. In SEM micrographs, the grains exhibited shapeless morphology, and the grain sizes varied from 0.5 to 7 m. In EDS results, the increase of Ta/Pb ratio in grain surfaces indicated some lead evaporation, as reported in previous studies. The absorption spectrum of PbTa2O6 host peaked around 275-280 nm, and the band gap was found to be 3.7±0.2 eV. The absorptions of Nd3+ doped phophors shifted the high wavelenght or the low band gap, where the band gaps were found between 3.1±0.2 and 3.3±0.2 eV. The PL emissions of the phosphors in near-inrared region were observed with the transitions of 4 F3/2→4I9/2 (at 875 nm) and4F3/2→4I11/2 (at 1060 nm) of Nd3+. The RL emissions or X-ray excited luminescence were monitored with the transitions of4F3/2→4I9/2 (at 875 nm),4F3/2→4I11/2 (at 1065 nm) in the infrared region, and the transitions of2F(2)5/2→4F9/2,2F(2)5/2→2H(2)11/2,2F(2)5/2→4G5/2,2F(2)5/2→4G7/2,2F(2)5/2→4G9/2 in the visible region corresponding to at around 430, 455, 490, 525, and 570 nm, respectively. PL and RL emissions of the phosphors exhibited the decreasing emission intensity over 5 mol% due to the concentration quenching which may be associated with cross-relaxing mechanism. In the PL and RL spectral profiles, the similarity of splitting levels was attributed to the similarity of the local symmetry of the ligand ions surrounding the Nd3+ ion. The CIE coordinates obtained using RL emissions were found close to the blue region due to visible region transitions. © 2023, Turkish Chemical Society. All rights reserved.Item Synthesis and Characterization of New Anderson-Type Polyoxometalates: [M((1,10phen)(OH)x]3[Cr(OH)6Mo6O18]•16H2O (M=Cr, Mn, Co, Ni, Cu; x=1,2)(Turkish Chemical Society, 2023) Özbek Avci H.Five new Anderson-type polyoxometalate compounds [M((1,10-phen) (OH)x]3[Cr(OH)6Mo6O18]∙16H2O (M=Cr(1), Mn(2), Co(3),Ni(4),Cu(5);x=1,2) were obtained from Na2MoO42H2O and CrCl3∙6H2O within acidic aqueous medium (pH=2-3). The compounds are characterized by means of FT-IR, TGA, ICP-MS, and elemental analysis techniques. The structural analysis show that compounds (1-5) consist of a Anderson-type polyanion [Cr(OH)6Mo6O18]3-. © 2023, Turkish Chemical Society. All rights reserved.