Geri Dön

Karbon kuantum noktaları ile modifiye edilmiş zıf-8 nanokompozitlerin sentezi, karakterizasyonu ve özelliklerinin incelenmesi

Synthesis, characterization, and investigation of the properties of carbon quantum dot-modified zif-8 nanocomposites

  1. Tez No: 1010626
  2. Yazar: HİLAL NAZAN AĞAR
  3. Danışmanlar: DOÇ. DR. CANER ÜNLÜ
  4. Tez Türü: Yüksek Lisans
  5. Konular: Kimya, Chemistry
  6. Anahtar Kelimeler: Belirtilmemiş.
  7. Yıl: 2026
  8. Dil: Türkçe
  9. Üniversite: İstanbul Teknik Üniversitesi
  10. Enstitü: Lisansüstü Eğitim Enstitüsü
  11. Ana Bilim Dalı: Kimya Ana Bilim Dalı
  12. Bilim Dalı: Kimya Bilim Dalı
  13. Sayfa Sayısı: Belirtilmemiş.

Özet

Günümüzde nanoteknoloji alanındaki gelişmeler, optik özellikleri ayarlanabilir ve yüzey davranışları geliştirilebilir hibrit malzemelerin tasarlanmasına olanak sağlamaktadır. Bu bağlamda, güçlü fotolüminesans, kimyasal kararlılık ve geniş yüzey alanı gibi özelliklere sahip karbon kuantum noktaları, sensör, optoelektronik ve çevresel arıtım uygulamalarında dikkat çekmektedir. Metal-organik çerceveler ise yüksek gözeneklilikleri, kimyasal esneklikleri ve geniş uygulama alanlarıyla önemli malzeme sınıflarından biridir. Metal-organik çercevelerden biri olan ZIF-8, termal ve kimyasal kararlılığıyla öne çıkmakla birlikte, floresans özelliklerine sahip olmaması nedeniyle optik uygulamalarda tek başına yeterli değildir. Bu nedenle karbon kuantum noktaları ZIF-8 iskeletine entegre edilmesi, yapının hem optik hem de yüzey özelliklerinin iyileştirilmesi açısından önemli bir yaklaşım sunmaktadır. Bu çalışmada, ZIF-8 yapılarının floresans özelliklerini iyileştirmek ve yüzey davranışlarını incelemek amacıyla karbon kuantum noktaları modifiye edilmiş kompozit malzemeler sentezlenmiştir. Karbon kuantum noktaları, borik asit, üre ve farklı miktarlarda sitrik asit kullanılarak mikrodalga destekli yöntemle elde edilmiştir. Sitrik asit oranının değiştirilmesi, karbon kuantum noktaları optik özelliklerinin ve ZIF-8 içerisindeki dağılımının kontrol edilebildiğini göstermiştir. Elde edilen karbon kuantum noktaları metanolde çözülerek ZIF-8 sentez sürecine dâhil edilmiştir. Sentez koşullarının hassas kontrolü, karbon kuantum noktaları ZIF-8 yapısıyla etkin ve homojen etkileşim kurmasını sağlamıştır. Elde edilen saf ZIF-8 ve karbon kuantum noktaları ile modifiye edilmiş ZIF-8 yapıları, XRD, FTIR, SEM, PL, UV-Vis ve BET yüzey alanı analizi ile karakterize edilmiştir. XRD analizleri, karbon kuantum noktaları eklenmesine rağmen ZIF-8'in karakteristik kristal yapısının korunduğunu göstermiştir. FTIR spektroskopisi, imidazol grubuna ait temel titreşim bantlarının modifiye yapıda da varlığını sürdürdüğünü doğrulamıştır. SEM görüntüleri, karbon kuantum noktaları entegrasyonuna bağlı olarak partikül morfolojisinde ve yüzey dokusunda belirgin değişiklikler olduğunu ortaya koymuştur. BET analizleri ise karbon kuantum noktaları eklenmesinin ZIF-8'in yüzey alanı ve gözeneklilik özelliklerinde değişimlere yol açtığını göstermiş, gözenek yapısındaki düzenlenmenin karbon kuantum noktaları yüklemesiyle ilişkili olduğunu ortaya koymuştur. Optik analizler, modifikasyonun ZIF-8'in floresans şiddetini anlamlı derecede artırdığını ve karbon kuantum noktaları konsantrasyonunun optik ayarlanabilirlik sağladığını göstermiştir. Sonuç olarak, karbon kuantum noktaları modifiye ZIF-8 yapılarının geliştirilmiş floresans özellikleri ve BET analizinin doğruladığı yüzey yapısındaki değişimler, bu hibrit malzemeleri sensör teknolojileri, optoelektronik sistemler ve ışığa duyarlı uygulamalar için güçlü adaylar hâline getirmektedir.

Özet (Çeviri)

Recent advances in the field of nanotechnology have enabled the design of hybrid materials with tunable optical properties and enhanced surface behaviors. In this context, carbon quantum dots (CQDs), which exhibit strong photoluminescence, low toxicity, high chemical stability, and extensive surface functionality, have attracted significant attention in areas such as sensing, biomedical applications, optoelectronics, and environmental remediation. These carbon-based nanostructures have gained considerable interest in recent years due to their biocompatibility and rich surface functional groups, which make them highly suitable for various modification processes. Furthermore, the ease of surface functionalization renders carbon quantum dots particularly advantageous for environmental applications and adsorption studies. To utilize these advantages more efficiently, integrating carbon quantum dots with porous materials possessing high surface areas has become increasingly important. In this regard, the formation of hybrid systems through the combination of carbon quantum dots with different materials represents a strategic approach for the development of functional materials. Metal–organic frameworks (MOFs) constitute an important class of materials due to their high porosity, chemical tunability, and wide range of applications. Also referred to as porous coordination polymers, MOFs are highly porous and crystalline hybrid materials composed of inorganic metal nodes and organic ligands. Owing to their high surface areas, ordered porous structures, and chemical flexibility, MOFs have been widely employed in various application fields such as gas storage, catalysis, drug delivery, and separation technologies. Among the MOF family, Zeolitic Imidazolate Framework-8 (ZIF-8) is one of the most prominent members, known for its high porosity and structural stability, formed through the coordination of zinc ions with 2-methylimidazole ligands. ZIF-8 is widely utilized in applications such as gas storage, molecular separation, and catalysis due to its excellent thermal and chemical stability. However, despite its large surface area, ZIF-8 does not inherently exhibit fluorescence and may show limited selectivity toward target molecules in adsorption processes, which restricts its performance in optical-based sensor systems and advanced environmental applications. Therefore, the integration of carbon quantum dots into the ZIF-8 framework creates a synergistic effect by enhancing both the optical and surface properties of the structure. The combination of carbon quantum dots with ZIF-8 structures is of great importance for improving fluorescence characteristics and enhancing surface properties. In this context, imparting fluorescence to ZIF-8 structures via carbon quantum dots and investigating their adsorption properties present a significant approach for the development of potential applications of these materials. While evaluating the effects of carbon quantum dot integration on the fluorescence behavior of ZIF-8 structures, the importance of surface property characterization of these materials is also emphasized. The integration of carbon quantum dots with ZIF-8 structures not only reveals their fluorescent properties but also enables the regulation of active surface groups. These active groups facilitate the formation of interactions and catalytic sites for targeted applications. Moreover, the interaction between carbon quantum dots and ZIF-8 not only enhances optical properties but also contributes to the optimization of the porous structure within the material, potentially increasing gas storage capacity. While carbon quantum dots offer high surface functionality and optical activity, ZIF-8 provides a high surface area and porous framework. By combining these two materials, it becomes possible to integrate the advantages of both structures into a single hybrid system. In this study, the integration of carbon quantum dots into the ZIF-8 framework was aimed at enhancing adsorption performance and developing a functional material for environmental applications. The primary objective of this thesis is to develop next-generation hybrid nanocomposites by integrating carbon quantum dots, which possess notable optical and surface properties, into highly porous ZIF-8 structures. The study follows a comprehensive methodological approach consisting of three main stages. In the first stage, within the scope of nanocomposite synthesis, high-efficiency carbon quantum dots were synthesized using a microwave-assisted bottom-up method and subsequently integrated into the ZIF-8 framework under controlled conditions. Owing to the rapid heating and homogeneous thermal distribution provided by the microwave method, the distribution and interaction of carbon quantum dots within the ZIF-8 crystal structure were optimized. The microwave-assisted synthesis enabled controlled particle size distribution and efficient heteroatom (boron and nitrogen) doping through rapid heating and homogeneous nucleation. Variation in the amount of citric acid monohydrate demonstrated that the optical properties of carbon quantum dots and their distribution within the ZIF-8 structure could be effectively controlled. The synthesized carbon quantum dots were dissolved in methanol and incorporated into the ZIF-8 synthesis process. Precise control of synthesis conditions ensured effective and homogeneous interaction between the carbon quantum dots and the ZIF-8 framework. During this integration process, interactions between carboxyl and hydroxyl groups on the surface of carbon quantum dots and the metal centers or ligands of ZIF-8 enhanced the stability of the composite structure. In the second stage, characterization of the synthesized hybrid materials was carried out. The crystallinity, chemical bonding structure, surface morphology, pore size distribution, and optical responses of the synthesized structures were comprehensively analyzed using advanced characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area analysis, and photoluminescence (PL) spectroscopy. XRD analyses revealed that the characteristic crystalline structure of ZIF-8 was preserved despite the incorporation of carbon quantum dots, suggesting that the CQDs were either embedded within the pores or attached to the surface without disrupting the ZIF-8 framework. FTIR spectroscopy confirmed the presence of characteristic vibrational bands of the imidazole group in the modified structures and supported the successful modification through the detection of characteristic bonds originating from CQDs. SEM images demonstrated significant changes in particle morphology and surface texture as a result of carbon quantum dot integration. BET analyses indicated that the incorporation of carbon quantum dots led to changes in the surface area and porosity of ZIF-8, revealing that the regulation of pore structure was closely associated with CQD loading. Optical analyses showed that the modification significantly enhanced the fluorescence intensity of ZIF-8 and that the concentration of carbon quantum dots enabled optical tunability. In the final stage, the functional properties of the developed nanocomposites were investigated. Within this scope, adsorption performance and optical tunability were evaluated to determine the potential of the modified materials for environmental applications. The effects of varying carbon quantum dot content on the surface reactivity of ZIF-8 and its molecular interactions with target molecules were systematically assessed. Accordingly, the adsorption performances of synthesized ZIF-8, CQD, and ZIF-8–CQD composites were examined using five commonly encountered model dyes in water pollution—Methylene Blue, Methyl Violet, Rhodamine B, Indigo Carmine, and Methyl Orange—via UV–Vis spectrophotometric measurements. Experimental results demonstrated that the amount of carbon quantum dots integrated into the ZIF-8 structure had a direct and decisive impact on adsorption efficiency. However, it was also observed that an increase in functional group content did not always result in a proportional increase in adsorption performance, and excessive CQD loading could lead to pore blockage. Among the investigated samples, the ZIF-8–CQD3 composite, which contained the lowest amount of citric acid monohydrate, emerged as the most effective adsorbent due to its largely preserved pore structure, balanced functional group density, and versatile interactions with both anionic and cationic dyes. Overall, the results demonstrate that carbon quantum dot incorporation significantly imparts fluorescence properties to ZIF-8 and modifies its surface, thereby altering its dye adsorption capacity. Through this approach, non-fluorescent ZIF-8 structures were successfully transformed into fluorescent materials. Such hybrid structures exhibit broad application potential in areas such as sensor technologies, optoelectronic applications, and the removal of environmental pollutants. Future studies may focus on more detailed optical tuning and selective adsorption mechanisms using different types of carbon quantum dots, as well as further enhancement of material properties through the integration of various carbon quantum dots and MOF structures. This study reveals the improvements in optical properties achieved by carbon quantum dot-modified ZIF-8 structures and highlights their potential applications in fields such as sensing, optoelectronics, and dye-related technologies.

Benzer Tezler

  1. Tez No

    880576

    Hidrotermal olarak sentezlenen gümüş nanopartikül ile deklore edilmiş propolis karbon kuantum noktasının antibakteriyel ve antioksidan aktivitesinin araştırılması

    Investigation of antibacterial and antioxidant activity of hydrothermally synthesized silver nanoparticle decorated with propolis carbon quantum dot

    RUBA MAHER MOHAMMAD JEBRIL

    Yüksek Lisans

    Türkçe

    Türkçe

    2024

    MikrobiyolojiAtatürk Üniversitesi

    Moleküler Biyoloji ve Genetik Ana Bilim Dalı

    PROF. DR. AHMET ADIGÜZEL

  2. Tez No

    920687

    Propolis CQD modifiye Satureja hortensis ve Achillea millefolium nanoemülsiyonlarının üretimi, karakterizasyonu ve bazı biyolojik aktivitelerinin araştırılması

    Investigation of the production, characterization and some biological activities of propolis CQD modified Satureja hortensis L. and Achillea millefolium L. nanoemulsions

    HATİCE GİRGİN

    Yüksek Lisans

    Türkçe

    Türkçe

    2025

    Mühendislik BilimleriAtatürk Üniversitesi

    Nanobilim ve Nanomühendislik Ana Bilim Dalı

    PROF. DR. HAYRUNNİSA NADAROĞLU

  3. Tez No

    997287

    Fonksiyonel grup içeren tetrapirol türevlerinin sentezi ve karakterizasyonu

    Synthesis and characterization of tetrpyrolle derivatives containing functional groups

    YAĞMUR ZEYNEP YURDAKUL

    Yüksek Lisans

    Türkçe

    Türkçe

    2026

    Kimyaİstanbul Teknik Üniversitesi

    Kimya Ana Bilim Dalı

    PROF. DR. ESİN HAMURYUDAN

    DOÇ. DR. MUKADDES ÖZÇEŞMECİ

  4. Tez No

    1014634

    Deneysel parkinson hastalığı modelinde modifiye edilmiş kuantum dotların nöron koruyucu etkilerinin incelenmesi

    Investi̇gati̇on of neuroprotecti̇ve effects of modi̇fi̇ed quantum dots i̇n an experi̇mental model of parki̇nson's di̇sease

    VOLKAN KARABUDAK

    Yüksek Lisans

    Türkçe

    Türkçe

    2026

    BiyoteknolojiErzurum Teknik Üniversitesi

    Moleküler Biyoloji ve Genetik Ana Bilim Dalı

    DOÇ. DR. MEHMET ENES ARSLAN

  5. Tez No

    734817

    Keçi tüyünden üretilen karbon kuantum Dot/ZnO nanohibrit materyalinin organik kirleticilerin fotokatalitik gideriminde kullanılabilirliğinin araştırılması

    Investigation of usability of carbon quantum Dot/ZnO nanohybrid material produced from mohair in photocatalytic removal of organic pollutants

    MERVE VURUCUEL

    Yüksek Lisans

    Türkçe

    Türkçe

    2022

    KimyaErciyes Üniversitesi

    Nanobilim ve Nanoteknoloji Ana Bilim Dalı

    DOÇ. DR. ERKAN YILMAZ

Geri Dön