Electrogenerated chemiluminescence of anatase TiO2 nanotubes film

Highly ordered titanium dioxide (TiO2) nanotubes film was successfully synthesized via anodic oxidation of a Ti foil in an ammonium fluoride-based ethylene glycol solution. The electrogenerated chemiluminescence (ECL) behavior of the resulting TiO2 nanotubes film was subsequently studied. Strong ECL emission was observed at −1.40 V (vs. Ag/AgCl) and the ECL spectrum displayed three emission peaks which were bathochromatically shifted by ca. 140 nm as compared to its corresponding photoluminescence (PL) emission peaks, indicating that the surface state plays an important role in the emission process. The ECL emission can also occur in a deareated solution attributing to the surface adsorbed O2 molecules. The ECL emission intensity was quenched by dopamine and greatly enhanced in the presence of dissolved O2 and H2O2, making it possible to detect these analytes. The TiO2 nanotubes film has been successfully applied to determine the dissolved O2 content in river and pond water samples, the H2O2 concentration in commercial disinfectant samples and the dopamine concentration in commercial dopamine injections with satisfactory results. The plausible ECL mechanisms of TiO2 nanotubes film in aqueous solution are discussed.