Shape-Enhanced Photocatalytic Activity of Single-Crystalline Anatase TiO2 (101) Nanobelts

Details

• Personal Author:
  Leonard, Stephen S. ; Lewis JP ; Liu XG ; Manivannan A ; Tafen D ; Wang H ; Wang J ; Wu NQ ; Zheng JG
• Description:
  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 TiO2 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-2, 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-2 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. [Description provided by NIOSH]
• Subjects:
  Chemistry Chemistry, Analytic Chromatography Occupational Health Particulate Matter Safety Spectrum Analysis
• Keywords:
  Analytical-chemistry Biological-effects Chromatographic-analysis Microscopy Nanoparticles Nanotechnology Nanotubes Particulate-dust Particulates Spectrographic-analysis
• ISSN:
  0002-7863
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  132
• Issue:
  19
• NIOSHTIC Number:
  nn:20037036
• Citation:
  J Am Chem Soc 2010 May; 132(19):6679-6685
• Contact Point Address:
  Nianqiang Wu, W Virginia Univ, Department of Mechanical and Aerospace Engineering, WV Nano Initiative, Morgantown, WV 26506
• Email:
  nick.wu@mail.wvu.edu
• Federal Fiscal Year:
  2010
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Journal of the American Chemical Society
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a670030e20feb63e7b1c3f54619bbe93928b05cf8a33a73d186865935ef283fc17126f5c6c3f7c9483e780309e1326376897f597e56075ceb50e89a4a6c9268c
• Download URL:
  https://stacks.cdc.gov/view/cdc/188209/cdc_188209_DS1.pdf
• File Type:
  [PDF - 2.76 MB ]