Electrosorption-promoted Photodegradation of Opaque Wastewater on A Novel TiO2/Carbon Aerogel Electrode

A novel electrosorption-photocatalysis synergistic electrode of TiO2/carbon aerogel (TiO2/CA) is prepared. The thermal stability and dispersion of the anatase TiO2 particles are well facilitated by the porous and discontinuous microstructure of CA. The degradation experiments show that the TiO2/CA material is not only a good photocatalyst but also an excellent electrosorptive electrode. The TiO2/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 photocatalyfic process with the conventional ITO-supported TiO2 (TiO2/ITO) is 0.55 x 10(-3) min(-1) and that the electrosorption-promoted photocatalysis with TiO2/CA is 10.27 x 10(-3) min(-1), which is 18 times the former. In the electrosorption-promoted photocatalytic process with TiO2/CA, the energy consumption removing per unit TOC is only 15% of that in the electro-assisted photocatalysis with TiO2/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.