TiO2 nanotubes modified with cadmium oxide for photoelectrocatalytic oxidation of alcohols

TiO 2 nanotube (TNT) electrodes were fabricated by electrochemical anodization of titanium in ethylene glycol electrolyte with added NH4F (0.5 wt.%) and water (2 % w/w). The (TNT)-cadmium oxide (CdO) composite was fabricated using potentiostatic cathodic deposition. Structural properties of the obtained coatings have been investigated by scanning electron microscopy and X-Ray photoelectron spectroscopy, Raman spectroscopy, X-Ray diffraction and transmission electron microscopy. The TNT-CdO electrode demonstrates high efficiency in photoelectrochemical degradation of methanol, ethylene glycol, glycerol and sorbitol in aqueous solutions of 0.1 M Na 2 SO 4 upon irradiation by a simulated sunlight. The highest photooxidation currents were obtained for sorbitol. Intensity-modulated photocurrent spectroscopy shows that the photoelectrocatalysis efficiency is due to suppression of the electron-hole pairs’ recombination and to increase in the rate of photo-induced charge transfer. Thus, the TNT-CdO composite is an effective photoanode for developing the technology of photoelectrochemical degradation of sorbitol and other alcohols by-products of biofuel production.