Yazar "Fellah, M. Ferdi" seçeneğine göre listele
Listeleniyor 1 - 15 / 15
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A DFT study of H2S adsorption and sensing on Ti, V, Cr and Sc doped graphene surfaces(Springer/Plenum Publishers, 2024) Tunali, omer Faruk; Yuksel, Numan; Gece, Gokhan; Fellah, M. FerdiFinding cost-effective and sustainable methods for the removal of hydrogen sulfide (H2S), a highly toxic gas released as a byproduct in many industrial activities, is crucial for environmental health. In this study, the adsorption and electronic sensor properties of Ti, V, Cr and Sc doped graphene nanosheets (GN) for H2S molecule have been investigated using Density Functional Theory (DFT) method. The WB97XD method with 6-31G(d,p)/LanL2DZ basis sets have been utilized in DFT calculations. The charge distribution indicates that the charge transfer occurred between metal doped graphenes and H2S. DFT calculations of H2S molecule adsorption on Ti, V, Cr and Sc doped graphenes demonstrate that the ability to adsorb H2S molecule. The obtained adsorption energy (triangle E) values vary in the range of -54.4 to -71.0 kJ/mol. Furthermore, the electrical conductivity of the Cr doped graphene nanosheet (Cr-GN) changed due to the change in the HOMO-LUMO gap (triangle E-g = 24.8 kJ/mol). This result indicates that the Cr-GN structure is a potential candidate as an electronic sensor for H2S molecule at room temperature. Through methods like DFT, which are cost-effective and highly compatible with experimental results, predicting suitable adsorbents, understanding their properties, and enhancing them are expected to make substantial contributions to the industrial-scale production of these materials in terms of cost and accuracy in the future.Öğe A DFT study of hydrogen adsorption on Pt modified carbon nanocone structures: Effects of modification and inclination of angles(Pergamon-Elsevier Science Ltd, 2023) Kose, Ahmet; Fellah, M. FerdiThe adsorption of hydrogen molecule on Pt modified carbon nanocone (CNC) structures was investigated by density functional method. Pt atom was modified by both doping and decorating on the structures with 180 & DEG;, 240 & DEG; and 300 & DEG; inclination angles of the CNC. The interactions of the hydrogen molecule on the ring and top sites of these modified structures were explored. Effect of doping and decorating of Pt atom on CNC structures has been also investigated. The adsorption enthalpy and Gibbs free energy values of the structure formed by doping the Pt atom at the ring are-118.4 and-85.3 kJ/mol, respectively. With the increase of the angle of inclination, the hydrogen interaction decreased at the ring and increased at the top. According to the results of this study, it is predicted that CNCs modified with Pt atom can be a promising hydrogen storage material under ambient conditions.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe Biosensor for the early diagnosis of lung cancer: A DFT study on the applicability of metal-doped graphene structures(Elsevier Science Sa, 2024) Korucu, Seyma; Kose, Ahmet; Fellah, M. FerdiThe usability of metal-doped graphene structures as biosensor was investigated to develop a preliminary diagnosis of lung cancer in this study. The adsorption and sensing properties of graphene structures formed by doping metal atoms (Pt, Pd, Ni, Ir and Cu) toward aniline, toluene, styrene and benzene gases were examined. Using the DFT/WB97XD method with 6-31 G (d, p)/LANL2DZ basis sets, significant charge transfer from the target gases to the metal-doped graphene structures were observed. After adsorption, the HOMO-LUMO gap values of graphene structures doped with Pt, Cu, and Ni atoms have decreased. All adsorption processes are spontaneous according to the adsorption Gibbs free energy. The findings indicate that copper-doped and platinum-doped graphene have strong potential as electronic and work function sensors for detecting aniline, toluene, styrene, and benzene, which are biomarkers for lung cancer.Öğe Computational insights from GCMC, MD and DFT simulations of propane separation in Mg-based MOFs: Binary selectivity toward methane, ethane, and nitrogen(Elsevier, 2026) Tunali, Omer Faruk; Kose, Ahmet; Yuksel, Numan; Ozbek, M. Olus; Fellah, M. FerdiThe separation of light hydrocarbons represents a critical challenge in both industrial and environmental contexts. The binary separation of propane from ethane, methane, and nitrogen was investigated, and selected MOF structures containing Mg atoms were evaluated using GCMC and MD simulations. For Mg-MOF-74, propane uptake was found to be in the range of 297.5-378.7 mg/g at pressures 0.1, 1 and 10 bar. Adsorption properties were specifically examined at 1 bar and 298 K, and isotherm fitting (Langmuir/Freundlich) confirmed the strong affinity of propane toward the MOF surface. Key transport and separation parameters, including diffusion selectivity, permeability, and membrane selectivity, were calculated, showing that propane exhibited significantly higher selectivity compared to other gases. DFT calculations revealed adsorption energies of -6.1 kJ. mol- 1 (without dispersion correction) and - 41.4 kJ.mol- 1 (including dispersion effects) for propane binding to the MOF framework. These findings highlight the promise of Mg-based MOFs for the selective adsorption of propane.Öğe Experimental and computational (DFT) study of a binary system of triethanolamine and ethanol at temperatures from 293.15 to 323.15 K under 101.3 kPa(Academic Press Ltd- Elsevier Science Ltd, 2025) Muzhaqi, Evis; Kavakli, Aycan Altun; Sara, Osman Nuri; Fellah, M. FerdiIn this study, the density and viscosity of binary mixtures of triethanolamine (TEA) and ethanol were measured over the entire composition range at temperatures of 293.15 and 323.15 K under a pressure of 101.3 kPa. Correlations were obtained expressing density and viscosity values as a function of temperature. Excess molar volume (VE) and viscosity deviation (Delta eta) were calculated from the measured values. These properties were further fitted to the Redlich-Kister polynomial equation. Thermodynamic parameters such as partial molar volumes, apparent molar volumes, coefficients of thermal expansion, and excess Gibbs free energy of activation for viscous flow were also determined. Moreover, activation enthalpy and entropy values for viscous flow were evaluated. The experimental results and the Density Functional Theory (DFT) calculations were used to discuss the molecular interactions for binary mixtures of TEA and ethanol. Negative values of VE and Delta eta were observed across all studied temperatures and compositions, indicating strong specific interactions between TEA and ethanol molecules. There is a distinct difference in the temperature dependence of VE and Delta eta. As the temperature increases, the VE values become increasingly negative, while the Delta eta values decrease. Both experimental results and Density Functional Theory (DFT) calculations confirm the presence of intermolecular hydrogen bonding in the binary mixtures. Furthermore, FTIR spectroscopy suggests the possible presence of intermolecular interactions between the components.Öğe Experimental and Computational Insights into the Thermophysical Properties of Glycerol and Triethanolamine Mixtures(Springer/Plenum Publishers, 2026) Muzhaqi, Evis; Altun Kavakli, Aycan; Sara, Osman Nuri; Fellah, M. FerdiThe density and viscosity of binary mixtures of triethanolamine (TEA) and glycerol were investigated over the full composition range at temperatures from 293.15 K to 323.15 K, under atmospheric pressure. The experimentally measured density and viscosity data were correlated with temperature-dependent equations. The excess molar volume (VE) and viscosity deviation (Delta eta) were determined and fitted using the Redlich-Kister polynomial equation. In addition, thermodynamic parameters, including partial molar volumes, apparent molar volumes, and thermal expansion coefficients, were evaluated to provide further insight into the mixing behavior of the system. Negative values of VE and Delta eta were observed over the entire range of temperatures and compositions investigated, indicating the presence of strong specific interactions between TEA and glycerol molecules. These interactions were further elucidated through Density Functional Theory (DFT) calculations. The computational results are consistent with the experimental observations, providing molecular-level support for the non-ideal volumetric and viscosity behavior of the mixtures.Öğe Hydrogen adsorption and sensing properties of p-tert-butylcalix[4]arene and its transition metal complexes: A DFT study(Pergamon-Elsevier Science Ltd, 2023) Yuksel, Numan; Fellah, M. FerdiThe safety storage of hydrogen molecule is an important issue for researchers. Today, hydrogen adsorption and detection is one of these issues. In this study, the interactions of calix[4]arene macrocycle and its metal complexes with hydrogen molecule were investi-gated by Density Functional Theory (DFT) method. WB97XD hybrid method was used in DFT calculations. The most stable complexes of calix[4]arenes with metal atoms were determined. All interactions were determined to be weak van der Waals interactions. It has been revealed that metal atoms in the complexes have positive effect on adsorption and the best adsorbent is the Fe-calix[4]arene complex. It has been determined that pristine calix[4]arene compound can be used as an electronic sensor against hydrogen molecule at room temperature.& COPY; 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe Hydrogen adsorption, desorption, sensor and storage properties of Cu doped / decorated boron nitride nanocone materials: A density functional theory and molecular dynamic study(Pergamon-Elsevier Science Ltd, 2024) Kose, Ahmet; Fellah, M. FerdiThe hydrogen storage and sensor properties of Cu-modified boron nitride nanocone (BNNC) structure were comprehensively investigated using the density functional theory method (DFT). By replacing nitrogen atoms with copper atoms on the BNNC structure, the hydrogen molecule's adsorption enthalpy and Gibbs free energy values were calculated as -48.6 and -16.9 kJ/mol, respectively. 4 Cu-doped BNNC structure achieved a notable hydrogen storage capacity of 5.38 wt%. The molecular dynamics calculations demonstrate that the structure modified with four Cu atoms maintains its dynamic stability. Furthermore, this study reveals that the desorption temperatures tend to rise with an increase in the number of adsorbed hydrogen molecules, and the average desorption temperature under 1 atm pressure is determined to be 332 K. The changes of work function values after hydrogen adsorption point out that the Cu-modified BNNC has Phi-sensor feature. Overall, Cu-modified BNNC structures show promising potential as hydrogen storage materials in ambient conditions.Öğe Hydrogen molecule adsorption and sensing on lanthanide (La) doped/decorated carbon nanotube and graphene structures(A V S Amer Inst Physics, 2023) Yuksel, Numan; Kose, Ahmet; Duzenli, Derya; Fellah, M. FerdiThe use of carbon nanotube (CNT) and graphene structures as doped and decorated with La atom as an adsorbent and a sensor material for hydrogen molecules was investigated by the density functional theory method. It is seen that the hydrogen interaction increased significantly after the La modification on the CNT and graphene. The fact that the adsorption enthalpy values are smaller than the liquefaction enthalpy value of hydrogen indicates that they can be used as adsorbent materials for hydrogen adsorption. While the adsorption energy values are better in the modification with La doping in the CNT structure, the results in the graphene structure are better in the decoration with the La atom. Charge transfer has occurred between the structures modified with La and the hydrogen molecule. After the hydrogen interaction, HOMO-LUMO gap values decreased in La-modified CNT structures and increased in graphene structures. This signifies that the La-modified CNT structures could be electronic sensors for hydrogen molecules. Consequently, the CNT and graphene structures doped and decorated with La can be used as adsorbents for hydrogen molecules. In addition, La-modified structures have electronic sensor properties.Öğe Hydrogen sensing and storage on the metal-complexes of calix[4]arene derivative: A combinatorial study on density functional theory, perturbation theory and molecular dynamics(Pergamon-Elsevier Science Ltd, 2025) Yuksel, Numan; Fellah, M. FerdiHydrogen is a type of fuel that has a high calorific value and does not pollute the environment. For this reason, interest in hydrogen is increasing today. However, the most important problem in the studies on hydrogen energy is the safe storage of hydrogen. Storing hydrogen as gas or liquid has very serious disadvantages. For this reason, storage of hydrogen by adsorption on a substance is seen as an important alternative research area. In recent years, there has been considerable interest in metallo-organic complexes in hydrogen adsorption and sensing studies. Research on metal complexes of macrocyclic organic compounds is increasing. In this study, a calix[4]arene derivative that can form complexes with metal atoms in different configurations and Cu, Fe, Ni, and Zn metals were used for complex formation. All theoretical calculations were carried out by DFT method. The wB97XD hybrid-method and 6-31G(d,p)/LANL2DZ basis sets were used in DFT calculations. The structure with the lowest adsorption energy values was determined as the C4-Curing complex structure and hydrogen storage studies were carried out. Gravimetric storage capacity was calculated as 4.7 %. Cu-benzene association in the interaction of C4-Cu complex against hydrogen molecule was elucidated by perturbation analysis. Moreover, a significant change in the HOMO-LUMO cavity occurred when the C-Cu complex interacted with the H2 molecule, showing electronic sensor properties. In the future, it is of great importance to form more calixarene derivatives and complexes with metal atoms and to reveal their hydrogen sensing and adsorption properties.Öğe Molecular Adsorption of Silane on Ge, Ga and Al-doped CNT Structures: A Density Functional Theory Study(Maik Nauka/Interperiodica/Springer, 2022) Baydir, Enver; Altun, Aycan; Fellah, M. FerdiThe adsorption of silane molecule on the pristine CNT structure and metal-doped (Ge, Ga and Al) CNT (4,0) structure were investigated by DFT (density functional theory). Adsorption enthalpy, energy, chemical potential, chemical hardness values and electronic properties of CNT structures were obtained and reported. All metal-doped CNT structures gave more negative adsorption energy values for silane adsorption compared to the pristine CNT structure. The adsorption enthalpy energy value for silane adsorption on Ga doped CNT was calculated as -31 kJ/mol. In other words, the Ga-doped CNT structure may be a suitable material for silane adsorption with high adsorption energy change as a negative value. It was also investigated whether metal-doped and pristine CNT structures act as sensors for silane. In this study, metal-doped CNT structures examined show high adsorption properties but not sensor properties.Öğe Neurotransmitter amino acid adsorption on metal doped boron nitride nanosheets as biosensor: DFT study on neural disease prediagnosis system(Elsevier Science Sa, 2024) Balkanli, Bugracan; Yuksel, Numan; Fellah, M. FerdiIn this study, pristine and iron (Fe), copper (Cu) and platinum (Pt) metal doped boron nitride nanosheet (BNNS) structures possibility of biosensor, adsorbent and neural disease prediagnosis system for gama amino butyric acid (GABA) and Glutamate (Glu) molecules were investigated by Density Functional Theory (DFT). Metal atoms were doped to replace both boron (B) and nitrogen (N) atoms of BNNS. All the adsorption energies on the structure were calculated as negative values for all structures after the GABA and Glu adsorption. The lowest adsorption energy and enthalpy values reached to - 42.1 kcal/mol and - 42.7 kcal/mol, respectively. According to Gibbs free energy (Delta G) values of adsorption, most of the adsorption reactions can occur spontaneously. The charge transfer during adsorption happened from GABA and Glu molecules to BNNS structures. Based on the results, Fedoped BNNS and Cu-doped BNNS could be utilized as electronic and work function type biosensors for GABA molecule and Glu molecule respectively. This study may lead to future biosensor studies, adsorption studies of neurotransmitter amino acids other than GABA and Glu, and BN nanostructure studies modified with different metal doping.Öğe Pt, Pd and Au decorated reduced graphene oxide: Sensing properties for phenol gas detection at room temperature(Elsevier Science Sa, 2024) Korucu, Seyma; Kose, Ahmet; Fellah, M. FerdiThe adsorbent and sensor properties of metal decorated (Pt, Au and Pd) reduced graphene oxide (rGO) structures for phenol gas were investigated using Density Functional Theory (DFT) method with WB97XD formalism. The NBO charge values suggest the occurrence of charge transfer from the phenol molecule to the rGO structures. After the adsorption of phenol, the HOMO-LUMO gap values of the Pt-decorated rGO structure were observed to decrease, while the work function values of the Pt-decorated rGO structure were found to increase. The recovery time for phenol molecule on the Pt-rGO structure was determined to be 0.0019 seconds. These results imply that the Pt-decorated rGO structure can function as a work function sensor in addition to an electronic sensor for phenol gas molecule.Öğe Sensing properties of propylene oxide on Pt and Pd doped graphene sheets: A DFT Investigation(Elsevier Science Sa, 2022) Yuksel, Numan; Kose, Ahmet; Fellah, M. FerdiThe adsorption and detection of propylene oxide (PO), which is a volatile organic compound produced on a large scale industrially and used in polymerization reactions, is an important issue. In this study, the adsorption of propylene oxide on the metal-doped graphene sheets were investigated by periodical Density Functional Theory calculations. The HSEH1PBE (HSE06) hybrid method was used for theoretical calculations. It has been deter-mined that Pt-doped and Pd-doped graphene structures give adsorption energy values of -78.6 and -75.4 kJ/ mol, respectively. The sensors have been evaluated in terms of work function (phi) showing that each can be described as an phi-type gas sensor. In addition, it has been revealed that periodical theoretical calculations utilized in this study give more accurate results than calculations made with the GGA-PBE method. As a result, it has been determined that Pt-doped and Pd-doped graphene sheets are effective for PO adsorption, Pt-doped graphene layer can be used as an electronic sensor for PO, whereas Pd-graphene layer cannot be used.Öğe The Adsorption and Sensing Characteristics of Metal-Calix[4]Arenes Toward Hydrogen Molecule: Density Functional Theory, Perturbation Theory and Molecular Dynamics Approaches(Wiley-V C H Verlag Gmbh, 2024) Yuksel, Numan; Fellah, M. FerdiCalixarenes, which can be functionalized in a wide range of derivatives, are one of the chemicals that should be considered for safe energy storage. This research focused on utilization Density Functional Theory (DFT) method to investigate the hydrogen sensing and adsorption characteristics of two distinct calix[4]arene compounds and their corresponding metal complexes. In the study, electronic sensor properties were investigated by using different approaches. In addition, the dynamic stability was determined by Molecular dynamics (MD) calculations. Perturbation theory analysis has revealed the importance of the relationship between Fe and S atoms. The adsorption energy on the C1 structure with the best adsorption ability was calculated as -10.3 kJ/mol. According to RDG analysis, weak van der Waals interactions play a role in adsorption. The C2-Fe complex with a substantial decrease in the HOMO-LUMO gap has been identified and explained as an applicant material for electronic sensor against hydrogen molecule. Moreover, it was also determined that the C2-Fe complex has work function type gas sensor property against hydrogen molecule. According to the results, metal-calixarene complexes can play an important role in hydrogen safety in the future.
