Abstract
Reduction of contaminants in polluted water can be effectively enhanced by a suitable photocatalyst that utilizes an extended light adsorption spectrum, presents a large surface-to-volume ratio to enhance contact with the contaminants, and reduces the inefficiency from recombination of electron-hole pairs. Based on these objectives, TiO2/ZnO nanofibers are synthesized with small diameter having 10-nm poly-crystallites of large surface area by electrospinning followed by calcination. With different concentrations of zinc acetate in the precursor solutions between 0.15%-0.6%, the diameter of the finished nanofibers ranges from 80 to 130 nm. The photocatalytic activities of nanofibers are studied systematically by the degradation of Rhodamine B dye under the 420-nm visible-light irradiation. Photocatalytical activity can be optimized by introducing an appropriate amount of Zn (0.30 wt.% ZnAc in precursor) to maximize the available hydroxyl radicals for oxidation of the dye. Also, the optimal catalyst loading has been determined to be 2 g of TiO2/ZnO nanofibers per liter of water treated after balancing the enhanced active sites with increasing catalyst and catalyst over-dosage that results in solution opacity and catalyst agglomeration. Therefore, enhanced photodegradation of dyes with photocatalyst nanofiber under visible irradiation can be realized. A kinetic model has been developed to describe successfully the photodegradation of RhB.
Original language | English |
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Pages (from-to) | 108-116 |
Number of pages | 9 |
Journal | Separation and Purification Technology |
Volume | 114 |
DOIs | |
Publication status | Published - 28 May 2013 |
Keywords
- Dyed wastewater
- Nanofibers
- Photocatalytic
- Titanium dioxide
- Zinc oxide
ASJC Scopus subject areas
- Analytical Chemistry
- Filtration and Separation