Effect of Au position on the photoelectrochemical and photocatalytic activity of TiO2 nanotubes under UV irradiation

Heterostructures have excellent physicochemical properties, which have attracted much attention in photoelectrochemical and photocatalytic fields. Au-TiO2NTs and Au@TiO2NTs were fabricated by the impregnation method and a vacuum-assisted-impregnation route, respectively. The effects of Au position on the structural and photoelectrochemical properties and photocatalytic activity of TiO2 have been characterized and studied. The Au@TiO2NTs photoelectrode showed a significant photocurrent (similar to 17 mu A/cm(2)), which was approximately 8.5 and approximately 2.3 times greater than that of TiO2NTs and Au-TiO2NTs. Meanwhile, Au@TiO2NTs also exhibited the best photocatalytic activity and stability for tetracyclines degradation. The characterization and experimental results revealed that the better performance of Au@TiO2NTs may be attributed to the smaller Au nanoparticles inside the nanotube space, the reduced interfacial charge transfer resistance, and the stronger electronic interaction between Au nanoparticles and TiO2NTs.