One-dimensional titania nanotubes annealed at various temperatures for the photocatalytic degradation of low concentration gaseous pollutants--颗粒学报PARTICUOLOGY

Chun, H.-H., & Jo, W.-K. (2015). One-dimensional titania nanotubes annealed at various temperatures for the photocatalytic degradation of low concentration gaseous pollutants. Particuology, 19, 86–92. https://doi.org/10.1016/j.partic.2014.06.003

One-dimensional titania nanotubes annealed at various temperatures for the photocatalytic degradation of low concentration gaseous pollutants

Ho-Hwan Chun^a, Wan-Kuen Jo ^b *

a Department of Naval Architecture and Ocean Engineering, Pusan National University, Busan 609-735, Republic of Korea
b Department of Environmental Engineering, Kyungpook National University, Daegu 702-701, Republic of Korea

10.1016/j.partic.2014.06.003

Volume 19, April 2015, Pages 86-92

Received 17 March 2014, Revised 28 May 2014, Accepted 2 June 2014, Available online 18 September 2014.

E-mail: wkjo@knu.ac.kr

Highlights

• 1D titania nanotubes (TNTs) were prepared via a combined chemical and hydrothermal process.

• Photocatalytic activity of the annealed TNTs was tested for four sub-ppm aromatic VOCs.

• Photocatalytic function of TNTs varied with annealing temperature.

• Photocatalytic activities were influenced by airstream flow rate and inlet concentration.

Abstract

In this study, one-dimensional titania nanotubes (TNTs) were synthesized using a combined process of chemical and hydrothermal treatments, and their activities for the photocatalytic reactions of selected gaseous pollutants at sub-ppm levels were determined. Additionally, the properties of the TNTs were examined using selected spectroscopic methods. The annealed TNTs showed higher photocatalytic activities for the four target compounds than did the unannealed TNTs. For all the target compounds except benzene, the effect of the annealing temperature on the degradation efficiency was difficult to determine because all degradation efficiencies were very high. However, for benzene, which decomposed with a low efficiency, the degradation activities of the TNTs increased as the treatment temperature was increased from 250 to 300 °C, while they decreased slightly when the temperature was increased from 300 to 400 °C. These findings confirm the presence of an optimal annealing temperature for the synthesis of TNTs. Moreover, the average degradation extents for benzene, toluene, ethylbenzene, and o-xylene decreased from 92%, 96%, 99%, and 98% to 77%, 86%, 92%, and 94%, respectively, as the airstream flow rate increased within the range of 1–4 L/min. The average degradation extents decreased from 12%, 75%, 87%, and 88% to 3%, 29%, 46%, and 51%, respectively, as the input concentration increased from 0.4 to 1.9 ppm. Overall, these findings suggest that one-dimensional TNTs can be effectively utilized for the degradation of gaseous pollutants under optimal operational conditions.

Graphical abstract

Keywords

Gaseous pollutant; Annealing temperature; Degradation efficiency; Airstream flow rate

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