Synergetic effects of ultraviolet and microwave radiation for enhanced activity of TiO 2 nanoparticles in degrading organic dyes using a continuous-flow reactor Article

Genuino, HC, Hamal, DB, Fu, YJ et al. (2012). Synergetic effects of ultraviolet and microwave radiation for enhanced activity of TiO 2 nanoparticles in degrading organic dyes using a continuous-flow reactor . JOURNAL OF PHYSICAL CHEMISTRY C, 116(26), 14040-14051. 10.1021/jp3040192

cited authors

  • Genuino, HC; Hamal, DB; Fu, YJ; Suib, SL

authors

abstract

  • A novel continuous-flow reactor was developed to investigate the synergetic effects of ultraviolet (UV) and microwave (MW) radiation on TiO 2 nanoparticles for the enhancement of photodegradation of Direct Red-81 (DR-81) and Bromothymol Blue (BTB) dyes. The efficiency of the combined UV and MW radiation was higher than the sum of the isolated and corresponding thermal effects and directly proportional to the MW power. The % photodegradation of DR-81 after 105 min irradiation at ambient conditions was 40%, 68%, 72%, and 100% using UV/MW 100W, UV/MW 300W, UV/MW 500W, and UV/MW 700W methods, respectively. The % photodegradation of BTB under the same conditions was 58%, 78%, 82%, and 88%, respectively. High dissolved oxygen concentration increased DR-81 photodegradation, whereas ambient air conditions were optimum for BTB. The extent of photomineralization of both dyes was dependent on MW power. Degradation products showed that both dyes were successfully oxidized through different intermediate species. The properties of TiO 2 nanoparticles did not change before and after reaction; however, the positive surface charge was reduced by as much as 14 mV. Accelerated rates of dye degradation on incorporation of MW to UV were attributed to the generation of more hydroxyl and superoxide anion radicals and an increase in hydrophobicity of TiO 2. © 2012 American Chemical Society.

publication date

  • July 5, 2012

published in

Digital Object Identifier (DOI)

start page

  • 14040

end page

  • 14051

volume

  • 116

issue

  • 26