Ultrases destekli AgO/zno katkılı g-C3N4 sentezi ve fotokatalitik etkilerinin araştırılması
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Dosyalar
Tarih
2023
Yazarlar
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Yayıncı
Bursa Teknik Üniversitesi, Lisansüstü Eğitim Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Günümüzde başta tekstil olmak üzere çeşitli sektörlerin atık boyalarının çevreye verebilecekleri ciddi boyuttaki zararların en aza indirilmesi, ekonomik olarak büyük maliyetlere neden olmaktadır. Bu sebeple tekstil atık boyaları içeren sulardan boyaların giderilmesi için yoğun çalışmalar yürütülmektedir. Bu çalışmalar ile doğaya verilen zararın en aza indirilmesi amaçlanmaktadır. Bu tez çalışması kapsamında ise ultrases destekli AgO/ZnO katkılı g-C3N4 fotokatalizörlerin sentezi gerçekleştirildi ve bu katalizörlerin giderim verimleri incelendi. Bu amaçla laboratuvar ortamında melaninden saf grafitik karbon nitrür üretimi tüp fırın içerisinde gerçekleştirildi. Sonrasında Ag/Zn/g-CN kompozitinin hazırlanması için iki farklı yöntem kullanıldı. Bu yöntemlerden biri ultrasese dayalı birlikte çökeltme yöntemi ve diğeri ise ultrases desteksiz sentezlenen birlikte çökeltme yöntemidir. Farklı oranlarda Zn ve Ag içeren g-C3N4/AgO/ZnO çözeltileri, sabit sıcaklıkta tutulan yarı kesikli bir sistemde NaOH çözeltisi varlığında indirgenerek sentezlendi. Ardından süzme, kurutma ve kalsinasyon adımları gerçekleştirildi. Sonrasında sabit konsantrasyondaki metilen mavisi çözeltisi ile batch reaktörlerde fotokatalitik reaksiyonlar başlatıldı. Hazırlanan çözeltideki giderim performansında beş farklı parametrenin etkisi incelendi. Zamana bağlı giderimin etkisi, katalizördeki metal tuzların oranı, katalizör miktarı, katalizör sentezlenirken kullanılan farklı yöntemler, fotokatalitik reaksiyon için kullanılan farklı ışık türleri, bu tez çalışması kapsamında incelenen parametrelerdir. Sentezlenen katalizörler taramalı elektron mikroskobu (SEM), fourier dönüşümlü kızılötesi spektroskopisi (FTIR), X-Işını kırınım yöntemi (XRD) ile karakterize edilerek yüzey morfolojileri ve yapıları incelendi. Grafitik karbon nitrüre eklenen ZnO ve AgO miktarının artmasıyla giderimde bir artış olduğu görüldü. %25 ZnO-%2 AgO ile en az metal oksitin eklendiği g-C3N4 hetero fotokatalizörü kullanılarak 1 saat sonunda %91 giderim 3 saat sonunda da %96 oranında giderim elde edildi. Çalışma sonucunda, UV ışığın yanı sıra sentezlenen katalizörün görünür ışıkta da iyi bir performan gösterebileceği sonucuna varıldı. Görünür ışık varlığı altında ilk 1 saatte %44, 3. saatin sonunda da %75 giderimin olduğu gözlemlendi
Nowadays, minimizing the serious environmental damage caused by waste dyes of various sectors especially textiles, is economically costly. For this reason, intensive studies are carried out to remove dyes from waters containing textile waste dyes. With these efforts, it is aimed to minimize the damage to nature. In the scope of this thesis, the synthesis of ultrasound assisted AgO/ZnO doped g-C3N4 photocatalysts was carried out and the removal efficiencies of these catalysts were investigated. For this purpose, pure graphitic carbon nitride was synthesized from melanin in the laboratory environment in a tube furnace. Then, two different methods were used for the preparation of Ag/Zn/g-CN composite. One of these methods is the ultrasound based co-precipitation method and the other is the co-precipitation method synthesized without ultrasound support. The g-C3N4/AgO/ZnO solutions containing different ratios of Zn and Ag were synthesized by reduction in the presence of NaOH solution in a semi-batch system maintained at constant temperature. Then, filtration, drying and calcination steps were carried out. Photocatalytic reactions were then initiated in batch reactors with a constant concentration of methylene blue solution. The effect of five different parameters on the removal performance of the prepared solution was investigated. The effect of time-dependent removal, the ratio of metal oxide in the catalyst, the amount of catalyst, different methods used in synthesizing the catalyst, different types of light used for photocatalytic reaction; are the parameters investigated in this thesis. The synthesized catalysts were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction method (XRD) and their surface morphologies and structures were investigated. It was observed that there was an increase in removal with the increase in the amount of ZnO and AgO added to graphitic carbon nitride. Using g-C3N4 hetero photocatalyst with 25% ZnO-2% AgO and minimum metal oxide added, 91% removal after 1 hour and 96% removal after 3 hours were obtained. As a result of the study, it was concluded that the synthesized catalyst can perform well in visible light as well as UV light. In the presence of visible light, 44% removal in the first 1 hour and 75% removal was observed at the end of the 3rd hour.
Nowadays, minimizing the serious environmental damage caused by waste dyes of various sectors especially textiles, is economically costly. For this reason, intensive studies are carried out to remove dyes from waters containing textile waste dyes. With these efforts, it is aimed to minimize the damage to nature. In the scope of this thesis, the synthesis of ultrasound assisted AgO/ZnO doped g-C3N4 photocatalysts was carried out and the removal efficiencies of these catalysts were investigated. For this purpose, pure graphitic carbon nitride was synthesized from melanin in the laboratory environment in a tube furnace. Then, two different methods were used for the preparation of Ag/Zn/g-CN composite. One of these methods is the ultrasound based co-precipitation method and the other is the co-precipitation method synthesized without ultrasound support. The g-C3N4/AgO/ZnO solutions containing different ratios of Zn and Ag were synthesized by reduction in the presence of NaOH solution in a semi-batch system maintained at constant temperature. Then, filtration, drying and calcination steps were carried out. Photocatalytic reactions were then initiated in batch reactors with a constant concentration of methylene blue solution. The effect of five different parameters on the removal performance of the prepared solution was investigated. The effect of time-dependent removal, the ratio of metal oxide in the catalyst, the amount of catalyst, different methods used in synthesizing the catalyst, different types of light used for photocatalytic reaction; are the parameters investigated in this thesis. The synthesized catalysts were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction method (XRD) and their surface morphologies and structures were investigated. It was observed that there was an increase in removal with the increase in the amount of ZnO and AgO added to graphitic carbon nitride. Using g-C3N4 hetero photocatalyst with 25% ZnO-2% AgO and minimum metal oxide added, 91% removal after 1 hour and 96% removal after 3 hours were obtained. As a result of the study, it was concluded that the synthesized catalyst can perform well in visible light as well as UV light. In the presence of visible light, 44% removal in the first 1 hour and 75% removal was observed at the end of the 3rd hour.
Açıklama
Anahtar Kelimeler
Fotokatalizör, Grafitik Karbon Nitrür, AgO, ZnO, UV, Metilen Mavisi, Photocatalyst, Graphitic Carbon Nitride, Methylene Blue
