Degradation of gas-phase organic contaminants via nitrogen-embedded one-dimensional rod-shaped titania in a plug-flow reactor

Environ Technol. 2014 Sep-Oct;35(17-20):2132-9. doi: 10.1080/09593330.2014.894581.

Abstract

In this study, one-dimensional rod-shaped titania (RST) and nitrogen-doped RST (N-RST) with different ratios of N to Ti were prepared using a hydrothermal method and their applications for purification of indoor toxic organic contaminants in a plug-flow reactor were examined under visible or ultraviolet (UV) irradiation. The surface characteristics of as-prepared photocatalysts were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-visible spectroscopy. The TEM images revealed that both pure RSTs and N-RSTs displayed uniform and nanorod-shaped structures. XRD revealed that the photocatalysts had crystalline TiO2. The UV-visible spectra demonstrated that the N-RSTs could be activated in the visible region. In most cases, N-RSTs showed higher degradation efficiencies than pure RSTs under visible-light and UV irradiation. N-RSTs with a N-to-Ti ratio of 0.5 exhibited the highest degradation efficiencies of benzene, toluene, ethyl benzene, and o-xylene (BTEX), suggesting the presence of an optimal N-to-Ti ratio for preparation of N-RSTs. In addition, the average degradation efficiencies of BTEX determined for the N-RSTs with a N-to-Ti ratio of 0.5 under visible-light irradiation for the lowest initial concentration (IC, 0.1 ppm) were 19%, 53%, 85%, and 92%, respectively, while the degradation efficiencies for the highest IC (2.0 ppm) were 2%, 8%, 17%, and 33%. These values decreased as the stream flow rate increased. Overall, the as-prepared N-RSTs could be effectively applied for degradation of toxic gas-phase organic contaminants under visible-light as well as UV irradiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / analysis*
  • Air Pollutants / chemistry
  • Environmental Restoration and Remediation / instrumentation*
  • Gases / analysis*
  • Gases / chemistry
  • Nitrogen / chemistry
  • Organic Chemicals / analysis*
  • Organic Chemicals / chemistry
  • Photochemical Processes
  • Titanium / chemistry

Substances

  • Air Pollutants
  • Gases
  • Organic Chemicals
  • Titanium
  • Nitrogen