Electrocatalytic characterization and dye degradation of Nano-TiO2 electrode films fabricated by CVD

A 20-40 nm anatase-titania film on a titanium electrode was fabricated using chemical vapor deposition (CVD). The film was characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD). and atomic force microscopy (AFM). The CVD deposition time and number of deposition coatings were evaluated to establish the appropriate film fabrication parameters. Results indicate that two coatings at a deposition time of 6 h each produced the best nano-TiO2 electrode films (NTEFs) with an even distribution of ca. 20 nm diameter nanoparticles in the anatase lattice. The NTEF was tested as an electrocatalytic anode to investigate the degradation efficiency in treating methyl orange dye wastewater. A high removal efficiency of methyl orange dye and total organic carbon (TOC) of 97 and 56%, respectively; was achieved using a current density of 20 mA cm(-2) for 160 min. Cyclic voltammetry showed that the electrochemical degradation reaction rate at the NTEF surface was predominately driven by molecular diffusion. The electrocatalytic decomposition rate of organic pollutants at the NTEF is controlled by mass transport, which was associated with the nanostructure of the electrocatalytic electrode. (C) 2009 Elsevier B.V. All rights reserved.