https://scholars.lib.ntu.edu.tw/handle/123456789/425157
Title: | Synthesis of TiO <inf>2-x</inf> visible-light photocatalyst using N <inf>2</inf> /Ar/He thermal plasma for low-concentration elemental mercury removal | Authors: | HSING-CHENG HSI Tsai, Cheng Yen |
Keywords: | Elemental mercury | Oxygen vacancy | Plasma torch | Titanium dioxide | Issue Date: | 15-May-2012 | Publisher: | ELSEVIER SCIENCE SA | Journal Volume: | 191 | Start page/Pages: | 378 | Source: | Chemical Engineering Journal | Abstract: | Oxygen-vacant titanium dioxide (TiO 2-x ) nanoparticles possessing a narrower band gap were synthesized with a single-step process using N 2 /Ar/He thermal plasma as a heating source. Sample characterization showed that the formed TiO 2-x nanoparticles had a size within 5-40nm and were in a mixing form of anatase and rutile. An evident absorption red shift to 470nm wavelength was observed. The deconvolution results of XPS spectra supported the formation of TiO 2-x due to the presence of Ti 3+ 2p peaks. The Hg removal efficiency of TiO 2-x nanoparticles increased with increasing O 2 concentration and in the presence of light irradiation, suggesting an enhancement in Hg 0 oxidation. H 2 O molecules, however, greatly reduced the Hg removal of TiO 2-x under visible-light (VL) irradiation. The photoinduced hydrophilicity of TiO 2-x under VL irradiation was suspected to amplify the competitive adsorption of H 2 O that decreased Hg capture. Hg removal performances at 50°C were better than those at 25 and 100°C, suggesting that both adsorption and catalytic oxidation limit the Hg removal. These observations also implicate that the bonding between TiO 2-x and adsorbed Hg was weak and adsorption reaction may be reversible. © 2012 Elsevier B.V. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/425157 | ISSN: | 13858947 | DOI: | https://api.elsevier.com/content/abstract/scopus_id/84860557395 10.1016/j.cej.2012.03.035 |
Appears in Collections: | 環境工程學研究所 |
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