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Öğe A Density Functional Theory study for adsorption and sensing of 5-Fluo-rouracil on Ni-doped boron nitride nanotube(Elsevier, 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this research, the use of Ni-doped (8,0) boron nitride nanotube (Ni-BNNT) as both a sensor and an adsorbent for 5-Fluorouracil (5-FU) molecule was investigated by Density Functional Theory (DFT) method. The B3LYP method with 6-31G(d,p) basis set have been utilized. Six different adsorption configurations have been studied theoretically. After 5-FU adsorption on Ni-BNNT, the adsorption energy values were calculated as negative values in all configurations. Adsorption energy (Delta E) value and adsorption enthalpy (Delta H) value reached 0.75 eV and -0.78 eV values, respectively. Moreover, Gibbs free energy changes were computed to be negative values in all configurations and thus it was determined that the process could occur spontaneously. Charge transfer occurred between all configurations of Ni-BNNT and the 5-FU molecule. The HOMO-LUMO gap decreased in the NiN-BNNT (Ni-doped instead of N) structure, while it increased in the Ni-B-BNNT (Ni-doped instead of B) structure. The Ni-BNNT structure assistances from a recovery time as a sensor for 5-FU drug molecule. Moreover, the workfunction change occurred somewhat in all configurations, but it was calculated that there was more change (16.22%) in the NiN-O1-BNNT configuration. In addition, solvent (water) effect was also examined. Consequently, Ni-doped (8,0) BNNT structure can be used as both a sensor and an adsorbent for 5-FU molecule at room temperature.Öğe A Density Functional Theory study of molecular hydrogen adsorption on Mg site in OFF type zeolite cluster(Pergamon-Elsevier Science Ltd, 2020) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this study, hydrogen molecule adsorption was investigated on additional framework of Mg atom in OFF type zeolite by way of DFT (Density Functional Theory). The adsorption enthalpy and adsorption energy, chemical potential, HOMO energy, electronegativity, LUMO energy, chemical hardness values have been computed on a 8T zeolite cluster model and compared with those of Mg exchanged ERI, LTL and DFT zeolite structures previously reported in literature. Hydrogen adsorption enthalpy value was computed as -17 kJ/mol. This value is meaningfully larger than the hydrogen molecule's liquefaction enthalpy value. This accordingly specifies that Mg-OFF zeolite structure appears to be an encouraging candidate cryoadsorbent for hydrogen storing. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe A Density Functional Theory Study on Rechargeable Mg-ion Batteries: C20 Fullerene as a Promising Anode Material(Wiley, 2022) Köse, Ahmet; Yüksel, Numan; Fellah, Mehmet FerdiIn this study, the applicability of C-20 fullerene as anode material in Mg-ion batteries was investigated by Density Functional Theory (DFT). The interaction energy of the Mg2+ ion on C-20 structure was found as -147.3 kcal/mol. The HOMO-LUMO gap value decreased during Mg interaction on C-20 structure while it increased during Mg2+ interaction. The charge distributions obtained after the interactions of Mg atoms on C-20 show that charge transfer has taken place. The storage capacity value of C-20 structure was calculated to be 893 mAhg(-1). The diffusion barrier was calculated as 1.9 kcal/mol. In addition, the diffusion coefficient for Mg and Mg2+ on C-20 structure were computed as 1.5x10(-25) and 4.61x10(-4), respectively. Consequently, the high storage capacity, high conductivity and low diffusion barrier for discharge/charge process and the suitability of the diffusion coefficient suggest that C-20 fullerene structure can be used as a potential anode material in rechargeable Mg-ion batteries.Öğe A DFT investigation of hydrogen adsorption and storage properties of Mg decorated IRMOF-16 structure(ELSEVIER, 2022) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiHerein, the hydrogen storage property of the Mg decorated isoreticular metal organic framework-16 (IRMOF-16) is investigated by Density Functional Theory (DFT) method. The WB97XD hybrid method (including dispersion) was used for hydrogen adsorption on Mg decorated IRMOF-16 structure. It was determined that the adsorption enthalpy for the structure was negative (-4.2 kJ/mol) at room temperature and thus it could be a potential adsorbent material for the hydrogen. The gravimetric hydrogen storage capacity of the IRMOF-16 structure decorated with four Mg atoms was determined as ~5.8 wt%. According to the electronic properties, it was revealed that the Mg-IRMOF-16 structure could not be used as an electronic sensor against the hydrogen molecule.Öğe Element modifiye edilmiş CNC, BNNC ve ALNC yapılarının hidrojen depolama ve sensör özelliklerinin yoğunluk fonksiyoneli teorisi (DFT) ile incelenmesi(Bursa Teknik Üniversitesi, 2023) Köse, Ahmet; Fellah, Mehmet FerdiHidrojen, çevre dostu ve yüksek verimli bir enerji kaynağı olarak önemli bir potansiyele sahiptir. Ayrıca, enerji taşıyıcısı olarak da kullanılabilir. Ancak, hidrojenin yaygın kullanımını sınırlayan ana engel, istenen verimde depolanamamasıdır. Güvenli ve etkili bir şekilde, hidrojenin gaz veya sıvı formunda depolanması zor bir süreçtir. Bu bağlamda, hidrojenin bir malzeme üzerine adsorplanarak depolanması, şu an için en etkili çözüm olarak kabul edilmektedir. Çeşitli malzemeler, hidrojen depolama amacıyla incelenmiş olsa da, hidrojenin ekonomik ve yeterli kapasitede depolanmasını sağlayacak bir çözüm henüz tam anlamıyla bulunamamıştır. Bu nedenle, hidrojen depolama malzemeleri araştırması üzerine devam eden çalışmalar büyük bir öneme sahiptir. Özellikle, nanotüplere benzer yapıdaki nanokoni yapılar, elektronik ve mekanik özellikleri sayesinde gaz adsorpsiyon çalışmalarında ön plana çıkmaktadır. Bu tez çalışması kapsamında, karbon nanokoni (CNC), bor nitrür nanokoni (BNNC) ve alüminyum nitrür nanokoni (AlNC) yapılarının farklı eğilim açılarında (180?, 240?, 300?), hidrojen depolama kapasiteleri ve sensör özellikleri yoğunluk fonksiyoneli teorisi (DFT) yöntemi ile incelenmiştir. Nanokonilerin hidrojen depolama kapasitelerini artırmak ve sensör özelliklerini iyileştirmek için alkali/toprak alkali (Li, K, Ca) ve geçiş (Ni, Cu, Pt) metal atomları ile yükleme ve dekorasyon yapılıp modifikasyonları gerçekleştirilmiştir. Tez çalışması kapsamında yapılan DFT hesaplamaları için WB97XD metodu kullanılmıştır. Optimizasyon sonucu elde edilen yapıların bağ uzunluklarının literatür ile uyumlu olduğu bulunmuş ve IR frekanslarında hayali frekansa (negatif) rastlanmamıştır. Saf CNC, BNNC ve AlNC yapılarının hidrojen adsorpsiyon özellikleri incelendiğinde, bu yapılar üzerinde hidrojenin adsorpsiyonunun ya hiç gerçekleşmediği ya da hidrojen etkileşiminin çok zayıf olduğu tespit edilmiştir. Alkali/Toprak alkali metal atomları ile yapılan modifikasyonlar, nanokoni yapıların hidrojen adsorpsiyonunu bir miktar artırmış olsa da, elde edilen enerji değerleri etkili adsorpsiyon ve desorpsiyon işlemleri için gerekli olan enerji aralığı (-19,3 ile -67,5 kJ/mol) dışındadır. Ancak, geçiş metal atomları ile yapılan modifikasyonlar, adsorpsiyon ve desorpsiyon işlemleri için gerekli olan enerji değerlerini büyük oranda sağlamıştır. Eğilim açısının değişimi ile yapılardaki hidrojen adsorpsiyonu arasında doğrusal bir ilişki bulunmamıştır. NBO atomik yük değerleri ve HOMO-LUMO görüntüleri incelendiğinde, genellikle hidrojen molekülünden nanokoni yapılara doğru bir yük transferi olduğu gözlemlenmiştir. Ayrıca, ESP görüntüleri kullanılarak nanokoni yapılarındaki hidrojen etkileşimleri de incelenmiştir. Pthy CNC180 ve CuNy BNNC180 yapıları üzerinde hidrojen etkileşimini gösteren RDG analizleri ve RDG izo yüzey grafikleri, bu iki yapıda hidrojen adsorpsiyonunun Van der Waals etkileşimi ile gerçekleştiğini göstermiştir. 4Pt-CNC180, 4Cu-BNNC180 ve 3Ni-BNNC300 yapıları için gravimetrik hidrojen depolama kapasiteleri sırasıyla %4,67, %5,38 ve %5,86 olarak hesaplanmıştır. İlk iki yapı, DOE'nin 2020 hedefini (%4,5) aşarken, 3Ni-BNNC300 yapısı DOE'nin 2025 hedefini (%5,5) aşmıştır. Pthy CNC180 ve CuNy BNNC180 yapılarının, 1 atm basınç altında ortalama desorpsiyon sıcaklıkları sırasıyla 222 K ve 332 K olarak belirlenmiştir. Bu sonuçlar göz önüne alındığında, geçiş metali ile modifiye edilmiş nanokoni yapılarının umut verici bir hidrojen depolama malzemesi olabileceği sonucuna varılmıştır. Hidrojen moleküllerinin adsorpsiyonları sonucunda, bazı nanokoni yapıların %Eg ve %? değerlerinde önemli düşüşler tespit edilmiştir. Bu değişikliklerin en yükseği, CuBy BNNC180 yapısının ? değerinde (-%22,1) ve CaNhy AlNC300 yapısının Eg değerinde (-%29,7) gerçekleşmiştir. Bu sonuçlar, alkali/toprak alkali ve geçiş metal atomları ile modifiye edilen nanokoni yapılarının, hidrojen ile etkileşerek elektronik ve ? sensör özellikleri sergileyebileceklerini göstermiştir.Öğe Hydrogen adsorption on Ni doped carbon nanocone(ELSEVIER SCIENCE SA, 2022) Köse, Ahmet; Yüksel, Numan; Fellah, Mehmet FerdiHydrogen adsorption was investigated on Ni doped carbon nanocone (Ni-CNC) 180 degrees C by Density Functional Theory (DFT). The WB97XD method was used with the 6-31G(d,p) and LanL2DZ basis sets. The electronegativity, HOMO and LUMO energies, chemical hardness, chemical potential, adsorption enthalpy and adsorption energy values have been calculated for hydrogen adsorption on Ni-CNC structure. The adsorption enthalpy value of hydrogen molecule was calculated as-27.8 kJ/mol. According to the storage capacity study for the Ni-CNC structure, it was found that this structure adsorbed eight hydrogen molecules and the hydrogen storage capacity was calculated to be similar to 4.3 wt%. After hydrogen adsorption, there was no significant decrease in HOMO-LUMO gap value. In addition, this situation indicates that the electrical conductivity of the Ni-CNC structure does not increase. These results show that the Ni-CNC structure cannot be used as a sensor for the hydrogen molecule, but it is a promising candidate material for hydrogen storage at room temperature.Öğe Metal-Porphyrin Complexes: A DFT Study of Hydrogen Adsorption and Storage(Koray SAYIN, 2022) Köse, Ahmet; Yüksel, Numan; Fellah, Mehmet FerdiIt has been performed hydrogen adsorption on four metallo-porphyrin complexes by Density Functional Theory (DFT) calculations at room temperature. The WB97XD hybrid formalism method was used for hydrogen adsorption on metallo-porphyrin complexes formed with alkaline metal and alkaline earth metal (Na, K, Mg and Ca) atoms. It was determined that the adsorption energies for all complexes were negative, so that each of them could be a potential adsorbent for hydrogen storage. The adsorption enthalpy (?H) was calculated as -21.9 kJ/mol for the Na-Porphyrin (Na-P) complex structure. Moreover, the gravimetric hydrogen storage capacity for the Na-P complex was calculated to be ?5.5 wt%. Thus, the DOE's target for 2025 has been achieved. In addition, van der Waals weak interactions were found to be effective in hydrogen adsorption and storage studies. Based on the electronic properties the metallo-porphyrin complexes could not be used as electronic sensors against the hydrogen molecule.Öğe Methyl-mercaptane adsorption and sensing on Fe-/Co-graphene structures: A DFT study(DergiPark, 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this research, the adsorption and detection abilities of Fe and Co doped graphene structures for methyl-mercaptan molecule were investigated by Density Functional Theory (DFT) method. B3LYP hybrid functional and LANL2DZ/6-31G(d, p) basis sets were used in the calculations. At the end of the adsorption processes, Fe and Co doped graphene structures were determined to be suitable adsorbents for the methyl-mercaptan molecule. In addition, charge transfer happened from the methyl-mercaptan molecule to the Fe and Co-doped graphene structures. The electronic sensor and the Φ-type sensor properties were also investigated and it was determined that Fe-graphene structure could be only used as an electronic sensor for methyl-mercaptan molecule at room temperature.Öğe Pd, Ag and Rh doped (8,0) single-walled carbon nanotubes (SWCNTs): A DFT study on furan adsorption and detection(Elsevier, 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this study, the use of single-walled carbon nanotubes (SWCNTs) with doping Pd, Ag and Rh as both a sensor and an adsorbent for furan molecule was investigated by Density Functional Theory (DFT) method. The WB97XD method with 6-31G(d,p)/LanL2DZ basis sets have been utilized in theoretical calculations. The charge distribution indicates that the charge transfer happened (as an electron accepting system) from the adsorbed furan molecule to the Pd, Ag and Rh atoms of SWCNT structures. The HOMO-LUMO gaps of the Pd, Ag and Rh doped carbon nanotubes decreased slightly with adsorption of furan molecule. The electrical conductivities of Pd, Ag and Rh doped (8,0) SWCNT clusters increased somewhat after a furan molecule adsorption. Furthermore, adsorption enthalpies (-49.6 kJ/mol, -62.9 kJ/mol and -64.3 kJ/mol, respectively) of furan molecule adsorption on Pd, Ag and Rh doped (8,0) SWCNTs show that these materials have the ability to adsorb furan molecule. Consequently, Pd, Ag and Rh-doped SWCNTs might be used as both sensors and adsorbents for furan molecule at room temperature.Öğe The supramolecularly complexes of calix[4]arene derivatives toward favipiravir antiviral drug (used to treatment of COVID-19): a DFT study on the geometry optimization, electronic structure and infrared spectroscopy of adsorption and sensing(Springer Science and Business Media B.V., 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiWhile the world is in search of a vaccine that can cure COVID-19 disease, favipiravir is the most commonly used antiviral drug in the treatment of patients during the pandemic process. In this study, we investigated the host–guest interaction between the popular supramolecule calix[4]arene derivatives and the favipiravir drug by using the DFT (Density Functional Theory) method. The B3LYP hybrid method and 6-31G (d,p) basis set were utilized to determine the optimized structures of the host and guest molecules and their complexes. The negative adsorption energy (∆E) and adsorption enthalpy (∆H) calculated for the complexes formed between calix[4]arene compounds and favipiravir drug molecule mentioned that adsorption of favipiravir molecule was an exothermic process on calix[4]arene structures. On the other hand, among the calixarene derivatives in the study, Gibbs free energy change (∆G) value for the adsorption was only negative on calix[4]arene4 molecule. The infrared spectroscopy (IR) calculations were performed by examining the C=O, O–H and NH2 vibrational frequencies to see the adsorption behavior in the favipiravir-calix[4]arene complex. After adsorption of the favipiravir molecule, HOMO–LUMO gap values decreased significantly for the structures and therefore electrical conductivity increased proportionally. In addition, sensor response factors, Fermi energy levels and workfunction changes of calix[4]arene derivatives were calculated and examined. Charge transfer between the four calix[4]arene compounds and the favipiravir molecule has occurred after adsorption. This attributes that calix[4]arene derivatives can be used as a well-suited favipiravir sensor (electronic and workfunction) and adsorbent at room temperature. Based on the calculations made to see the solvent effect on the adsorption of favipiravir it was determined that it did not affect the interaction between the drug molecule and the calix[4]arene compound too much and the adsorption energy turned into a slightly less negative value.
