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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 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 Density functional theory study of ?-lactam anti-biotics (penicillin, floxacillin and ampicillin) detection and adsorption onto calix[4]arene(Gumushane University, 2025) Yuksel, NumanIn this work, the adsorption and sensing behavior of a calixarene macrocycle toward three ?-lactam anti-biotics was probed by density functional theory (DFT). All calculations were carried out with the B3LYP hybrid functional using the 6-31G(d,p) basis set. The simulations demonstrate that the calix[4]arene scaffold exhibits a pronounced sensing response exclusively for floxacillin: its sensor response factor is roughly six orders of magnitude greater than those obtained for ampicillin and penicillin. Additionally, analysis of frontier orbitals shows a 16.4% contraction of the HOMO–LUMO gap upon floxacillin binding, a perturbation that is visually evident in the density of states profile. Taken together, these findings establish calix[4]arene as a viable electronic sensor for floxacillin under ambient conditions. © 2025, Gumushane University. All rights reserved.Öğe Formaldehyde Adsorption and Sensing: A Density Functional Theory Study on Pd4 Nanocluster Decorated CNT Structure(Budapest Univ Technology Economics, 2023) Yuksel, Numan; Kose, Ahmet; Fellah, Mehmet FerdiThe sensing of formaldehyde, one of the volatile organic compounds used in chemical processes, is very important. In this study, the adsorption and sensing of formaldehyde molecule on Pd-4 nanocluster decorated carbon nanotube (Pd-4-CNT) was investigated by using DFT method. The WB97XD hybrid method was used in DFT calculations. The adsorption energy value was calculated as -8.1 kJ/mol. This low adsorption energy confirms the very short recovery time and the predominance of weak interactions. There was a decrease of approximately 20% in the HOMO-LUMO gap after the interaction. This result shows that the Pd-4-CNT can be used as a sensor at room temperature.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 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 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 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.
