Nikel oksit nanopartiküllerin sentezi ve karakterizasyonu
Küçük Resim Yok
Tarih
2025
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Bursa Teknik Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, kimyasal çöktürme yöntemiyle nikel oksit (NiO) nanopartiküllerinin sentezi gerçekleştirilmiş ve sentez parametrelerinin nanopartikül özelliklerine olan etkileri detaylı bir şekilde incelenmiştir. Deney tasarımında yanıt yüzey yöntemi tabanlı Box-Behnken tasarımı kullanılarak sıcaklık, karıştırma hızı ve reaktan mol oranı gibi üç temel parametrenin NiO nanopartiküllerinin ortalama tane boyutu üzerindeki etkisi incelenmiştir. Çalışmanın amacı, optimum sentez koşullarını belirleyerek, nanopartiküllerin spesifik özelliklerini kontrol edebilmek ve süreç üzerinde daha iyi bir hakimiyet sağlamaktır. İlk aşamada, nikel nitrat hekzahidrat (Ni(NO?)?·6H?O) başlangıç maddesi ve sodyum hidroksit (NaOH) çöktürücü olarak kullanılarak nikel hidroksit (Ni(OH)?) sentezi gerçekleştirilmiştir. Sentez işlemleri, karıştırmalı ve sıcaklık kontrollü bir reaktörde yürütülmüş, homojen çöktürme sağlanarak nanopartiküllerin morfolojisi üzerinde süreç parametrelerinin etkileri incelenmiştir. Çöktürme deneyleri hem mikrodalga destekli reaktörlerde hem de normal koşullarda gerçekleştirilerek mikrodalganın partikül çapı, yüzey alanı ve gözenek yapısı üzerindeki etkisi analiz edilmiştir. Farklı morfolojik özellikler elde etmek amacıyla, CTAB (sitril trimetil amonyum bromür), SDS (sodyum dodesil sülfat), PVP (polivinilpirolidon), NP10 (noniyonik sürfaktan), Tween 80 ve PEG (poli etilen glikol) gibi farklı sürfaktanlar çöktürme sürecine dahil edilmiştir. Bu sürfaktanların, NiO nanopartiküllerinin yüzey morfolojisi, boyut dağılımı ve gözeneklilik özellikleri üzerindeki etkileri araştırılmıştır. Sürfaktan etkisiyle partiküllerin birikme eğilimleri, aglomerasyon düzeyleri ve yüzey alanı değişimleri incelenmiştir. Çöktürme sonrası elde edilen nikel hidroksit (Ni(OH)?) nanopartikülleri, farklı sıcaklıklarda (300, 400, 500 ve 600 °C) kalsinasyon işlemine tabi tutularak nikel oksit (NiO) nanopartiküllerine dönüştürülmüştür. Bu aşamada, kalsinasyon sıcaklığının partikül boyutu, yüzey alanı ve gözenek yapısı üzerindeki etkileri araştırılmıştır. Karakterizasyon aşamasında FTIR (Fourier Dönüşümlü Kızılötesi Spektroskopi) ile kimyasal yapı analizi, XRD (X-ışını Kırınımı) ile faz analizi gerçekleştirilmiştir. SEM (Taramalı Elektron Mikroskobu) ile nanopartiküllerin yüzey morfolojisi incelenmiş, zetasizer ve SEM görüntüleri ile partikül boyut dağılımları belirlenmiştir. BET analizi kullanılarak yüzey alanı ve gözeneklilik özellikleri de analiz edilmiştir. Karakterizasyon sonuçlarına göre, kimyasal çöktürme yöntemi ile NiO nanopartiküllerinin başarıyla sentezlendiği doğrulanmıştır. Reaktan mol oranı, ortalama parçacık boyutu üzerinde en etkili parametre olarak belirlenirken, karıştırma hızının bu etkiyi takip ettiği tespit edilmiştir. Partikül boyut analizlerinde, sentezlenen NiO nanopartiküllerinin polidispers olduğu ve bir araya gelme (aglomerasyon) eğilimi gösterdiği görülmüştür. SEM görüntüleri, nanopartiküllerin 50 nm'nin altında bir boyuta sahip olduğunu, ancak yoğun aglomerasyon nedeniyle daha büyük kümeler oluşturduğunu ortaya koymuştur. Kalsinasyon deneylerinde, partikül boyutunun 300 °C'de en büyük değere ulaştığı, ancak bu sıcaklıkta kalsinasyonun tamamlanmadığı TGA (Termogravimetrik Analiz) ile doğrulanmıştır. Sıcaklık arttıkça partikül boyutunun azaldığı, ancak 600 °C'de tekrar bir artış eğilimi gözlemlenmiştir. Bu sonuçlar, NiO nanopartikül sentezi için uygun kalsinasyon sıcaklığının 400-500 °C aralığında olduğunu göstermiştir. Mikrodalga destekli çöktürme işlemi, partiküllerin gözenek yapısı ve boyutunda değişikliklere yol açmış, BET analizi bu koşullarda yüzey alanının azaldığını ortaya koymuştur. Sonuç olarak, bu çalışma, NiO nanopartikül sentezinde mikrodalga etkisini, farklı sentez parametrelerinin partikül özellikleri üzerindeki etkilerini ve optimum sentez koşullarını detaylı bir şekilde ortaya koyarak literatüre önemli katkılar sağlamayı hedeflemiştir. Elde edilen bulgular, NiO nanopartiküllerinin yüzey özelliklerinin, morfolojisinin ve fiziksel yapısının sentez parametreleriyle doğrudan kontrol edilebileceğini göstermiştir.
In this study, nickel oxide (NiO) nanoparticles were synthesized using the chemical precipitation method, and the effects of synthesis parameters on nanoparticle properties were investigated in detail. The response surface methodology-based Box-Behnken design was employed to investigate three key parameters—temperature, stirring speed, and reactant molar ratio—and their influence on the average particle size of the NiO nanoparticles was analyzed. The aim of this research was to identify the optimal synthesis conditions to control the specific properties of the nanoparticles and gain better control over the process. In the initial step, nickel nitrate hexahydrate (Ni(NO?)?·6H?O) was used as the precursor and sodium hydroxide (NaOH) as the precipitating agent to synthesize nickel hydroxide (Ni(OH)?). The synthesis was conducted in a stirred and temperature-controlled reactor to ensure homogeneous precipitation and to study the effects of process parameters on the morphology of the nanoparticles. Precipitation experiments were carried out both under microwave-assisted and conventional conditions to analyze the impact of microwave irradiation on particle size, surface area, and pore structure. To achieve diverse morphological characteristics, various surfactants, including CTAB (cetyltrimethylammonium bromide), SDS (sodium dodecyl sulfate), PVP (polyvinylpyrrolidone), NP10 (nonionic surfactant), Tween 80, and PEG (polyethylene glycol), were incorporated into the precipitation process. The effects of these surfactants on the surface morphology, size distribution, and porosity of the NiO nanoparticles were investigated. The role of surfactants in particle aggregation, agglomeration tendencies, and changes in surface area was also examined. After precipitation, the synthesized nickel hydroxide (Ni(OH)?) nanoparticles were calcined at different temperatures (300, 400, 500, and 600 °C) to convert them into nickel oxide (NiO) nanoparticles. At this stage, the influence of calcination temperature on particle size, surface area, and pore structure was studied. For characterization, FTIR (Fourier Transform Infrared Spectroscopy) was used to analyze the chemical structure, and XRD (X-ray Diffraction) was applied for phase analysis. The surface morphology of the nanoparticles was observed using SEM (Scanning Electron Microscopy), while particle size distributions were determined through zetasizer and SEM analysis. Additionally, BET analysis was conducted to evaluate surface area and porosity. The characterization results confirmed the successful synthesis of NiO nanoparticles using the chemical precipitation method. Among the investigated parameters, the reactant molar ratio was identified as the most influential factor on the average particle size, followed by stirring speed. Particle size analysis revealed that the synthesized NiO nanoparticles were polydisperse and exhibited a tendency to agglomerate. SEM images showed that the nanoparticles were smaller than 50 nm, but significant agglomeration resulted in larger clusters. Calcination experiments indicated that particle size was largest at 300 °C, but TGA (Thermogravimetric Analysis) revealed that calcination was incomplete at this temperature. As the calcination temperature increased, the particle size decreased, but a subsequent increase was observed at 600 °C. These findings suggested that the suitable calcination temperature for NiO nanoparticle synthesis lies between 400 and 500 °C. Microwave-assisted precipitation altered the pore structure and size of the particles, leading to a reduction in BET surface area under these conditions. In conclusion, this study provides a detailed evaluation of the effects of microwave irradiation and synthesis parameters on the properties of NiO nanoparticles. It identifies the optimal synthesis conditions and contributes valuable insights to the literature. The findings demonstrate that the surface properties, morphology, and physical structure of NiO nanoparticles can be effectively controlled by adjusting the synthesis parameters.
In this study, nickel oxide (NiO) nanoparticles were synthesized using the chemical precipitation method, and the effects of synthesis parameters on nanoparticle properties were investigated in detail. The response surface methodology-based Box-Behnken design was employed to investigate three key parameters—temperature, stirring speed, and reactant molar ratio—and their influence on the average particle size of the NiO nanoparticles was analyzed. The aim of this research was to identify the optimal synthesis conditions to control the specific properties of the nanoparticles and gain better control over the process. In the initial step, nickel nitrate hexahydrate (Ni(NO?)?·6H?O) was used as the precursor and sodium hydroxide (NaOH) as the precipitating agent to synthesize nickel hydroxide (Ni(OH)?). The synthesis was conducted in a stirred and temperature-controlled reactor to ensure homogeneous precipitation and to study the effects of process parameters on the morphology of the nanoparticles. Precipitation experiments were carried out both under microwave-assisted and conventional conditions to analyze the impact of microwave irradiation on particle size, surface area, and pore structure. To achieve diverse morphological characteristics, various surfactants, including CTAB (cetyltrimethylammonium bromide), SDS (sodium dodecyl sulfate), PVP (polyvinylpyrrolidone), NP10 (nonionic surfactant), Tween 80, and PEG (polyethylene glycol), were incorporated into the precipitation process. The effects of these surfactants on the surface morphology, size distribution, and porosity of the NiO nanoparticles were investigated. The role of surfactants in particle aggregation, agglomeration tendencies, and changes in surface area was also examined. After precipitation, the synthesized nickel hydroxide (Ni(OH)?) nanoparticles were calcined at different temperatures (300, 400, 500, and 600 °C) to convert them into nickel oxide (NiO) nanoparticles. At this stage, the influence of calcination temperature on particle size, surface area, and pore structure was studied. For characterization, FTIR (Fourier Transform Infrared Spectroscopy) was used to analyze the chemical structure, and XRD (X-ray Diffraction) was applied for phase analysis. The surface morphology of the nanoparticles was observed using SEM (Scanning Electron Microscopy), while particle size distributions were determined through zetasizer and SEM analysis. Additionally, BET analysis was conducted to evaluate surface area and porosity. The characterization results confirmed the successful synthesis of NiO nanoparticles using the chemical precipitation method. Among the investigated parameters, the reactant molar ratio was identified as the most influential factor on the average particle size, followed by stirring speed. Particle size analysis revealed that the synthesized NiO nanoparticles were polydisperse and exhibited a tendency to agglomerate. SEM images showed that the nanoparticles were smaller than 50 nm, but significant agglomeration resulted in larger clusters. Calcination experiments indicated that particle size was largest at 300 °C, but TGA (Thermogravimetric Analysis) revealed that calcination was incomplete at this temperature. As the calcination temperature increased, the particle size decreased, but a subsequent increase was observed at 600 °C. These findings suggested that the suitable calcination temperature for NiO nanoparticle synthesis lies between 400 and 500 °C. Microwave-assisted precipitation altered the pore structure and size of the particles, leading to a reduction in BET surface area under these conditions. In conclusion, this study provides a detailed evaluation of the effects of microwave irradiation and synthesis parameters on the properties of NiO nanoparticles. It identifies the optimal synthesis conditions and contributes valuable insights to the literature. The findings demonstrate that the surface properties, morphology, and physical structure of NiO nanoparticles can be effectively controlled by adjusting the synthesis parameters.
Açıklama
Anahtar Kelimeler
Kimya Mühendisliği, Chemical Engineering
