HYDROGEN PRODUCTION THROUGH ARTIFICIAL PHOTOSYNTHESIS WITH CHEMICALLY PRECIPITATED RARE EARTH DOPED TITANIA POWDERS

Öz

In this study, rare earth (RE) doped/undoped TiO2 powders were prepared by chemical precipitation/co-precipitation method and used in photocatalytic hydrogen production through artificial photosynthesis. Relatively high hydrogen production rates were obtained at low heat treatment temparatures due to the high surface areas. RE doped TiO2 powders heat treated at 700 oC produced more hydrogen per unit area due to their higher surface reactivity compared to all the other pure TiO2 powders. Properties of the doped powders like favorable anatase-rutile ratio and high light absorption capacity enhanced the photocatalytic activity by several folds by a relatively low RE doping level of 0.1%

Anahtar Kelimeler

• Titania, Photocatalysis, Hydrogen, Rare earth element

NADİR TOPRAK ELEMENTİ KATKILI KİMYASAL ÇÖKTÜRME TİTANYA TOZLARI İLE YAPAY FOTOSENTEZLE HİDROJEN ÜRETİMİ

Öz

Bu çalışmada nadir toprak elementi (NTE) katkılı/katkısız titanya (TiO2) tozları yapay fotosentezle fotokatalitik hidrojen eldesine yönelik uygulamalarda kullanılmak üzere kimyasal çöktürme/birlikte çöktürme yöntemi ile hazırlanmıştır. Düşük ısıl işlem sıcaklıklarında yüksek yüzey alanlarından dolayı yüksek hidrojen üretim miktarları elde edilmiştir. Yüzey aktivitesi bakımından ise 700 oC’de ısıl işlem görmüş katkılı tozların diğer tüm saf tozlara göre birim alan başına daha fazla hidrojen ürettiği saptanmıştır. NTE katkısı ile TiO2’in faz yapısında değişiklikler meydana getirilmiş, optimum anataz-rutil faz oranına sahip ve ışık soğurma kapasitesi yüksek bir nanoyapı elde edilmiştir. Katkıyla tozlarda oluşturulan bu özellikler görece düşük bir miktar olan % 0,1 katkı düzeyinde bile TiO2’in fotokatalitik aktivitesinin birkaç kat artmasını sağlamıştır

Anahtar Kelimeler

• Titanya, Fotokataliz, Hidrojen, Nadir toprak elementi

Kaynakça

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