Electrosorption-promoted photodegradation of opaque wastewater on a novel TiO(2)/carbon aerogel electrode

Environ Sci Technol. 2010 Mar 1;44(5):1780-5. doi: 10.1021/es903201m.

Abstract

A novel electrosorption-photocatalysis synergistic electrode of TiO(2)/carbon aerogel (TiO(2)/CA) is prepared. The thermal stability and dispersion of the anatase TiO(2) particles are well facilitated by the porous and discontinuous microstructure of CA. The degradation experiments show that the TiO(2)/CA material is not only a good photocatalyst but also an excellent electrosorptive electrode. The TiO(2)/CA is easily molded to an agglomerate electrode. The opaque wastewater with dyestuff is degraded effectively by the electrosorption-promoted photocatalytic process on this electrode. For the simulated methylene blue (MB) wastewater (150 mg L(-1)), the rate constant of MB degradation in the electro-assisted photocatalytic process with the conventional ITO-supported TiO(2) (TiO(2)/ITO) is 0.55 x 10(-3) min(-1) and that the electrosorption-promoted photocatalysis with TiO(2)/CA is 10.27 x 10(-3) min(-1), which is 18 times the former. In the electrosorption-promoted photocatalytic process with TiO(2)/CA, the energy consumption removing per unit TOC is only 15% of that in the electro-assisted photocatalysis with TiO(2)/ITO, because the electrosorption is a nonfaradic process irrelative to any electron transfer and requires very low consumption. This study provides a new method for exploring highly efficient electrosorption-promoted photocatalytics technology in the treatment of opaque wastewater.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry*
  • Catalysis
  • Electrodes
  • Gels
  • Kinetics
  • Microscopy, Electron, Scanning
  • Photolysis
  • Sorption Detoxification / methods*
  • Titanium / chemistry*
  • Waste Disposal, Fluid / methods*
  • Water Purification / methods*

Substances

  • Gels
  • titanium dioxide
  • Carbon
  • Titanium