Preparation of TiO2-loaded activated carbon fiber hybrids and application in a pulsed discharge reactor for decomposition of methyl orange

TiO2-loaded activated carbon fiber (TiO2/ACF) hybrids were prepared in a sol through a dip-coating method and added to a pulsed discharge reactor to enhance the decomposition of methyl orange. The crystalline phase transformation and the surface morphology of TiO2/ACF were investigated after calcination at various temperatures. X-ray diffraction results revealed the intensity of the diffraction peaks resulting from anatase increased in accordance with increasing calcination temperatures. An anatase-to-rutile phase transformation was observed for calcination at 1173 K. Morphology studies indicate that the TiO2 film fractured into irregular flakes on the ACF surface. TiO2/ACF calcined at 1173 K demonstrated the highest photocatalytic activity compared with samples calcined at lower temperatures. The enhancement of chemical oxygen demand removal may be due to the adsorption of ACF and the photocatalytic zonation of TiO2 in the combined treatment. The surface morphology of TiO2/ACF showed no change after re-use. Although micropores slightly increased, mesopores significantly decreased, and some oxygen-containing surface groups increased on the ACF surface after re-use, the photocatalytic activity of TiO2/ACF was not affected. (C) 2010 Elsevier Inc. All rights reserved.