Shape-Enhanced Photocatalytic Activity of Single-Crystalline Anatase TiO (101) Nanobelts.
Particle size is generally considered to be the primary factor in the design of nanocrystal photocatalysts, because the reduction of particle size increases the number of active sites. However, the benefit from the size reduction can be canceled by a higher electron-hole recombination rate due to th...
| Publicado en: | Journal of the American Chemical Society Vol. 132; no. 19; pp. 6679 - 6686 |
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| Autores principales: | , , , , , , , , |
| Formato: | Artículo |
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American Chemical Society
5/19/2010
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=50860357&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 50860357 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 5/19/2010 vid: 132 iid: 19 pid: 997 pub: American Chemical Society artinfo: ui: 50860357 10.1021/ja909456f ppf: 6679 ppct: 7 formats: tig: atl: Shape-Enhanced Photocatalytic Activity of Single-Crystalline Anatase TiO (101) Nanobelts. aug: au: Nianqiang Wu Jin Wang De Nyago Tafen Hong Wang Jian-Guo Zheng Lewis, James P. Xiaogang Liu Leonard, Stephen S. Ayyakkannu Manivannan affil: Department of Mechanical and Aerospace Engineering, WVNano Initiative, West Virginia University, Morgantown, West Virginia 26506-6106 Department of Physics, West Virginia University, Morgantown, West Virginia 26506 Materials Characterization Center (MC2), LEXI, California Institute for Telecommunication and Information Technology, University of California, Irvine, California 92697 Department of Chemistry, National University of Singapore, Singapore 117543, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505 National Energy Technology Laboratory, U.S. Department of Energy, Morgantown, West Virginia 26507 su: Catalysts Titanium dioxide Size reduction of materials Nanoparticles Nanostructures Density functionals sug: subj: Catalysts Titanium dioxide Size reduction of materials Nanoparticles Nanostructures Density functionals ab: Particle size is generally considered to be the primary factor in the design of nanocrystal photocatalysts, because the reduction of particle size increases the number of active sites. However, the benefit from the size reduction can be canceled by a higher electron-hole recombination rate due to the confined space in sphere-shaped nanoparticles. Here we report a mechanistic study on a novel nanobelt structure that overcomes the drawback of sphere-shaped nanoparticles. Single-crystalline anatase TiO nanobelts with two dominant surfaces of (101) facet exhibit enhanced photocatalytic activity over the nanosphere counterparts with an identical crystal phase and similar specific surface area. The ab initio density functional theory (DFT) calculations show that the exposed (101) facet of the nanobelts yields an enhanced reactivity with molecular O, facilitating the generation of superoxide radical. Moreover, the nanobelts exhibit a lower electron-hole recombination rate than the nanospheres due to the following three reasons: (i) greater charge mobility in the nanobelts, which is enabled along the longitudinal dimension of the crystals; (ii) fewer localized states near the band edges and in the bandgap due to fewer unpassivated surface states in the nanobelts; and (iii) enhanced charge separation due to trapping of photogenerated electrons by chemisorbed molecular O on the (101) facet. Our results suggest that the photocatalysis efficiency of nanocrystals can be significantly improved by tailoring the shape and the surface structure of nanocrystals, which provides a new concept for rational design and development of high-performance photocatalysts. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2010 holdings: @attributes: islocal: N |
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