Browsing by Author "Ece, Mehmet Şakir"

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Comparative and competitive adsorption of gaseous toluene, ethylbenzene, and xylene onto natural cellulose-modified Fe3O4 nanoparticles
(ScienceDirect, 2022) Ece, Mehmet Şakir; Kutluay, Sinan
Many industrial processes produce volatile organic compound (VOC) pollutants within multicomponent systems. Therefore, exploring the comparative and competitive adsorption of VOCs is of both practical and scientific interest. This study elucidates the adsorption behavior of gaseous toluene, ethylbenzene, and xylene (TEX) targeted as VOCs onto natural cellulose-modified Fe3O4 (NC-Fe3O4) nanoparticles (NPs) both individually and in multicomponent systems for the first time in the literature. The characterization of NC-Fe3O4 synthesized via co precipitation method was carried out with analysis techniques including BET, SEM, EDS, FTIR, and TGA-DTA. The adsorption capacities of TEX as a single-component onto NC-Fe3O4 (for 20 mg L-1 TEX inlet concentration) were found as 477, 550, and 578 mg g(-1), respectively. In contrast, with TEX in a binary-component system, the adsorption capacity of the T (for 20 mg L-1 T with 10 mg L-1 E and 10 mg L-1 X, respectively) decreased by approximately 43% and 50% for the binary-mixtures of T-E and T-X, respectively, due to competition with E and X for adsorption sites. Similarly, the adsorption capacity of the E (for 20 mg L-1 E with 10 mg L-1 X) decreased by approximately 46% due to competition with the X for adsorption sites. With TEX in a ternary-component system, the adsorption capacity of the X remained consistent, indicating its competitive dominance over the E and T. The adsorption capacity of NC-Fe3O4 followed the order of X > E > T in the ternary-component system, which agrees with the adsorption results for the single-component system. The adsorption mechanism of TEX was explained by fitting the adsorption data to diverse kinetic and isotherm models. The NC-Fe3O4 with a superior performance in terms of both reuse efficiency and adsorption capacity, could be used as a promising and renewable adsorbent for efficient treatment of VOC pollutants. The findings of the current study will contribute to a better understanding of the comparative and competitive adsorption behaviors among different VOC pollutants in relation to a given adsorbent.
Competitive adsorption of VOCs (benzene, xylene and ethylbenzene) with Fe3O4@SiO2-NH@BENZOPHENONE magnetic nanoadsorbents
(Elsevier, 2023) Güngör, Çetin; Ece, Mehmet Şakir
Volatile organic compounds (VOCs), which are toxic, mutagenic and carcinogenic, are considered a critical factor for air pollution and cause serious harm to the eco-environment and human health. In this study, Fe3O4, Fe3O4@SiO2-NH2, Fe3O4@SiO2-NH@BENZOFENONE were synthesized as new magnetic nanoadsorbents (MNAs) and used for the first time in the removal of gas-phase benzene, xylene and ethylbenzene. The synthesised MNAs were characterized by SEM-EDS, TEM, FTIR, XRD, VSM, TGA and BET analyses. The characterization results showed that the MNAs have mesoporous structure, type IV physioresorption and type H3 hysteresis loop character. In order to clarify the comparative and competitive adsorption behaviour, the adsorption capacity of Fe3O4@SiO2-NH@BENZOFENONE MNA was found to be in the order of xylene > ethylbenzene > benzene in both single, binary and ternary component systems. The adsorption kinetics of benzene, xylene and ethylbenzene with Fe3O4@SiO2-NH@BENZOFENONE MNA were found to be governed by multistep mechanisms. Fe3O4@SiO2-NH@BENZOFENONE MNA showed reuse efficiencies of 83.07%, 84.35% and 82.99% after 5 cycles for benzene, xylene and ethylbenzene respectively. In the framework of the results, Fe3O4@SiO2-NH@BENZOPHENONE MNA, which has a high potential in terms of both adsorption capacity and reuse efficiency, is proposed as a promising adsorbent for the efficient removal of benzene, xylene and ethylbenzene. © 2023 Elsevier B.V.
Development of Novel Fe3O4/AC@SiO2@1,4-DAAQ Magnetic Nanoparticles with Outstanding VOC Removal Capacity: Characterization, Optimization, Reusability, Kinetics, and Equilibrium Studies
(Industrial and Engineering Chemistry Research, 2021) Ece, Mehmet Şakir; Kutluay, Sinan; Şahin, Ömer; Horoz, Sabit
The adsorption of pollutants to the surface of adsorbents plays a critical role in the effectiveness of adsorption technology for air purification applications. Herein, novel magnetic nanoparticles functionalized with 1,4-diaminoanthraquinone (1,4-DAAQ), namely, Fe3O4/activated carbon (AC)@SiO2@1,4-DAAQ, were innovatively synthesized via co-precipitation and sol-gel techniques. After that, these nanoparticles were used for high-efficiency removal of volatile organic compounds (VOCs) (i.e., benzene and toluene). The synthesized nanoparticles were characterized by various techniques such as Fourier transform IR spectroscopy, thermogravimetric analysis/differential thermal analysis, scanning electron microscopy, and Brunauer-Emmett-Teller analysis. The dynamic adsorption process of VOCs was optimized based on operating parameters. The adsorption experiments revealed that Fe3O4/AC@SiO2@1,4-DAAQ showed exceptional performance for the removal of VOCs. It was observed that for benzene, Fe3O4, AC, Fe3O4/AC, Fe3O4/AC@SiO2, and Fe3O4/AC@SiO2@1,4-DAAQ exhibited dynamic adsorption capacities of 180.25, 228.87, 295.84, 382.10, and 1232.77 mg/g, respectively. Additionally, for toluene, they exhibited dynamic adsorption capacities of 191.08, 274.53, 310.26, 421.30, and 1352.16 mg/g, respectively. This indicated that the modification of 1,4-DAAQ could greatly enhance the dynamic adsorption capacity of Fe3O4/AC@SiO2@1,4-DAAQ for VOCs. In addition to the apparent adsorptive behavior in removing VOCs, Fe3O4/AC@SiO2@1,4-DAAQ exhibited high repeatability. After ten consecutive adsorption/desorption cycles, for benzene and toluene, Fe3O4/AC@SiO2@1,4-DAAQ retained 79.36 and 78.24% of its initial adsorption capacity, respectively. According to the characterization results, the average pore diameter for Fe3O4/AC@SiO2@1,4-DAAQ was determined to be 24.46 nm, indicating that they were in the mesopore range. The adsorption mechanism of the VOCs on Fe3O4/AC@SiO2@1,4-DAAQ was clarified by investigating the isotherm and kinetic criteria in detail. Isotherm models suggested that the adsorption process of VOCs is physical. Moreover, from the analysis of diffusion-based rate-limiting kinetic models, the findings reveal a combination of intraparticle diffusion as well as film diffusion throughout the adsorption process of VOCs. In addition, it was concluded from the analysis of the mass transfer model factors that global mass transfer and internal diffusion are more effective than film diffusion. The results demonstrated that the Fe3O4/AC@SiO2@1,4-DAAQ nanoadsorbent is a promising material for the effective removal of VOCs.
Fabrication and characterization of 3,4-diaminobenzophenone-functionalized magnetic nanoadsorbent with enhanced VOC adsorption and desorption capacity
(Environmental Science and Pollution Research, 2021) Ece, Mehmet Şakir; Şahin, Ömer; Kutluay, Sinan; Horoz, Sabit
The present study, for the first time, utilized 3,4-diaminobenzophenone (DABP)-functionalized Fe3O4/AC@SiO2 (Fe3O4/AC@SiO2@DABP) magnetic nanoparticles (MNPs) synthesized as a nanoadsorbent for enhancing adsorption and desorption capacity of gaseous benzene and toluene as volatile organic compounds (VOCs). The Fe3O4/AC@SiO2@DABP MNPs used in adsorption and desorption of benzene and toluene were synthesized by the co-precipitation and sol-gel methods. The synthesized MNPs were characterized by SEM, FTIR, TGA/DTA, and BET surface area analysis. Moreover, the optimization of the process parameters, namely contact time, initial VOC concentration, and temperature, was performed by applying response surface methodology (RSM). Adsorption results demonstrated that the Fe3O4/AC@SiO2@DABP MNPs had excellent adsorption capacity. The maximum adsorption capacities for benzene and toluene were found as 530.99 and 666.00 mg/g, respectively, under optimum process parameters (contact time 55.47 min, initial benzene concentration 17.57 ppm, and temperature 29.09 °C; and contact time 57.54 min, initial toluene concentration 17.83 ppm, and temperature 27.93 °C for benzene and toluene, respectively). In addition to the distinctive adsorptive behavior, the Fe3O4/AC@SiO2@DABP MNPs exhibited a high reproducibility adsorption and desorption capacity. After the fifth adsorption and desorption cycles, the Fe3O4/AC@SiO2@DABP MNPs retained 94.4% and 95.4% of its initial adsorption capacity for benzene and toluene, respectively. Kinetic and isotherm findings suggested that the adsorption mechanisms of benzene and toluene on the Fe3O4/AC@SiO2@DABP MNPs were physical processes. The results indicated that the successfully synthesized Fe3O4/AC@SiO2@DABP MNPs can be applied as an attractive, highly effective, reusable, and cost-effective adsorbent for the adsorption of VOC pollutants. Graphical abstract[Figure not available: see fulltext.]
Fabrication and characterization of Fe3O4/perlite, Fe3O4/perlite@SiO2, and Fe3O4/perlite@SiO2@sulfanilamide magnetic nanomaterials
(SpringerLink, 2022) Kutluay, Sinan; Şahin, Ömer; Ece, Mehmet Şakir
Abstract In this study, the fabrication of perlite-supported Fe3O4 (Fe3O4/perlite), SiO2-coated Fe3O4/perlite (Fe3O4/perlite@SiO2), and sulfanilamide-modified Fe3O4/perlite@SiO2 (Fe3O4/perlite@SiO2@sulfanilamide) magnetic nanomaterials and their characterization by various spectroscopic techniques were presented. For this purpose, first, Fe3O4/perlite was fabricated via the co-precipitation method. Then, Fe3O4/perlite@SiO2 and Fe3O4/perlite@SiO2@sulfanilamide nanomaterials were fabricated using the sol–gel method. The structural properties of the fabricated nanomaterials were characterized using Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), SEM-energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis-differential thermal analysis, and X-ray diffraction (XRD) analyses. The SEM, SEM–EDX, FTIR, and XRD analyses revealed that the fabrication and surface coatings of the Fe3O4/perlite, Fe3O4/perlite@SiO2, and Fe3O4/perlite@SiO2@sulfanilamide were successfully performed. It was concluded that the Fe3O4/perlite, Fe3O4/perlite@SiO2, and Fe3O4/perlite@SiO2@sulfanilamide showed a type IV-H3 hysteresis loop according to the International Union of Pure and Applied Chemistry classification. According to the BET analysis, it was found that the specific surface areas of the Fe3O4/perlite, Fe3O4/perlite@SiO2, and Fe3O4/perlite@SiO2@sulfanilamide were 8.09, 12.71, and 5.89 m2/g, respectively. The average pore radius of the Fe3O4/perlite, Fe3O4/perlite@SiO2, and Fe3O4/perlite@SiO2@sulfanilamide were 9.68, 7.91, and 34.69 nm, respectively, using the Barrett-Joyner-Halenda method. Moreover, the half-pore widths of the Fe3O4/perlite, Fe3O4/perlite@SiO2, and Fe3O4/perlite@SiO2@sulfanilamide were 2.27, 1.58, and 17.99 nm, respectively, using the density functional theory method. Furthermore, in light of characterization findings, the Fe3O4/perlite, Fe3O4/perlite@SiO2, and Fe3O4/perlite@SiO2@sulfanilamide were in crystalline cubic spinel form, and they had mechanical and thermal stability and a mesoporous structure. Within the framework of the results, these developed nanomaterials, which have potential in many applications, such as sustainable technologies and environmental safety technologies, were brought to the attention of related fields.
Facile synthesis and comprehensive characterization of Ni-decorated amine groups-immobilized Fe3O4@SiO2 magnetic nanoparticles having enhanced solar cell efficiency
(Journal of Materials Science: Materials in Electronics, 2021) Ece, Mehmet Şakir; Ekinci, Arzu; Kutluay, Sinan; Şahin, Ömer; Horoz, Sabit
In this study, the synthesis and comprehensive characterization of Fe3O4@SiO2 magnetic nanoparticles (MNPs) immobilized with L-Arginine decorated with nickel (Ni) was achieved, and their ability in solar cell efficiency was evaluated. Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@L-Arginine and Fe3O4@SiO2@L-Arginine-Ni MNPs were prepared by co-precipitation and sol-gel methods. The structural, morphological, optical and textural properties of the prepared MNPs were clarified by Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-Ray (EDX), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET), Thermal Gravimetric Analysis (TGA) and Ultraviolet-Visible (UV-Vis) analyzes. From the BET data, it is understood that the specific surface area of the prepared Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@L–Arginine MNPs is 60.85, 28.99 and 29.84 m2/g, respectively. From the pore size distribution determined by Barrett-Joyner-Halenda (BJH) method, it was understood that the pore radius of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@L–Arginine MNPs were in the range of mesopore and the average pore radius was equal to approximately 11.03, 9.11 and 28.45 nm, respectively. It is assumed that the half pore widths calculated by the density functional theory (DFT) method of the prepared of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@L-Arginine MNPs are 5.58, ∼ 0.88, and ∼ 17.98 nm, respectively. The energy band gap of the prepared MNPs with spinel structure was determined as approximately 3.10 eV. In addition to the structural, morphological, optical and textural properties, the photovoltaic properties of the prepared MNPs were examined. Au/CuO/Fe3O4@SiO2@L–Arginine-Ni/ZnO/SnO2:F solar cell device was created by using existing Fe3O4@SiO2@L–Arginine-Ni MNPs as buffer layer. The power conversion efficiency (%) of the prepared Fe3O4@SiO2@L–Arginine-Ni MNPs based solar cell device was calculated as 1.84 %. This numerical result shows that the prepared Fe3O4@SiO2@L-Arginine-Ni MNPs can be used as a promising buffer layer in a solar structure.
Fe3O4/AC@SiO2@EDTA Manyetik Nano-Adsorbentin Sentezlenmesi ve Toluenin Gaz Adsorpsiyonunda Kullanılması
(Bitlis Eren Üniversitesi Fen Bilimleri Dergisi, 2020) Ece, Mehmet Şakir
Bu çevreci çalışma, daha derin bir bakış açısı kazandırmakla mevcut çesitli toluen adsorbsiyonu teknolojijisine katkı sunmaktadır. Bu çalışmada, hayati risk oluşturan toluenin adsorpsiyonu için nano-teknolojiden faydalanmıştır. Etilendiamin tetraasetik asit (EDTA) daha önce direkt Fe3O4’e bağlanmış olsa da bu çalışma da Fe3O4, önce aktif karbonla, sonra SiO2 ile daha sonra da EDTA ile kaplanmış, böylelikle toluen adorbsiyonu için sentezi çok basit ve adsorbsiyon kapasitesi pekiyi, literatürde rastlanmayan nano manyetik adsorbent sentezlenmiş, sentezlenen bu nano manyetik adsorbent toluen adsorbsiyonunda başarılı ve verimli bir şekilde uygulanmıştır. Toluenin gaz adsorpsiyonunda kullanılan manyetik nano-adsorbent, birlikte çökeltme ve sol-gel yöntemiyle sentezlendi. Sentezlenen manyetik nano-adsorbentin karakterizasyonu ise FTIR ve TGA/DTA analizleri ile gerçekleştirilmiştir. Adsorpsiyon işleminde önemli bir rol oynayan adsorpsiyon süresi, girişteki toluen konsantrasyonu ve adsorpsiyon sıcaklığı gibi adsorpsiyon koşulları, Merkezi Kompozit Tasarım (MKT) yaklaşımı temelli Yanıt Yüzey Yöntemi (YYY) kullanılarak optimize edilmiştir. Deneysel tasarımda, MKT ve YYY, adsorpsiyon koşulları ile adsorpsiyon kapasitesi arasındaki ilişkiyi daha iyi anlamak için bir yaklaşım geliştirmek üzere başarıyla uygulanmıştır. MKT ve YYY kullanılarak bulunan 53.36 dk adsorpsiyon süresi, 18.02 ppm başlangıç konsantrasyonu ve 26.21°C adsorpsiyon sıcaklığı gibi optimum adsorpsiyon koşulları altında, toluen için maksimum adsorpsiyon kapasitesi 484.16 mg/g olarak belirlenmiştir. Sonuçlar, manyetik Fe3O4/AC@SiO2@EDTA nanopartiküllerinin, toluenin gaz adsorpsiyonunda uygulanabileceğini göstermiştir.
Fe3O4@SiO2-NH@benzofenon manyetik nanoadsorbent ile uçucu organik bileşiklerin yarışmalı adsorpsiyonu
(Mardin Artuklu Üniversitesi, 2022) Güngör, Çetin; Ece, Mehmet Şakir
Uçucu organik bileşiklerin salınımı, insanların hayati endişelerinden biri haline gelmiştir. Çoğu toksik, mutajenik ve kanserojen olan benzen, ksilen ve etilbenzen, hava kirliliği için kritik bir faktör olarak kabul edilmekte ve eko-çevre ve insan sağlığına ciddi zararlar vermektedir. Uçucu organik bileşiklerin giderilmesinde kullanılan adsorpsiyon teknolojisi, maliyet etkinliği, basitlik ve düşük enerji tüketimi özellikleri sayesinde uçucu organik bileşiklerin giderilmesi için en umut verici strateji olarak kabul edilmektedir. Nanoteknolojik yöntemlerle olağanüstü fiziksel ve kimyasal özelliklere sahip yeni nesil adsorbentler (nanoadsorbentler) geliştirilmektedir. Nanoadsorbentler içerisinde manyetik nanoadsorbentler çeşitli potansiyel uygulamalar için uygun özellikleri nedeniyle son zamanlarda yoğun olarak araştırılmaktadır. Bu çalışmada yeni nesil nanoadsorbentler olarak sırasıyla Fe3O4, Fe3O4@SiO2-NH2, Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentler üretilip benzen, ksilen ve etilbenzen gideriminde kullanıldı. Üretilen manyetik nanoadsorbentler, SEM-EDS, TEM, FTIR, XRD, VSM, TGA ve BET analizleriyle karekterize edildi. Fe3O4, Fe3O4@SiO2-NH2, Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentler, sırasıyla benzen, ksilen ve etilbenzen gideriminde adsorpsiyon kapasiteleri karşılaştırıldı. Adsorpsiyon kapasiteleri karşılaştırılmasında daha fazla verim elde edilen Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentler, gaz-fazı benzen, ksilen ve etilbenzenin tekli, ikili ve çoklu bileşenli adsorpsiyonunda, gaz-fazı benzen, ksilen ve etilbenzenin adsorpsiyon kinetiğinde, gaz-fazı benzen, ksilen ve etilbenzenin adsorpsiyon izotermlerinde, gaz-fazı benzen, ksilen ve etilbenzenin adsorpsiyon/desorpsiyon döngülerinde ve yeniden kullanım verimliliğinde kullanıldı. Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentler ile literatürde bildirilen diğer adsorbentler arasında adsorpsiyon kapasitelerinin karşılaştırıldı. Fe3O4, Fe3O4@SiO2-NH2, Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentlerin mezo gözenek apısına sahip olduğu, Tip IV fiziyorpsiyon ve Tip H3 histerezis döngü karekterde olduğu anlaşıldı. Karşılaştırmalı ve rekabetçi adsorpsiyon davranışının iyi anlaşılması için yapılan uygulamalarda, Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentlerin adsorpsiyon kapasitesi, hem tekli, hem ikili ve hem üçlü bileşenli sistemlerde ksilen > etilbenzen > benzen sırası şeklinde bulundu. Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentleri ile gaz-fazı benzen, ksilen ve etilbenzenin adsorpsiyon kinetiğinin çok basamaklı mekanizmalar tarafından yönetildiği anlaşıldı. Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentleri ile gaz-fazı benzen, ksilen ve etilbenzen adsorbatları arasında yeniden kullanım verimliliği yüksek kapasitede çıktı. Yapılan çalışma, Fe3O4@SiO2-NH@BENZOFENON manyetik nanoadsorbentlerin adsorpsiyon davranışının, zararlı kirleticilerin giderimleri için umut verici olduğunu gösterdi.
Güneş Pili Malzemesi Olarak Fe3O4@SiO2@3,4-DABF Sentezi,Karakterizasyonu ve Performansının Belirlenmesi
(2024) Koçhan, Ali; Ece, Mehmet Şakir
Bu tez çalışmasında, Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörler sentezlenip karakterize edilip güneş hücresi cihazlarının karmaşık yapısındaki sensör olarak kullanımını test edildi. Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörlerin yapısını karekterize etmek için FTIR analizi, SEM-EDS analizi, TEM analizi, VSM analizi, XRD analizi, TGA analizi ve BET analizi kullanıldı. Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörler ile güneş hücresi cihazlarının karmaşık yapısındaki sensör olarak kullanımını testi gerçekleştirildi. Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörler ≈ 10 nm çapa sahip olduğu, doyma manyetizasyon değerlerinin sırasıyla 61,64 emu/g, 37,31 emu/g ve 20,13 emu/g olduğu bulundu. Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörlerin sıcaklığın bir fonksiyonu olarak meydana gelen kütle değişimi ve kütle kaybının sırasıyla % 6.5, % 12 ve % 28.1 olduğu, kristal özelliklerinin yüzey merkezli kübik spinel yapı olduğu anlaşıldı. Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörlerin IUPAC sınıflamasına göre tip IV histerezis H3 döngüler sunduğu, mezogözenekli yapıya sahip olduğu tespit edildi. Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörlerin, güneş hücrelerinde elde edilen verimlerin sırasıyla %1.49, %1.77 ve verim %2.15 olduğu, Fe3O4@SiO2@3,4-DABF'nin en yüksek verim değerine sahip olduğu analaşılmıştır. Elde edilen bulgular, Fe3O4, Fe3O4@SiO2 ve Fe3O4@SiO2@3,4-DABF manyetik nano katalizörlerin güneş hücresi teknolojisinde umut verici bir duyarlılaştırıcı olarak kullanılabileceğini gösterdi. Ayrıca bu çalışmada, ucuz, kolay ve çevre dostu olarak hazırlanan Fe3O4@SiO2@3,4-DABF manyetik nano katalizörlerin güneş pili teknolojisinin kullanımındaki etkinliği ilk kez ortaya konuldu.
Hydrogen production by using Ru nanoparticle decorated with Fe3O4@SiO2–NH2 core-shell microspheres
(International Journal of Hydrogen Energy, 2020) Ece, Mehmet Şakir; İzgi, Mehmet Sait; Kazıcı, Hilal Çelik; Şahin, Ömer; Onat, Erhan
Noble metals are commonly used in order to accelerate the NH3BH3 hydrolysis for H2 production as heterogeneous catalysts. The nanoparticles (NPs) of these metals can be applied as active catalysts in fluid reactions. Metal NPs included in the core-shell nanostructures emerged as well-defined heterogeneous catalysts. Additionally, unsupported NPs catalysts can be gathered easily among neighboring NPs and the separation/recovery of these catalysts are not efficient with traditional methods. For this reason, here, silica-shell configuration was designed which was functionalized with a magnetic core and amine groups and Ru NPs were accumulated on Fe3O4@SiO2–NH2 surface for H2 production from NH3BH3. Fe3O4@SiO2–NH2–Ru catalysts demonstrated high catalytic activity as long as it has a hydrogen production rate of 156381.25 mLgcat−1 min−1 and a turnover frequency (TOF) of 617 molH2molcat−1min−1 towards the hydrolysis dehydrogenation of AB at 30 °C. This result is significantly higher than most of the known catalysts.
Synthesis and characterization of activated carbon supported magnetic nanoparticles (Fe3O4/AC@SiO2@Sulfanilamide) and its application in removal of toluene and benzene
(Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021) Ece, Mehmet Şakir
In this study, the Fe3O4/AC@SiO2@Sulfanilamide magnetic nanoparticles were successfully synthesized as a highly effective magnetic nano adsorbent and applied for the adsorption of toluene and benzene in the gas phase for the first time. The magnetic nano-adsorbents were characterized by the Brunauer-Emmett-Teller surface area analysis, Differential Thermal Analysis, Thermal Gravimetric Analysis, Fourier Transform Infrared Spectroscopy, Vibrating Sample Magnetometer, Scanning Electron Microscopy and Energy-Dispersive X-Ray Spectroscopy measurements. Besides, the process parameters that affect the adsorption were optimized using the response surface methodology. Optimum conditions of process factors such as contact time, temperature and initial concentration were determined as 59 min, 25 °C and 18 mg/L for toluene, and as 55 min, 28 °C and 15 mg/L for benzene. The maximum adsorption capacity for toluene and benzene was as 612 and 557 mg/g, respectively, under optimal process conditions. Even after five consecutive repetitions, the Fe3O4/AC@SiO2@Sulfanilamide showed high repeatability and retained 89 % and 88 % of its initial adsorption capacity for toluene and benzene, respectively. Kinetic and equilibrium models were investigated. According to these study results, it can be said that having easy synthesis process, high adsorption capacity and reusability performance makes the Fe3O4/AC@SiO2@Sulfanilamide a promising magnetic nano adsorbent.
Synthesis, characterization and investigation of some physical textures of magnetite-silica-L-Proline nanoparticles modified with some transition metals (Co, Mn, Cu, Ni)
(ScienceDirect, 2023) Ece, Mehmet Şakir
Background: The search for new magnetic nanomaterials continues for many solution-oriented applications such as material science, surface science, coating technology, surface engineering, battery, energy storage, catalyst and adsorption. Magnetic nanomaterials have a wide and effective range of applications in solving many problems. While nanomaterials have found solutions to many problems, the production processes of these materials have increased concerns about the natural balance of the environment and human health. The concepts of “green chemistry” and “sustainable materials” find solutions to these concerns. In this study, new magnetic nanomaterials were produced with the approaches of “green chemistry” and “sustainable material”. Considering the physical and chemical properties of these magnetic nanomaterials, they are potential candidate materials that can be used in different applications. Methods: Fe3O4 magnetic nanomaterials were synthesized through co-precipitation and then Fe3O4 magnetic nanomaterials were coated with silica (Fe3O4@SiO2) using sol–gel (Stober ¨ process) method. Subsequently, Fe3O4@SiO2 magnetic nanomaterials were bonded with organic functional group containing amine (Fe3O4@SiO2@L-Pro). Finally, Fe3O4@SiO2@L-Pro magnetic nanomaterials were immobilized with transition metals (Fe3O4@SiO2@L-Pro-X, (X = Co, Mn, Cu, Ni)). Magnetic nanomaterials were characterized by various spectroscopic techniques (VSM, SEM, SEM-EDX, TGA, DTA, FT-IR, UV–Vis.Spect., XRD, BET,) analyzes revealed that the production of magnetic nanomaterials was carried out successfully. Significant findings: Fe3O4@SiO2@L-Pro-X (X = Co, Mn, Cu, Ni) is new products. The magnetic nanomaterials produced in this study were found to be capable of magnetic property, superparamagnetic character, mesopore character, suitable surface area, visible-light active character, crystalline cubic spinel form, thermal/mechanical stability.