Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026Scopus SJRQ2/r/bayburt/12820
  Exploring the role of rare earth elements doped TiO₂ based photoanodes on the performance of dye-sensitized solar cells

  Caliskan, Berrak; Sayan, Enes; Igman, Erdal

  This study investigates the synthesis and characterization of rare earth elements (REEs) doped TiO₂ thin films based photoanodes for use in dye-sensitized solar cells (DSSCs). For this purpose, TiO₂ films were doped with Ho³⁺, La³⁺, Er³⁺, and Yb³⁺ ions to enhance photoelectrochemical properties. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy, BET surface area analysis, and X-ray photoelectron spectroscopy (XPS) were employed for the structural, morphological, and optical characterization of the synthesized photoanodes and CEs. REEs doping improved the surface morphology and optical properties of TiO₂, in particular, it increased photon absorption in the visible light range. La³⁺ and Ho³⁺ significantly improved photovoltaic performance, achieving power conversion efficiencies of 3.78% and 2.87%, respectively, compared to that of pure TiO₂. These enhancements indicate improved charge transport and light harvesting due to incorporation of REEs. Additionally, replacing the conventional platinum counter electrode (CE) with reduced graphene oxide (rGO) further enhanced performance, offering a low-cost and efficient alternative. The study highlights the combined benefits of REEs doping and rGO integration in improving DSSCs efficiency. These findings contribute to the development of more sustainable, cost-effective solar energy technologies and underline the potential of REEs-doped TiO₂ films and rGO electrodes in advancing next-generation photovoltaic devices.

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  AtıfScopus3·WoS3·OpenAlex2

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• MakaleAçık Erişim2026Scopus SJRQ2/r/bayburt/11359
  Exploring the ımpact of metal doping and alternative electrodes on the performance of dye-sensitized solar cells

  Calıskan, Berrak; Sayan, Enes; Igman, Erdal

  This study explores the synthesis and characterization of metal-doped TiO2 thin films for applications in dye-sensitized solar cells (DSSCs). Titanium dioxide (TiO2) films were doped with various metal ions such as Ag+, Zn2+, Fe3+, and Co2+, to enhance the photoelectrochemical properties of the photoanode. The films were characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS). The doping process was found to influence the morphology, surface area, and optical properties of the TiO2 films, resulting in enhanced light absorption, particularly in the visible range. The effects of metal doping on the performance of the DSSCs were evaluated, showing that Co2+ and Ag+ doping resulted in improved efficiency compared to undoped TiO2, with the Co2+-doped TiO2 achieving the highest power conversion efficiency of 2.85%. Additionally, the incorporation of reduced graphene oxide (rGO) as a counter electrode demonstrated a significant enhancement in DSSC performance, even surpassing traditional platinum-based counter electrodes. The results suggest that metal doping and rGO incorporation offer promising strategies for improving DSSC efficiency. This study highlights the potential of metal-doped TiO2 photoanodes and rGO counter electrodes in advancing the development of cost-effective, high-performance DSSCs for sustainable solar energy applications.

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  AtıfScopus1·WoS1

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• MakaleAçık Erişim2020Scopus SJRQ2/r/bayburt/12153
  Graphene/polyaniline nanocomposite as platinum-free counter electrode material for dye-sensitized solar cell: its fabrication and photovoltaic performance

  Bayram, Ozkan; Igman, Erdal; Guney, Harun; Demir, Zeynep; Yurtcan, Mustafa Tolga; Cirak, Cagri; Hasar, Ugur Cem; Simsek, Onder

  In this study, it was aimed to produce graphene/polyaniline nanocomposite thin films as counter electrode materials by PECVD system and to determine the photovoltaic performances of these counter electrodes in dye-sensitized solar cells (DSSCs). Graphene/polyaniline counter electrode (GPCE) material was produced in two different steps. Firstly, a single-layer and multilayer graphene thin films were produced on the fluorine-doped tinoxide (FTO) substrates. Then, polyaniline (PANI) thin films were grown on each graphene thin films using plasma polymerization technique, and eventually the production of the graphene/PANI nanocomposite was completed. The fabricated graphene/PANI nanocomposites were used in place of platinum (Pt)-counter electrode which is widely used in DSSCs and the photovoltaic performance of these counter electrodes was investigated. The DSSCs consisted of titanium dioxide (TiO2) nanotube photoanode, N719 dye, iodolyte liquid electrolyte, and graphene/PANI nanocomposite counter electrode. I–V measurements were carried out in order to calculated photoconversion efficiency (PCE) and it was found that the these efficiency of GPCEs changed between 0.56 and 1.36% according to the number of graphene layers. The photovoltaic performance of DSSC, consisting of TiO2 nanotube photoanode and Pt-counter electrode was 1.1%.

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  AtıfScopus33·WoS25·OpenAlex29

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• MakaleAçık Erişim2019Scopus SJRQ2/r/bayburt/13630
  The role of cobalt doping on the optical and structural properties of Mn 3 O 4 nanostructured thin films obtained by SILAR technique

  Bayram, Ozkan; İgman, Erdal; Guney, Harun; Simsek, Onder

  Cobalt doped manganese oxide thin films (Mn 3 O 4 :Co) were successfully deposited on soda lime glass substrates using SILAR technique. Mn 3 O 4 :Co thin films were characterized using XRD, SEM, Uv–VIS and Raman spectroscopy. The XRD spectra showed that thin films had substantially Hausmannite crystal structure. The preferential orientation of the pure and 0.5 at.% Co doped manganese oxide thin films (Mn 3 O 4 ) was (002), but with increasing Co doping, it was detected that this preferential orientation shift towards the (211) plane. The absorbance, transmittance and optical band gap of the Mn 3 O 4 :Co thin films were determined using Uv–Vis spectroscopy and these properties of the thin films differed considerably due to cobalt doping. The optical band gap of pure Mn 3 O 4 thin films was 2.00 eV, but on the other hand, due to the Co doping this value increased before and then decreased slightly. Optical transmittance of Mn 3 O 4 :Co films increased from 60% to 72% with the effect of Co doping. A1g mode, which is the characteristic vibration peak of Mn 3 O 4 films, was confirmed for pure and doped Mn 3 O 4 thin films at a wavelength of 658 nm.

  AtıfScopus26·WoS24·OpenAlex25

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• MakaleYalnız künye2019Scopus SJRQ4/r/bayburt/13594
  Evaluating the grinding process of granitic rocks using the physico-mechanical and mineralogical properties

  Kahraman, Sair; Ucurum, Metin; Yogurtcuoglu, Emine; Fener, Mustafa

  Granitic rocks are sometimes ground for different purposes. Predicting the mean particle size (d50) is useful for planning and cost estimation of purposes. In order to investigate the possibility of predicting the d50 of ground rock from the physico-mechanical rock properties, six different granites were tested in the laboratory. First, the d50 values were correlated with the corresponding physico-mechanical properties. The simple regression analysis showed that there were no good correlations between the d50 and the physico-mechanical properties. Then, the multiple regression analysis was carried out and strong prediction equations were developed. It was also shown that the dominant parameter in grinding was the abrasive mineral content of rock. It is concluded that the d50 of granites can be predicted from the derived multiple regression equations especially for preliminary investigations. The developed estimation equations including index test values are especially useful since they are easy to use.

  AtıfScopus2·WoS1

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• MakaleYalnız künye2018Scopus SJRQ2/r/bayburt/13812
  Changes of surface properties of calcite particles with calcium stearate using conventional experimental design and properties of coated calcite

  Ucurum, Metin; Bayram, Ozkan; Toraman, O. Yusuf; Kilic, Habibe; Yalcin, Seyma

  Calcite is utilized as a filler mineral in the industries such as plastics, rubber, and paint, to gain products with a variety of features. In order to use a calcite ore as a filler, some specific physical and physico-chemical properties are required such as ultra-fine sizes and conversion of hydrophilic to hydrophobic structure. In the present study, for these purposes, surfaces of the ultra-fine calcite powder (d50=2.94 μm) were coated by a mechano-chemical process with calcium stearate [Ca(C17H35COO)2] in a stirred ball mill. The influence of operating parameters such as calcite filling-ratio, ball-filling ratio, operation speed, grinding time and chemical dosage on the active ratio (%) was systematically examined. Then, the properties of modified calcite product were measured and evaluated by contact angle, TGA, DTA, FTIR, and SEM. The results showed that the mechano-chemical technology is very effective for modifying the surface of micronized calcite products using calcium stearate chemical.

  AtıfScopus20·WoS18

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• MakaleYalnız künye2018Scopus SJRQ2/r/bayburt/12591
  Investigation of the effect of RF energy on optical, morphological, chemical and antibacterial properties of PolyTerpenol thin films obtained by RF-PECVD technique

  Bayram, Ozkan; Simsek, Onder

  In this study, it was aimed to obtain PolyTerpenol thin films by radio frequency plasma enhanced chemical vapor deposition technique using Terpinen-4-ol essential oil, which is organic compounds. The surface morphology and chemical properties of polymer thin films were investigated by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy. AFM analyzes of PolyTerpenol thin films revealed that the thin films are homogeneous, smooth and nonporous. The optical properties of the thin films were determined using UV–Vis spectrophotometer. When optical band gaps of thin films were examined, it was found that this value varied from 3.83 to 3.20 eV. The extinction coefficients of the obtained thin films according to the increasing RF energy were calculated as 0.0011, 0.0060, 0.0085 and 0.0150, respectively, at a wavelength of 320 nm. In addition, antibacterial effects of these thin films against Escherichia Coli (E.Coli) bacteria were also investigated. The PolyTerpenol thin films were found to have high antibacterial activity against E. Coli bacteria.

  AtıfScopus8·WoS8·OpenAlex11

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• MakaleAçık Erişim2018Scopus SJRQ2/r/bayburt/12524
  Synthesis and characterization of Zn-doped Mn3O4 thin films using successive ionic layer adsorption and reaction technique: Its structural, optical and wettability properties

  Bayram, Ozkan; Ertargin, Mehmet Emrah; Igman, Erdal; Guney, Harun; Simsek, Onder

  In this study, it is aimed to obtain Zn doped Mn3O4 (manganese oxide) nanostructured thin films on the soda lime glass substrates by successive ionic layer adsorption and reaction technique. The tetragonal crystal structure of the all thin films was detected using XRD spectroscopy. The average crystallite size of undoped Mn3O4 thin films was calculated to be 29 nm and for Zn-doped thin films, this value decreased to 23 nm with increasing Zn concentration. Characteristic peaks for thin films were also confirmed by RAMAN spectroscopy. The morphological structures of zinc-doped manganese oxide nano-sheets thin films were revealed by SEM. Using UV–Vis spectroscopy, it was found that the optical band gap of Mn3O4 thin films decreased from 2.05 to 1.73 eV with Zn doping. It has also been understood from the wettability analyzes of thin films that all thin films have a hydrophilic character. From all these analyzes, it is thought that the Zn doped Mn3O4 thin films have the potential to be used in supercapacitor applications.

  AtıfScopus25·WoS22·OpenAlex25

  İncele
• MakaleAçık Erişim2018Scopus SJRQ2/r/bayburt/12377
  Effect of doping concentration on the structural and optical properties of nanostructured Cu-doped Mn3O4 films obtained by SILAR technique

  Bayram, Ozkan; Guney, Harun; Ertargin, Mehmet Emrah; Igman, Erdal; Simsek, Onder

  In this study, the effect of Cu doping on the optical, structural and wettability properties of the nanostructured Cu-doped Mn3O4 (CMO) thin films obtained by using successive ionic layer adsorption and reaction technique was systematically investigated. The optical, morphological, structural and wettability properties of the nanostructured CMO films were determined using scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–Vis spectroscopy, and water contact angle (WCA) measurements. There were significant differences in the crystal structure of the nanostructured CMO thin films. The Cu doping disrupted this structure of pure (undoped) Mn3O4 films and caused the formation of the porous structure. Optical properties such as extinction coefficient, refractive index, and dielectric constants and optical band gap, were determined for nanostructured CMO films. Compared with pure films, the band gap of Cu-doped films decreased from 2.06 to 1.71 eV with increasing Cu concentration. The dielectric constants of the films showed that the nanostructured CMO films have a transparent structure. At 300 nm wavelength, the dielectric constants of pure Mn3O4 films were 2.22 while the calculated dielectric constants at increasing doping concentrations were 3.55, 2.41 and 2.25. It was also found from the WCA measurements that the thin films were hydrophilic in character and the WCA values for the nanostructured CMO thin films were measured as 24, 29 and 40 of degree.

  AtıfScopus23·WoS22·OpenAlex26

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• MakaleAçık Erişim2018Scopus SJRQ3/r/bayburt/12320
  Investigation of high-temperature-resistant rhenium–boron neutron shields by experimental studies and Monte Carlo simulations

  Korkut, Turgay; Korkut, Hatun; Aygün, Bünyamin; Bayram, Özkan; Karabulut, Abdulhalik

  In this study, novel rhenium–boron neutron-shielding high-temperature-resistant materials were designed. The considered samples, Re60–B40, Re58–B42, Re50–B50, and Re40–B60, with different concentrations of rhenium and boron were investigated to elucidate their neutron-shielding performances, and compare them with well-known neutron-shielding materials such as the 316LN quality nuclear steel. In addition to the experimental studies, Monte Carlo simulations were performed using the FLUKA and GEANT4 codes, where 4.5-MeV neutrons emitted by a 241Am–Be source were employed. Experimental equivalent dose rates, simulated track lengths, energy balances, and neutron mass absorption cross sections were discussed in detail.

  AtıfScopus5·WoS2·OpenAlex4

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