Fabrication of Au nanoparticle/TiO2 hybrid films for photoelectrocatalytic degradation of methyl orange

Au nanoparticles and TiO2 nanotube hybrid materials were prepared electrochemically. The Ti wire was used to form TiO2 nanotube arrays via anodization and subsequent annealing process. The Au nanoparticles were then electrodeposited in chloroauric acid solution to form Au/TiO2 hybrid layers. These two steps were repeated to prepare Au/TiO2, TiO2/Au/TiO2 and Au/TiO2/Au/TiO2 hybrid materials, and the preparation mechanism is discussed. The Au/TiO2 hybrid materials also exhibited different photoelectrocatalytic activities for decomposing methyl orange. The application of the Au/TiO2/Au/TiO2 hybrid material as a photo-anode has been simultaneously examined toward electrochemical-oxidation, photo-oxidation, and photoelectro-oxidation of methyl orange. The photoelectrocatalytic mechanism of Au/TiO2/Au/TiO2 hybrid material and its degradation reaction mechanism for methyl orange were evaluated.