Sürdürülebilir Kalkınma Amaçları
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- ArticleAçık Erişim2026Experimental and theoretical investigation of a benzazole-2-carboxamide derivative: Crystal structure, spectroscopic characterization, antiproliferative evaluation, and molecular docking studies
Kılıç, Selçuk; Aktekin, Mine Buga; Turkmenoglu, Burcin; Sert, Yusuf; Caglar, Bulent; Çırak, Çağrı; Algul, Oztekin
In this study, the structural, spectroscopic, and biological properties of a benzazole-2-carboxamide derivatives, N-(1H-benzo[d]imidazole-2-yl)-4-chlorobenzamide, were comprehensively investigated through both experimental and theoretical approaches. First, the crystal structure of the compound was revealed with the help of single-crystal X-ray diffraction (XRD). Subsequently, density functional theory (DFT) calculations were performed using Gaussian 09 W to optimize the molecular geometry, simulate vibrational spectra, predict nuclear magnetic resonance (NMR) parameters, analyze frontier molecular orbitals HOMO (Highest Occupied Molecular Orbital) - LUMO (Lowest Unoccupied Molecular Orbital), and generate molecular electrostatic potential (MEP) surface maps. To enhance the accuracy of vibrational assignments, potential energy distribution (PED) analysis was conducted via the VEDA4 software. Furthermore, theoretical infrared (IR) and NMR data were compared with experimental results, with results from FT-IR, ¹H-NMR, and ¹³CNMR spectra demonstrating strong agreement and validating the computational models. In addition to spectroscopic characterization, the antiproliferative activity of the synthesized compound against human breast cancer cell line MCF7 and a normal mouse fibroblast cell line (L929) was evaluated. Among the tested compounds, those exhibiting the highest inhibitory activity against MCF7 cells were selected for further analysis. In order to explain the underlying molecular interactions, molecular placement studies were carried out with the help of the Schrödinger Maestro software program, which targets the basic protein binding sites to predict binding affinity and interaction patterns. Collectively, this integrated study provides valuable insights into the structural, spectroscopic, and biological behavior of benzazole-based derivatives, highlighting the synergy between experimental techniques and computational modeling in modern drug discovery research.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2026High-sensitivity Ag@CuxO and Ag@CuxO:rGO core–shell heterostructure photodetectors with broad spectral range: Enhanced UV–IR response and superior long-term stability
Eden, Cigdem; Çırak, Çağrı
Herein, Ag@CuxO and Ag@CuxO:rGO core–shell nanocomposite architectures were synthesized in the wet chemical method which was further analyzed by UV–Vis, XRD, XPS, SEM and TEM study. The as-prepared colloidal nanostructures were drop-casted onto n-type Si substrates to obtain n-Si/Ag@CuxO and n-Si/Ag@CuxO:rGO heterojunction photodetector devices. Current–voltage (I–V) characteristics under different light intensity and 365, 395, 590 and 850 nm wavelengths of illumination were measured. Under 365 nm illumination at −2 V bias, the responsivities of the n-Si/Ag@CuxO and n-Si/Ag@CuxO:rGO devices were determined to be 1.53 A/W and 4.26 A/W, respectively, indicating external quantum efficiencies exceeding 100 %. The better UV photosensitivity of n-Si/Ag@CuxO:rGO heterojunction is probably due to the improved electron transport capacity by rGO. Our findings demonstrate homojunction structure-based nanocomposites with very good photodetection performance, thus opening the door for next-generation optoelectronic device application.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2024Development of a novel hydrothermal process for surface modification of galvanized steel, characterization, and photocatalytic application
Zorlu, Rabia; Özdokur, K. Volkan; Acımert, Özlem Baran; Demir, Zeynep; Çağlar, Bülent; Çırak, Çağrı; Koçak, Süleyman
In this study, the hydrothermal surface modification of galvanized steel was performed on the substrate without any precursor ion for the first time to achieve a photocatalytic activity under UV light irradiation. The structural, morphological and optical properties of the modified and bare samples were examined by XRD, SEM-EDX, XPS, FTIR, UV-DRS and PL analyses. Electrochemical and wettability properties were determined with potentiostat and contact angle goniometry, respectively. The photocatalytic performances of surface modified galvanized steel samples were also investigated and comparatively evaluated by photo-degradation of quinoline yellow dye under UV light irradiation. Upon the doping silver ions into the structure, the photocatalytic degradation efficiency of fabricated composite material was determined as 100 % after the periods of 65 min. To the best of our knowledge this study is the first study dealing with photodegradation of quinolone yellow by using modified galvanized samples. The modified galvanized steel samples exhibited 96.1 % of its initial activity after 5 cycles. The surface modification by hydrothermal treatment improved the electrochemical properties of galvanized steel.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2021Bi2S3 nanorods decorated on bentonite nanocomposite for enhanced visible-light-driven photocatalytic performance towards degradation of organic dyes
Caglar, Bulent; Guner, Eda Keles; Ersoy, Selin; Caglar, Sema; Özdemir, Agah Oktay; Özdokur, Kemal Volkan; Doğan, Bilge; İçer, Fatih; Çırak, Çağrı
In this study, we prepared bentonite-Bi2S3 nanocomposite via decoration of Bi2S3 nanorods on bentonite for the first time to enhance the photocatalytic performance of Bi2S3 nanorods under visible light irradiation. XRD, TEM, SEM-EDX, XPS, UV-DRS, PL, electrochemical impedance spectroscopy, chronoamperometry, zeta potential, and BET techniques were used to compare analysis of structural, morphological, optical, electrochemical and textural properties of raw bentonite, bare Bi2S3 nanorods and bentonite-Bi2S3 nanocomposite. The photocatalytic performances of bentonite-Bi2S3 nanocomposite and bare samples were also investigated and comparatively evaluated by photodegradations of crystal violet and rhodamine B dyes under visible light irradiation. The photocatalytic degradation efficiencies of fabricated bentonite-Bi2S3 nanocomposite for crystal violet and rhodamine B were determined as 100% and 85% after the periods of 30 min and 90 min, respectively, which were more superior compared with those of bare Bi2S3 nanorods. The enhanced photodegradation activity of bentonite-Bi2S3 nanocomposite was assigned to the good visible light absorption ability, enlarged surface area, increased adsorption capability and decreased aggregation of Bi2S3 nanorods with the inclusion of bentonite platform as well as suppressed hole-electron recombination process due to electrostatic interaction between negatively charged bentonite surface and positively charged holes. The reactive species trapping revealed that hydroxyl radicals played a major role on the photodegradation and a plausible mechanism for photodegradation of dye molecules on bentonite-Bi2S3 nanocomposite was suggested. The photodegradation of dyes was found to follow the pseudo-first-order kinetic model. The prepared photocatalyst exhibited good reusability and stability after 4 cycles.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2021A novel amperometric H2O2 biosensor constructed by cress peroxidase entrapped on BiFeO3 nanoparticles
Caglar, Bulent; İçer, Fatih; Özdokur, Kemal Volkan; Caglar, Sema; Özdemir, Agah Oktay; Guner, Eda Keles; Beşer, Burcu Meryem; Altay, Ahmet; Çırak, Çağrı; Doğan, Bilge
Herein, we synthesized ferromagnetic BiFeO3 nanoparticles with sizes of 20–60 nm and rhombohedral distorted perovskite structure without any co-formed impurity phases by sol-gel method. Structural, morphological, magnetic, electronic and textural properties of BiFeO3 nanoparticles were characterized by using XRD, SEM-EDX, TEM, FTIR, XPS, VSM, UV-DRS, PL and BET techniques. The peroxidase was isolated from the Cress (Lepidium sativum) and purified by using precipitation of ammonium sulfate and chromatographic techniques; gel filtration and ion exchange chromatography which is showed wide range of thermal stability, maximum activity in the acidic environment and close to the body temperature. Afterwards, a novel amperometric biosensor based on Cress peroxidase entrapped on BiFeO3 nanoparticles modified carbon paste electrode was prepared for the first time to sensitive detection of H2O2. The prepared H2O2 biosensor was operated with the aid of choro-amperometry technique by applying −0.8 V vs Ag/AgCl electrode. The developed biosensor exhibited a linear response towards to H2O2 in the concentration range of 2.0 10−7 to 1.0 10−5 M under the optimal conditions and limit of detection and quantification were estimated as 7.0 10−8 M (2.7 μg L−1) and 2.0 10−7 M (8.7 μg L−1), respectively. The repeatability of the electrode was calculated as 19.2 for 2.0 10−7 M (N = 7) and the accuracy was 81.2% for this concentration. In addition, the H2O2 biosensor exhibited excellent stability up to ten days. Finally, the sensor developed was used for the analysis of H2O2 in milk samples and satisfactory recoveries were obtained under the operating conditions.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2021Application of BiFeO3 and Au/BiFeO3 decorated kaolinite nanocomposites as efficient photocatalyst for degradation of dye and electrocatalyst for oxygen reduction reaction
Caglar, Bulent; Guner, Eda Keles; Özdokur, Kemal Volkan; Özdemir, Agah Oktay; İçer, Fatih; Caglar, Sema; Doğan, Bilge; Beşer, Burcu Meryem; Çırak, Çağrı; Tabak, Ahmet
To improve the photocatalytic performance and solve the aggregation problem of BiFeO3 nanoparticles, kaolinite-BiFeO3 photocatalyst was successfully prepared for the first time by decoration of ferromagnetic BiFeO3 nanoparticles onto kaolinite surface. Comparative characteristics of kaolinite, bare BiFeO3 and kaolinite-BiFeO3 photocatalyst were investigated in detail by XRD, TEM, SEM-EDX, XPS, FTIR, VSM, UV-DRS, PL, zeta potential and BET techniques. The photocatalytic activities of the samples were also evaluated by photodegradation of rhodamine B as a model reaction under different irradiations like UVA, visible and sunlight. The kaolinite-BiFeO3 exhibited more superior photocatalytic activity as compared with other samples, which is best fitted to pseudo-first-order kinetic. The reactive species trapping experiments indicated that photogenerated-holes play major roles in the degradation process whereas superoxide radicals possess a secondary effect. Enhanced photocatalytic activity of kaolinite-BiFeO3 is attributed to its kaolinite platform that reduces the recombination opportunities of the photogenerated holes and electrons as well as increases the surface area, decreases the particle size and aggregation of nanoparticles. In addition, we also designed a novel electrocatalytic platform based on gold nanoparticles loaded on kaolinite-BiFeO3 modified carbon paste electrode surface for the examination of electrocatalytic activity for oxygen reduction reaction in alkaline medium. Electrochemical characterizations of the Au/BiFeO3/kaolinite modified carbon paste electrode and other bare surfaces were comparatively carried out with the aid of cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. Au/BiFeO3/kaolinite modified carbon paste electrode exhibited 15-fold current enhancement together with 100 mV anodic potential shift compared with bare carbon paste electrode.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2021WO3 decorated TiO2 nanotube array electrode: Preparation, characterization and superior photoelectrochemical performance for rhodamine B dye degradation
Davaslıoğlu, İrem Çakar; Volkan Özdokur, K.; Koçak, Süleyman; Çırak, Çağrı; Çağlar, Bülent; Çırak, Burcu Bozkurt; Nil Ertaş, F.
An efficient photoelectrocatalyst was synthesized by electrochemical deposition of WO3 on the titanium nanotube (TNT) array by subsequent cycling the potential between -0.6 – 1.0 V vs Ag/AgCl. The structural and morphological properties of the electrode obtained (TNT-WO3) was characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques and it was revealed that TNT surfaces were successfully decorated by WO3 species without formation of another oxidation species. Then, the photoelectrocatalytic activity of the composite electrode set at 0.2 V (vs Ag/AgCl), was tested under UV light irradiation on the degradation of Methylene blue (MB), Orange G (OG) and Rhodamine B (RhB), as the model pollutants. Among the azo dyes studied, the electrode has given the best performance against RhB in comparison to the bare TNT electrode. The influence of the deposition conditions on the efficiency was examined and under optimal conditions and it was noted that efficient removal of the dye can be achieved within 10 min. Another advantage of the composite electrode is that PEC performance can be tuned by simply changing the parameters of deposition.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2020Facile synthesis and enhanced photo-electrocatalytic performance of TiO2 nanotube/g-C3N4 composite catalyst by a novel synthesis approach
Özdokur, Kemal Volkan; Bozkurt Çırak, Burcu; Eden, Çiğdem; Ahmad Boda, Muzaffar; Çırak, Çağrı
TiO2 nanotube/graphene-like carbon nitride (g-C3N4) composite structure was fabricated by a novel synthesis approach. Amorphous TiO2 nanotube arrays was synthesized by anodization. Afterward, g-C3N4 structures were decorated on the amorphous TiO2 nanotube arrays by using thermal polymerization process while anatase phase transformation of TiO2 in progress for the first time. The nanocomposite electrodes were further used for photo-electrochemical degradation of Rhodamine B dye. The homogenous surface morphology, higher crystallinity and more efficient photo-electrochemical performance were obtained by TiO2 nanotube/g-C3N4 composite structure due to better electrical contact and electron transportation by described synthesis approach.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2020Effect of illumination intensity on the characteristics of Co/Congo Red/p-Si/Al hybrid photodiode
Kaçuş, Hatice; Çırak, Çağrı; Aydoğan, Şakir
In this study, Congo Red (CR) organic dye interlayer was covered by sping coating on p-Si semiconductor wafer and Co/CR/p-Si/Al photodiode was fabricated. The surface morphology of CR film was characterized by SEM measurement. Current–voltage (I–V) characteristics of the photodiode were obtained under different illumination intensities. The electrical, sensitivity, and photoresponsivity properties of Co/CR/p-Si/Al photodiode were investigated using the current–voltage and capacitance–voltage measurements. While the calculated barrier height (Φb) and ideality factor (n) were 0.58 eV and 1.52 under the dark, these values were 0.55 eV and 1.62 under the 400 mW cm−2, respectively. The exponent of photocurrent was found to be 1.10. This value indicates that the photodiode exhibited a linear photocurrent variation with power of the light. It was found that the interface-state intensity of the photodiode decreased from 1.64 × 1015 to 8 × 1012 eV−1 cm−2 under the 400 mW cm−2 light intensity. The rectification rate of photodiode (RR) of the photodiode was found under the dark and illumination. All experimental results indicate that the photodiode exhibits a photoconducting characteristic.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2020The enhanced light harvesting performance of dye-sensitized solar cells based on ZnO nanorod-TiO2 nanotube hybrid photoanodes
Bozkurt Çırak, Burcu; Eden, Çiğdem; Erdoğan, Yaşar; Demir, Zeynep; Özdokur, K. Volkan; Caglar, Bulent; Morkoç Karadeniz, Sibel; Kılınç, Tuba; Ercan Ekinci, Ali; Çırak, Çağrı
In this study, TiO2/ZnO hybrid nanocomposites (TZ) were fabricated by two step synthesis route for potential applications as photoanode in dye sensitized solar cells (DSSC). Titania nanotubes were grown on titanium sheets by electrochemical oxidation. ZnO nanorods were decorated with hydrothermal method by equimolar (0.1 M) precursors on TiO2 nanotubes. Hydrothermal temperatures values were changed to find the optimal ZnO decoration density to increase photo conversion efficiency. The characterization of the photoanodes was made using FE-SEM, XRD and XPS techniques. The results show that hydrothermal reaction temperature can dramatically enhance the light harvesting performance of TZ photoanodes. The photo conversation efficiency of DSSC by TZ photoanode was reached 1.67 % for hydrothermal temperature of 130 °C which is twofold higher than that of DSSC by TiO2 nanotubes (0.81 %). The improvement in photo conversation conversion efficiency can be assigned to synergetic effect in TZ photoanode, lower recombination rate and charge transfer resistance.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2019Synthesis and characterization of ZnO nanorice decorated TiO2 nanotubes for enhanced photocatalytic activity
Bozkurt Çırak, Burcu; Caglar, Bulent; Kılınç, Tuba; Morkoç Karadeniz, Sibel; Erdoğan, Yaşar; Kılıç, Selçuk; Kahveci, Enver; Ercan Ekinci, Ali; Çırak, Çağrı
In present study, we report on the synthesis of TiO2/ZnO nanocomposite (TZN) films for potential applications as photocatalyst in heterogeneous photo-degradation of Rhodamine B under UVA irradiations. ZnO nano-rice decorated TiO2 nanotubes were successfully synthesized via a facile and effective two-step route. Firstly, TiO2 nanotube arrays were grown by anodic oxidation. Afterwards, ZnO rice shaped nanostructures were decorated by successive chemical bath deposition cycles of 2, 4, 6 and 8. The XRD, FESEM, XPS and μ-XRF results showed that the rice-shaped wurtzite ZnO nanoparticles with dimensions of ca. 1μm × 100 nm were homogeneously distributed on the anatase TiO2 nanotube arrays with highly uniform in the presence of in zinc nitrate hexahydrate and hexamethylenetetramine precursors with 1:4 M ratios. The photodegradation results showed that the photocatalytic activity of TZN films were gradually increased in parallel with the number of ZnO deposition cycles and the best performance was found for TNZ8 film. The RhB photodegradation efficiency was determined to be 65% for bare TiO2 whereas 95% degradation of Rhodamine B was occurred for TNZ8 film which follow pseudo-first-order kinetic. In addition, TZN films exhibited good photostability after four reuses. Also, photocatalytic activity of TZN were tested under UVC, UVB, UVA and visible region irradiations for comparative purposes.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2019Facile synthesis of hybrid ZnO nanostructures by combined electrodeposition and chemical bath deposition for improved performance of dye-sensitized solar cell
Boda, Muzaffar Ahmad; Bozkurt Çırak, Burcu; Demir, Zeynep; Çırak, Çağrı
Herein, equimolar hexamethylenetetramine (HMT) were used to couple chemical bath deposition (CBD) and electrode deposition (ED) techniques to decorate electrodeposited one-dimensional (1-D) ZnO nano-rods with wurtzite nano-spindles in the attempt of increasing surface area to fabricate efficient and cost-effective dye sensitized solar cell (DSSC) photo-anode. The resulting hybrid photo-anode offers an enhancement of 43% in photocurrent density than bare ZnO nano-rods. The corresponding augmentation in photocurrent response is attributed to comparative increase in crystallinity and considerable decrease in charge transfer resistance across the interface as being analyzed by X-ray diffraction and electrochemical impedance spectroscopy (EIS), respectively.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2019Molecular docking and vibrational spectroscopy studies of (E)-N′-hydroxy-1,3-diphenyl-4,5-dihydro-1H-pyrazole-5-carboximidamide
Sert, Yusuf; Gökce, Halil; Chandra; Mahendra, M.; Srikantamurthy, N.; Çırak, Çağrı
The experimental (FT-IR and Laser-Raman spectra) and theoretical (DFT studies) vibrational modes of (E)-N′-Hydroxy-1,3-diphenyl-4,5-dihydro-1H-pyrazole-5-carboximidamide were studied in detail. FT-IR and Laser-Raman data were collected in the range 4000-400 cm −1 and 4000-100 cm −1 , respectively in solid phase. Optimized structural parameters and frequency values were theoretically calculated using DFT/B3LYP and DFT/M06-2X chemical methods with 6–311++G (d,p) basis set by Gaussian 09W software. Theoretical frequency assignments and potential energy distributions (PED) analysis were performed by VEDA 4 program. With the optimized structures, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies and clouds were obtained and evaluated. Additionally, molecular docking studies for potent pyruvate kinase activators (PDB codes: 4RPP, 4FXJ, 4QG6, 4WJ8) and previously used targets (PDB codes: 2QU5, 2W1G and 2VTO-three different cancers related proteins) were employed for docking by AutoDock Vina program considering Swiss-Target reports and related literature knowledge.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2019Synthesis of TiO 2 nanotube/ZnO nanorod hybrid nanocomposite photoanodes for dye-sensitized solar cells
Çırak, Burcu Bozkurt; Demir, Zeynep; Eden, Çiğdem; Erdoğan, Yaşar; Caglar, Bulent; Karadeniz, Sibel Morkoç; Kılınç, Tuba; Ekinci, Ali Ercan; Çırak, Çağrı
TiO 2 nanotube/ZnO nanorod hybrid nanocomposite (ZTN) photoanodes were synthesized, characterized and assembled as dye-sensitized solar cells (DSSCs) at optimum conditions for improving photovoltaic efficiency. The self-organized and high ordered TiO 2 nanotube arrays were growth on titanium foil by anodic oxidation as a substrate for ZnO decoration by hydrothermal method. Zinc nitrate hexahydrate and hexamethylenetetramine precursor concentrations were varied to designate the optimum ZnO decoration density for enhanced photoconversion efficiency. XRD, FESEM and XPS results showed that the crystal structure, morphology, elemental composition and density of ZnO nanorods on the surface of TiO 2 nanotubes are very sensitive to ZnO precursor concentrations. It is found that, the highest overall efficiency of DSSC based on ZTN photoanode was measured 1.8% for precursor concentration of 60 mM which was more than double compared to DSSC based on bare-TiO 2 nanotubes (0.8%). The improvement of DSSC efficiency originates from suppressing the recombination rate and decreasing the charge transfer resistance due to synergetic effect between TiO 2 nanotubes and ZnO nanorods.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2018Fabrication of TiO2/ZnO/Pt nanocomposite electrode with enhanced electrocatalytic activity for methanol oxidation
Özdokur, Kemal Volkan; Çırak, Burcu Bozkurt; Caglar, Bulent; Çırak, Çağrı; Karadeniz, Sibel Morkoç; Kılınç, Tuba; Erdoğan, Yaşar; Ekinci, Ali Ercan
Platinum decorated heterogeneous catalysts for methanol oxidation reaction have crucial importance for the commercial sustainability of Direct Methanol Fuel Cells (DMFC). In this study, TiO2/ZnO/Pt nanocomposite film was fabricated as a promising electrocatalytic surface to enhance methanol oxidation in alkaline medium. Firstly, an TiO2/ZnO layer was prepared via DC sputtering followed by electrodeposition techniques on FTO electrode and then platinum nanoparticles were decorated onto the obtained nanocomposite film for the first time. The characterization of the developed transparent films was performed by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cycling voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The XRD, FESEM and XPS results showed that metallic Pt nanoparticles were uniformly distributed onto the TiO2/ZnO film consisting of anatase TiO2 and wurtzite ZnO layers with a thickness of ca. 370 and 320 nm, respectively. Five cycles of deposition of ZnO and Pt nanoparticles showed best catalytic activity after optimization. The oxidation peak of 0.5 M methanol at TiO2/ZnO/Pt was located at −0.17 V and the corresponding peak current increased about 10- and 5-fold in comparison to FTO/Pt and FTO/TiO2/Pt electrodes, respectively.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2017Synthesis, surface properties, crystal structure and dye sensitized solar cell performance of TiO2 nanotube arrays anodized under different voltages
Bozkurt Çırak, Burcu; Karadeniz, Sibel Morkoç; Kılınç, Tuba; Caglar, Bulent; Ekinci, Ali Ercan; Yelgin, Hüseyin; Kürekçi, Mehmet; Çırak, Çağrı
In this study, anodic TiO2 nanotube (TNT) arrays with average nanotube diameter from 26 nm to 115 nm and length from 1.3 μm to 6.4 μm were grown by electrochemical method. Anodization process were performed under different voltages from 10 to 50 V in ethylene glycol – ammonium fluoride – water electrolyte. Formation mechanism of TNTs was summarized. Surface morphology, crystal structure, roughness, wettability and elasticity of TNT arrays were characterized by using field emission scanning electron microscope (FESEM), X-Ray diffraction (XRD), atomic force microscope (AFM), optical tensiometer and universal mechanical tester, respectively. Water contact angle measurements and nanoindentation tests proved that water contact angle and elastic modulus of TNT arrays decrease with increasing anodization voltage. Photocurrent-photovoltage curves and electrochemical impedance spectroscopy (EIS) measurements of dye sensitized solar cells (DSSC) were made to investigate the effects of anodization voltages on photoanode performance. The light conversion efficiency and photocurrent density of TNT photoanodes was increased with increasing anodization voltage due to larger nanotube length and surface area. The results show that anodization voltage is significant parameter for the surface properties and dye sensitized solar cell (DSSC) performance TNT arrays.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2016Structural, morphological and optical properties of well-ordered CdO nanostructures synthesized by easy-economical chemical bath deposition technique
Karadeniz, Sibel Morkoç; Kılınç, Tuba; Çırak, Burcu Bozkurt; Sakaoğlu, Tuba Irmak; Çırak, Çağrı; Ertuğrul, Mehmet; Ekinci, Ali Ercan
In this Study, Cadmium Oxide (CdO) nanostructures were synthesized by using Chemical Bath Deposition Technique. The synthesized process was carried out at room temperature. The structural and optical properties of nanostructures was characterized by XRD, SEM and UV-Vis techniques. As a result, the CdO nanostructures are oriented along (111) plane of cubic crystal structure. The morphology of CdO nanostructures showed interconnected prism-like and cauliflower-type cluster nanostructure. The UV results of this structures with high absorbtion coefficient are observed to be in accordance with the CdO nanoparticles.
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