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A STUDY ON THE STRUCTURAL, OPTICAL AND PHOTOVOLTAIC PROPERTIES OF Fe(II) SCHIFF BASE COMPLEX WITH 5 AMINO-2,4-DICHLOROPHENOL-3,5-DITERTBUTHYSALISYLALDIMINE LIGAND
(Inst Materials Physics, 2019) Kilinc, D.; Sahin, O.; Horoz, S.
In our present study, 5 amino-2,4-dichlorophenol-3,5-ditertbuthysalisylaldimine ligand was synthesized and we used this ligand to prepare its-Fe(II) complex with using the wet chemical method. The structural, optical and electronic properties of Fe(II) Schiff base complex with ligand were characterized using the x-ray diffraction (XRD), optical absorption and Fourier transform-infrared (FT-IR) measurements, respectively. The structure of Fe(II) Schiff base complex with ligand was determined as a monoclinic crystal system. Two absorption bands were observed in the UV-visible region. They are assigned to intraligand and charge transfer transitions, respectively. The FT-IR spectra of Fe(II) Schiff base complex with ligand are similar to the ligand spectra. Despite the similarity, a shift toward higher frequencies was observed in the vibration modes of azomethine groups. Furthermore, Fe(II) Schiff base complex was used as a photosensitizer on TiO2 film in a DSSC device. Thus, the effect of Fe(II) Schiff base complex on the efficiency of DSSC device was investigated and photovoltaic parameters such as power conversion efficiency (eta), open circuit voltage (V-OC) and short circuit current density (J(SC)) were determined. The obtained J(SC) and V-OC value for samples is 3.75mA/cm(2) and 600 mV, respectively. The. % value was calculated as 0.80. Our result leads to obtain improved conversion efficiency of Fe(II) Schiff base complex with ligand based DSSC device.
Al2O3 SUPPORTED Co-Cu-B (Co-Cu-B/Al2O3) CATALYST FOR HYDROGEN GENERATION BY HYDROLYSIS OF AQUEOUS SODIUM BOROHYDRIDE (NaBH4) SOLUTIONS
(Inst Materials Physics, 2019) Baytar, O.; Izgi, M. S.; Horoz, S.; Sahin, O.; Nar, S.
In this study, Al2O3 supported Co-Cu-B (Co-Cu-B/Al2O3) catalyst was synthesized by chemical impregnation and precipitation method to be used for catalytic hydrogen generation from NaBH4. Co-Cu-B/Al2O3 catalyst was synthesized at various ratios using Co-Cu-B/Al2O3 (5-20%). The effect of some parameters such as NaOH concentration (0-7%), NaBH4 concentration (2.5-7.5%), catalyst amount (25-150 mg) and solution ambient temperature was investigated on the catalytic hydrolysis of NaBH4 . The hydrogen generation rate was found as 2519 and 8962 mL*g(-1)*min(-1) for Co-Cu-B and Co-CuB/Al2O3 catalysts in NaBH4 hydrolysis, respectively. The order rate kinetics and activation energy for Co-Cu-B/Al2O3 catalyst were determined as 0.125 and 27 kJ*mol(-1), respectively. The obtained results suggest that Co-Cu-B/Al2O3 catalysts can be used for mobile applications of PEMFC systems.
AN EFFICIENT TiO2-SUPPORTED RUTHENIUM (Ru/TiO2) CATALYST FOR ELECTROCHEMICAL HYDROGEN GENERATION FROM AQUEOUS POTASSIUM BOROHYDRIDE
(Inst Materials Physics, 2020) Keskin, M. S.; Agirtas, M. S.; Sahin, O.; Horoz, S.
In this study, a TiO2-supported ruthenium catalyst (denoted as Ru/TiO2) was facilely synthesized by chemical reduction method without the use of any chemical reducing reagents. Using a 2 wt.% KBH4 + 1 wt.% KOH solution, hydrogen generation rate was as high as 137423.9 mL* min(-1) g(-1) at 30 C-0, and apparent activation energy was calculated as 55.48 kJ*mol(-1). Compared with similar Ru-based catalysts reported in literature, the Ru/TiO2 catalyst synthesized by chemical reduction method in this study indicates higher catalytic activity and lower apparent activation energy.
An Experimental Study on Drying of Pistacia Terebinthus in a Fixed Bed Dryer
(Tech Science Press, 2013) Balbay, A.; Ulker, H.; Sahin, O.
In this study, drying behaviours of the outer shell peeled Bittim (Pistacia terebinthus) with initial moisture content of 42.2% (dry basis (d.b)) was investigated in a novel fixed bed drying system. The drying experiments were performed at different temperatures (40 degrees C, 60 degrees C and 80 degrees C), air velocities (0.5 m/s and 1 m/s) and weights (30 g and 40 g). A constant rate period was not observed in the drying of bittims; all the drying process occurred in falling rate period. Three models in literature were selected to fit the experimental data. The fit quality of models was evaluated using the coefficient of determination (R-2), sum square error (SSE) and root mean square error (RMSE). Balbay and Sahin model has a good agreement with the experimental data and gave the best results for bittims in a fixed bed system.
Biohydrogen Production from Waste Substrates as a Clean Energy
(Taylor & Francis Inc, 2012) Kahyaoglu, M.; Sahin, O.; Saka, C.
Demand of energy is increasing continuously due to rapid development in industrialization, population, economic growth, and rising living standards. Therefore, energy production is very important for living things, human and industrial activities. Hydrogen is a clean energy that has a great potential to be an alternative fuel. Hydrogen is an environmentally friendly fuel that possesses a high energy yield, provides clean energy generation without pollution when burned in air, and produces no greenhouse gases when combusted. It is an odorless, colorless, tasteless, and non-poisonous gas. Hydrogen is a sustainable energy system, which is produced from available sources and is used in every application where fossil fuels are being used in transportation, residential, commercial, and industrial sectors, and for electricity generation. In nature, some microorganisms with biological processes can produce hydrogen gas. In this review, biohydrogen production from industrial waste substrate, microbial producers, bioprocessing strategies, and the recent developments are discussed with their relative advantages.
DETERMINATION OPTIMUM Ni CONCENTRATION IN Zn2SnO4/Ni-DOPED Sb2S3 THIN FILMS WITH DIFFERENT Ni CONCENTRATIONS USING INCIDENT PHOTONS TO CURRENT EFFICIENCY (IPCE) AND CURRENT DENSITY (J) - VOLTAGE (V) MEASUREMENTS
(Natl Inst R&D Materials Physics, 2018) Nar, S.; Sahin, O.; Horoz, S.
In this present study, Ni-doped Sb2S3 thin films with different Ni concentrations were synthesized on Zn(2)Sna(4) coated with FTO conductive glasses by CBD method at room temperature using Ni as the dopant material. The concentration of Ni to be doped during the experiment was determined as 0.25%, 0.5%, 0.75%, and 1%. In the first stage of this study, incident photons to current efficiency (IPCE) and current density (J) - voltage (V) measurements were conducted to investigate the photovoltaic properties of Zn(2)Sna(4)/Nidoped Sb2S3 thin films with different Ni concentrations for the first time. The main reason for performing IPCE and J-V measurements is to determine Ni-doped Sb2S3 thin film with optimum Ni concentration with the best solar cell performance. It was found that Sb2S3: Ni(0.75%) thin film has the highest IPCE (%) and power conversion efficiency values compare to other Ni concentrations.
Determination optimum ni concentration in Zn2SnO4/Ni-Doped Sb2S3 thin films with different ni concentrations using incident photons to current efficiency (IPCE) and current density (J)-voltage (V) measurements
(S.C. Virtual Company of Phisics S.R.L, 2018) Nar, S.; Sahin, O.; Horoz, S.
In this present study, Ni-doped Sb2S3 thin films with different Ni concentrations were synthesized on Zn2SnO4 coated with FTO conductive glasses by CBD method at room temperature using Ni as the dopant material. The concentration of Ni to be doped during the experiment was determined as 0.25%, 0.5%, 0.75%, and 1%. In the first stage of this study, incident photons to current efficiency (IPCE) and current density (J)-voltage (V) measurements were conducted to investigate the photovoltaic properties of Zn2SnO4 /Ni-doped Sb2S3 thin films with different Ni concentrations for the first time. The main reason for performing IPCE and J-V measurements is to determine Ni-doped Sb2S3 thin film with optimum Ni concentration with the best solar cell performance. It was found that Sb2S3: Ni(0.75%) thin film has the highest IPCE (%) and power conversion efficiency values compare to other Ni concentrations. © 2018, S.C. Virtual Company of Phisics S.R.L. All rights reserved.
EFFECT OF Ce DOPING ON THE CHARACTERISTIC PROPERTIES OF CdS NANOPARTICLES
(Natl Inst R&D Materials Physics, 2020) Ekinci, A.; Horoz, S.; Sahin, O.
In our present study, Ce doped CdS nanoparticles were synthesized in room temperature environment by using chemical co-precipitation technique which is cheap in cost. Ce doped CdS nanoparticles (average particle size: 3.7 nm) were found to have cubic structure as a result of XRD measurements. It has also been clearly observed that Ce dopant ions do not alter the structure of the host semiconductor CdS. Using the spectrum obtained as a result of UV-Vis measurement, the energy band gap of Ce doped CdS nanoparticles was determined as 2.73 eV. This value was observed to be higher than the energy band gap of bulk CdS (2.42 eV). Thus, it can be said that this change in the energy band gap is due to the quantum confinement effect. The maximum IPCE value was 27% for Ce doped CdS nanoparticles while the IPCE values was 4% for pure CdS nanoparticles, respectively. The IPCE of the solar cells improves with the Ce dopant ion. Moreover, the spectral response range of Ce doped CdS nanoparticles widens with the Ce dopant ion. This is attributed to the long lifetimes of the Ce3+ excited states that facilities the transfer of the charge carries to the photoelectrode.
EFFECT OF Mo DOPING ON THE PHOTOVOLTAIC PROPERTIES OF Mo DOPED Cd1-xZnxS (x= 3 %) QUANTUM DOTS SYNTHESIZED BY SILAR
(Virtual Inst Physics, 2018) Ekinci, A.; Sahin, O.; Horoz, S.
Cd1-xZnxS (x=3 %) and Mo-doped Cd1-xZnxS (x=3 %) quantum dots (QDs) with different Mo concentrations were synthesized at room temperature using successive ionic layer adsorption and reaction (SILAR) method. The aim of the study is to determine the optimum Mo concentration in Mo-doped CdZnS QDs using the incident photon to electron conversion efficiency (IPCE) measurements. To be obtained IPCE% values of samples, Cd1-xZnxS (x=3 %) and Mo-doped Cd1-xZnxS (x=3 %) QDs with different Mo concentrations were grown on TiO2 coated onto FTO conductive glass substrates. As a last part of the study, the structural, elemental and optical properties of Mo-doped Cd1-xZnxS (x=3 %) QDs containing optimum Mo content were investigated, respectively. Consequently, it appears that Mo-doped Cd1-xZnxS (x=3 %) QDs have a higher efficiency than Cd1-xZnxS (x=3 %) QDs and that Mo content plays an important role in this improvement.
HYDROGEN GENERATION BY HYDROLYSIS OF NaBH4 WITH EFFICIENT Co-La-W-B CATALYST FOR PEM FUEL CELLS
(Virtual Inst Physics, 2020) Ekinci, A.; Horoz, S.; Baytar, O.; Sahin, O.
In this study, Co-B based quaternary alloy catalysts were synthesized for use in NaBH4 hydrolysis. Lanthanum (La) and tungsten (W) metals were added to Co-B catalyst by chemical reduction method. The effect of metal content (La and W), NaBH4 concentration, NaOH concentration, catalyst amount and temperature parameters were investigated in NaBH4 hydrolysis. Activity results show that the hydrolysis reaction rate first increases and then decreases with increasing NaBH4 concentration as well as NaOH concentration. The activation energy of the hydrolysis for Co-La-W-B catalysts was calculated as 39.2 kJ / mol. The maximum value of hydrogen generation rate was 3280 ml / min. In terms of application, hydrogen produced in the presence of the Co-La-W-B catalyst was used in PEM fuel cell application. Average yield value according to power and ideal voltage and maximum power value of the system were determined as 57%, 73% and 1.4 Watt, respectively. This original study demonstrates that the Co-La-W-B catalyst can be used as an ideal catalyst for PEM fuel cell applications.
INVESTIGATION OF PHOTOVOLTAIC PROPERTIES OF Al2O3 SUPPORTED Ni (II)-SCHIFF BASE COMPLEX SYNTHESIZED BY WET CHEMICAL METHOD
(Natl Inst R&D Materials Physics, 2018) Kilinc, D.; Sahin, O.; Horoz, S.
In our present study, 5-amino-2, 4-dichlorophenol-3,5-ditertbutylsalisylaldimine ligand, Ni (II)-Schiff Base complex and Al2O3 supported Ni (II)-Schiff Base complex were synthesized by wet chemical method. Current density (J)-voltage (V) measurement was performed to investigate the effect of Al2O3 support material on the photovoltaic properties of Ni (II) Schiff Base complex. The power conversion efficiencies (eta%) for Ni (II)-Schiff Base and Al2O3 supported Ni (II)-Schiff Base complexes were calculated as 0,72 and 0.85, respectively. This result suggests that Al2O3 supported Ni (II)-Schiff Base complex with ligand which shows higher solar cell performance than pure Ni (II) Schiff based complex, can be used as a sensitizer in DSSC technology. Moreover, the structural, morphological and optical properties of Al2O3 supported Ni (II)-Schiff Base complex were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and optical absorption measurements, respectively.
Investigation of photovoltaic properties of Al2O3 supported Ni (II)-Schiff base complex synthesized by wet chemical method
(S.C. Virtual Company of Phisics S.R.L, 2018) Kilinc, D.; Sahin, O.; Horoz, S.
In our present study, 5-amino-2, 4-dichlorophenol-3,5-ditertbutylsalisylaldimine ligand, Ni (II)-Schiff Base complex and Al2O3 supported Ni (II)-Schiff Base complex were synthesized by wet chemical method. Current density (J)–voltage (V) measurement was performed to investigate the effect of Al2O3 support material on the photovoltaic properties of Ni (II) Schiff Base complex. The power conversion efficiencies (?%) for Ni (II)-Schiff Base and Al2O3 supported Ni (II)-Schiff Base complexes were calculated as 0,72 and 0.85, respectively. This result suggests that Al2O3 supported Ni (II)-Schiff Base complex with ligand which shows higher solar cell performance than pure Ni (II) Schiff based complex, can be used as a sensitizer in DSSC technology. Moreover, the structural, morphological and optical properties of Al2O3 supported Ni (II)-Schiff Base complex were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and optical absorption measurements, respectively. © 2018, S.C. Virtual Company of Phisics S.R.L. All rights reserved.
Investigation of structural, morphological, electronic and photovoltaic properties of Co(II) complex with ligand
(Springer, 2018) Kilinc, D.; Sahin, O.; Horoz, S.
The dye sensitized solar cells (DSSCs) used as an alternative to inorganic semiconductor sensitized solar cells (ISSCs), have favorable ecological and economical properties. In our current study, Co(II) complex with 4,4'-methylene bis (2,6-diethyl) aniline-3,5-di-tert-butylsalicylaldimine ligand was used as a sensitizer in DSSC by growing on TiO2 coated on FTO conductive glass substrate. Current density (J) versus voltage (V) measurement was applied to investigate the photovoltaic properties of the synthesized Co(II) complex with ligand. The calculated power conversion efficiency (eta%) of the complex using the obtained current density (J) versus voltage (V) curve shows that this device can be used as a promising sensitizer in solar cell application. Furthermore, structural, morphological and electronic properties of Co(II) complex with ligand were characterized by x-ray diffraction, Fourier transform-infrared spectroscopy, scanning electron microscopy and electronic absorption measurements, respectively.
STUDIES ON CATALYTIC BEHAVIOR OF Co-Cr-B/Al2O3 IN HYDROGEN GENERATION BY HYDROLYSIS OF NaBH4
(Inst Materials Physics, 2019) Izgi, M. S.; Baytar, O.; Sahin, O.; Horoz, S.
In this present study, the chemical reduction technique was used to synthesize Al2O3 supported Co-Cr-B catalyst (Co-Cr-B/Al2O3). The effects of the concentration of NaBH4, NaOH, amount of catalyst, ratio of metal/Al2O3 and temperature were discussed in detail. The results show that the reaction rate of hydrolysis first rises up and then goes down subsequently with the increase of NaBH4 concentration, as well as the concentration of NaOH. It was observed that the hydrogen generation rate increases with the molar content of metal changing from 2.5% to 5 wt%. However, when the metal/Al2O3 molar ratio is located from 5% to 20 wt%, the rate of hydrogen generation goes down. The hydrolysis kinetic order and the activation energy (E-a) of NaBH4 in the presence of Co-Cr-B/Al2O3 catalyst were found as 0.15 and 37.34 kJ*mol(-1), respectively. According to the results obtained, Co-Cr-B/Al2O3 catalyst can be used as a promising material in PEMFC mobile systems.
Synthesis and characterization of Fe:MgZnO/AC as a prospective high photocatalytic material
(Virtual Co Physics Srl, 2021) Cevik, M. S.; Horoz, S.; Baytar, O.; Sahin, O.; Ekinci, A.
The motivation of our current study is to carry out photocatalytic degradation experiments of methylene blue in the presence of Fe doped MgZnO/AC (Fe:MgZnO/AC) and MgZnO/AC catalysts and thus to examine the effect of the Fe-dopant metal on the photocatalytic activity of the catalysts. In this context, both catalysts (MgZnO/AC and Fe:MgZnO/AC) are synthesized by hydrothermal technique. Structural (XRD analysis) and optical (UV-Vis) properties of the synthesized catalysts are discussed. How the Fe-dopant metal affects the crystallite size and energy band gap of the MgZnO/AC catalyst is examined and the experimental data obtained are interpreted.
SYNTHESIS OF ACTIVATED CARBON IN THE PRESENCE OF HYDROCHAR FROM CHICKPEA STALK AND ITS CHARACTERIZATION
(Natl Inst R&D Materials Physics, 2021) Genli, N.; Sahin, O.; Baytar, O.; Horoz, S.
In this study, hydrochar was obtained from chickpea stalk by hydrothermal method. Then, activated carbon was synthesized by chemical activation method using ZnCl2 activator in the presence of this hydrochar. The effects of parameters such as impragnation rate (hydrochar/ZnCl2), impragnation rate, activation temperature and activation time on activated carbon synthesis were investigated. The iodine number of the obtained activated carbon was determined and its characterization was performed by SEM, BET, FTIR measurements. It was determined that the highest iodine number of synthesized activated carbon was 734 mg/g under conditions of impragnation time (24 hour), impragnation rate (1/2), activation temperature (400 degrees C), and activation time (45 minutes). The BET surface area of the activated carbon with the highest iodine number was determined as 572 m(2)/g. The methylene blue number of synthesized activated carbon and hydrochar were found as 105 mg/g and 45 mg/g, respectively.
SYNTHESIS OF AN EFFICIENT PHOTOCATALYST (ACTIVATED CARBON SUPPORTED ZnS) FOR METHYLENE BLUE DEGRADATION
(Virtual Co Physics Srl, 2020) Zorer, C.; Baytar, O.; Sahin, O.; Horoz, S.; Izgi, M. S.
In the present study, activated carbon (AC) supported ZnS catalysts at different concentrations of AC were synthesized using hydrothermal method. The MB photocatalytic degradation efficiency of AC supported ZnS catalysts at different concentrations of AC was examined in the presence of UV-C lamp. As a result of photocatalytic measurements, the catalyst having the best photocatalytic activation was determined. The effect of different parameters, such as the amount of catalyst and dye concentration, on the photocatalytic degradation of methylene blue was investigated in the presence of this catalyst.Moreover, The photocatalytic degradation kinetics of methylene blue in the presence of catalyst were investigated by first and second order kinetic model. In the last part of the study, structural, morphological and elemental properties of the catalyst having the best photocatalytic activity were examined by x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive x-ray (EDX)measurements, respectively.
SYNTHESIS OF CE-DOPED ZNS NANOPARTICLES BY CHEMICAL PRECIPITATION METHOD AND INVESTIGATION OF THEIR STRUCTURAL, OPTICAL AND PHOTOVOLTAIC PROPERTIES
(Inst Materials Physics, 2018) Gunbat, M.; Horoz, S.; Sahin, O.; Ekinci, A.
The synthesized Ce-doped ZnS nanoparticles by chemical precipitation method were dropped on TiO2 coated on FTO conductive glass substrates. The photovoltaic property of the obtained Ce-doped ZnS/TiO2/FTO structure was investigated by measuring current density (J) voltage (V) and incident photon to current efficiency (IPCE), respectively. Power conversion efficiency of nanoparticles was calculated using the recorded J-V curve. Thus, both IPCE and J-V measurements have been shown experimentally that Ce-doped ZnS nanoparticles can be used as promising sensitizers in photovoltaic applications. Morever, the structural, elemental and photovoltaic properties of Ce-doped nanoparticles were studied by x-ray diffraction (XRD), energy dispersive x-ray (EDX), optical absorption and photoluminescence (PL) measurements, respectively. The characterization results were discussed.
SYNTHESIS OF Mo-DOPED ZnS NANOPARTICLES AND INVESTIGATION OF THEIR STRUCTURAL, OPTICAL AND PHOTOVOLTAIC PROPERTIES
(Virtual Inst Physics, 2018) Gunbat, M.; Horoz, S.; Sahin, O.; Ekinci, A.
ZnS and molybdenum (Mo) doped ZnS nanoparticles were synthesized at room temperature by co-precipitation method without any capping agent. The crystal structures of the synthesized ZnS and Mo-doped ZnS nanoparticles were determined to be zinc blend by x-ray powder diffraction (XRD). The calculated average crystal sizes are 2.70 and 2.68 nm for ZnS and Mo-doped ZnS nanoparticles, respectively. As a result of optical absorption measurements, it was observed that Mo dopant affects the energy band gap value of ZnS nanoparticles. The band gap value for ZnS and Mo-doped ZnS nanoparticles was determined as 4.07 and 4.17 eV, respectively. EDX measurement indicated that elemental percentages of Zn, S and Mo in the Mo-doped ZnS nanoparticles are 48.91, 50.25 and 0.84, respectively. The photovoltaic properties of Mo-doped ZnS nanoparticles were investigated for the first time in this study. The photon-to-current conversion (IPCE) measurements were carried out for ZnS and Mo-doped ZnS nanoparticles to compare their IPCE (%) values. The obtained result provides a new way to improve performance of ZnS-based solar cell structure.
SYNTHESIS OF PbS AND Ni-DOPED PbS THIN FILMS BY CBD METHOD AND INVESTIGATION OF THEIR STRUCTURAL, OPTICAL AND PHOTOVOLTAIC PROPERTIES
(Natl Inst R&D Materials Physics, 2018) Horoz, S.; Ekinci, A.; Sahin, O.
In the first part of the present work, the structural, elemental and optical properties of PbS and PbS:Ni(3%) thin films synthesized by chemical bath deposition (CBD) technique on glass substrates at room temperature were analyzed by x-ray diffraction (XRD), energy dispersive x-ray (EDX) and absorption measurements, respectively. It was determined that the particle size of PbS:Ni(3%) thin film in the presence of Ni additive material is smaller than that of PbS although both thin films have the same structure (cubic phase). A similar result was achieved using the data obtained as a result of the optical measurements. Moreover, when the PbS thin film was doped with Ni, its energy band gap was observed to be wider. In the second part; the photovoltaic properties of FTO/Zn2SnO4/PbS and FTO/Zn2SnO4/PbS: Ni(3%) thin films were investigated by performing incident photon-tocurrent efficiency (IPCE) and current density (J)- voltage (V) measurements, respectively, using Zn2SnO4 coated on FTO conductive glasses instead of glass susbtrates. Based on the data obtained from both measurements, it was observed that the Ni dopant significantly enhance the performance of the PbS-based solar cell devices.

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