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Öğe Crystallinity Improvement of Co3O4 by Adding Thiourea(2020) Ercan, Filiz; Mahmood, Bahroz Kareem; Agıd, Riyadh Saeed; Bulut, Niyazi; Ercan, Ismail; Yahıa, I.S.; Ateş, TankutTricobalt tetraoxide (Co3O4) samples having different thiourea/Co molar ratio of 0, 5 and 10 were prepared by wetchemical synthesis. The effects of thiourea content on the crystal structure-related parameters of Co3O4 weredetermined. The increase in the amount of thiourea caused a gradual decrease in the lattice parameters and specificsurface area and an increase in the crystallinity and crystallite size. The experimental analysis results showed thatthiourea content can be used to control the crystal structure-related parameters of Co3O4.Öğe Highly efficient magnetically separable SrFe12O19 for photo-assisted oxidation of benzylic alcohol derivatives under visible light(Elsevier Science Sa, 2024) Aldhawi, Zainah A.; Alousi, Latifah; Ercan, Ismail; Ozcelik, Bekir; Kochkar, Hafedh; Benali, AmorThe selective oxidation of the C alpha- OH group of benzylic alcohols is a crucial process for the conversion of lignin into useful products. In this study, we describe the synthesis and characterization of magnetic strontium hexaferrite, SrFe12O19. The SrFe12O19 nano-powder was produced through coprecipitation at a pH level of 10. The catalyst has been studied using various methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray analysis (EDX), UV-vis diffuse reflectance spectroscopy (DRS), and magnetic field dependence measurements. The study aimed to evaluate the photocatalytic performance of SrFe12O19 in selective oxidation of benzylic alcohols and degradation of methylene blue under visible light. Additionally, the magnetic properties of the catalyst were also investigated. Magnetic properties were also investigated. M-SrFe12O19 with a band near 2 eV, showed excellent photocatalytic degradation performance at ca. 90% of MB under visible light. The photocatalytic degradation activity was evaluated for three cycles, and the results demonstrate that it maintains its photodegradation potency, with significant photo-degradation conversion of 89%, 87%, and 84%. The experiment clearly demonstrated that the reaction kinetics followed a pseudofirst order. The oxidation of benzyl alcohol (BzOH) was successfully carried out over SrFe12O19 in the presence of hydrogen peroxide, a highly effective green oxidant, under visible light. Notably, the experiment results showed a maximum conversion of BzOH, reaching approximately 70%, with absolute selectivity towards benzaldehyde (BzCHO). Furthermore, the yield of aldehyde increases according to the Hammett constant, with the highest yield being obtained for 2-hydroxybenzaldehyde (sigma = -0.37). The synthesized M-SrFe12O19 material shows potential as an eco-friendly method for lignin valorization.Öğe Impact of magnetic field on the translocation of iron oxide nanoparticles (Fe3O4) in barley seedlings (Hordeum vulgare L.)(Springer Heidelberg, 2023) Tombuloglu, Huseyin; Ercan, Ismail; Alqahtani, Noha; Alotaibi, Bayan; Bamhrez, Muruj; Alshumrani, Raghdah; Turumtay, HalbayThe effect and contribution of an external magnetic field (MF) on the uptake and translocation of nanoparticles (NPs) in plants have been investigated in this study. Barley was treated with iron oxide NPs (Fe3O4, 500 mg/L, 50-100 nm) and grown under various MF strengths (20, 42, 125, and 250 mT). The root-to-shoot translocation of NPs was assessed using a vibrating sample magnetometer (VSM) and inductively coupled plasma optical emission spectrometry (ICP-OES). Additionally, plant phenological parameters, such as germination, protein and chlorophyll content, and photosynthetic and nutritional status, were examined. The results demonstrated that the external MF significantly enhances the uptake of NPs through the roots. The uptake was higher at lower MF strengths (20 and 42 mT) than at higher MF strengths (125 and 250 mT). The root and shoot iron (Fe) contents were approximately 2.5-3-fold higher in the 250 mT application compared to the control. Furthermore, the MF treatments significantly increased micro-elements such as Mn, Zn, Cu, Mo, and B (P < 0.005). This effect could be attributed to the disruption of cell membranes at the root tip cells caused by both the MF and NPs. Moreover, the MF treatments improved germination rates by 28%, total protein content, and photosynthetic parameters. These findings show that magnetic field application helps the effective transport of magnetic NPs, which could be essential for NPs-mediated drug delivery, plant nutrition, and genetic transformation applications.Öğe Influence of UV light intensity on dielectric behaviours of pure and dye-doped cholesteric liquid crystals(Springer, 2020) Kocakulah, Gulsum; Yildirim, Mert; Koysal, Oguz; Ercan, IsmailThis study aims to explore the ultraviolet (UV) light effects on dielectric properties of azo dye methyl red (MR)-doped cholesteric liquid crystal (CLC) composite. The CLC composite formed in the study contains 5CB nematic liquid crystal (LC) and S811 chiral additive. To obtain CLC/MR composite, CLC was dispersed with 2% wt/wt MR azo dye. Dielectric measurements of the CLC and CLC/MR samples were performed using dielectric spectroscopy technique in wide frequency range in the absence of UV light and at various UV light intensities (30, 60 and 90 mW/cm(2)) for 0 and 40 V. It was observed that the dielectric constant increased with UV light at low-frequency values. Dielectric loss data were utilized to extract relaxation frequency which was observed to increase with UV light exposure. Dielectric anisotropy of CLC sample exhibited typical transition from p-type to n-type, but this behaviour disappears for CLC/MR composite above 60 mW/cm(2) UV light intensity. Cole-Cole plots were used for extraction of dielectric relaxation data and obtained results showed that CLC sample shows Debye type relaxation only at 0 V whereas CLC/MR composite exhibits non-Debye type relaxation both at 0 V and 40 V. Moreover, conductivity properties of the samples were also investigated, and dc conductivity values were extracted from experimental ac conductivity values. It was found that MR incorporation increased dc conductivity, also it was significantly increased by UV light exposure and thus similar effect was also observed in current-voltage characteristics of the samples. The results show that azo dye MR molecules are suitable for CLCs since they lead to some enhancements in dielectric and electrical properties.Öğe Investigation on structural, optical, thermal, and dielectric properties of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum nanocomposite prepared by pulsed laser ablation(Elsevier, 2024) Haladu, Shamsuddeen A.; Elsayed, Khaled A.; Ercan, Ismail; Ercan, Filiz; Kayed, T. S.; Demirci, Tuna; Yildiz, MesutPolymer nanocomposite films of cellulose propionate/styrene-maleic anhydride copolymer/molybdenum (CP/ SMAC/Mo) were fabricated by pulsed laser ablation of Mo in the polymer solution for 10, 20, and 30 min. The films were then characterized by various analytical methods. X-ray diffraction (XRD) revealed that the addition of Mo to CP/SMAC removed the crystalline peaks of Mo without changing the amorphous nature of the copolymer. According to the scanning electron microscopy (SEM) and atomic force microscopy (AFM) patterns, Mo atoms were trapped in the amorphous polymer stacks. The energy -dispersive X-ray (EDX) spectrum features C, O, and Mo. FTIR confirmed the embedding of Mo in the polymers. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were carried out on the samples. The pristine polymer film exhibited a band gap energy of 2.9 eV, which decreased to 2.05 eV because of the loading of the Mo nanoparticles. The intensity of the photoluminescence (PL) peak of the films increases with ablation time such that the absorption intensity of the film at a lambda max of 426 nm increases by trifold during the 30 min of irradiation, which is consequently due to the increased amount of Mo in the nanostructure. The incorporation of Mo in the polymer matrix enhances the dielectric constant ( epsilon') (6.28 -18.13) and ac conductivity ( sigma ac ) (3.19 x 10 - 5 -1.12 x 10 -4 S/cm) of the polymer with negligible dielectric loss. The results suggest possible technological utilization of these materials in such applications as supercapacitors, light -emitting diodes, and organic optoelectronic devices, among others.Öğe Low-Cost synthesis of Ag-doped NiO thin Films: Their structural, optical, photocatalytic and antimicrobial properties(Elsevier, 2024) Benseghier, Sid Ahmed; Bennabi, Farid; Ercan, Ismail; Nehmar, Hamid; Khane, Yasmina; Moulayat, Nasreddine; Ercan, FilizIn this study, the influence of Ag atom doping on NiO thin films was investigated, focusing on their optical, structural, surface morphological, and chemical composition properties. The NiO thin films were doped with Ag atoms at concentrations of 2 at.% and 4 at.%, resulting in significant changes in their structural and surface morphological characteristics. Optical measurements showed variations in transmittance and optical band gap energies for the doped films compared to undoped NiO. FTIR analysis revealed distinctive peaks corresponding to Ni-O and Ag-O bonds, confirming the successful doping process. The Ag-doped NiO thin films exhibited improved antibacterial activity against E. coli and enhanced photodegradation efficiency for Methylene Blue and Malachite Green dyes. These findings highlight the potential of Ag-doped NiO thin films for applications in photocatalysis and antimicrobial materials.Öğe Structural, spectroscopic, dielectric, and magnetic properties of Fe/Cu co-doped hydroxyapatites prepared by a wet-chemical method(Elsevier, 2022) Ercan, Ismail; Kaygili, Omer; Kayed, Tarek; Bulut, Niyazi; Tombuloglu, Huseyin; Ince, Turan; Koysal, OguzIn this study, the effects of Cu and Fe additives on the structural, dielectric, magnetic, thermal and morphology of hydroxyapatite (HAp) samples were investigated and reported in detail for the first time. The prepared systems were also modeled and examined theoretically. It can be said that both additives affect the thermal behavior of the HAp structure. The addition of Cu affected the morphology of submicron-sized particles with spherical-like shapes with a low degree of agglomeration. Diffuse reflection data revealed that the energy band gap values decreased as Cu was added to the Fe-based HAp structure. The dielectric constant (epsilon') had high values at low frequencies in all samples and decreased with increasing frequency. It could be concluded that Fe/Cu incorporation to hydroxyapatites enhanced its thermal, magnetic, and dielectric properties required for mimicking natural HAps to open a successful venue for medical application in the healing regeneration of bone.Öğe Synthesis and Structural Characterization of Y-doped Pyramidal ZnO Powders(2020) Seçkin, Turgay; Köytepe, Süleyman; Okur, Havva Esma; Ercan, Filiz; Ercan, Ismail; Ateş, Tankut; Yahıa, I.S.The present study focuses on the structural changes in ZnO powder induced by doping of a rare earth metal of Y.For this aim, we synthesized four ZnO samples with different Y-content using the combustion reaction method.X-ray powder diffraction (XRPD) technique and scanning electron microscopy (SEM) results confirm that the asinvestigated structural parameters and morphology of the ZnO structure were affected directly by the concentrationof Y dopant. For each Y-doped sample, randomly-oriented pyramidal morphology and the formation of a minorityphase of Y2O3 were observed. A gradual increase in both lattice parameters and unit cell volume was detected withincreasing Y content. All samples were found to be thermally stable in the temperature interval of 25-950 °C.
