Petrol asfalteninden türetilen aktif karbon üzerine desteklenmiş gümüş nanopartiküllerin sentezi ve uygulamaları
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Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Kırıkkale Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Gümüş nanopartiküllerin (AgNP'lerin) kullanım alanlarını sınırlayan bazı zorluklar vardır. Büyük yüzey alanına ve yüksek kararlılığa sahip küçük boyutlu AgNP'ler, yüksek yüzey enerjileri nedeniyle katalitik reaksiyonlarda geri dönüşümsüz olarak topaklanma eğilimindedir. Bu sorunları önlemek için, bu tez çalışmasında AgNP'ler oldukça gözenekli bir yapıya sahip aktif karbon üzerine desteklendi. Nitrofenoller çoğunlukla endüstriyel ve tarımsal atık sularda bulunan zararlı ve toksik kirleticilerdir. Bu nedenle, atık sulardan nitrofenollerin uzaklaştırılması çevresel açıdan önem kazanmaktadır. Bu çalışmada, aktif karbon destekli AgNP'ler, sodyum borhidrür (NaBH4) ve amonyum hidroksit (NH4OH) kullanılarak tek aşamalı bir kimyasal indirgeme yöntemi ile sentezlendi. Metal tuzu öncülü olarak AgNO3 kullanıldı. Asfalten-bazlı aktif karbon (AAC), KOH kullanılarak kimyasal aktivasyon yöntemi ile hazırlandı. Hazırlanan AgNP-AAC'ler, NaBH4 varlığında 4-nitrofenol, 2,4-dinitrofenol ve 2,4,6-trinitrofenolün indirgenmesinde heterojen katalizör olarak kullanıldı. Katalizör yüksek katalitik aktivite gösterdi ve nitrofenollerin aminofenollere dönüşümü kısa sürede tamamlandı. Bu çalışmada ayrıca iki ve üç metal içeren aktif karbon destekli nanokatalizörler sentezlendi. AgNO3 ve Ni(acac)2'nin oleilaminli ortamda indirgenmesi ile AgNiNP-AAC elde edildi. Daha sonra çekirdek/kabuk yapısına sahip AgNi/MnAgNiNP-AAC ve AgNi/FeAgNiNP-AAC, organik çözücü ortamında, tohum-aracılı büyüme yöntemi ile sentezlendi.. İki ve üç metal içeren destekli katalizörlerin katalitik aktivitesi 4-nitrofenolün NaBH4 varlığında indirgenmesi model reaksiyonunda test edildi.Her üç katalizörün de yüksek katalitik aktiviteye sahip olduğu belirlendi.
Silver nanoparticles (AgNPs) are some difficulties limiting AgNPs area of utilization. Small sized AgNPs with large surface area and high stability tend to irreversibly aggregate in catalytic reactions due to their high surface energy. To prevent these problems, AgNPs were supported on the surface of a highly porous activated carbon surface in this thesis. Nitrophenols are harmful and toxic pollutants mostly found in industrial wastewater. Therefore, the removal of nitrophenols from wastewater becomes environmentally important. In this study, activated carbon supported AgNPs were synthesized via a single-step chemical reduction method using sodium borohydride (NaBH4) and ammonium hydroxide (NH4OH). AgNO3 was used as the metal salt precursor. Asphaltene-derived activated carbon (AAC) was prepared by chemical activation method using KOH. Prepared AgNP-AACs were used as a heterogeneous catalyst in the reduction of 4-nitrophenol, 2,4-dinitrophenol and 2,4,6-trinitrophenol in the presence of NaBH4. The catalyst showed high catalytic activity and the conversion of nitrophenols to aminophenols was completed in a short time. In this study, activated carbon supported nanocatalysts containing two and three metals were also synthesized. AgNiNP-AAC was synthesized by reduction of AgNO3 and Ni(acac)2 in oleylamine medium. Subsequently, core/shell structure AgNi/FeAgNiNP-AAC and AgNi/MnAgNiNP-AAC were synthesized via the seed-mediated growth method in organic solvent medium.
Silver nanoparticles (AgNPs) are some difficulties limiting AgNPs area of utilization. Small sized AgNPs with large surface area and high stability tend to irreversibly aggregate in catalytic reactions due to their high surface energy. To prevent these problems, AgNPs were supported on the surface of a highly porous activated carbon surface in this thesis. Nitrophenols are harmful and toxic pollutants mostly found in industrial wastewater. Therefore, the removal of nitrophenols from wastewater becomes environmentally important. In this study, activated carbon supported AgNPs were synthesized via a single-step chemical reduction method using sodium borohydride (NaBH4) and ammonium hydroxide (NH4OH). AgNO3 was used as the metal salt precursor. Asphaltene-derived activated carbon (AAC) was prepared by chemical activation method using KOH. Prepared AgNP-AACs were used as a heterogeneous catalyst in the reduction of 4-nitrophenol, 2,4-dinitrophenol and 2,4,6-trinitrophenol in the presence of NaBH4. The catalyst showed high catalytic activity and the conversion of nitrophenols to aminophenols was completed in a short time. In this study, activated carbon supported nanocatalysts containing two and three metals were also synthesized. AgNiNP-AAC was synthesized by reduction of AgNO3 and Ni(acac)2 in oleylamine medium. Subsequently, core/shell structure AgNi/FeAgNiNP-AAC and AgNi/MnAgNiNP-AAC were synthesized via the seed-mediated growth method in organic solvent medium.
Açıklama
Anahtar Kelimeler
Kimya, Chemistry
