Investigation of the photocatalytic properties of polyoxometalates
Başlık çevirisi mevcut değil.
- Tez No: 400863
- Danışmanlar: DR. JOHN L. FERRY
- Tez Türü: Doktora
- Konular: Kimya, Chemistry
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2002
- Dil: İngilizce
- Üniversite: Unıversıty Of South Carolıne
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Belirtilmemiş.
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: Belirtilmemiş.
Özet
Özet yok.
Özet (Çeviri)
In this dissertation the thermal and photocatalytic properties of different photoactive heteropolyoxometalates ([PWi2O40]3\ [SiW^o]4“, [PM012O40]3”. [W,o03;]4“ . and [NaP5W30Oiio]14') are investigated in several model systems. The photodegradation kinetics of a probe compound, 1.2-dichlorobenzene. are used as a probe of the reactivity of these oxidation catalysts in solution and supported on Ti02 or Y-zeolite surfaces. In all cases. POM-mediated photocatalytic oxidation of DCB is first order in [DCB]. Competition experiments employing OH radical scavengers (including a comparison of the effectiveness of protonated vs deuterated probes) revealed that the degradation reaction is initiated by electron transfer rather than OH radicals. Combination of POMs with Ti02 resulted in eight-fold rate enhancement on the photooxidation of DCB upon illumination at 350 nm in aqueous medium. In this system. POMs act as electron transfer catalysts for removing electrons from the conduction band of excited Ti02 to molecular oxygen. Y-zeolites were also used as solid support for POM photocatalysis and it was found adsorption onto Y-zeolites increased the photocatalytic activity of POMs by a factor of 4-10 times. A new type of photocatalytic system was developed based on Y-zeolite-supported [NaPsWsoOuo]14' which functions at environmentally relevant pHs (5-10). We explored the relationship between the oxidation rate of 1,2-DCB and a variety of zeolites, varying the Si/Al ratio, pore sizes and surface areas. Maximum rates were attainted with the Y-zeolite with highest Si/Al (80). We hypothesize that adsorption of POMs on the surface of Y-zeolites plays the primary role in the observed rate enhancement of Y-zeolite/POM systems. This system is also less likely to be affected by the presence of common ion scavengers like bicarbonate and natural organic matter. The increased quantum efficiency of zeolite-supported [NaPsW^oOno]14”in the presence of these scavengers is attributed to the electrostatic repulsion between scavengers and the negatively charged photocatalyst.
Benzer Tezler
- Yarı iletken metal oksitlerin fotokatalitik özelliklerinin incelenmesi
Investigation of the photocatalytic properties of semi conductive metal oxides
SÜREYYA DÖŞLÜ ÇETİNKAYA
Yüksek Lisans
Türkçe
2023
Fizik ve Fizik MühendisliğiMersin ÜniversitesiNanoteknoloji ve İleri Malzemeler Ana Bilim Dalı
PROF. DR. NADİR DİZGE
- Metal bezeli silika partiküllerinin yarı-biyosentezle üretimi, yapısal analizi ve (antibakteriyel ve fotokatalitik) özelliklerinin incelenmesi
The semi-biosynthetic production of metal decorated silica particles, investigation of structural analysis and antibacterial and photocatalytic properties
SÜREYYA KADIOĞLU
- Yeni periferal tip ftalosiyaninle katkılandırılmış ZnO partiküllerin sentezi karakterizasyonu ve fotokatalitik özelliklerinin incelenmesi
The synthesis, characterization and investigation of photocatalytic properties of novel hybrid ZnO materials additive with novel peripherally Zinc(II) phthalocyanine
HANİFE TURAN
Yüksek Lisans
Türkçe
2019
KimyaRecep Tayyip Erdoğan ÜniversitesiKimya Ana Bilim Dalı
DOÇ. DR. HAKKI TÜRKER AKÇAY
- TiO2 ince filmlerin fotokatalitik özelliklerinin incelenmesi
The investigation of photocatalytic properties of TiO2 thin films
ALİ ŞAHİN
Yüksek Lisans
Türkçe
2020
Fizik ve Fizik MühendisliğiEskişehir Osmangazi ÜniversitesiFizik Ana Bilim Dalı
PROF. DR. SUAT PAT
- Değişik özelliklerdeki ZnO kristallerinin brillant black boyar maddesinin bozundurulmasına fotokatalitik etkisinin incelenmesi
Investigation of the photocatalytic effect of ZnO crystals with different properties on the degradation of brillant black dyes
HANİM ESRA SAĞLAM
Yüksek Lisans
Türkçe
2021
Kimya MühendisliğiÇankırı Karatekin ÜniversitesiKimya Mühendisliği Ana Bilim Dalı
DR. ÖĞR. ÜYESİ MUHAMMED BORA AKIN