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Preparation of Ag-Based Novel Adsorbents for Environmental Remediation
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- Author / Creator
- Xie, Yijun
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With the rapid development of industry, air and water pollution has become a critical topic to the public and scientific community since the quality of air and water is essential for the prosperity of life. In this study, two novel adsorbents, Fe3O4@polydopamine (PDA)-Ag microspheres and SBA-15-Ag composites, have been synthesized by facile wet chemical methods. Monodisperse Ag nanoparticles (NPs) are densely deposited on the surface of PDA layers and within the mesopores of SBA-15, respectively. High catalytic activity of Fe3O4@PDA-Ag on the reduction of methylene blue (MB) and effective removal of Hg0 by SBA-15-Ag have been achieved mainly due to the presence of monosized Ag NPs. The capture of Hg0 by Ag NPs is due to the amalgamation mechanism of Ag-Hg alloy. Fe3O4@PDA-Ag microspheres also exhibit high adsorption rate on MB because of the electrostatic interaction between PDA layer and MB molecules. More importantly, the as-prepared Fe3O4@PDA-Ag microspheres demonstrate excellent reusability and cyclic stability (>27 cycles), and the regeneration process could be completed within several minutes by using NaBH4 as the desorption agent via a unique catalytic desorption process. The Fe3O4@PDA-Ag microspheres can be easily recycled from the solution by an external magnetic field, thanks to the good magnetic performance of Fe3O4 cores. In addition, the Fe3O4@PDA-Ag microspheres show good aqueous and acid stability in aqueous solution without significant change in morphology and performance for over half a year. The new adsorbents developed in this work show important potentials in practical applications for adsorption and catalysis.
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- Subjects / Keywords
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- Graduation date
- Fall 2014
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.